JP3312330B2 - Refrigeration cycle device and air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the prevention of liquid back to a compressor of a refrigerating air conditioner and the optimal control of the amount of refrigerant in accordance with the operating state, the improvement of the startup characteristics at the time of thermo-ON, and the charging of refrigerant. The present invention relates to a refrigeration cycle apparatus that informs that a proper amount has been charged.

[0002]

2. Description of the Related Art FIG. 5 is a configuration diagram of a refrigerant circuit of a conventional refrigeration cycle apparatus. In FIG. 5, 1 is a compressor that compresses a refrigerant into high-temperature and high-pressure gas, 2 is a four-way valve that changes the direction of flow of the refrigerant to switch between cooling operation and heating operation, and 3 is a condenser or evaporator. An outdoor heat exchanger that operates, 4 controls the flow rate of the refrigerant to reduce the pressure and a flow control valve that flows the required amount of refrigerant, 5 a receiver for storing liquefied refrigerant, and 6 functions as an evaporator or a condenser. An indoor heat exchanger, 7 is an accumulator for separating gas from refrigerant, and 8 is a capillary provided in a circuit that bypasses the flow control valve 4.

[0003] The conventional refrigeration cycle apparatus is configured as described above. Since the amount of refrigerant in heating and cooling operation is smaller in heating, the appropriate amount of refrigerant in cooling operation and the amount of appropriate refrigerant in heating operation are different. Is adjusted by the receiver 5. First, the operation during the heating operation will be described. The refrigerant is mainly a compressor 1-a four-way valve 2-an indoor heat exchanger 6 acting as a condenser-a receiver 5-a flow control valve 4-
It flows on the path of the outdoor heat exchanger 3 acting as the evaporator 3-the four-way valve 2-the accumulator 7-the compressor 1. Although the refrigerant flows through such a path, in the heating operation, the flow rate of the refrigerant is controlled by the flow control valve 4 so that the refrigerant state at the outlet of the outdoor heat exchanger 3 is always constant heating steam regardless of the operation state. Therefore, the surplus refrigerant in the heating operation is supplied to the receiver 5
It accumulates inside and is adjusted to an appropriate amount for heating operation.

Next, the operation at the time of cooling operation will be described. The refrigerant is mainly a compressor 1-a four-way valve 2-an outdoor heat exchanger functioning as an evaporator 3-a flow control valve 4-a receiver 5-
It flows on the path of the indoor heat exchanger 6 functioning as a condenser, the four-way valve 2, the accumulator 7, and the compressor 1. Although the refrigerant flows through such a path, in the cooling operation, the flow rate of the refrigerant is controlled by the flow control valve 4 so that the refrigerant state at the outlet of the indoor heat exchanger 6 becomes a constant heating steam regardless of the operation state. However, since the low-pressure gas-liquid two-phase refrigerant at the outlet of the flow control valve 4 flows into the receiver 5, the refrigerant does not accumulate. At the time of startup in the heating and cooling operations, the refrigerant liquid is not sucked into the compressor 1 because the accumulator 7 is provided on the suction side of the compressor 1, and only the gas refrigerant is sucked into the compressor 1. The liquid back is prevented.
As described above, the conventional refrigeration cycle apparatus includes a receiver 5 that adjusts an appropriate refrigerant amount according to an operation state, and an accumulator 7 that is provided on the suction side of the compressor 1 and that protects the compressor 1 by preventing liquid back. Two containers are provided.

[0005]

Since the conventional refrigeration cycle apparatus is configured as described above, the difference in refrigerant amount between the proper refrigerant amount in the cooling operation and the proper refrigerant amount in the heating operation is adjusted by the receiver 5. Of the accumulator 7 that protects the compressor 1 by preventing liquid back to the compressor 1
There is a problem that one container must be provided, and the unit is increased in size and the cost is increased. In addition, in the conventional refrigeration cycle device, when the thermostat is turned off in the heating and cooling operations, the high-pressure side refrigerant moves to the low-pressure side by the capillary tube 8 to balance the high and low pressures.
At the time of thermo-ON, it is necessary to increase the pressure to a high pressure at the time of operation, which causes a problem that the start-up is delayed. Further, since the conventional refrigeration cycle device is not provided with a means for notifying the amount of refrigerant charged, it is necessary to check the amount of refrigerant filled with the refrigerant cylinder when filling the refrigerant. There was a problem that it took time and effort.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it has been made possible to make the amount of refrigerant appropriate in each operation of cooling and heating, to prevent liquid back to the compressor, and to use a flash when filling the refrigerant. The purpose is to obtain a refrigeration cycle device that can know the appropriate amount.

