JP6986911B2 - Refrigeration cycle device - Google Patents

Description

The present invention relates to a refrigeration cycle device, and more particularly to a refrigeration cycle device that forms an air curtain on an open surface of a showcase body.

Conventionally, an open type open showcase that is installed in a supermarket or a convenience store to store and display beverages, foods, and the like has been known.

Such an open showcase includes, for example, an air outlet and a suction port arranged so as to face each other on the inner wall of the accommodation space of the showcase body having one side open. An air curtain is formed on the open surface by sucking the cooling air blown out from the air outlet into the suction port. With this air curtain, it is possible to suppress the air outside the open showcase from flowing into the accommodation space through the open surface, and to improve the cooling effect inside the showcase body.

In such an open type open showcase, preventing the intrusion of outside air by an air curtain greatly contributes to the improvement of energy saving. However, for example, in a super store or a convenience store, air may be blown from an air conditioner installed around the open showcase to the open surface of the showcase body. Airflow around the open showcase can cause the air curtain on the open surface to collapse. As a result, the air outside the showcase body may flow into the accommodation space, and the energy saving performance of the open showcase may be impaired.

In order to prevent the air curtain from collapsing due to the air flow around the open showcase, for example, in Patent Document 1, in the storage space of the showcase main body, in the vicinity of the open surface, the temperature detector inside the refrigerator. Is provided. The internal temperature sensor detects the temperature in the accommodation space of the showcase body, and the amount of air blown by the internal air blower is controlled so that the detected internal temperature approaches the optimum internal temperature.

Japanese Unexamined Patent Publication No. 2008-164209

According to Patent Document 1, the amount of air blown by the air blower in the refrigerator is increased or decreased based on the detected temperature inside the refrigerator. However, if the wind speed of the air curtain is excessive, the air curtain itself entrains the airflow outside the open surface, and as a result, the outside air flows into the accommodation space. The amount of air invading the outside increases the cooling load, and the energy saving of cooling in the accommodation space is impaired. Conventionally, such entrainment of air outside the open showcase by the air curtain itself has not been considered.

Therefore, an object of the present invention is to provide a refrigerating cycle apparatus capable of suppressing a temperature rise in the showcase accommodating space due to the influence of an air flow outside the showcase body.

The refrigerating cycle device of the present invention has a showcase main body having a storage space with one open surface, an air suction port and an air outlet, and a circulation passage from the suction port to the air outlet, and air in the circulation passage. The inside air blower that blows air, the cooling part that cools the air in the circulation passage, the inside temperature detection part that detects the inside temperature of the showcase body, and the outside air temperature outside the showcase body. It is provided with an outside air temperature detecting unit, and a control unit that controls the amount of air blown by the internal air blower unit according to the difference between the detected internal air temperature and the target temperature of the internal air temperature. An air curtain is formed on the open surface of the accommodation space by sucking the air blown out from the air outlet through the suction port. When the amount of air blown in the refrigerator exceeds the first amount of air, the control unit reduces the amount of air blown in the refrigerator to a second amount smaller than the first amount of air.

According to the present invention, when the airflow amount of the airflow unit in the refrigerator exceeds the first airflow amount, the control unit sets the airflow amount of the airflow unit in the refrigerator up to the second airflow amount smaller than the first airflow amount. Since the temperature is lowered, it is possible to suppress the temperature rise in the showcase accommodating space due to the influence of the air flow outside the showcase body.

It is a schematic diagram which shows the main part of the open showcase 100 which is a kind of refrigerating cycle apparatus which concerns on Embodiment 1. FIG. It is a schematic diagram which shows the main part of the separate type open showcase 100. It is a schematic diagram which shows the main part of the built-in flat type open showcase 100. It is a flowchart which shows the procedure of the control operation of the air blowing part 22 in a refrigerator which concerns on Embodiment 1. FIG. It is a schematic diagram which shows the relationship of the cooling load P, the cooling capacity Q, and the inside temperature Tt with respect to the air volume of the inside air blowing part 22 when the outside air temperature To is constant. Outline showing the relationship between the cooling load P, the cooling capacity Q, and the internal temperature Tt with respect to the air volume of the internal air blower 22 when the outside air temperature To changes, and the change of the optimum point of the air flow amount of the internal air blower 22. It is a figure. It is a flowchart which shows the procedure of the control operation of the air blowing part 22 in a refrigerator which concerns on Embodiment 2. FIG. It is a flowchart which shows the procedure of the control operation of the air blowing part 22 in a refrigerator which concerns on Embodiment 2. FIG. It is a figure which shows the example of the data table of Embodiment 2. It is a figure which shows the example of the data table which updated the air volume in Embodiment 1. FIG. It is a figure which shows the control and a setting point when a cooling capacity decreases. It is a figure which shows the relationship between the temperature | chamber temperature Tt, and the target temperature Ts when the decrease of a cooling capacity is too large. It is a figure which shows the example of the data table of the modification of Embodiment 2. It is a schematic diagram which shows the main part of the open showcase 100 which concerns on Embodiment 3. FIG. It is a schematic diagram which shows the main part of the open showcase 100 which concerns on Embodiment 4. FIG. It is a schematic diagram which shows the main part of the open showcase 100 which concerns on Embodiment 5.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1.
[Open showcase configuration]
FIG. 1 is a schematic view showing a main part of an open showcase 100, which is a kind of refrigerating cycle apparatus according to the first embodiment. As shown in FIG. 1, the open showcase 100 includes a main body 10, an outdoor unit 30, and an outside air temperature detecting unit 11.

The main body 10 includes a plurality of display shelves 19 for storing and displaying beverages, foods, and the like in the accommodation space 13. The main body 10 includes a cooling heat exchanger 21, an internal air blower unit 22, and an internal temperature detecting unit 12.

The cooling heat exchanger 21 and the outdoor unit 30 are connected by the gas pipe 41 (a) and the liquid pipe 41 (b) to form a refrigerant circuit. A steam compression type refrigeration cycle is realized by circulating the refrigerant filled inside the refrigerant circuit.

The open showcase 100 of FIG. 1 is a so-called built-in type in which the showcase main body 10 and the outdoor unit 30 are integrated, but may be a separate and separate type. FIG. 2 is a schematic view showing a main part of a separate open showcase 100. In FIG. 2, the outdoor unit 30 is separated from the inside of the showcase main body 10, but other components are the same as those in FIG. 1. In the separately installed open showcase 100, a plurality of showcase main bodies 10 may be connected to one outdoor unit 30.

The open showcase 100 shown in FIGS. 1 and 2 is a multi-stage type having a plurality of display shelves 19, but may be a flat type having only one stage. FIG. 3 is a schematic view showing a main part of a built-in flat open showcase 100. In FIG. 3, the display shelf 19 has only one stage, and the openings of the air outlet 14 and the suction port 15 face each other on the left and right, but the other components are the same as those in FIG.

In the first embodiment and all other embodiments, the open showcase 100 will be described as a built-in multi-stage.

The outdoor unit 30 includes a compressor 31, an outdoor heat exchanger 32, an expansion valve 34, and an outdoor air blower 33.

The compressor 31, the outdoor heat exchanger 32, and the expansion valve 34 are connected in order. That is, the refrigerant circuit is configured by connecting the compressor 31, the outdoor heat exchanger 32, the expansion valve 34, and the cooling heat exchanger 21 with pipes. The refrigerant circuit corresponds to a cooling unit.

