JP6840992B2 - Freezing system and freezing method - Google Patents

Description

The present invention relates to a refrigeration system and a refrigeration method using a vapor compression refrigeration cycle, and more particularly to a refrigeration system and a refrigeration method including a heat exchanger that exchanges heat between refrigerants.

In the vapor compression refrigeration cycle, it is known that the stability and performance of the refrigeration system are improved by heating the refrigerant steam before flowing into the compressor. Patent Document 1 describes an example of an air conditioning system using such a vapor compression refrigeration cycle.

The related air conditioning systems described in Patent Document 1 include a compressor, a low heat source heat exchanger (evaporator), a first high heat source heat exchanger (sensible heat exchanger), and a second high heat source heat exchanger. It is equipped with a (condenser) and a steam compression refrigeration cycle with an expansion valve as a component. In addition to this vapor compression refrigeration cycle, the vapor compression heat pump of the related air conditioning system has a configuration in which a refrigerant heat exchanger is provided in the path from the low heat source heat exchanger (evaporator) to the compressor. In this refrigerant heat exchanger, the low-pressure refrigerant before suction from the compressor and the high-pressure wet steam discharged from the sensible heat exchanger exchange heat. After that, the cycle is configured so that the high-pressure moist steam flows into the condenser.

According to the related desiccant air-conditioning system using the heat pump configured as described above as a heat source, the temperature of the regenerated air can be heated to a temperature higher than the condensation temperature by the sensible heat of the superheated steam. Therefore, it is said that the dehumidifying capacity of desiccant will be improved compared to the past.

Further, Patent Document 2 describes an example in which a double-tube heat exchanger as a heat exchanger (inter-refrigerant heat exchanger) for exchanging heat between refrigerants as described above is applied to an air conditioner.

The related air conditioner described in Patent Document 2 includes an indoor heat exchanger, an outdoor heat exchanger, a four-way valve, a compressor, and a double tube heat exchanger. This double tube heat exchanger is placed in front of the compressor inlet. In the related air conditioner, a refrigerant flow switching device is further arranged between the indoor heat exchanger and the outdoor heat exchanger, and the refrigerant flow direction at the inlet and outlet of the double tube heat exchanger even when the heating / cooling operation is switched. Is configured to be kept constant.

In a related air conditioner, the degree of supercooling of the liquid refrigerant on the outlet side of the condenser is increased by exchanging heat between the medium-temperature and high-pressure liquid refrigerant on the outlet side of the condenser and the low-temperature and low-pressure refrigerant on the outlet side of the evaporator during cooling. Let me. The larger the supercooling degree, the smaller the enthalpy on the inlet side of the evaporator, and the larger the enthalpy difference between the inlet and the outlet of the evaporator, so that the cooling capacity increases.

Further, during heating, the degree of superheat on the compressor inlet side can be increased by exchanging heat between the medium-temperature and high-pressure liquid refrigerant on the condenser outlet side and the low-temperature and low-pressure refrigerant on the evaporator outlet side. As a result, the possibility of liquid compression occurring in the compressor is reduced, so that the operating reliability of the compressor can be improved.

Japanese Unexamined Patent Publication No. 10-267757 Japanese Unexamined Patent Publication No. 2005-83741

As described above, the related air conditioner using the vapor compression refrigeration cycle exchanges heat between the high temperature and high pressure refrigerant liquid flowing out of the condenser and the low temperature low pressure refrigerant vapor flowing out of the evaporator in the inter-refrigerant heat exchanger. It has a structure. As a result, the degree of superheat of the refrigerant vapor flowing into the compressor can be increased, and liquid compression in the compressor can be avoided.

However, the above effect can be obtained only when the temperature of the refrigerant liquid flowing out of the condenser is higher than the temperature of the refrigerant vapor flowing out of the evaporator. For example, when the refrigerant vapor is cooled and liquefied by exchanging heat with the outside air in the condenser, the temperature of the refrigerant liquid flowing out of the condenser is lower than the temperature of the refrigerant steam flowing out of the evaporator depending on the outside air temperature. Become. In this case, in the inter-refrigerant heat exchanger, the refrigerant vapor flowing into the compressor cannot be heated, but rather is cooled by the refrigerant liquid flowing out from the condenser. Then, the possibility that liquid compression occurs in the compressor increases, and the cooling performance of the refrigeration system deteriorates.

As described above, when the inter-refrigerant heat exchanger is used in the vapor compression refrigeration system, there is a problem that the cooling performance fluctuates depending on the usage environment.

An object of the present invention is to provide a refrigeration system and a refrigeration method that solve the above-mentioned problem that the cooling performance fluctuates depending on the usage environment when a refrigerant heat exchanger is used in a vapor compression refrigeration system. There is.

In the refrigeration system of the present invention, an evaporating means for generating refrigerant vapor by vaporizing the refrigerant liquid by receiving heat, a compression means for compressing the refrigerant vapor to generate high-pressure refrigerant vapor, and a compression means for condensing the high-pressure refrigerant vapor to generate the high-pressure refrigerant liquid. A condensing means for generating, an expanding means for generating a refrigerant liquid in which a high-pressure refrigerant liquid is expanded to a low pressure, and a refrigerant-to-refrigerant heat exchange means for heat exchange between the refrigerant steam and either the high-pressure refrigerant steam or the high-pressure refrigerant liquid. And a refrigerant supply means for supplying either one of the high-pressure refrigerant vapor and the high-pressure refrigerant liquid to the refrigerant heat exchange means.

In the refrigerating method of the present invention, the refrigerant liquid is vaporized by receiving heat from the object to be cooled to generate refrigerant vapor, and the refrigerant vapor is compressed to generate high-pressure refrigerant vapor, and the heat of the high-pressure refrigerant vapor is released to the outside air. As a result, the high-pressure refrigerant vapor is condensed to generate a high-pressure refrigerant liquid, and the refrigerant steam is heat-exchanged with either the high-pressure refrigerant steam or the high-pressure refrigerant liquid.