[0007]

The refrigeration cycle apparatus according to the first aspect of the present invention includes a compressor, an outdoor heat exchanger functioning as a condenser or an evaporator, and an indoor functioning as an evaporator or a condenser. A heat exchanger, at least one flow control valve, and a flow path for returning the refrigerant from the compressor to the compressor through the indoor heat exchanger, the flow control valve and the outdoor heat exchanger during the heating operation, and compressing the refrigerant during the cooling operation. In the refrigeration cycle device, which is connected in sequence with an outdoor heat exchanger, a flow control valve, and a four-way valve that switches to form a flow path returning to the compressor through the indoor heat exchanger, the liquid is separated from the refrigerant to separate the liquid from the gas. It is provided between the refrigerant reservoir to be stored, the indoor heat exchanger and the flow control valve, and conducts only between the indoor heat exchanger and the flow control valve at the time of activation of cooling and heating. And flow control A first flow path switching means for communicating with the valve via a refrigerant reservoir, and a first flow path switching means provided between the suction side of the compressor and the four-way valve; And a second flow path switching means for conducting only between the suction side of the compressor and the four-way valve after a predetermined time from the start of the compressor. Further, in the refrigeration cycle apparatus according to the second aspect of the present invention, a flow control valve is provided on the indoor heat exchanger side of the first flow path switching means, and the opening thereof is gradually closed when the operation is stopped.

In the refrigeration cycle apparatus according to the third aspect of the present invention, the flow control valve on the outlet side of the first flow path switching means is closed at the start of operation, and the flow control valve on the inlet side is opened. The degree is gradually increased. An air conditioner according to a fourth aspect of the present invention includes the refrigeration cycle device according to the first, second, or third aspect. In the air conditioner according to the invention of claim 5 of the present application, the refrigerant reservoir is provided with liquid level detecting means capable of detecting an appropriate amount of refrigerant during the heating operation and an appropriate amount of refrigerant during the cooling operation.

Further, in the air conditioner according to the invention of claim 6 of the present application, the liquid level detecting means includes a bypass pipe provided on the suction side of the compressor, and an on-off valve provided in the middle of the bypass pipe. A first capillary provided between the bottom of the refrigerant reservoir and the bypass pipe, a first temperature sensor for detecting the temperature of the refrigerant flowing through the first capillary, and a portion above the bottom of the refrigerant reservoir A second capillary provided between the position indicating the liquid level of the appropriate amount of refrigerant during the heating operation and the bypass pipe, and a second temperature sensor for detecting the temperature of the refrigerant flowing through the second capillary. A third capillary provided between a position above the bottom of the refrigerant reservoir above the bottom indicating a proper refrigerant level during cooling operation and a bypass pipe, and a temperature of the refrigerant flowing through the third capillary. And a third temperature sensor for detecting . In addition, the air conditioner according to the invention of claim 7 of the present application indicates that the amount of refrigerant is appropriate for the heating operation based on the detection signals of the first temperature sensor and the second temperature sensor being matched. , A first temperature sensor and a third
And a display for indicating that the refrigerant amount is appropriate during the cooling operation based on the coincidence of the detection signals of the temperature sensors.

[0010] In the present invention, the first flow path switching means provided between the indoor heat exchanger and the flow control valve is adapted to conduct only between the indoor heat exchanger and the flow control valve at the time of activation of cooling and heating. A predetermined time after the start, a connection is made between the indoor heat exchanger and the flow control valve via the refrigerant reservoir, and a second flow path switching means provided between the suction side of the compressor and the four-way valve. so,
At the start of cooling and heating, conduction is established between the suction side of the compressor and the four-way valve communicating with the suction side via the refrigerant reservoir, and conduction is made only between the suction side of the compressor and the four-way valve after a predetermined time from startup. Since the refrigerant reservoir functions as an accumulator when the heating and cooling operations are activated, and the refrigerant reservoir functions as a receiver after a predetermined time from the activation,
The refrigerant reservoir can prevent liquid backing at the time of startup, and can operate with an appropriate amount of refrigerant for each of the cooling and heating operations, thus eliminating the need for two containers of a receiver and an accumulator as in the conventional case, and The size and cost can be reduced.