The outdoor air blower 33 sends outdoor air to the outdoor heat exchanger 32. The outdoor air blower 33 and the expansion valve 34 are driven by a power supply device (not shown) for supplying electric power.

The compressor 31 is a variable capacitance type or fixed capacitance type compressor. In the case of the variable capacity type, the rotation speed of the electric motor of the compressor 31 can be switched according to the output frequency of the inverter to change the operating capacity thereof. In the case of the fixed capacity type, the rotation speed of the electric motor of the compressor 31 is constant, but the cooling amount of the refrigerant circuit can be changed by controlling the start and stop of the compressor 31. The discharge side of the compressor 31 is connected to the outdoor heat exchanger 32.

The outdoor heat exchanger 32 is a heat exchanger on the heat source side and corresponds to a radiator. In the outdoor heat exchanger 32, the outdoor air blown by the outdoor air blower unit 33 and the refrigerant flowing in the outdoor heat exchanger 32 exchange heat.

The expansion valve 34 is for decompressing and expanding the refrigerant flowing out of the outdoor heat exchanger 32, and corresponds to a throttle device.

In the cooling heat exchanger 21 housed in the showcase main body 10, the refrigerant inflow side is connected to the expansion valve 34 via the liquid pipe 41 (b), and the refrigerant outflow side has the gas pipe 41 (a). It is connected to the compressor 31 via.

The cooling heat exchanger 21 is a heat exchanger on the user side and corresponds to an evaporator. In the cooling heat exchanger 21, the air in the showcase body 10 (air in the refrigerator) blown by the air blower unit 22 in the refrigerator and the refrigerant flowing in the cooling heat exchanger 21 exchange heat.

The internal air blower unit 22 is composed of an internal fan. The air blower unit 22 in the refrigerator blows the air in the circulation passage 16. The internal air blower 22 is a so-called inverter type that can adjust the rotation speed of the motor that rotates the fan (blade). By controlling the rotation speed of the motor of the air blower unit 22 in the refrigerator, the amount of air blown in the circulation passage 16 can be controlled. The internal air blower unit 22 is driven by a power supply device (not shown) that supplies electric power.

The showcase main body 10 is configured in a box shape as a whole, and an open surface 18 is formed on one surface thereof. In the present embodiment, the open surface 18 is provided on the front side of the showcase main body 10. A storage space 13 capable of storing food or the like to be cooled is formed inside the showcase main body 10. A plurality of display shelves 19 for displaying food and the like are arranged and attached in the accommodation space 13 in the vertical direction. Further, an air outlet 14 that opens along the upper peripheral edge of the open surface 18 of the showcase main body 10 is formed, and a suction port 15 that opens along the lower peripheral edge of the open surface 18 is formed.

The air outlet 14 faces the accommodation space 13 and opens downward. The suction port 15 is open toward the upper side so as to face the accommodation space 13. That is, the air outlet 14 and the suction port 15 are formed so as to face each other inside the open surface 18.

The showcase main body 10 is provided with a circulation passage 16 from the air outlet 14 to the suction port 15. The circulation passage 16 is a passage separated from the accommodation space 13. In the first embodiment, the circulation passage 16 is provided along the lower side wall surface, the rear side wall surface, and the upper wall surface surrounding the accommodation space 13, and the vertical cross section thereof has a "U" shape. .. The circulation passage 16 is provided with a cooling heat exchanger 21 and an in-compartment air blower 22.

In the accommodation space 13, an internal temperature detecting unit 12 is provided, and an outside air temperature detecting unit 11 is provided in the vicinity of the showcase main body 10.

The outside air temperature detecting unit 11 detects the outside air temperature To around the outside of the showcase main body 10.

The internal temperature detection unit 12 detects the internal temperature Tt inside the showcase body 10. In the first embodiment, the internal temperature detection unit 12 detects the air temperature in the accommodation space 13 as the internal temperature Tt.

The outside air temperature detection unit 11 and the inside temperature detection unit 12 are, for example, a thermistor.
The control unit 50 determines the operating state of the compressor 31, the opening degree of the expansion valve 34, the amount of air blown by the outdoor air blower unit 33, and the air blown inside the refrigerator, based on the outputs from the outside air temperature detection unit 11 and the internal temperature detection unit 12. The amount of air blown by the unit 22 is controlled. Specific control by the control unit 50 will be described later. The control unit 50 can be configured by hardware such as a circuit device that realizes the function, or is composed of a computing device such as a microcomputer or a CPU (Central Processing Unit) and software executed on the arithmetic unit. You can also do it. The control unit 50 may be held in the open showcase 100, or may be held on the cloud or the like.

[Operation overview]
The cooling operation operation of the open showcase 100 configured in this way will be described. The open showcase 100 performs a refrigerating operation or a freezing operation of the object to be cooled contained in the accommodation space 13. The refrigeration operation and the freezing operation are collectively called the cooling operation.

During the cooling operation, the control unit 50 puts the compressor 31, the outdoor air blower 33, and the in-compartment air blower 22 into an operating state, and appropriately adjusts the opening degree of the expansion valve 34. The control unit 50 controls each unit so that the internal temperature Tt detected by the internal temperature detection unit 12 becomes a target temperature set by a temperature setting unit (not shown). The target temperature is usually determined by the user.

Here, a plurality of internal temperature detection units 12 may be installed, and the average value of each value may be used as the internal temperature Tt, or the maximum or minimum value of the plurality of internal temperature detection units 12 may be set as the internal temperature. It may be Tt.

Further, the temperature detection unit 12 in the refrigerator may be installed anywhere as long as it is on the accommodation space 13 side of the air curtain 17.

During the cooling operation, the refrigerant discharged from the compressor 31 flows through the outdoor heat exchanger 32. In the outdoor heat exchanger 32, the refrigerant is cooled and condensed by the outside air blown by the outdoor air blower unit 33. The refrigerant condensed by the outdoor heat exchanger 32 is decompressed and expanded when passing through the expansion valve 34, and then flows into the cooling heat exchanger 21. In the circulation passage 16 in which the cooling heat exchanger 21 is installed, the air blower unit 22 in the refrigerator is in an operating state, and air is blown. Therefore, in the cooling heat exchanger 21, the refrigerant absorbs heat from the air flowing through the circulation passage 16 and evaporates. As a result, the air flowing through the circulation passage 16 is cooled.

The air cooled in the circulation passage 16 is blown out from the outlet 14 into the accommodation space 13. The air blown out from the air outlet 14 is sucked into the suction port 15 by the suction force generated by the drive of the air blower unit 22 in the refrigerator. That is, the air curtain 17 which is an air flow that is blown out from the air outlet 14 and sucked into the suction port 15 and covers the open surface 18 is formed. When the air curtain 17 is formed, the cold air of the blown air is applied to the air in the accommodation space 13, and the fresh food or the like displayed in the accommodation space 13 is cooled. The air curtain 17, which is an air flow covering the open surface 18 of the open showcase 100, suppresses the air outside the showcase body 10 from flowing into the accommodation space 13 through the open surface 18.

The air sucked into the suction port 15 flows through the circulation passage 16 by the drive of the air blower unit 22 in the refrigerator, and is cooled again by the cooling heat exchanger 21.