According to the refrigeration system and the refrigeration method of the present invention, even when the inter-refrigerant heat exchanger is used in the vapor compression refrigeration system, the fluctuation of the cooling performance depending on the usage environment can be suppressed.

It is the schematic which shows the structure of the refrigeration system which concerns on 1st Embodiment of this invention. It is the schematic which shows the structure in one state of the refrigeration system which concerns on 1st Embodiment of this invention. It is the schematic which shows the structure in the other state of the refrigeration system which concerns on 1st Embodiment of this invention. It is the schematic which shows the structure of the refrigeration system which concerns on 2nd Embodiment of this invention. It is the schematic which shows the structure in one state of the refrigeration system which concerns on 2nd Embodiment of this invention. It is the schematic which shows the structure in the other state of the refrigeration system which concerns on 2nd Embodiment of this invention. It is the schematic which shows another structure of the refrigeration system which concerns on 2nd Embodiment of this invention. It is a schematic diagram which shows still another structure of the refrigeration system which concerns on 2nd Embodiment of this invention, and shows the case where a three-way valve is used as a flow path switching means. It is a schematic diagram which shows still another structure of the refrigeration system which concerns on 2nd Embodiment of this invention, and shows the case where the four-way valve is used as the flow path switching means. It is a flowchart for demonstrating operation of the refrigeration system which concerns on 2nd Embodiment of this invention. It is the schematic which shows the structure of the refrigeration system which concerns on 3rd Embodiment of this invention. It is a flowchart for demonstrating operation of the refrigeration system which concerns on 3rd Embodiment of this invention. It is the schematic which shows the structure of the refrigeration system which concerns on 4th Embodiment of this invention. It is a flowchart for demonstrating operation of the refrigeration system which concerns on 4th Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic view showing the configuration of the refrigeration system 100 according to the first embodiment of the present invention. In the figure, the dashed arrow indicates the flow of refrigerant in the refrigeration cycle.

The refrigeration system 100 according to the present embodiment includes an evaporator (evaporation means) 110, a compressor (compression means) 120, a condenser (condensing means) 130, an expansion valve (expansion means) 140, and a refrigerant heat exchanger (refrigerant heat exchanger). It has a replacement means) 150 and a refrigerant supply structure (refrigerant supply means) 160.

The evaporator 110 vaporizes the refrigerant liquid by receiving heat to generate the refrigerant vapor R1. The compressor 120 compresses the refrigerant vapor to generate the high-pressure refrigerant vapor R2. The condenser 130 condenses the high-pressure refrigerant vapor to generate the high-pressure refrigerant liquid R3. The expansion valve 140 expands the high-pressure refrigerant liquid to generate a low-pressure refrigerant liquid R4. As described above, the evaporator 110, the compressor 120, the condenser 130, and the expansion valve 140 constitute the vapor compression refrigeration cycle.

The inter-refrigerant heat exchanger 150 exchanges heat between the refrigerant vapor R1 and either the high-pressure refrigerant vapor R2 or the high-pressure refrigerant liquid R3. Then, the refrigerant supply structure 160 supplies either the high-pressure refrigerant vapor R2 or the high-pressure refrigerant liquid R3 to the inter-refrigerant heat exchanger 150.

That is, as shown in FIG. 2A, the refrigerant supply structure 160 has a function of supplying the high-pressure refrigerant liquid R3 to the inter-refrigerant heat exchanger 150. Further, as shown in FIG. 2B, the refrigerant supply structure 160 has a function of supplying the high-pressure refrigerant vapor R2 to the inter-refrigerant heat exchanger 150.

As described above, the refrigerating system 100 can select the refrigerant that exchanges heat with the refrigerant vapor R1 in the inter-refrigerant heat exchanger 150 from the high-pressure refrigerant vapor R2 and the high-pressure refrigerant liquid R3 according to the usage environment. Therefore, according to the refrigeration system 100 of the present embodiment, even when the inter-refrigerant heat exchanger is used in the vapor compression refrigeration system, it is possible to suppress fluctuations in cooling performance depending on the usage environment.

A material having a low boiling point can be used as the refrigerant used in the refrigeration system 100. For example, an organic refrigerant such as hydrofluorocarbon or hydrofluoroether can be used.

The inter-refrigerant heat exchanger 150 includes a first pipe through which the refrigerant vapor R1 flows, a second pipe through which the high-pressure refrigerant vapor R2 or the high-pressure refrigerant liquid R3 flows, and heat exchange that mediates heat exchange between these refrigerants. It can be configured to include a part. Specifically, for example, it is composed of an outer layer pipe through which the refrigerant steam R1 flows and an inner layer pipe through which the high-pressure refrigerant steam R2 or the high-pressure refrigerant liquid R3 flows, and shares the outer peripheral surface of the inner layer pipe and the inner peripheral surface of the outer layer pipe. It can be configured to include a heavy pipe.

Next, the freezing method according to this embodiment will be described.

In the freezing method according to the present embodiment, first, the refrigerant liquid is vaporized by receiving heat from the cooling target to generate refrigerant vapor. High-pressure refrigerant vapor is generated by compressing this refrigerant vapor. Subsequently, the high-pressure refrigerant vapor is condensed by releasing the heat of the high-pressure refrigerant vapor to the outside air to generate a high-pressure refrigerant liquid. Then, the refrigerant vapor is heat-exchanged with either the high-pressure refrigerant vapor or the high-pressure refrigerant liquid.

As described above, according to the refrigeration system 100 and the refrigeration method of the present embodiment, even when a refrigerant heat exchanger is used in the vapor compression refrigeration system, fluctuations in cooling performance depending on the usage environment are suppressed. be able to.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. FIG. 3 schematically shows the configuration of the refrigeration system 200 according to the second embodiment of the present invention. In the figure, the dashed arrows R1 to R4 indicate the flow of the refrigerant in the refrigeration cycle.