In another aspect of the present invention, a flow rate control valve is provided on the indoor heat exchanger side of the first flow path switching means so as to gradually close its opening when the operation is stopped. High and low pressures are balanced and stable operation is possible. Further, in another invention of the present application, at the start of operation, the flow control valve on the outlet side of the first flow path switching means is closed, and the opening of the flow control valve on the inlet side is gradually increased. Therefore, refrigerant noise due to pressure fluctuation at the time of switching can be reduced. In another invention of the present application,
When performing the refrigerant charging operation in the heating and cooling operations, since it is possible to know that the refrigerant has been charged in an appropriate amount in the heating and cooling operations based on the signal of the liquid level detecting means, it is necessary to prepare the balm as in the conventional case. Saves labor and cost.

In another aspect of the present invention, the liquid level detecting means includes three capillaries having one end provided in the refrigerant reservoir, three temperature sensors provided in the three capillaries, and three capillaries. It can be manufactured inexpensively by a simple configuration of a bypass pipe having one end connected and the other end connected to the suction side of the compressor.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a configuration diagram of a refrigerant circuit of a refrigeration cycle apparatus according to Embodiment 1 of the present invention, FIG. 2 is a time chart of a control flow during a heating operation in the refrigeration cycle apparatus according to Embodiment 1, and FIG. 3 is a time chart of a control flow at the time of cooling operation in the refrigeration cycle apparatus showing No. 1. In the figure, 1 is a compressor that compresses a refrigerant into a high-temperature and high-pressure gas, 2 is a four-way valve that changes the flow direction of the refrigerant to switch between cooling operation and heating operation, and 3 functions as a condenser or an evaporator The outdoor heat exchanger 4A is provided near the outdoor heat exchanger 3 and controls the amount of the refrigerant to flow to lower the pressure and the first electric flow control valve for flowing the required amount of the refrigerant.
Is provided near the indoor heat exchanger side, which will be described later, controls the amount of the refrigerant to flow, lowers the pressure, and flows the required amount of the refrigerant. The second electric flow control valve 6 functions as an evaporator or a condenser. The indoor heat exchanger 9 is a refrigerant reservoir that separates gas from the refrigerant and stores the liquid.

Reference numeral 11 is provided between the first electric type flow control valve 4A, the second electric type flow control valve 4B on the side of the indoor heat exchanger 6, and the refrigerant reservoir 9, and the first electric type flow control valve is provided when the cooling and heating is started. Only the electric flow control valve 4A and the second electric flow control valve 4B are electrically connected, and the refrigerant flows between the first electric flow control valve 4A and the second flow control valve 4B after a predetermined time from the start. This is first flow path switching valve means to be conducted through the reservoir 9. This first flow path switching valve 11 is provided with a first electric flow control valve 4A.
And a second electric type flow control valve 4B, which is opened at the time of startup and closed after a predetermined time from the startup.
Between the connection between the first electric flow control valve 4A and the solenoid valve 13 and the first inlet / outlet 9a at one end of the refrigerant reservoir 9, which is closed at the time of startup and opened after a predetermined time from the startup. Solenoid valve 14, second electric flow control valve 4B and solenoid valve 1
3 and the second inlet / outlet 9 at one end of the refrigerant reservoir 9
The solenoid valve 15 is provided between the solenoid valve 15 and the solenoid valve 15 and is closed at the time of startup and opens after a predetermined time from the startup.

Numeral 12 is provided between the suction side of the compressor 1 and the four-way valve 2 and the refrigerant reservoir 9. When the cooling and heating is started, the refrigerant reservoir 9 is connected between the suction side of the compressor 1 and the four-way valve 2. And a second flow path switching valve means for conducting only between the suction side of the compressor 1 and the four-way valve 2 after a predetermined time from the start. The second flow path switching valve 12 is provided between the suction side of the compressor 1 and the four-way valve 2 and the refrigerant reservoir 9, and is closed at the time of startup and opened after a predetermined time from the startup, and a four-way valve A solenoid valve 17 that is provided between the connection between the solenoid valve 2 and the solenoid valve 16 and the third inlet / outlet 9c at the other end of the refrigerant reservoir 9 and that opens at startup and closes after a predetermined time from startup; It is provided between the connection between the suction side and the solenoid valve 16 and the fourth port 9d at the other end of the refrigerant reservoir 9, and opens at the time of startup,
And a solenoid valve 18 that closes after a predetermined time from the start.