When the compressor 31 is a fixed-capacity compressor, the control unit 50 switches and controls the start and stop of the compressor 31. When the compressor 31 is a variable displacement compressor, the control unit 50 controls the output frequency to switch the rotation speed of the electric motor of the compressor 31. The control unit 50 adjusts the opening degree of the expansion valve 34. By controlling the compressor 31 and the expansion valve 34 in this way, the amount of refrigerant circulating in the refrigerant circuit of the open showcase 100 is adjusted, and the cooling capacity of the cooling heat exchanger 21 is controlled.

In the cooling operation described above, the air curtain 17 is formed to cool the inside of the accommodation space 13, but the formation of the air curtain 17 may be hindered by the influence of the external air flow. The external airflow means an airflow from the outside of the showcase body 10 toward the open surface 18. As an example of the external air flow, for example, an air flow blown from an air conditioner such as a super store or a convenience store where the open showcase 100 is installed toward the open surface 18 of the showcase main body 10 can be mentioned. When an external airflow is generated, the air curtain 17 may collapse due to the external airflow.

Even when no external airflow is generated, if the wind speed of the air curtain 17 is excessive, the air forming the air curtain 17 may excessively entrain the air outside the open surface 18.

When external airflow or entrainment of external air occurs, the outside air of the showcase main body 10 invades into the accommodation space 13 through the open surface 18. Then, the cooling load of the open showcase 100 increases, and the energy saving property is impaired.

Therefore, the open showcase 100 according to the present embodiment controls the air flow amount of the in-compartment air flow unit 22 in consideration of the influence of the external air flow as described above or the change in the cooling load due to the entrainment of the external air.

[Control of the air blower in the refrigerator]
The control unit 50 controls the amount of air blown by the internal air blower unit 22 according to the difference between the detected internal temperature Tt and the target internal temperature Ts.

When the temperature Tt in the refrigerator is higher than the predetermined target temperature Ts and the air volume in the air blower unit 22 in the refrigerator exceeds the first air volume F1, the control unit 50 blows air in the air chamber 22. Is reduced to the second air volume F2 (<F1). The control unit 50 has a temperature Tt higher than the target temperature Ts and the air blower unit 22 in the refrigerator after a certain period of time (Tα + Tβ) has elapsed after reducing the air blower amount of the air blower unit 22 in the refrigerator to the second air blower amount. When the amount of air blown is equal to or less than the first amount of air blown F1, the amount of air blown by the in-compartment air blower unit 22 is increased. The control unit 50 determines that the internal temperature Tt is lower than the target temperature Ts after a certain period of time (Tα + Tβ) has elapsed since the amount of air blown by the internal air blower unit 22 is reduced to the second air supply amount. 22 The amount of air blown is reduced.

When the outside air temperature To rises and the amount of air blown by the internal air blower unit 22 exceeds the first air blower amount F1, the control unit 50 reduces the air flow amount of the internal air blower unit 22 to the second air blower amount F2. Let me. In the control unit 50, after a certain period of time (Tα + Tβ) has elapsed after the air volume of the air blower unit 22 in the refrigerator is lowered to the second air blower amount F2, the outside air temperature To rises and the air flow amount of the air blower unit 22 in the refrigerator increases. When the first air blowing amount is F1 or less, the air blowing amount of the in-compartment air blowing unit 22 is increased. The control unit 50 blows air from the refrigerator 22 when the outside air temperature To drops after a certain period of time (Tα + Tβ) has elapsed since the air blower from the refrigerator 22 was reduced to the second air blower F2. To reduce.

The second air blowing amount F2 is a blowing amount that can eliminate the entrainment of external air by the air curtain 17, and can be determined in advance. Alternatively, the second air blowing amount F2 may be an air blowing amount corresponding to the minimum rotation speed of the motor of the in-compartment air blowing unit 22.

The control unit 50 may set the first air flow rate F1 for each outside air temperature To. Further, in general, the influence of entraining the outside air increases as the outside air temperature To increases, so that the first air flow rate F1 may be set to a smaller value each time the outside air temperature To increases.

FIG. 4 is a flowchart showing the procedure of the control operation of the in-compartment air blower unit 22 according to the first embodiment. FIG. 5 is a schematic diagram showing the relationship between the cooling load P, the cooling capacity Q, and the internal temperature Tt with respect to the amount of air blown by the internal air blower unit 22 when the outside air temperature To is constant. FIG. 6 shows the relationship between the cooling load P, the cooling capacity Q, and the internal temperature Tt with respect to the amount of air blown by the internal air blower 22 when the outside air temperature To changes, and the optimum point of the air flow amount of the internal air blower 22. It is a schematic diagram which shows the change. When the outside air temperature To is constant, the cooling load becomes constant, and when the outside air temperature To changes, the cooling load changes.

The processing of the flowchart of FIG. 4 is performed every Tα for a certain period of time. Hereinafter, control of the amount of air blown by the air blower unit 22 in the refrigerator will be described with reference to FIGS. 5 and 6.

In step S101, the outside air temperature detecting unit 11 detects the outside air temperature To of the open showcase 100.

In step S102, the control unit 50 calculates the temperature difference ΔTo (= To-To_old) between the detected outside air temperature To and the previously detected outside air temperature To_old (hereinafter, the previous outside air temperature To_old). The control unit 50 updates the previous outside air temperature To_old with the detected outside air temperature To.

In step S103, when the absolute value of the temperature difference ΔTo is equal to or less than the specified value β (S103: YES), the process proceeds to step S109. The specified value β is a permissible amount of error, and a value that can be considered that the outside air temperature To has not changed is set.

In step S109, the internal temperature detection unit 12 detects the internal temperature Tt of the accommodation space 13.

In step S110, the control unit 50 calculates the temperature difference ΔTt (= Tt−Ts) between the detected internal temperature Tt and the predetermined target temperature Ts.

In step S111, when the absolute value of the temperature difference ΔTt is equal to or less than the specified value α (S111: YES), the process returns without changing the amount of air blown by the in-compartment air blower unit 22. The specified value α is a permissible amount of error, and a value that can be regarded as having Tt and Ts almost equal is set. The process returns without causing it.

When Tt and Ts are substantially equal, the reason why the air blowing amount of the in-compartment air blowing unit 22 is not changed will be described. When the cooling load P and the cooling capacity Q are equivalent in the upper part of the graph of FIG. 5, the internal temperature Tt can be maintained at the target temperature Ts in the lower part of the graph of FIG. When the temperature Tt in the refrigerator is substantially equal to the target temperature Ts, it can be determined that the cooling load P and the cooling capacity P are substantially the same, so that the current air volume of the air blower unit 22 in the refrigerator is maintained.

In step S111, when the absolute value of the temperature difference ΔTt exceeds the specified value α (S111: NO), the process proceeds to step S112.

In step S112, when the temperature difference ΔTt is smaller than (−α) (S112: YES), the process proceeds to step S113. That is, when the temperature inside the refrigerator Tt is lower than the target temperature Ts by more than the permissible error α, the air curtain 17 is sufficiently formed on the open surface 18. In this case, it can be said that the cooling capacity Q is higher than the cooling load P in the upper part of the graph in FIG. 5 (Tt2, P2, Q2 in FIG. 5).

In step S113, the control unit 50 reduces the amount of air blown by ΔF by reducing the rotation speed of the motor of the air blower unit 22 in the refrigerator by a certain amount. After that, the process returns. In the lower part of the graph of FIG. 5, the amount of air blown by the air blower unit 22 in the refrigerator is reduced. By doing so, the cooling capacity is reduced at the same time while maintaining the air curtain 17. Since the air curtain 17 is maintained, it is possible to maintain an appropriate internal temperature. By reducing the rotation speed of the motor of the air blower unit 22 in the refrigerator, the power of the motor of the air blower unit 22 in the refrigerator and the compressor 31 can be reduced, so that the energy saving of the open showcase 100 can be achieved.