The refrigeration system 200 according to the present embodiment includes an evaporator (evaporation means) 110, a compressor (compression means) 120, a condenser (condensing means) 130, an expansion valve (expansion means) 140, and a refrigerant heat exchanger (refrigerant heat exchanger). It has a replacement means) 150 and a refrigerant supply structure (refrigerant supply means). This constitutes a vapor compression refrigeration cycle. The configuration up to this point is the same as the configuration of the refrigeration system 100 according to the first embodiment.

In the refrigeration system 200 of the present embodiment, the refrigerant supply structure (refrigerant supply means) is configured to include a flow path structure and a flow path switching means. FIG. 3 shows a configuration in which valves 261 to 266 are provided as the flow path switching means. Then, the control unit 290 as the control means controls the valves 261 to 266 as the flow path switching means based on the state of the high-pressure refrigerant liquid R3. The valves 261 to 266 are typically open / close valves, and the flow path structure is typically a metal pipe.

The refrigeration system 200 further includes a first thermometer 211 and a second thermometer 212. The first thermometer 211 measures the temperature of the refrigerant steam R1 and outputs the first temperature T1. The second thermometer 212 measures the temperature of the high-pressure refrigerant liquid R3 and outputs the second temperature T2. At this time, the control unit 290 can be configured to control the valves 261 to 266 by using the second temperature T2 as the state of the high-pressure refrigerant liquid R3.

That is, when the second temperature T2 is larger than the temperature obtained by adding the first temperature difference ΔT1 to the first temperature T1 (T2> T1 + ΔT1), the control unit 290 puts the high-pressure refrigerant liquid in the inter-refrigerant heat exchanger 150. The valves 261 to 266 as the flow path switching means are controlled so as to supply R3. Specifically, as shown in FIG. 4A, the valves 261 and 264, 265 are controlled to be in the open state, and the valves 262, 263, and 266 are controlled to be in the closed state. In this case, a refrigeration cycle is configured in which the compressor 120, the condenser 130, the inter-refrigerant heat exchanger 150, and the expansion valve 140 are connected in this order.

With such a configuration, in the inter-refrigerant heat exchanger 150, the refrigerant vapor R1 is heated by the high-pressure refrigerant liquid R3 (broken line arrow H in FIG. 4A). As a result, the effect that liquid compression in the compressor 120 can be avoided can be obtained. At the same time, in the inter-refrigerant heat exchanger 150, the high-pressure refrigerant liquid R3 is cooled, so that it is possible to obtain the effect that the degree of supercooling of the refrigerant liquid can be increased. In particular, when a low-pressure refrigerant is used, the effect of avoiding liquid compression is great, and the performance of the refrigeration cycle can be greatly improved.

On the other hand, when the second temperature T2 is smaller than the temperature obtained by adding the second temperature difference ΔT2 to the first temperature T1 (T2 <T1 + ΔT2), the control unit 290 puts the high-pressure refrigerant vapor in the inter-refrigerant heat exchanger 150. The valves 261 to 266 as the flow path switching means are controlled so as to supply R2. Specifically, as shown in FIG. 4B, the valves 262, 263, and 266 are controlled to be in the open state, and the valves 261, 264, and 265 are controlled to be in the closed state. In this case, a refrigeration cycle is configured in which the compressor 120, the inter-refrigerant heat exchanger 150, the condenser 130, and the expansion valve 140 are connected in this order.

With such a configuration, in the inter-refrigerant heat exchanger 150, the refrigerant vapor R1 is heated by the high-pressure refrigerant vapor R2 generated by the compressor 120 (broken line arrow H in FIG. 4B). As a result, even when the second temperature T2 is smaller than the temperature obtained by adding the second temperature difference ΔT2 to the first temperature T1, the liquid compression in the compressor 120 can be avoided. can get.

The first temperature difference ΔT1 and the second temperature difference ΔT2 described above can be set to predetermined values based on the heat load of the refrigeration system 200 and the performance of the inter-refrigerant heat exchanger 150. In this case, the control unit 290 can be configured to include a storage device (storage means) 291 that stores the first temperature difference ΔT1 and the second temperature difference ΔT2.

As described above, in the refrigerating system 200 of the present embodiment, the refrigerant heat exchanger 150 is based on the temperature difference between the first temperature T1 based on the refrigerant vapor R1 and the second temperature T2 based on the high-pressure refrigerant liquid R3. The configuration is such that the connection order of the condenser 130 and the condenser 130 is switched. This makes it possible to maximize the performance of the refrigeration cycle under each temperature condition. That is, according to the refrigeration system 200 of the present embodiment, even when the inter-refrigerant heat exchanger is used in the vapor compression refrigeration system, it is possible to suppress fluctuations in cooling performance depending on the usage environment.

In the above description, the refrigeration system 200 is provided with a second thermometer 212 that measures the temperature of the high-pressure refrigerant liquid R3 and outputs the second temperature T2. However, the present invention is not limited to this, and a third thermometer 213 that measures the temperature of the outside air in the vicinity of the condenser 130 and outputs the third temperature may be provided in place of the second thermometer 212. .. The configuration of the refrigeration system 201 having such a configuration is shown in FIG.

When the condenser 130 included in the refrigeration system 201 has sufficient heat dissipation performance with respect to the amount of heat of the inflowing high-pressure refrigerant vapor R2, the condenser 130 is a high-pressure refrigerant cooled to a third temperature which is the outside air temperature. Drain the liquid R3. Therefore, in this case, as described above, the configuration may include a third thermometer 213 for measuring the outside air temperature instead of the second thermometer 212. As a result, the configuration of the refrigeration system 201 can be simplified.