Reference numerals 21 to 26 denote temperature sensors, and the temperature sensors 22 and 25 are attached to the wall of the heat transfer tubes of the outdoor and indoor heat exchangers 3 and 6 at a substantially intermediate portion from the refrigerant inlet to the refrigerant outlet. In addition, other temperature sensors 21, 2
Reference numerals 3, 24, and 26 are attached to the refrigerant inlet and outlet wall surfaces of the heat transfer tubes of the indoor and outdoor heat exchangers 3, 6, respectively.

Next, the operation of the refrigeration cycle apparatus according to the first embodiment of the present invention will be described with reference to FIGS. First, the operation during the heating operation will be described with reference to FIGS. T from the start of the compressor 1 in the heating operation
Until one hour has passed (for example, about one minute for a small device), the first and second electric flow control valves 4A and 4B and the solenoid valves 13, 14, 15, 16, 17, and 18 are operated as shown in FIG. Is controlled as shown in FIG. Then, the refrigerant flows into the compressor 1-the four-way valve 2-the indoor heat exchanger functioning as a condenser 6-the second electric flow control valve 4B-the electromagnetic valve 13-one of the first flow path switching valve means. First electric flow control valve 4A-Outdoor heat exchanger 3 functioning as evaporator 3-Four-way valve 2-Electromagnetic valve 17 which is one of second flow path switching valve means-Third of refrigerant reservoir 9
9c-refrigerant reservoir 9-fourth inlet / outlet 9d of refrigerant reservoir 9-electromagnetic valve 1 as one of second flow path switching valve means
8- Flow through the compressor 1 path. Therefore, the refrigerant sucked into the compressor 1 is performed through the refrigerant reservoir 9 functioning as an accumulator from the start of the compressor 1 until the time t1 has elapsed.

Therefore, when the compressor 1 is started, gas-liquid is separated by the refrigerant reservoir 9, the liquid refrigerant is stored in the refrigerant reservoir 9, and only the gas refrigerant is sucked into the compressor 1. When the time t1 has elapsed, all the liquid refrigerant accumulated on the low-pressure side such as the outdoor heat exchanger 3 at the time of startup is accumulated in the refrigerant reservoir 9, so that only the gas refrigerant flows into the refrigerant reservoir 9. Therefore, after the elapse of the time t1, the first time as shown in FIG.
Then, the flow of the refrigerant is switched as follows by switching the second flow path switching means 11 and 12. That is, the refrigerant is supplied to the compressor 1-the four-way valve 2-the indoor heat exchanger 6-functioning as a condenser.
Second electric type flow control valve 4B-Electromagnetic valve 15 which is one of first flow path switching valve means-Second inlet / outlet 9 of refrigerant reservoir 9
b- Refrigerant reservoir 9-first inlet / outlet 9a of refrigerant reservoir 9-
Solenoid valve 14 which is one of the first flow path switching valve means-first electric flow control valve 4A-outdoor heat exchanger functioning as evaporator 3 3-way valve 2-second flow path switching valve It flows in the path of the solenoid valve 16 to the compressor 1 which is one of the means. Therefore, t1
After a lapse of time, the refrigerant discharged from the indoor heat exchanger 6 is discharged through the refrigerant reservoir 9 acting as a receiver.

Further, as shown in FIG. 2, the degree of supercooling of the refrigerant liquid at the outlet of the indoor heat exchanger 6 is determined by the second flow control valve 4B and the degree of superheating of the refrigerant gas at the outlet of the outdoor heat exchanger 3 is determined. First
, Respectively. These first
Of the superheat of the refrigerant gas by the electric flow control valve 4A of FIG.
The supercooling degree of the refrigerant liquid is controlled by the electric flow control valve 4B in the following manner. The degree of supercooling is determined by the temperature sensors 24 and 2
The superheat degree can be known from the temperature difference between the temperatures that can be detected by the temperature sensors 22 and 21, respectively. Therefore, in order to obtain a predetermined degree of superheat or supercooling, a predetermined temperature difference indicating the predetermined degree of superheat or supercooling is to be constant, and these temperature differences are If it is greater than the predetermined value, the first
Electric flow control valve 4A or second electric flow control valve 4
B is opened according to the difference, and when these temperature differences are smaller than a predetermined value, the first electric flow control valve 4A or the second electric flow control valve 4B is closed according to the difference. Is what you do.