In step S112, when the temperature difference ΔTt exceeds α (S112: NO), the process proceeds to step S114. That is, when the temperature inside the refrigerator Tt is higher than the target temperature Ts by an error α, the process proceeds to step S114.

When the temperature inside the refrigerator Tt is higher than the target temperature Ts, the cooling load P is larger than the cooling capacity Q due to the collapse of the air curtain 17 (Tt1 in FIG. 5). P1, Q1), the cooling load P may be larger than the cooling capacity Q due to the large amount of external air entrained, and the temperature inside the refrigerator may be diverged (shaded part in FIG. 5, Tt3, P3, Q3). ).

In step S114, when the amount of air blown by the internal air blower unit 22 does not exceed the first amount of air blown F1 (S114: No), that is, in the upper part of the graph of FIG. 5, the amount of air blown inside the refrigerator is small and the cooling capacity Q. When the cooling load P is higher than that (Tt1, P1, Q1 in FIG. 5), the process proceeds to step 116.

In step S116, the control unit 50 increases the amount of air blown by ΔF by increasing the rotation speed of the motor of the air blower unit 22 in the refrigerator by a certain amount. After that, the process returns. In the lower part of the graph of FIG. 5, the amount of air blown by the air blower unit 22 in the refrigerator increases. By doing so, the wind speed of the suction air of the suction port 15 and the wind speed of the blown air of the outlet 14 increase, so that a stronger air curtain 17 is formed on the open surface 18, thereby reducing the influence of the external airflow. , The cooling load can be reduced. Further, since the wind speed in the cooling heat exchanger 21 is increased by increasing the rotation speed of the motor of the in-compartment air blower unit 22, the cooling capacity in the cooling heat exchanger 21 can be improved. That is, by increasing the amount of air blown by the air blower unit 22 in the refrigerator, it is possible to simultaneously realize a reduction in the cooling load by strengthening the air curtain 17 and an increase in the cooling capacity by increasing the wind speed in the cooling heat exchanger 21.

In step S114, when the amount of air blown by the in-compartment air blower unit 22 exceeds the first amount of air blown F1 (S114: YES), the process proceeds to step 115. That is, in the upper part of the graph of FIG. 5, when the amount of air blown into the refrigerator is large and the cooling load P is higher than the cooling capacity Q (Tt3, P3, Q3 in FIG. 5), air is applied to the cooling load P. When the wind speed of the curtain 17 is excessive, the entrainment of external air increases. If the rotation speed of the motor of the air blower unit 22 in the refrigerator is further increased while the wind speed of the air curtain 17 is excessive, the outside air is further entrained and the temperature Tt in the refrigerator rises further. Eventually, the motor of the internal air blower unit 22 reaches the maximum rotation speed, and the internal temperature Tt becomes stable at a temperature higher than the target temperature Ts.

In order to avoid this state, in step S115, the control unit 50 reduces the rotation speed of the motor of the internal air blower unit 22 to a specified value, thereby reducing the air flow amount of the internal air blower unit 22 to the second air blow amount. Decrease to F2 (<F1). The control unit 50 maintains the air flow amount of the in-compartment air blower unit 22 at the second air blow amount F2 for a certain period of time Tβ. In the lower part of the graph in FIG. 5, the amount of air blown into the refrigerator decreases. It is possible to eliminate the state in which the external air is entrained due to the excessive wind speed of the air curtain 17, and it is possible to control the wind speed of the air curtain 17 to an appropriate state.

After the flowchart of FIG. 4 returns and Tα elapses for a certain period of time, the process is repeated from step S101 (recontrol).

In step S103, when the absolute value of the temperature difference ΔTo exceeds the specified value β (S103: NO), the process proceeds to step S104.

In step S104, when the temperature difference ΔTt is smaller than (−β) (S104: YES), the process proceeds to step S105.

In this case, the outside air temperature To acquired this time is lower than the previous outside air temperature To_old by exceeding the permissible error β. At this time, the air curtain 17 is sufficiently formed on the open surface 18, and as shown in FIG. 6, the cooling capacity Q is higher than the cooling load P (point A in FIG. 6).

In step S105, the control unit 50 reduces the rotation speed of the motor of the in-compartment air blower unit 22 by a certain amount, thereby reducing the air blow amount ΔF. By doing so, the cooling capacity can be reduced at the same time while the air curtain 17 is maintained, and the temperature inside the refrigerator can be maintained at an appropriate temperature (point C in FIG. 6). By reducing the amount of air blown by the air blower unit 22 in the refrigerator by ΔF, the power of the motor and the compressor 31 of the air blower unit 22 in the refrigerator can be reduced, so that the energy saving of the open showcase 100 can be achieved. After this, the process returns.

On the other hand, in step S104, when the temperature difference ΔTt is larger than β (S104: NO), the process proceeds to step S106.

In step S106, if the amount of air blown by the in-compartment air blower unit 22 does not exceed the first amount of air blown F1 (S106: NO), the process proceeds to step 108. In this case, as shown in FIG. 6, the cooling load P is higher than the cooling capacity Q (point B in FIG. 6).

In step S108, the control unit 50 increases the amount of air blown by ΔF by increasing the rotation speed of the motor of the air blower unit 22 in the refrigerator by a certain amount. After that, the process returns. By doing so, the wind speed of the suction air of the suction port 15 and the wind speed of the blown air of the outlet 14 increase, so that a stronger air curtain 17 is formed on the open surface 18, thereby reducing the influence of the external airflow. , The cooling load can be reduced. Further, since the wind speed in the cooling heat exchanger 21 is increased by increasing the rotation speed of the motor of the in-compartment air blower unit 22, the cooling capacity in the cooling heat exchanger 21 can be improved. That is, by increasing the amount of air blown by the air blower unit 22 in the refrigerator, the cooling load is reduced by strengthening the air curtain 17, and the cooling capacity is increased by increasing the wind speed in the cooling heat exchanger 21 at the same time (FIG. 6). D point).

In step S106, when the amount of air blown by the in-compartment air blower unit 22 exceeds the first amount of air blown F1 (S106: YES), the process proceeds to step 107. In this case, as shown in FIG. 6, the cooling load P is higher than the cooling capacity Q (point B'in FIG. 6). At this time, the wind speed of the air curtain 17 is excessive, so that the outside air is present. It can be judged that the temperature inside the refrigerator is diverging due to the large amount of entrainment.

In step S107, the control unit 50 reduces the air flow rate of the internal air blower unit 22 to the second air flow rate F2 (<F1) by reducing the rotation speed of the motor of the internal air blower unit 22 to a specified value. (Point D in FIG. 6). The control unit 50 maintains the air flow amount of the in-compartment air blower unit 22 at the second air blow amount F2 for a certain period of time Tβ. After this, the process returns. As a result, it is possible to eliminate the state in which the air curtain 17 is entrained with external air due to the excessive wind speed, and it is possible to control the wind speed of the air curtain 17 to an appropriate state.

After the flowchart of FIG. 4 returns and Tα elapses for a certain period of time, the process is repeated from step S101 (recontrol).

The control of the internal air blower unit 22 may change the rotation speed of the motor of the internal air blower unit 22 so as to correspond to the output signal of the internal air blower unit 22. For example, the rotation speed of the internal air blower 22 is changed stepwise according to the internal temperature Tt by using a database in which the relationship between the internal temperature Tt and the air flow amount of the internal air blower 22 is determined. You may.