When the third temperature T3 is larger than the temperature obtained by adding the first temperature difference ΔT1 to the first temperature T1 (T3> T1 + ΔT1), the control unit 290 of the refrigerating system 201 puts the high-pressure refrigerant in the inter-refrigerant heat exchanger 150. The valves 261 to 266 as the flow path switching means are controlled so as to supply the liquid R3. On the other hand, when the third temperature T3 is smaller than the temperature obtained by adding the second temperature difference ΔT2 to the first temperature T1 (T3 <T1 + ΔT2), the control unit 290 supplies the high-pressure refrigerant vapor to the inter-refrigerant heat exchanger 150. The valves 261 to 266 as the flow path switching means are controlled so as to supply R2.

The refrigeration system 201 having such a configuration also makes it possible to maximize the performance of the refrigeration cycle under each temperature condition.

In the above description, the opening / closing valve is used as the flow path switching means, but the present invention is not limited to this, and the flow path switching means may be configured to include at least one of a three-way valve and a four-way valve.

FIG. 6 shows the configuration of the refrigeration system 202 using the three-way valves 271-274 as the flow path switching means. In the figure, the unmarked triangular shapes of the three-way valves 271-274 indicate the valves that are always open, and "A" and "B" indicate the valves that are in the open state in each switching pattern.

Further, FIG. 7 shows the configuration of the refrigeration system 203 using the four-way valves 281 and 282 as the flow path switching means. In the figure, the solid lines in the four-way valves 281 and 282 indicate a state forming a first flow path for supplying the high-pressure refrigerant liquid R3 to the inter-refrigerant heat exchanger 150. Further, the broken lines in the four-way valves 281 and 282 indicate a state forming a second flow path for supplying the high-pressure refrigerant vapor R2 to the inter-refrigerant heat exchanger 150.

Next, the operation of the refrigeration system according to the present embodiment will be described in more detail by taking the refrigeration system 203 shown in FIG. 7 as an example.

FIG. 8 shows a flowchart for explaining the operation of the refrigeration system 203 according to the present embodiment.

The control unit 290 included in the refrigeration system 203 first sets the four-way valves 281 and 282 in a state of forming a second flow path for supplying the high-pressure refrigerant steam R2 to the inter-refrigerant heat exchanger 150 (step S11). ). Then, the first temperature T1 obtained by measuring the temperature of the refrigerant steam R1 is acquired from the first thermometer 211 (step S12). Further, the second temperature T2 obtained by measuring the temperature of the high-pressure refrigerant liquid R3 is acquired from the second thermometer 212 (step S13).

Next, the control unit 290 determines whether or not the second temperature T2 is larger than the temperature obtained by adding the first temperature difference ΔT1 to the first temperature T1 (step S14). When the second temperature T2 is equal to or lower than the temperature obtained by adding the first temperature difference ΔT1 to the first temperature T1 (step S14 / NO), the first temperature T1 and the second temperature T2 are acquired again. (Step S12, step S13).

On the other hand, when the second temperature T2 is larger than the temperature obtained by adding the first temperature difference ΔT1 to the first temperature T1 (step S14 / YES), the control unit 290 switches the four-way valves 281 and 282. That is, the control unit 290 sets the four-way valves 281 and 282 in a state of forming a first flow path for supplying the high-pressure refrigerant liquid R3 to the inter-refrigerant heat exchanger 150 (step S15). In this state, the first temperature T1 obtained by measuring the temperature of the refrigerant steam R1 is acquired from the first thermometer 211 (step S16). Further, the second temperature T2 obtained by measuring the temperature of the high-pressure refrigerant liquid R3 is acquired from the second thermometer 212 (step S17).

Subsequently, the control unit 290 determines whether or not the second temperature T2 is larger than the temperature obtained by adding the second temperature difference ΔT2 to the first temperature T1 (step S18). When the second temperature T2 is larger than the temperature obtained by adding the second temperature difference ΔT2 to the first temperature T1 (step S18 / YES), the first temperature T1 and the second temperature T2 are acquired again. (Step S16, step S17).

On the other hand, when the second temperature T2 is equal to or lower than the temperature obtained by adding the second temperature difference ΔT2 to the first temperature T1 (step S18 / NO), the control unit 290 switches the four-way valves 281 and 282. That is, the control unit 290 sets the four-way valves 281 and 282 in a state of forming a second flow path for supplying the high-pressure refrigerant vapor R2 to the inter-refrigerant heat exchanger 150 (step S11). After that, the above-mentioned steps S12 to S18 are repeated.

Here, the first temperature difference ΔT1 and the second temperature difference ΔT2 are the first temperature T1 required for heat exchange so that the refrigerant steam R1 is heated in the inter-refrigerant heat exchanger 150. This is the minimum temperature difference of the second temperature T2. The first temperature difference ΔT1 and the second temperature difference ΔT2 are determined depending on the heat load of the refrigeration system 203 and the performance of the inter-refrigerant heat exchanger 150. Here, it is assumed that the first temperature difference ΔT1 and the second temperature difference ΔT2 are predetermined values and are stored in the storage unit 291 included in the control unit 290. Specifically, for example, the first temperature difference ΔT1 can be set to about 20 ° C., and the second temperature difference ΔT2 can be set to about 15 ° C. By setting the first temperature difference ΔT1 to a value larger than the second temperature difference ΔT2 (ΔT1> ΔT2) in this way, it is possible to suppress the frequent switching operation of the four-way valves 281 and 282.

Next, the freezing method according to this embodiment will be described.

In the freezing method according to the present embodiment, first, the refrigerant liquid is vaporized by receiving heat from the cooling target to generate refrigerant vapor. High-pressure refrigerant vapor is generated by compressing this refrigerant vapor. Subsequently, the high-pressure refrigerant vapor is condensed by releasing the heat of the high-pressure refrigerant vapor to the outside air to generate a high-pressure refrigerant liquid. Then, the refrigerant vapor is heat-exchanged with either the high-pressure refrigerant vapor or the high-pressure refrigerant liquid.