As described above, the first electric flow control valve 4A or the second electric flow control valve 4B controls the flow rate of the refrigerant, so that an extra amount of refrigerant required for the cooling operation is stored in the refrigerant reservoir 9. Since the refrigerant can be stored, the refrigerant amount can be adjusted to an appropriate amount in the heating operation. When the heating operation is stopped by turning off the power, the first and second electric flow control valves 4A and 4B are gradually throttled until the time t2 elapses.
After a lapse of time, the compressor 1 is closed and the compressor 1 is stopped. As described above, the pressure is gradually balanced between the stop after the power-off and the passage of the time t2, and thereafter the first and second flow path switching means 11, 12 and the first and second electric flow control valves 4A. , 4B are controlled to the same state as at startup. In addition, when the heating operation is started from the stop due to the power-off of the heating operation and switched from the low-pressure state to the high-pressure state, the first and second electric flow control valves 4A and 4B are located at the outlet side of the second electric flow control valves 4A and 4B. The electric flow control valve 4B is closed, and the opening of the first electric flow control valve 4A on the inlet side is gradually increased to gradually increase the pressure in the cooling reservoir 9. By doing so, it is possible to reduce refrigerant noise caused by pressure fluctuations at the time of switching.

Next, the operation during the cooling operation will be described with reference to FIGS. From the start of the compressor 1 in the cooling operation until the time t1 elapses, the four-way valve 2 is switched, and the first and second electric flow control valves 4A and 4B, the solenoid valves 13, 14, 15, 16, and 17 are operated. , 18 are controlled as shown in FIG. Then, the refrigerant is supplied to the compressor 1-the four-way valve 2-the outdoor heat exchanger functioning as a condenser 3-the first electric flow control valve 4A-the electromagnetic valve 13-one of the first flow path switching valve means. First flow control valve 4A-Outdoor heat exchanger functioning as evaporator 3-Four-way valve 2-Electromagnetic valve 17 which is one of second flow path switching valve means-Third inlet / outlet of refrigerant reservoir 9 9c—refrigerant reservoir 9—fourth inlet / outlet 9 of refrigerant reservoir 9
d- Flow through the path of the solenoid valve 18 which is one of the second flow path switching valve means-the compressor 1. Therefore, from the start of the compressor 1, t
Until one hour has elapsed, the refrigerant sucked into the compressor 1 is discharged through the refrigerant reservoir 9 functioning as an accumulator.

After the elapse of time t1, the flow of the refrigerant is switched as follows by switching the first and second flow path switching means 11 and 12 as shown in FIG. That is, the refrigerant is a compressor 1-a four-way valve 2-an outdoor heat exchanger functioning as a condenser 6-a first electric type flow control valve 4A-an electromagnetic valve 14-one of the first flow path switching valve means. A first inlet / outlet 9a of the refrigerant reservoir 9-a refrigerant reservoir 9-a second entrance / exit 9b of the refrigerant reservoir 9-an electromagnetic valve 15 which is one of first flow path switching valve means-
It flows on the path of the second electric flow control valve 4B-the indoor heat exchanger 6 functioning as an evaporator 6-four-way valve 2-the solenoid valve 16 which is one of the second flow path switching valve means-the compressor 1. Therefore,
After elapse of the time t1, the refrigerant discharged from the indoor heat exchanger 6 is discharged through the refrigerant reservoir 9 functioning as a receiver.

During the cooling operation, the outdoor heat exchanger 3 functions as a condenser, and the indoor heat exchanger 6 functions as an evaporator.
After elapse of t2, as shown in FIG. 3, the degree of superheating of the refrigerant gas at the outlet of the indoor heat exchanger 6 is determined by the second electric flow control valve 4B, and the degree of supercooling of the refrigerant liquid at the outlet of the outdoor heat exchanger 3 is determined by the second. Only the control by the electric flow control valve 4A is changed. Therefore, the refrigerant reservoir 9 functions as a low-pressure accumulator at the time of start-up, prevents the liquid pack from being supplied to the compressor 1 at the time of start-up, and functions as a high-pressure receiver after a predetermined time has elapsed since the start-up to reduce the amount of refrigerant in the cooling operation. Making the appropriate amount remains the same. Further, the operation of stopping the cooling operation by turning off the power supply and the case of starting the cooling operation from the time of stopping the cooling operation by turning off the power and switching from the low pressure state to the high pressure state are the same as the heating operation, and the description thereof will be omitted.