The first air flow rate F1 also changes depending on the cooling capacity. The cooling capacity decreases as the amount of frost adhering to the cooling heat exchanger 21 increases. For example, in an open showcase for freezing, the temperature of the refrigerant flowing in the cooling heat exchanger 21 must be set to -20 ° C or lower in order to keep the temperature inside the refrigerator at about -20 ° C. Therefore, when the air is cooled, frost adheres to the cooling heat exchanger 21.

FIG. 11 is a schematic view showing a change in the optimum operating point of the air blowing amount of the in-compartment air blowing unit 22 when the cooling capacity is lowered.

As shown at point E in FIG. 11, as the cooling capacity Q decreases, the ventilation resistance increases and the cooling capacity decreases. Therefore, the control unit 50 first sets the upper limit value of the amount of air blown that can be output by the in-compartment air blower unit 22 when the predicted value of the frost formation amount of the circulation passage 16 or the cooling heat exchanger 21 is the maximum (predicted maximum value). It may be set as the air flow rate F1 of.

Since the frost formation rate is maximized when the relative humidity of the internal air temperature is 100%, the predicted maximum value of the frost formation amount can be calculated from the growth model of the frost density at that time. The increase in ventilation resistance can be obtained from the predicted maximum value of the frost formation amount, and the upper limit value of the ventilation amount that can be output by the internal ventilation unit 22 can be obtained from the PQ curve, that is, the curve of the ventilation amount Q with respect to the ventilation resistance P. The experiment may be conducted under the condition where the frost formation is the largest among the installed environmental conditions (dry-bulb temperature and relative humidity are high), and the frost formation amount at that time may be set as the predicted maximum value.

As described above, using the flowchart of FIG. 4, the control of the in-compartment air blower unit 22 when the cooling load is constant and when the cooling load changes has been described. According to the first embodiment, it is possible to develop a series of open showcases having various capacities in which the air blower unit 22 in the refrigerator is shared. When an open showcase having a different capacity is configured by sharing the air blower unit 22 in the refrigerator, the wind speed of the air curtain 17 is too large for the accommodation space 13 in the open showcase with a small capacity. May be excessive. However, it is easy to maintain the wind speed of the air curtain 17 properly by recontrolling the air flow amount of the in-compartment air blower unit 22 as described above or by setting an upper limit value for the air flow amount of the in-compartment air blower unit 22. Therefore, it is possible to develop a series of open showcases having various capacities in which the air blower unit 22 in the refrigerator is standardized while realizing cooling and energy saving of the accommodation space 13.

Although the control method of the compressor 31 is not fixed, the control operation of the in-compartment air blower unit 22 according to the first embodiment is controlled to start and stop based on the evaporation temperature in the cooling heat exchanger 21. It is effective when a fixed-capacity compressor or a variable-capacity compressor whose capacity is controlled based on the evaporation temperature in the cooling heat exchanger 21 is used.

The processing of the flowchart of FIG. 4 is executed after the temperature inside the refrigerator Tt matches the target temperature Ts by controlling the rotation speed of the compressor 31 with the amount of air blown by the air blower unit 22 in the refrigerator as a constant value. May be.

Embodiment 2.
The configuration of the open showcase 100 of the second embodiment is the same as the configuration of the open showcase 100 of the first embodiment. The control operation of the internal air blower unit 22 of the second embodiment is different from the control operation of the internal air blower unit 22 of the first embodiment. Hereinafter, the differences from the first embodiment will be mainly described.

In the first embodiment, the control of the air flow amount when the cooling capacity of the refrigeration cycle apparatus does not change has been described, but in the present embodiment, the air flow amount is controlled in consideration of the case where the cooling capacity decreases due to frost formation or the like. explain.

The control unit 50 controls the amount of air blown by the internal air blower unit 22 according to the difference between the detected internal temperature Tt and the target internal temperature Ts.

The control unit 50 registers in the data table the relationship between the outside air temperature To when the internal temperature Tt matches the target temperature Ts and the amount of air blown by the internal air blower 22. The control unit 50 sets the amount of air blown in the refrigerator 22 corresponding to the detected outside air temperature To with reference to the data table that defines the relationship between the outside air temperature To and the amount of air blown in the refrigerator 22. When the internal temperature Tt detected after setting the air volume of the internal air blower 22 by referring to the data table is higher than the target temperature Ts, the control unit 50 sets the internal temperature Tt to the target temperature Ts. Until it reaches the limit, the amount of air blown by the air blower unit 22 in the refrigerator is increased. After increasing the amount of air blown by the internal air blower unit 22, the control unit 50 uses a data table to display the relationship between the outside air temperature and the amount of air blown through the internal air blower unit 22 when the internal air temperature Tt matches the target temperature Ts. Reset. The control unit 50 performs a defrost operation when the temperature Tt in the refrigerator does not reach the target temperature Ts even if the amount of air blown in the air blower unit 22 in the refrigerator is increased to the upper limit value. The control unit 50 generates heat by energizing a defrost heater provided in the vicinity of the cooling heat exchanger 21 (not shown), and melts and removes the frost adhering to the cooling heat exchanger 21 to execute the defrost operation. The control unit 50 outputs an alarm when the internal temperature Tt does not reach the target temperature Ts even after the defrost operation.

7 and 8 are flowcharts showing the procedure of the control operation of the air blower unit 22 in the refrigerator according to the second embodiment. With reference to FIGS. 7 and 8, control of the air blowing amount of the in-compartment air blowing unit 22 will be described.

In step S20, the control unit 50 sets Count to 0. Count is used as a determination condition in step S39.

In step S21, the outside air temperature detecting unit 11 detects the outside air temperature To, which is the ambient temperature of the open showcase 100.

In step S22, the control unit 50 calculates the temperature difference ΔTo (= To-To_old) between the detected outside air temperature To and the previously detected outside air temperature To_old (hereinafter, the previous outside air temperature To_old). The control unit 50 replaces the previous outside air temperature To_old with the outside air temperature To detected in step S21 this time.

In step S23, it is determined whether or not the temperature difference ΔTo is within the range β (for example, 5 ° C.) where the temperature difference is significantly changed. If there is no value of the outside air temperature To_old last time (that is, the first case), the process proceeds to step S24.

When the outside air temperature To is equivalent to the previous outside air temperature To_old, that is, when the outside air temperature To is substantially equal to the previous outside air temperature To_old (S23: Yes), the process is performed without changing the air blowing amount of the internal air blower unit 22. Returns.

On the other hand, when the outside air temperature To is not equal to the previous outside air temperature To_old but changes significantly (S23: No), the process proceeds to step S24.

In step S24, the control unit 50 determines whether or not the data of the air flow amount of the in-compartment air blower unit 22 corresponding to the detected outside air temperature To is registered in the data table. The data table is held in the control unit 50. Alternatively, the control unit 50 may acquire and update the data table held in another server or the like connected to the network. The outside air temperature To registered in the data table may be set to each range (β, for example, 5 ° C.) in which the inside temperature Tt changes significantly.

If the data of the amount of air blown by the in-compartment air blower unit 22 corresponding to the detected outside air temperature To is not registered in the data table (S24: No), the process proceeds to step S25.

In step S25, the control unit 50 minimizes the amount of air blown by the in-compartment air blower unit 22.
In step S26, the internal temperature detection unit 12 detects the internal temperature Tt of the accommodation space 13.