In the freezing method according to the present embodiment, the first temperature obtained by measuring the temperature of the refrigerant vapor is further obtained, and the second temperature obtained by measuring the temperature of the high-pressure refrigerant liquid is obtained. To do.

Then, when the second temperature is larger than the temperature obtained by adding the first temperature difference to the first temperature, the refrigerant vapor and the high-pressure refrigerant liquid are heat-exchanged. On the other hand, when the second temperature is smaller than the temperature obtained by adding the second temperature difference to the first temperature, the refrigerant vapor and the high-pressure refrigerant steam are heat-exchanged.

Further, the first temperature obtained by measuring the temperature of the refrigerant vapor may be obtained, and the third temperature obtained by measuring the temperature of the outside air may be obtained. At this time, when the third temperature is larger than the temperature obtained by adding the first temperature difference to the first temperature, the refrigerant vapor and the high-pressure refrigerant liquid are heat-exchanged. On the other hand, when the third temperature is smaller than the temperature obtained by adding the second temperature difference to the first temperature, the refrigerant vapor and the high-pressure refrigerant steam can be heat-exchanged.

As described above, according to the refrigeration systems 200 to 203 and the refrigeration method of the present embodiment, even when the inter-refrigerant heat exchanger is used in the vapor compression refrigeration system, the cooling performance varies depending on the usage environment. It can be suppressed.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. FIG. 9 schematically shows the configuration of the refrigeration system 300 according to the third embodiment of the present invention. In the figure, the dashed arrows R1 to R4 indicate the flow of the refrigerant in the refrigeration cycle.

The refrigeration system 300 according to the present embodiment includes an evaporator (evaporation means) 110, a compressor (compression means) 120, a condenser (condensing means) 130, an expansion valve (expansion means) 140, and a refrigerant heat exchanger (refrigerant heat exchanger). It has a replacement means) 150 and a refrigerant supply structure (refrigerant supply means). This constitutes a vapor compression refrigeration cycle.

Further, the refrigeration system 300 includes a first thermometer 211 and a second thermometer 212. The refrigerant supply structure includes a flow path structure and a flow path switching means, and uses four-way valves 281 and 282 as the flow path switching means.

The configuration up to this point is the same as the configuration of the refrigeration system 203 according to the second embodiment.

The refrigerating system 300 according to the present embodiment is configured to further include a refrigerant flow rate measuring unit (refrigerant flow rate measuring means) 310 that measures the flow rate of the refrigerant liquid R4 output by the expansion valve 140 and outputs the refrigerant flow rate. Then, the control unit as the control means provided in the refrigeration system 300 determines the first temperature difference ΔT1 and the second temperature difference ΔT2 based on the flow rate of the refrigerant. In FIG. 9, the description of the configuration of the control unit is omitted.

Next, the operation of the refrigeration system 300 according to the present embodiment will be described. FIG. 10 shows a flowchart for explaining the operation of the refrigeration system 300 according to the present embodiment.

The control unit included in the refrigeration system 300 first sets the four-way valves 281 and 282 in a state of forming a second flow path for supplying the high-pressure refrigerant vapor R2 to the inter-refrigerant heat exchanger 150 (step S201). .. Then, the first temperature T1 obtained by measuring the temperature of the refrigerant steam R1 is acquired from the first thermometer 211 (step S202). Further, the second temperature T2 obtained by measuring the temperature of the high-pressure refrigerant liquid R3 is acquired from the second thermometer 212 (step S203).

Next, the control unit acquires the refrigerant flow rate Q obtained by measuring the flow rate of the refrigerant liquid R4 from the refrigerant flow rate measuring unit 310 (step S204). Then, the first temperature difference ΔT1 is determined based on the refrigerant flow rate Q (step S205).

The control unit determines whether or not the second temperature T2 is larger than the temperature obtained by adding the first temperature difference ΔT1 obtained here to the first temperature T1 (step S206). When the second temperature T2 is equal to or lower than the temperature obtained by adding the first temperature difference ΔT1 to the first temperature T1 (step S206 / NO), the first temperature T1, the second temperature T2, and the refrigerant are again used. Acquire the flow rate Q (step S202 to step S204).

On the other hand, when the second temperature T2 is larger than the temperature obtained by adding the first temperature difference ΔT1 obtained here to the first temperature T1 (step S206 / YES), the control unit switches the four-way valves 281 and 282. .. That is, the control unit sets the four-way valves 281 and 282 in a state of forming a first flow path for supplying the high-pressure refrigerant liquid R3 to the inter-refrigerant heat exchanger 150 (step S207). In this state, the first temperature T1 obtained by measuring the temperature of the refrigerant steam R1 is acquired from the first thermometer 211 (step S208). Further, the second temperature T2 obtained by measuring the temperature of the high-pressure refrigerant liquid R3 is acquired from the second thermometer 212 (step S209).

Further, the control unit acquires the refrigerant flow rate Q obtained by measuring the flow rate of the refrigerant liquid R4 from the refrigerant flow rate measuring unit 310 (step S210). Then, the second temperature difference ΔT2 is determined based on the refrigerant flow rate Q (step S211).

The control unit determines whether or not the second temperature T2 is larger than the temperature obtained by adding the second temperature difference ΔT2 obtained here to the first temperature T1 (step S212). When the second temperature T2 is larger than the temperature obtained by adding the second temperature difference ΔT2 to the first temperature T1 (step S212 / YES), the first temperature T1, the second temperature T2, and the refrigerant are again present. Acquire the flow rate Q (step S208 to step S210).

On the other hand, when the second temperature T2 is equal to or lower than the temperature obtained by adding the second temperature difference ΔT2 obtained here to the first temperature T1 (step S212 / NO), the control unit switches the four-way valves 281 and 282. .. That is, the control unit sets the four-way valves 281 and 282 in a state of forming a second flow path for supplying the high-pressure refrigerant vapor R2 to the inter-refrigerant heat exchanger 150 (step S201). After that, the above-mentioned steps S202 to S212 are repeated.