The operation of the heating operation and the cooling operation has been described above. The thermo control for maintaining the temperature at a predetermined set temperature during these operations will be described. Note that the operation of the thermo control is the same in any operation, and the thermo control in the heating operation will be described. When the thermostat is off, the second
The electric flow control valve 4B is kept at the opening just before the thermo-OFF, and the compressor 1 is stopped after the first electric flow control valve 4A is fully closed. In addition, when the thermostat is turned on, the first electric flow control valve 4A is operated for a predetermined time during which the low pressure is sufficiently reduced (about 0.5 minute from thermostat in a small refrigeration cycle device).
Is kept closed, and then the degree of supercooling of the refrigerant liquid and the degree of superheating of the refrigerant gas at the outlets of the indoor and outdoor heat exchangers 6 and 3 are controlled by the first and second electric flow control valves 4A and 4B. .
When the thermostat is OFF, the four-way valve 2 does not switch.
The circuit from the first electric flow control valve 4A to the suction of the compressor 1 keeps a low pressure state, and the circuit from the refrigerant reservoir 19 to the discharge of the compressor 1 keeps a high pressure state and keeps a high and low pressure state close to the time of operation. As a result, the rising time at the time of thermo-ON becomes faster.

Embodiment 2 FIG. 4 is a configuration diagram of a refrigerant circuit of a refrigeration cycle apparatus according to Embodiment 2 of the present invention. In the drawing, the same components as those in the first embodiment of the present invention are denoted by the same reference numerals, and the description of the duplicated components will be omitted. Numeral 30 is a liquid level detecting means capable of detecting an appropriate amount of the refrigerant filled in the refrigerant reservoir 9 during the heating operation and an appropriate amount of the refrigerant charged into the refrigerant reservoir 9 during the cooling operation.

Reference numeral 31 denotes a first capillary tube having one end connected to the bottom of the refrigerant reservoir 9, and 32 denotes an upper portion above the bottom of the refrigerant reservoir 9 at a position indicating a liquid level of an appropriate amount of refrigerant during heating. The connected second capillary 33 is a third capillary whose one end is connected to a position above the bottom of the refrigerant reservoir 9 and which indicates a liquid level of an appropriate amount of refrigerant during cooling, and 34 is a first capillary. A self-heating type first temperature sensor for detecting the temperature of the refrigerant flowing through the first temperature sensor. 35 is a self-heating type second temperature sensor for detecting the temperature of the refrigerant flowing through the second capillary tube 32;
Reference numeral 6 denotes a self-heating type third temperature sensor that detects the temperature of the refrigerant flowing through the third capillary tube 33. Reference numeral 37 denotes a bypass pipe having one end connected to the suction side of the compressor 1, and an on-off valve 38 is provided in the middle of the bypass pipe. The other ends of the first to third capillaries 31 to 33 are connected to the other end of the bypass pipe 37, respectively. The liquid level detecting means 30 includes a first capillary 31 and an on-off valve 38.

The operation when the indoor / outdoor unit connection pipe is longer than the standard length or when charging the refrigerant to replenish the refrigerant due to leakage of the refrigerant will be described. First, the case of performing the refrigerant charging operation in the heating operation will be described. The flow of the refrigerant at this time is the same as the flow of the refrigerant after elapse of the time t1 from the start in the heating operation described above, and the degree of supercooling of the refrigerant liquid at the outlet of the indoor heat exchanger 6 is determined by the second flow control valve 4B. The degree of superheating of the refrigerant gas at the outlet of the outdoor heat exchanger 3 is controlled by the first flow control valve 4A. Then, the refrigerant is charged from a refrigerant charging port (not shown) provided in the flow path on the suction side of the compressor 1. At this time, the on-off valve 38 is opened so that a part of the refrigerant flows from the refrigerant reservoir 9 to the bypass pipe 37.