In step S27, the control unit 50 calculates the temperature difference ΔTt (= Tt−Ts) between the detected internal temperature Tt and the predetermined target temperature Ts.

In step S28, the control unit 50 determines whether or not the temperature difference ΔTt is within the range of the error α. The target temperature Ts may be a preset temperature or a temperature arbitrarily set by the user.

When the temperature difference ΔTt is within the range of the error α, that is, when the internal temperature Tt is substantially equal to the target temperature Ts (S28: Yes), the process proceeds to step S29.

In step S29, the control unit 50 writes a pair of the outside air temperature To and the current air flow amount of the in-compartment air blower unit 22 in the data table. After that, the process returns.

On the other hand, when the temperature difference ΔTt is outside the range of the error α, that is, when the temperature inside the refrigerator Tt is far from the target temperature Ts (S28: No), the process proceeds to step S30.

In step S30, the control unit 50 increases the amount of air blown by the in-compartment air blower unit 22 by a certain amount ΔF. After that, the process returns to step S26.

In steps S26 to S30, a data table in which the amount of air blown by the in-compartment air blower unit 22 is initially created with respect to the outside air temperature To detected in step S21.

FIG. 9 is a diagram showing an example of the data table of the second embodiment.
For example, when the outside air temperature To detected in step S21 is 2γ and the airflow amount (initial airflow amount) at YES in step 28 is f2, the data table shows the airflow amount f2 corresponding to the outside air temperature 2γ. Written.

In step S24, when the data of the air blowing amount of the in-compartment air blowing unit 22 corresponding to the detected outside air temperature To is registered in the data table (S24: Yes), the process proceeds to step S31.

In step S31, the control unit 50 refers to the data table, identifies the air blower amount F (To) corresponding to the detected outside air temperature To, and sets the in-compartment air blower unit 22 so as to have the air blown amount F (T0). Control.

In step S32, the internal temperature detection unit 12 detects the internal temperature Tt of the accommodation space 13.

In step S33, the control unit 50 calculates the temperature difference ΔTt (= Tt−Ts) between the detected internal temperature Tt and the predetermined target temperature Ts.

In step S34, similarly to step S28, the control unit 50 determines whether or not the temperature difference ΔTt is within the range of the error α.

When the temperature difference ΔTt is within the range of the error α, that is, when the internal temperature Tt is substantially equal to the target temperature Ts (S34: Yes), the process proceeds to step S35.

In step S35, the control unit 50 determines whether or not the current air blow amount of the in-compartment air blow unit 22 is different from the air blow amount F (T0) set in step S31.

When the current air blowing amount of the in-compartment air blowing unit 22 is the same as the air blowing amount F (T0) (S35: NO), the process returns. If the current air blowing amount of the in-compartment air blowing unit 22 is different from the air blowing amount F (T0) (S35: YES), the process proceeds to step S36.

In step S36, the control unit 50 updates the data table. That is, the control unit 50 changes the amount of air blown to the outside air temperature To in the data table from F (T0) to the current amount of air blown from the inside air blower unit 22. After that, the process returns.

FIG. 10 is a diagram showing an example of a data table in which the amount of air blown in the first embodiment is updated.

For example, when the outside air temperature To detected in step S21 is 2γ and the updated airflow amount is f2', the airflow amount corresponding to the outside air temperature 2γ in the data table is changed from f2 to f2'.

Here, the reason for updating the value of the air flow rate in step S36 will be described.
FIG. 11 is a diagram showing control and setting points when the cooling capacity is reduced.

If the open showcase 100 is operated for a long time, the cooling capacity is lowered, and the internal temperature Tt may deviate from the target temperature Ts. For example, frost adheres to the cooling heat exchanger 21, the ventilation resistance increases, the cooling capacity decreases, and the internal temperature Tt deviates from the target temperature Ts (point F in FIG. 11). Therefore, the amount of air blown by the internal air blower unit 22 is increased so that the internal temperature Tt becomes the target temperature Ts (step S38 described later). Therefore, the air volume of the air blower unit 22 in the refrigerator may be different from the air flow amount F (T0) set in step S31, so that the air flow amount in the data table is updated in step S36.

On the other hand, when the temperature difference ΔTt is outside the range of the error α, that is, when the temperature inside the refrigerator Tt is far from the target temperature Ts (S34: No), the process proceeds to step S37.

In step S37, the control unit 50 confirms whether or not the amount of air blown by the in-compartment air blower unit 22 is equal to or greater than the third amount of air blown F3. The third blast amount F3 can be, for example, a value close to the maximum blast amount or the maximum blast amount of the in-compartment blast unit 22.

In step S37, if the amount of air blown by the in-compartment air blower unit 22 is less than the third amount of air blown F3 (S37: No), the process proceeds to step S38.

In step S38, the control unit 50 increases the amount of air blown by the in-compartment air blower unit 22 by a certain amount ΔF. After that, the process returns to step S32.

In step S37, if the amount of air blown by the in-compartment air blower unit 22 is equal to or greater than the third amount of air blown F3 (S37: YES), the process proceeds to step S39.

In step S39, the control unit 50 determines whether the Count is smaller than 1.
If Count is less than 1 in step S39 (S39: Yes), the process proceeds to step S40.

In step S40, the control unit 50 defrosts. The air volume of the air blower unit 22 in the refrigerator is returned to the initial air volume F (T0) corresponding to the outside air temperature To detected in step S21. After that, the process proceeds to step S42.

In step S42, the control unit 50 increments Count. After that, the process returns to step S32.

Here, the reason for defrosting operation will be explained.
FIG. 12 is a diagram showing the relationship between the internal temperature Tt and the target temperature Ts when the decrease in the cooling capacity is too large.

If it is determined that the air volume of the air blower unit 22 in the refrigerator is the upper limit and the temperature Tt in the refrigerator is far from the target temperature Ts, the cooling capacity is too low to reach the target temperature Ts as shown in FIG. This is the case when there is no air flow. In such a case, it is considered that the amount of frost adhering to the cooling heat exchanger 21 becomes too large and the decrease in the cooling capacity becomes too large. Therefore, the cooling capacity is returned to the state before frost formation by performing the defrost operation.

In step S39, when Count is 1 or more (S39: No), the process proceeds to step S41. When the Count becomes 1 or more, it is a case where the internal temperature Tt is far from the target temperature Ts even though the defrost operation is performed in step S40.

In step S41, the control unit 50 determines that the decrease in cooling capacity is not due to frost on the cooling heat exchanger 21 but due to deterioration, and outputs an alarm.

Here, the deterioration may be, for example, clogging of the filter (not shown) of the outdoor heat exchanger 32. Adhesion of dust in the surrounding space to the outdoor heat exchanger 32 causes an increase in ventilation resistance of the outdoor heat exchanger 32 and a decrease in heat transfer performance, resulting in a decrease in the cooling capacity of the open showcase 100. Therefore, in order to prevent a decrease in the cooling capacity, a filter is generally provided at a place where the outdoor air blown by the outdoor air blowing unit 33 passes. The performance of the outdoor heat exchanger 32 is maintained by the adhesion of dust to the filter. However, as dust adheres to the filter, the ventilation resistance of the filter gradually increases, and as a result, the capacity of the outdoor heat exchanger 32 is reduced. For such a case, an alarm is issued in step S41 to prompt the filter to be cleaned.