As described above, in the refrigerating system 300 of the present embodiment, the first temperature difference ΔT1 and the second temperature difference ΔT2 are determined based on the refrigerant flow rate Q. Here, the first temperature difference ΔT1 and the second temperature difference ΔT2 are the first temperature T1 required for heat exchange so that the refrigerant steam R1 is heated in the inter-refrigerant heat exchanger 150. This is the minimum temperature difference of the second temperature T2.

Since the amount of heat exchange in the inter-refrigerant heat exchanger 150 largely depends on the refrigerant flow rate Q, the first temperature difference ΔT1 and the second temperature difference ΔT2 also depend on the refrigerant flow rate Q. On the other hand, the refrigerant flow rate Q is proportional to the heat load of the refrigeration system 300. As described above, according to the refrigerating system 300 of the present embodiment, the appropriate first temperature difference ΔT1 and second temperature difference ΔT2 can be set according to the refrigerant flow rate Q, so that the heat load fluctuates. Even if it occurs, it becomes possible to maintain stable operation.

Further, according to the refrigeration system 300 of the present embodiment, even when the inter-refrigerant heat exchanger is used in the vapor compression refrigeration system as in the case of the first embodiment and the second embodiment. Fluctuations in cooling performance depending on the usage environment can be suppressed.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described. FIG. 11 schematically shows the configuration of the refrigeration system 400 according to the fourth embodiment of the present invention. In the figure, the dashed arrows R1 to R4 indicate the flow of the refrigerant in the refrigeration cycle.

The refrigeration system 400 according to the present embodiment includes an evaporator (evaporation means) 110, a compressor (compression means) 120, a condenser (condensing means) 130, an expansion valve (expansion means) 140, and a refrigerant heat exchanger (refrigerant heat exchanger). It has a replacement means) 150 and a refrigerant supply structure (refrigerant supply means). This constitutes a vapor compression refrigeration cycle.

Further, the refrigeration system 400 includes a first thermometer 211 and a second thermometer 212. The refrigerant supply structure includes a flow path structure and a flow path switching means, and uses four-way valves 281 and 282 as the flow path switching means.

The configuration up to this point is the same as the configuration of the refrigeration system 203 according to the second embodiment.

The refrigerating system 400 according to the present embodiment is further provided with a refrigerant pressure measuring unit (refrigerant pressure measuring means) 410 that measures the pressure of the refrigerant steam and outputs the refrigerant pressure value. Then, the control unit as the control means provided in the refrigeration system 400 determines the first temperature difference ΔT1 and the second temperature difference ΔT2 based on the refrigerant pressure value and the condition value when compressing the refrigerant vapor. It was configured to be. Specifically, the compressor 120 is a rotary compressor, and the control unit determines the first temperature difference ΔT1 and the second temperature difference ΔT2 based on the refrigerant pressure value and the rotation speed of the compressor 120. It was configured to be. In FIG. 11, the description of the configuration of the control unit is omitted.

Next, the operation of the refrigeration system 400 according to the present embodiment will be described. FIG. 12 shows a flowchart for explaining the operation of the refrigeration system 400 according to the present embodiment.

The control unit included in the refrigeration system 400 first sets the four-way valves 281 and 282 in a state of forming a second flow path for supplying the high-pressure refrigerant vapor R2 to the inter-refrigerant heat exchanger 150 (step S301). .. Then, the first temperature T1 obtained by measuring the temperature of the refrigerant steam R1 is acquired from the first thermometer 211 (step S302). Further, the second temperature T2 obtained by measuring the temperature of the high-pressure refrigerant liquid R3 is acquired from the second thermometer 212 (step S303).

Next, the control unit acquires the refrigerant pressure value P obtained by measuring the pressure of the refrigerant vapor flowing into the compressor 120 from the refrigerant pressure measuring unit 410 (step S304). Further, the rotation speed f of the compressor 120 is acquired (step S305). Then, the first temperature difference ΔT1 is determined based on the refrigerant pressure value P and the rotation speed f (step S306).

The control unit determines whether or not the second temperature T2 is larger than the temperature obtained by adding the first temperature difference ΔT1 obtained here to the first temperature T1 (step S307). When the second temperature T2 is equal to or lower than the temperature obtained by adding the first temperature difference ΔT1 to the first temperature T1 (step S307 / NO), the first temperature T1, the second temperature T2, and the refrigerant are again used. The pressure value P and the rotation speed f are acquired (steps S302 to S305).

On the other hand, when the second temperature T2 is larger than the temperature obtained by adding the first temperature difference ΔT1 obtained here to the first temperature T1 (step S307 / YES), the control unit switches the four-way valves 281 and 282. .. That is, the control unit sets the four-way valves 281 and 282 in a state of forming a first flow path for supplying the high-pressure refrigerant liquid R3 to the inter-refrigerant heat exchanger 150 (step S308). In this state, the first temperature T1 obtained by measuring the temperature of the refrigerant steam R1 is acquired from the first thermometer 211 (step S309). Further, the second temperature T2 obtained by measuring the temperature of the high-pressure refrigerant liquid R3 is acquired from the second thermometer 212 (step S310).

Further, the control unit acquires the refrigerant pressure value P obtained by measuring the pressure of the refrigerant vapor flowing into the compressor 120 from the refrigerant pressure measuring unit 410 (step S311). Further, the rotation speed f of the compressor 120 is acquired (step S312). Then, the second temperature difference ΔT2 is determined based on the refrigerant pressure value P and the rotation speed f (step S313).

The control unit determines whether or not the second temperature T2 is larger than the temperature obtained by adding the second temperature difference ΔT2 obtained here to the first temperature T1 (step S314). When the second temperature T2 is larger than the temperature obtained by adding the second temperature difference ΔT2 to the first temperature T1 (step S314 / YES), the first temperature T1, the second temperature T2, and the refrigerant are again present. The pressure value P and the rotation speed f are acquired (steps S309 to S312).