As the refrigerant charging into the apparatus progresses,
The liquid level of the refrigerant reservoir 9 rises, and in the capillary tube 32, the gas refrigerant, which had flowed at the beginning of the filling operation, is now flowing the liquid refrigerant. Then, a low-temperature gas-liquid two-phase refrigerant state is established at the outlet of the capillary tube 32, so that the temperature of the temperature sensor 35 decreases and the capillary tube 31 connected to the bottom of the refrigerant reservoir 9.
Is substantially the same as the temperature of the temperature sensor 34 provided at Therefore, when the detection signals of these two temperature sensors 34 and 35 match, it is possible to know that the refrigerant liquid level has reached the level of the liquid level at the appropriate refrigerant amount during the heating operation. Thus, based on the coincidence of the detection signals of the two temperature sensors 34 and 35, although not shown, for example, a display provided on an outdoor unit or a buzzer sounds so that a refrigerant charging operation is performed. Can be notified. The on-off valve 37 is closed when it is detected that a proper amount of refrigerant has been charged.

The case where the refrigerant charging operation is performed in the cooling operation will be described. The flow of the refrigerant at this time is the same as the flow of the refrigerant after the elapse of the time t1 from the startup in the cooling operation described above, and the superheat degree of the refrigerant liquid at the outlet of the indoor heat exchanger 6 is the second degree.
The supercooling degree of the refrigerant gas at the outlet of the outdoor heat exchanger 3 is controlled by the first flow control valve 4A.

Thus, as the charging of the refrigerant into the apparatus progresses,
The liquid level of the refrigerant reservoir 9 rises, and in the capillary tube 33, the gas refrigerant that had been flowing at the beginning of the filling operation is now allowed to flow. Then, at the outlet of the capillary tube 33, a low-temperature gas-liquid two-phase refrigerant state is established, so that the temperature of the temperature sensor 36 decreases and becomes substantially the same as the temperature of the temperature sensor 34. Therefore, when the detection signals of the two temperature sensors 34 and 36 match, it is possible to know that the refrigerant liquid level has reached the liquid level position of the appropriate refrigerant amount during the cooling operation. Therefore, although not shown, based on the coincidence of the detection signals of the two temperature sensors 34 and 36, for example, the refrigerant is displayed on a display provided in the outdoor unit or by sounding a buzzer. It can inform the filling operator. The on-off valve 37 is closed when it is detected that a proper amount of refrigerant has been charged. Therefore, it is not necessary to mount the refrigerant cylinder on the fin and check the amount of the liquefied refrigerant as in the related art at the time of charging the refrigerant in either the heating operation or the cooling operation. When the refrigerant is charged from the beginning, such as after repair, the refrigerant is charged in a gaseous state from a refrigerant cylinder through a refrigerant charging port provided on the compressor suction side with the compressor stopped, and then the compressor is started and the above-described refilling is performed. Is the same as the operation at the time of charging the refrigerant.

In the above description, the operation of the air conditioner performing the cooling / heating operation has been described. However, the same control as the operation of the air conditioner may be performed at the time of start-up or after a predetermined time of start-up in the refrigerator used at a low temperature. .

[0032]

As described above, in the refrigeration cycle apparatus according to the present invention, the first flow path switching means provided between the indoor heat exchanger and the flow control valve has the indoor heat exchanger when the cooling and heating is started. Between the indoor heat exchanger and the flow rate control valve via the refrigerant reservoir after a predetermined time from the start, and between the suction side of the compressor and the four-way valve. The second flow path switching means provided, when the cooling and heating is started, conducts between the suction side of the compressor and the four-way valve communicating with the suction side via the refrigerant reservoir, and after a predetermined time from the start, the compressor Because only the suction side and the four-way valve are electrically connected, the refrigerant reservoir functions as an accumulator at the time of activation of the heating and cooling operations, and the refrigerant reservoir functions as a receiver after a predetermined time from the activation. To start the With prevention can be performed in, cooling and can be operated at proper refrigerant quantity for each of the heating operation, the second conventional receiver and the accumulator as
There is an effect that the size and cost of the device can be reduced without the need for two containers.

In the refrigeration cycle apparatus according to the present invention, a flow control valve is provided on the indoor heat exchanger side of the first flow path switching means, and the opening thereof is gradually closed when the operation is stopped. Therefore, there is an effect that the high and low pressures are balanced and the operation can be stably performed. Further, the refrigeration cycle apparatus according to the present invention is configured such that at the start of operation, the flow control valve on the outlet side of the first flow path switching means is closed, and the opening of the flow control valve on the inlet side is gradually increased. Because
There is an effect that refrigerant noise due to pressure fluctuation at the time of switching can be reduced. Further, when performing the refrigerant charging operation in the heating and cooling operations, the air conditioner according to the present invention can know that an appropriate amount of the refrigerant has been charged in the heating and cooling operations based on the signal of the liquid level detection unit. Therefore, there is an effect that the labor and cost for preparing the fins as in the related art can be saved.