The processing of the flowcharts of FIGS. 7 and 8 is performed every Tα for a certain period of time. Even if the process returns, the data registered in the data table is not deleted. Further, since the data table is stored in the non-volatile memory, the data registered in the data table can be prevented from being erased even when the power of the open showcase 100 is turned off.

As described above, the control of the in-compartment air blower unit 22 according to the cooling load has been described with reference to the flowcharts of FIGS. 7 and 8. Further, according to the second embodiment, it is possible to develop a series of open showcases having various capacities in which the in-compartment air blower unit 22 is shared as in the first embodiment. Further, when the cooling capacity of the open showcase 100 decreases due to frost on the cooling heat exchanger 21 or an increase in ventilation resistance due to dust adhering to the filter of the outdoor heat exchanger, it is appropriate to perform a defrost operation or a maintenance alarm. It is possible to provide an open showcase 100 that maintains a sufficient cooling capacity.

In the present embodiment, the data table defines the relationship between the outside air temperature and the amount of air blown by the air blower unit 22 in the refrigerator, but the data table is not limited to this.

FIG. 13 is a diagram showing an example of a data table of a modification of the second embodiment.
As shown in FIG. 13, the data table may determine the relationship between the outside air temperature and the target temperature and the amount of air blown by the in-compartment air blower unit 22. In this case, in step S24 and step S29 of FIG. 7, step S31 of FIG. 8, step S36 and the like, the control unit 50 executes processing according to the target temperature in addition to the outside air temperature.

Embodiment 3.
FIG. 14 is a schematic view showing a main part of the open showcase 100 according to the third embodiment. The difference between the open showcase 100 of the third embodiment and the open showcase 100 of the first and second embodiments is the position of the temperature detection unit 12 inside the refrigerator. As shown in FIG. 14, in the third embodiment, the internal temperature detecting unit 12 is installed at the position of the air outlet 14. Hereinafter, the differences from the first and second embodiments will be mainly described.

In the first and second embodiments, the internal air blower unit 22 is controlled so that the internal temperature Tt, which is the temperature of the accommodation space 13 acquired by the internal temperature detection unit 12, approaches the target temperature Ts.

In the third embodiment, the position of the internal temperature detection unit 12 is at the position of the air outlet 14. Therefore, the internal temperature detection unit 12 detects the temperature of the outlet 14 as the internal temperature Tt. The temperature detected at the outlet 14 is lower than the temperature of the accommodation space 13. This is because the accommodation space 13 is exposed to the surrounding space, and the air curtain 17 cannot completely block the outside air. Therefore, the temperature of the accommodation space 13 becomes higher than that of the outlet 14 due to the inflow of the outside air. Is.

The control unit 50 corrects the target temperature Ts based on the difference ΔT1 (> 0) between the predetermined temperature of the accommodation space 13 and the outlet 14, and then based on the control flowcharts of the first and second embodiments. The air blower unit 22 in the refrigerator is controlled. For example, the control unit 50 can correct the target temperature Ts to Ts−ΔT1. The temperature difference ΔT1 can be obtained by detecting the temperature of the accommodation space 13 and the temperature of the outlet 14 in advance by an experiment or the like.

Embodiment 4.
FIG. 15 is a schematic view showing a main part of the open showcase 100 according to the fourth embodiment. The difference between the open showcase 100 of the fourth embodiment and the open showcase 100 of the first and second embodiments is the position of the temperature detection unit 12 inside the refrigerator. As shown in FIG. 15, in the fourth embodiment, the internal temperature detecting unit 12 is installed at the position of the suction port 15. Hereinafter, the differences from the first and second embodiments will be mainly described.

In the first and second embodiments, the internal air blower unit 22 is controlled so that the internal temperature Tt, which is the temperature of the accommodation space 13 acquired by the internal temperature detection unit 12, approaches the target temperature Ts.

On the other hand, in the fourth embodiment, the position of the internal temperature detection unit 12 is at the position of the suction port 15. Therefore, the internal temperature detection unit 12 detects the temperature of the suction port 15 as the internal temperature Tt. The temperature detected in the suction port 15 is higher than the temperature detected in the accommodation space 13. This is because the cold air emitted from the outlet 14 reaches the suction port 15 via the accommodation space 13, so that the temperature of the suction port 15 is higher than that of the accommodation space 13 due to the influence of the surrounding space.

The control unit 50 corrects the target temperature Ts based on the difference ΔT2 (> 0) between the predetermined temperature of the suction port 15 and the temperature of the accommodation space 13, and then controls the control flowcharts of the first and second embodiments. 22 is controlled based on the above. For example, the control unit 50 can correct the target temperature Ts as Ts + ΔT2. The temperature difference ΔT2 can be obtained by detecting the temperature of the accommodation space 13 and the temperature of the suction port 15 in advance by an experiment or the like.

By correcting the target temperature Ts as described above, it is possible to provide the open showcase 100 in which the same effects as those of the first and second embodiments can be obtained.

Embodiment 5.
FIG. 16 is a schematic view showing a main part of the open showcase 100 according to the fifth embodiment. The difference between the open showcase 100 of the fifth embodiment and the open showcase 100 of the first and second embodiments is the position of the temperature detection unit 12 inside the refrigerator. As shown in FIG. 16, in the fifth embodiment, the internal temperature detecting unit 12 is installed in the circulation passage 16. Hereinafter, the differences from the first and second embodiments will be mainly described.

In the first and second embodiments, the internal air blower unit 22 is controlled so that the internal temperature Tt acquired by the internal temperature detection unit 12 approaches the target temperature Ts.

On the other hand, in the fifth embodiment, when the internal temperature detection unit 12 is installed in the circulation passage 16, the internal temperature detection unit 12 is installed on the windward side or the leeward side of the cooling heat exchanger 21. It is different whether the temperature detected by the internal temperature detecting unit 12 is higher or lower than the average temperature of the accommodation space 13. When the position of the internal temperature detection unit 12 is installed on the leeward side of the cooling heat exchanger 21, the air immediately after being cooled by the cooling heat exchanger 21 passes through the circulation passage 16, so that the internal temperature detection unit 12 detects it. The temperature is lower than the temperature of the accommodation space 13. On the other hand, if the position of the internal temperature detection unit 12 is installed above the cooling heat exchanger 21, the air immediately before being cooled by the cooling heat exchanger 21 passes through the circulation passage 16, so that the internal temperature detection unit 12 The temperature detected in is higher than the temperature of the accommodation space 13.

The internal temperature detection unit 12 detects the temperature of the circulation passage 16 as the internal temperature Tt.
The control unit 50 corrects the target temperature Ts based on the difference ΔT3 (> 0) between the temperature of the accommodation space 13 and the temperature of the circulation passage 16 determined in advance, and then the control flowcharts of the first and second embodiments. 22 is controlled based on the above. For example, when the internal temperature detection unit 12 is installed on the leeward side of the cooling heat exchanger 21, the control unit 50 corrects the target temperature Ts to Ts−ΔT3. On the other hand, when the internal temperature detection unit 12 is installed on the windward side of the cooling heat exchanger 21, the control unit 50 corrects the target temperature Ts to Ts + ΔT3. The temperature difference ΔT3 can be obtained by detecting the temperature of the accommodation space 13 and the temperature of the circulation passage 16 in advance by an experiment or the like.

The showcase has been described in detail with reference to the drawings. In the drawings used above, the relationship between the sizes of the constituent members may differ from the actual one. In addition, the forms of the components shown in the entire specification are merely examples, and are not limited to these descriptions.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

10 Showcase body, 11 Outside air temperature detector, 12 Inside temperature detector, 13 Storage space, 14 Air outlet, 15 Suction port, 16 Circulation passage, 17 Air curtain, 18 Open surface, 19 Display shelf, 21 Cooling heat exchange Instrument, 22 indoor air blower, 30 outdoor unit, 31 compressor, 32 outdoor heat exchanger, 33 outdoor air blower, 34 expansion valve, 41 (a) gas pipe, 41 (b) liquid pipe, 50 control unit.

Claims (17)

A showcase body having a storage space with one open surface, an air inlet and an outlet, and a circulation passage from the inlet to the outlet.
The air blower in the refrigerator that blows the air in the circulation passage,
A cooling unit that cools the air in the circulation passage,
An internal temperature detection unit that detects the internal temperature of the showcase body, and
An outside air temperature detection unit that detects the outside air temperature outside the showcase body,
It is provided with a control unit that controls the amount of air blown by the internal air blower according to the difference between the detected internal temperature and the target temperature of the internal temperature.
By sucking the air blown out from the air outlet through the suction port, an air curtain is formed on the open surface of the accommodation space.
When the amount of air blown by the internal air blower exceeds the first amount of air, the control unit reduces the amount of air blown by the internal air blower to a second amount smaller than the first amount of air. height,
When the amount of air blown in the refrigerator is the first amount of air, the cooling capacity of the cooling part and the cooling load become equal, and the amount of air blown in the inside of the refrigerator is larger than the amount of the first air blown. When the cooling capacity is smaller than the cooling load, the cooling capacity of the cooling unit is larger than the cooling load, and when the cooling capacity of the cooling unit is larger than the first air volume, the cooling capacity of the cooling unit is the cooling load. A refrigeration cycle device that is smaller than. When the temperature inside the refrigerator is higher than the target temperature and the amount of air blown by the air blower in the refrigerator exceeds the first air blown amount, the control unit sets the air blown amount of the air blower in the refrigerator to the second. The refrigeration cycle apparatus according to claim 1, wherein the air volume is reduced to the amount of air blown. The control unit has a temperature higher than the target temperature and an amount of air blown by the air blower in the refrigerator after a certain period of time has elapsed after reducing the air blown amount of the air blower in the refrigerator to the second air blower. When is equal to or less than the first air blowing amount, the air blowing amount of the internal air blower is increased, and when the internal temperature is lower than the target temperature, the air blown amount of the internal air blower is decreased. The refrigeration cycle apparatus according to claim 2. When the outside air temperature rises and the amount of air blown by the internal air blower exceeds the first amount of air, the control unit reduces the amount of air blown by the internal air blower to the second amount of air. The refrigeration cycle apparatus according to claim 1. In the control unit, the outside air temperature rises after a certain period of time has elapsed after the air volume of the air blower in the refrigerator is reduced to the second air volume, and the air volume of the air blower in the refrigerator is the first. The refrigeration cycle apparatus according to claim 4, wherein the amount of air blown in the refrigerator is increased when the amount of air blown in the refrigerator is equal to or less than the above, and the amount of air blown in the air blower in the refrigerator is reduced when the outside air temperature is lowered. The refrigeration cycle apparatus according to claim 1, wherein the first air flow rate is set for each outside air temperature. The refrigeration cycle apparatus according to claim 6, wherein the first air flow rate decreases as the outside air temperature increases. The first air blowing amount is an upper limit value of the air blowing amount that can be output by the in-compartment air blowing unit when the predicted value of the frost formation amount on the evaporator contained in the circulation passage or the cooling unit is maximum. The refrigeration cycle apparatus according to claim 1. A showcase body having a storage space with one open surface, an air inlet and an outlet, and a circulation passage from the inlet to the outlet.
The air blower in the refrigerator that blows the air in the circulation passage,
A cooling unit that cools the air in the circulation passage,
An internal temperature detection unit that detects the internal temperature of the showcase body, and
An outside air temperature detection unit that detects the outside air temperature outside the showcase body,
It is provided with a control unit that controls the amount of air blown by the internal air blower according to the difference between the detected internal temperature and the target temperature of the internal temperature.
By sucking the air blown out from the air outlet through the suction port, an air curtain is formed on the open surface of the accommodation space.
The control unit sets the amount of air blown by the inside air blower corresponding to the detected outside air temperature by referring to a data table that defines the relationship between the outside air temperature and the amount of air blown by the inside air blower .
When the amount of air blown in the refrigerator is the amount of air blown specified in the data table, the cooling capacity of the cooling unit and the cooling load become equal, and the amount of air blown in the air blower in the refrigerator is determined in the data table. When the cooling capacity of the cooling unit is smaller than the cooling load when the air volume is smaller than the air volume, and the air volume of the air blower unit in the refrigerator is larger than the air volume specified in the data table, the cooling unit is cooled. The capacity is larger than the cooling load,
The control unit increases the amount of air blown by the air blower in the refrigerator by a constant amount from the minimum value, and the outside air temperature and the outside air temperature when the difference between the temperature inside the refrigerator and the target temperature becomes a certain value or less. A refrigeration cycle device that registers the relationship with the air volume of the air blower in the refrigerator in the data table. The control unit refers to the data table, and when the temperature inside the refrigerator detected after setting the amount of air blown by the ventilation unit inside the refrigerator is higher than the target temperature, the temperature inside the refrigerator is the target. The refrigerating cycle apparatus according to claim 9, wherein the amount of air blown by the in-compartment air blower is increased until the temperature is reached. The control unit increases the amount of air blown by the air blower in the refrigerator, and then obtains the data on the relationship between the outside air temperature and the air blown amount of the air blower in the refrigerator when the temperature inside the refrigerator matches the target temperature. The refrigeration cycle apparatus according to claim 10 , which is reset to the table. The tenth aspect of the present invention, wherein the control unit performs a defrost operation when the temperature inside the refrigerator does not reach the target temperature even if the air blower amount of the air blower unit in the refrigerator is increased to the third air blower amount or more. Refrigeration cycle equipment. The refrigeration cycle apparatus according to claim 12 , wherein the control unit outputs an alarm when the temperature inside the refrigerator does not reach the target temperature even after the defrost operation. The internal temperature detection unit detects the temperature of the outlet as the internal temperature, and determines the temperature of the outlet.
The refrigeration cycle according to any one of claims 1 to 13 , wherein the control unit corrects the target temperature based on a predetermined difference between the temperature of the outlet and the temperature in the accommodation space. Device. The internal temperature detection unit detects the temperature of the suction port as the internal temperature, and determines the temperature of the suction port.
The refrigeration cycle according to any one of claims 1 to 13 , wherein the control unit corrects the target temperature based on a predetermined difference between the temperature of the suction port and the temperature in the accommodation space. Device. The internal temperature detection unit detects the temperature of the circulation passage as the internal temperature, and determines the temperature of the internal circulation passage.
The refrigeration cycle according to any one of claims 1 to 13 , wherein the control unit corrects the target temperature based on a predetermined difference between the temperature of the circulation passage and the temperature in the accommodation space. Device. The cooling unit includes a compressor, a radiator, a throttle device, and a refrigerant circuit to which an evaporator is connected by piping.
The refrigeration cycle apparatus according to claim 1 or 9, wherein the compressor is operated and controlled based on the evaporation temperature of the refrigerant in the evaporator.

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