On the other hand, when the second temperature T2 is equal to or lower than the temperature obtained by adding the second temperature difference ΔT2 obtained here to the first temperature T1 (step S314 / NO), the control unit switches the four-way valves 281 and 282. .. That is, the control unit sets the four-way valves 281 and 282 in a state of forming a second flow path for supplying the high-pressure refrigerant vapor R2 to the inter-refrigerant heat exchanger 150 (step S301). After that, the above-mentioned steps S302 to S314 are repeated.

As described above, in the refrigerating system 400 of the present embodiment, the first temperature difference ΔT1 and the second temperature difference ΔT2 are set by the refrigerant pressure value P of the refrigerant vapor flowing into the compressor 120 and the rotation speed f of the compressor 120. The configuration is determined based on. The refrigerant flow rate Q can be calculated from the refrigerant pressure value P and the rotation speed f. Therefore, the refrigerant flow rate Q can be estimated with a simpler configuration than the configuration in which the refrigerant flow rate Q is directly measured.

As described above, according to the refrigeration system 400, it is possible to set an appropriate first temperature difference ΔT1 and a second temperature difference ΔT2 according to the refrigerant flow rate Q by a simple configuration. Here, the refrigerant flow rate Q is proportional to the heat load of the refrigeration system 300. Therefore, according to the refrigeration system 400 of the present embodiment, stable operation can be maintained even if the heat load fluctuates.

Further, according to the refrigeration system 400 of the present embodiment, even when the inter-refrigerant heat exchanger is used in the vapor compression refrigeration system as in the case of the first embodiment and the second embodiment. Fluctuations in cooling performance depending on the usage environment can be suppressed.

It is said that the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Not to mention.

Some or all of the above embodiments may also be described, but not limited to:

(Appendix 1) Evaporating means for generating refrigerant vapor by vaporizing the refrigerant liquid by receiving heat, compression means for compressing the refrigerant vapor to generate high-pressure refrigerant vapor, and condensing the high-pressure refrigerant vapor to generate high-pressure refrigerant liquid. A refrigerant that exchanges heat between the condensing means, the expanding means for generating the refrigerant liquid by expanding the high-pressure refrigerant liquid to reduce the pressure, the refrigerant steam, and either the high-pressure refrigerant steam or the high-pressure refrigerant liquid. A refrigeration system having an inter-heat exchange means and a refrigerant supply means for supplying either the high-pressure refrigerant steam or the high-pressure refrigerant liquid to the inter-refrigerant heat exchange means.

(Appendix 2) Further having a control means for controlling the refrigerant supply means, the refrigerant supply means includes a flow path structure and a flow path switching means, and the control means is based on the state of the high-pressure refrigerant liquid. The refrigeration system according to Appendix 1, which controls the flow path switching means.

(Appendix 3) A first thermometer that measures the temperature of the refrigerant steam and outputs the first temperature, and a second thermometer that measures the temperature of the high-pressure refrigerant liquid and outputs the second temperature. When the second temperature is larger than the temperature obtained by adding the first temperature difference to the first temperature, the control means supplies the high-pressure refrigerant liquid to the inter-cooler heat exchange means. When the second temperature is smaller than the temperature obtained by adding the second temperature difference to the first temperature, the high-pressure refrigerant steam is supplied to the inter-solvent heat exchange means. The refrigeration system according to Appendix 2, which controls the flow path switching means so as to supply the above-mentioned flow path switching means.

(Appendix 4) A first thermometer that measures the temperature of the refrigerant steam and outputs the first temperature, and a third thermometer that measures the temperature of the outside air in the vicinity of the condensing means and outputs the third temperature. The control means further comprises a thermometer, and when the third temperature is larger than the temperature obtained by adding the first temperature difference to the first temperature, the control means supplies the high-pressure refrigerant to the inter-cooler heat exchange means. When the flow path switching means is controlled so as to supply the liquid and the third temperature is smaller than the temperature obtained by adding the second temperature difference to the first temperature, the heat exchange means between refrigerants is said to have the same temperature. The refrigeration system according to Appendix 2, which controls the flow path switching means so as to supply high-pressure refrigerant steam.

(Appendix 5) The freezing system according to Appendix 3 or 4, wherein the control means includes a storage means for storing the first temperature difference and the second temperature difference.

(Appendix 6) Further having a refrigerant flow rate measuring means for measuring the flow rate of the refrigerant liquid and outputting the refrigerant flow rate, the control means has the first temperature difference and the second temperature difference based on the refrigerant flow rate. The refrigeration system according to Appendix 3 or 4, which determines the temperature difference.

(Appendix 7) Further having a refrigerant pressure measuring means for measuring the pressure of the refrigerant steam and outputting the refrigerant pressure value, the compressing means includes a rotary compressor, and the controlling means has the refrigerant pressure value. The refrigeration system according to Appendix 3 or 4, which determines the first temperature difference and the second temperature difference based on the number of revolutions of the compressor.

(Supplementary Note 8) The refrigeration system according to any one of Supplementary note 3 to 7, wherein the control means sets the first temperature difference to a value larger than the second temperature difference.

(Supplementary note 9) The refrigeration system according to any one of Supplementary note 2 to 8, wherein the flow path switching means includes at least one of a three-way valve and a four-way valve.

(Appendix 10) The refrigerant liquid is vaporized by receiving heat from the object to be cooled to generate the refrigerant vapor, the high-pressure refrigerant vapor is generated by compressing the refrigerant vapor, and the heat of the high-pressure refrigerant vapor is released to the outside air. A refrigerating method in which the high-pressure refrigerant vapor is condensed to generate a high-pressure refrigerant liquid, and the refrigerant steam is heat-exchanged with either the high-pressure refrigerant steam or the high-pressure refrigerant liquid.

(Appendix 11) The first temperature obtained by measuring the temperature of the refrigerant steam is acquired, the second temperature obtained by measuring the temperature of the high-pressure refrigerant liquid is acquired, and the second temperature is obtained. However, when the temperature is larger than the temperature obtained by adding the first temperature difference to the first temperature, the refrigerant steam and the high-pressure refrigerant liquid are exchanged for heat, and the second temperature becomes the second temperature. The refrigerating method according to Appendix 10, wherein when the temperature is smaller than the sum of the temperature differences of the above, the temperature difference is exchanged between the refrigerant steam and the high-pressure refrigerant steam.

(Appendix 12) The first temperature obtained by measuring the temperature of the refrigerant steam is acquired, the third temperature obtained by measuring the temperature of the outside air is acquired, and the third temperature is When it is larger than the temperature obtained by adding the first temperature difference to the first temperature, the refrigerant vapor and the high-pressure refrigerant liquid are exchanged for heat, and the third temperature becomes the second temperature to the first temperature. The refrigerating method according to Appendix 10, wherein when the temperature is smaller than the sum of the differences, the temperature is exchanged between the refrigerant steam and the high-pressure refrigerant steam.

(Appendix 13) The freezing method according to Appendix 11 or 12, wherein the first temperature difference and the second temperature difference are determined in advance.

(Appendix 14) In Appendix 11 or 12, the refrigerant flow rate obtained by measuring the flow rate of the refrigerant liquid is acquired, and the first temperature difference and the second temperature difference are determined based on the refrigerant flow rate. The freezing method described.

(Appendix 15) The first temperature difference based on the condition value at the time of acquiring the refrigerant pressure value obtained by measuring the pressure of the refrigerant vapor and compressing the refrigerant vapor and the refrigerant pressure value. The refrigeration method according to Appendix 11 or 12, which determines the second temperature difference.

(Supplementary note 16) The freezing method according to any one of Supplementary note 11 to 15, wherein the first temperature difference is set to a value larger than the second temperature difference.

100, 100A, 100B, 200, 200A, 200B, 201, 202, 203, 300, 400 Refrigerant system 110 Evaporator 120 Compressor 130 Condenser 140 Expansion valve 150 Refrigerant inter-refrigerant heat exchanger 160 Refrigerant supply structure 211 First temperature Meter 212 Second thermometer 213 Third thermometer 261-266 Valve 271-274 Three-way valve 281, 282 Four-way valve 290 Control unit 291 Storage device 310 Refrigerant flow measurement unit 410 Refrigerant pressure measurement unit

Claims (8)

Evaporation means that vaporizes the refrigerant liquid by receiving heat to generate refrigerant vapor,
A compression means that compresses the refrigerant vapor to generate high-pressure refrigerant vapor,
A condensing means that condenses the high-pressure refrigerant vapor to generate a high-pressure refrigerant liquid,
An expansion means for generating the refrigerant liquid by expanding the high-pressure refrigerant liquid to a low pressure, and
Refrigerant-to-refrigerant heat exchange means for exchanging heat between the refrigerant vapor and either the high-pressure refrigerant steam or the high-pressure refrigerant liquid.
A refrigerant supply means for supplying either the high-pressure refrigerant vapor or the high-pressure refrigerant liquid to the refrigerant heat exchange means, and
It has a control means for controlling the refrigerant supply means , and
The refrigerant supply means includes a flow path structure and a flow path switching means.
The control means controls the flow path switching means based on the state of the high-pressure refrigerant liquid.
Refrigeration system. A first thermometer that measures the temperature of the refrigerant vapor and outputs the first temperature,
Further having a second thermometer, which measures the temperature of the high-pressure refrigerant liquid and outputs a second temperature,
The control means
When the second temperature is larger than the temperature obtained by adding the first temperature difference to the first temperature, the flow path switching means is controlled so as to supply the high-pressure refrigerant liquid to the inter-refrigerant heat exchange means. And
When the second temperature is smaller than the temperature obtained by adding the second temperature difference to the first temperature, the flow path switching means is controlled so as to supply the high-pressure refrigerant vapor to the inter-refrigerant heat exchange means. The refrigeration system according to claim 1. A first thermometer that measures the temperature of the refrigerant vapor and outputs the first temperature,
It further has a third thermometer, which measures the temperature of the outside air in the vicinity of the condensing means and outputs a third temperature.
The control means
When the third temperature is larger than the temperature obtained by adding the first temperature difference to the first temperature, the flow path switching means is controlled so as to supply the high-pressure refrigerant liquid to the inter-refrigerant heat exchange means. And
When the third temperature is smaller than the temperature obtained by adding the second temperature difference to the first temperature, the flow path switching means is controlled so as to supply the high-pressure refrigerant vapor to the inter-refrigerant heat exchange means. The refrigeration system according to claim 1. The freezing system according to claim 2 or 3 , wherein the control means includes a storage means for storing the first temperature difference and the second temperature difference. Further having a refrigerant flow rate measuring means for measuring the flow rate of the refrigerant liquid and outputting the refrigerant flow rate,
The refrigeration system according to claim 2 or 3 , wherein the control means determines the first temperature difference and the second temperature difference based on the flow rate of the refrigerant. Further, it has a refrigerant pressure measuring means for measuring the pressure of the refrigerant vapor and outputting the refrigerant pressure value.
The compression means includes a rotary compressor.
The refrigeration system according to claim 2 or 3 , wherein the control means determines the first temperature difference and the second temperature difference based on the refrigerant pressure value and the rotation speed of the compressor. The refrigeration system according to any one of claims 2 to 6 , wherein the control means sets the first temperature difference to a value larger than the second temperature difference. The refrigeration system according to any one of claims 1 to 7 , wherein the flow path switching means includes at least one of a three-way valve and a four-way valve.

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