Further, in the air conditioner according to the present invention, the liquid level detecting means has three capillaries whose one ends are provided in the refrigerant reservoir, three temperature sensors provided respectively in the three capillaries, and three With a simple configuration of a bypass pipe having one end connected to the capillary and the other end connected to the suction side of the compressor, there is an effect that it can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a refrigerant circuit of a refrigeration cycle apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a time chart of a control flow during a heating operation in the refrigeration cycle apparatus according to the first embodiment.

FIG. 3 is a time chart of a control flow during a cooling operation in the refrigeration cycle apparatus according to the first embodiment.

FIG. 4 is a configuration diagram of a refrigerant circuit of a refrigeration cycle apparatus according to Embodiment 2 of the present invention.

FIG. 5 is a configuration diagram of a refrigerant circuit of a conventional refrigeration cycle device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Compressor, 2 4-way valve, 3 outdoor heat exchanger, 6 indoor heat exchanger, 4A 1st electric flow control valve, 4B 2nd
Electrical flow control valve, 9 refrigerant reservoir, 11 first flow path switching means, 12 second flow path switching means.

Claims (7)

(57) [Claims] A compressor and a condenser or evaporator.
Functions as an outdoor heat exchanger and an evaporator or condenser
An indoor heat exchanger, at least one flow control valve,
During the heating operation, the refrigerant flows from the compressor to the indoor heat exchanger and flow rate control.
Forming a flow path that returns to the compressor via a valve and outdoor heat exchanger
During cooling operation, the compressor controls the outdoor heat exchanger and controls the flow rate.
Form a flow path that returns to the compressor via a valve and indoor heat exchanger
Refrigeration cycle sequentially connected with a four-way valve that switches
In the apparatus, a refrigerant reservoir that separates gas from refrigerant and stores liquid is provided between the indoor heat exchanger and the flow control valve, and is used for cooling and heating.
At start-up, there is only communication between the indoor heat exchanger and the flow control valve.
After a predetermined time from startup, the indoor heat exchanger and flow control valve
Channel switching means for connecting between the two via a refrigerant reservoir
Stage and between the compressor suction side and the four-way valve
During operation, a refrigerant reservoir is provided between the suction side of the compressor and the four-way valve.
Through the compressor, and after a predetermined time from the start, the suction side of the compressor.
And a second flow path switching means for conducting only between the flow path and the four-way valve . 2. The refrigeration cycle apparatus according to claim 1, wherein a flow control valve is provided on the indoor heat exchanger side of the first flow path switching means, and its opening is gradually closed when the operation is stopped. 3. The flow control valve on the outlet side of the first flow path switching means is closed at the start of operation, and the opening of the flow control valve on the inlet side is gradually increased. A refrigeration cycle apparatus as described in the above. 4. The method according to claim 1, 2 or 3.
An air conditioner comprising the refrigeration cycle device according to any one of the preceding claims. 5. A refrigerant reservoir unit proper refrigerant quantity during heating operation and cooling air conditioner according to claim 4, characterized in that a liquid level detecting means capable of detecting the proper refrigerant quantity during operation. 6. The liquid level detecting means includes a bypass pipe provided on the suction side of the compressor, an on-off valve provided in the middle of the bypass pipe, and a valve between the bottom of the refrigerant reservoir and the bypass pipe. A first capillary provided, a first temperature sensor for detecting the temperature of the refrigerant flowing through the first capillary, and a liquid level height of an appropriate refrigerant amount during a heating operation above a bottom of the refrigerant reservoir. The second provided between the indicated position and the bypass pipe
A second temperature sensor for detecting the temperature of the refrigerant flowing through the second capillary, a position above the bottom of the refrigerant reservoir indicating a liquid level of an appropriate refrigerant amount during cooling operation, and a bypass pipe. A third capillary tube provided between
The air conditioner according to claim 5, further comprising a third temperature sensor for detecting a temperature of the refrigerant flowing through the capillary. 7. The first temperature sensor and the second temperature sensor.
Based on the coincidence of the detection signals,
The first temperature sensor and the third temperature.
Cooling operation based on the matching of the detection signals of the degree sensor
Equipped with an indicator that indicates the proper refrigerant amount at the time.
The air conditioner according to claim 6, wherein: