JPWO2020174684A1 - Refrigeration cycle equipment - Google Patents

Abstract

In the refrigeration cycle apparatus (100) according to the present invention, the refrigerant containing R290 is a compressor (1), a first heat exchanger (3), a first decompression apparatus (31), and a second heat exchanger (4). It circulates in the first circulation direction of. The refrigeration cycle device (100) includes a heat storage material (10) and a first flow path switching unit (20). The heat storage material (10) is arranged around the compressor (1) and receives heat from the compressor (1). The first flow path switching unit (20) forms a first flow path (FP1) and a second flow path (FP2) for guiding the refrigerant from the second heat exchanger (4) to the compressor (1). It is possible. When the first flow path (FP1) is formed, the refrigerant flowing out from the first flow path (FP1) reaches the compressor (1) without passing through the heat storage material (10). When the second flow path (FP2) is formed, the refrigerant flowing out from the second flow path (FP2) reaches the compressor (1) via the heat storage material (10).

Description

The present invention relates to a refrigeration cycle device in which a heat storage material is formed around a compressor.

Conventionally, a refrigeration cycle device in which a heat storage material is formed around a compressor is known. For example, International Publication No. 2013/06523 (Patent Document 1) discloses a refrigeration cycle device in which a heat storage material is formed around a compressor. In the refrigeration cycle device, in the defrosting operation, a flow path is formed in which the refrigerant from the outdoor heat exchanger is guided to the suction port of the compressor via the heat storage material formed around the compressor. According to the refrigeration cycle device, the defrosting time can be shortened, the decrease in room temperature due to the defrosting operation can be suppressed, and the comfort can be improved.

International Publication No. 2013/06523

In recent years, from the viewpoint of preventing global warming, a refrigerant having a lower GWP (Global Warming Potential) has been required. Refrigerants that can reduce GWP more than before include, for example, R290 (propane), a refrigerant that improves the theoretical COP (Coefficient of Performance) of the refrigeration cycle device as the degree of superheat of the refrigerant sucked into the compressor increases. There is. However, it is known that if the temperature of the refrigerant flowing out of the evaporator is raised in order to increase the degree of superheat of the refrigerant sucked into the compressor, the performance of the evaporator deteriorates.

Patent Document 1 does not consider suppressing the temperature of the refrigerant flowing out of the evaporator in normal heating operation. When R290 is used for the refrigeration cycle apparatus disclosed in Patent Document 1, the performance of the refrigeration cycle apparatus may deteriorate.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to suppress deterioration of the performance of a refrigeration cycle apparatus while reducing GWP.

In the refrigeration cycle apparatus according to the present invention, the refrigerant containing R290 circulates in the first circulation direction of the compressor, the first heat exchanger, the first decompression apparatus, and the second heat exchanger. The refrigeration cycle device includes a heat storage material and a first flow path switching unit. The heat storage material is placed around the compressor and receives heat from the compressor. The first flow path switching unit can form a first flow path and a second flow path for guiding the refrigerant from the second heat exchanger to the compressor. When the first flow path is formed, the refrigerant flowing out of the first flow path reaches the compressor without passing through the heat storage material. When the second flow path is formed, the refrigerant flowing out of the second flow path reaches the compressor via the heat storage material.

According to the refrigeration cycle apparatus according to the present invention, a refrigerant containing R290 is used, and a flow path can be formed so that the refrigerant from the second heat exchanger reaches the compressor via the heat storage material. While reducing the GWP, it is possible to suppress the deterioration of the performance of the refrigeration cycle apparatus.

It is a functional block diagram which shows the structure of the refrigeration cycle apparatus which concerns on Embodiment 1. FIG. FIG. 3 is a plan view of the heat storage material of FIG. 1 from the normal direction of the side surface of the compressor 1. It is a figure which shows an example of the flow path formed in the heat storage material of FIG. It is a figure which shows a lot of examples of the flow path formed in the heat storage material of FIG. It is a figure which shows the relationship between the superheat degree of the refrigerant sucked into a compressor, and the theoretical COP. It is a ph diagram which shows the relationship of enthalpy, pressure, and temperature in the cooling operation with a low load of the refrigeration cycle apparatus which concerns on a comparative example. It is a flowchart which shows the flow of processing with respect to the flow path switching part performed by the control device of FIG. It is a figure which shows the specific structure of the flow path switching part of FIG. It is a figure which shows the specific structure of another example of the flow path switching part of FIG. It is a figure which shows an example of the heat storage material of FIG. It is a figure which shows another example of the heat storage material of FIG. It is a functional block diagram which shows the structure of the refrigeration cycle apparatus which concerns on Embodiment 2. FIG. It is a flowchart which shows the flow of the process with respect to the flow path switching part performed in the cooling operation by the control device of FIG. FIG. 5 is a ph diagram showing the relationship between enthalpy, pressure, and temperature when a cooling operation is performed in the refrigeration cycle apparatus according to the modified example of the second embodiment. It is a functional block diagram which shows the structure of the refrigeration cycle apparatus which concerns on Embodiment 3. It is a flowchart which shows the flow of the process with respect to the flow path switching part performed in the heating operation by the control device of FIG. It is a functional block diagram which shows the structure of the refrigerating cycle apparatus which concerns on modification 1 of Embodiment 3. It is a functional block diagram which shows the structure of the refrigerating cycle apparatus which concerns on modification 2 of Embodiment 3.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In principle, the same or corresponding parts in the drawings are designated by the same reference numerals and the description is not repeated.

Embodiment 1.
FIG. 1 is a functional block diagram showing the configuration of the refrigeration cycle device 100 according to the first embodiment. As shown in FIG. 1, the refrigeration cycle device 100 includes an outdoor unit 110 and an indoor unit 120. The outdoor unit 110 includes a compressor 1, a four-way valve 2 (second flow path switching unit), an outdoor heat exchanger 3 (first heat exchanger), an electromagnetic expansion valve 31 (first decompression device), and a flow. It includes a path switching unit 20 (first flow path switching unit), an outdoor fan 41, a control device 90, and temperature sensors 11 to 15. The indoor unit 120 includes an indoor heat exchanger 4 (second heat exchanger), an indoor fan 42, and temperature sensors 16 to 18. The control device 90 may be included in the indoor unit 120, or may be provided separately from the outdoor unit 110 and the indoor unit 120.

The refrigeration cycle device 100 can perform a cooling operation and a heating operation with respect to the space in which the indoor unit 120 is arranged. In the refrigeration cycle device 100, R290 is used as the refrigerant.

In the cooling operation, the four-way valve 2 communicates the discharge port Pd of the compressor 1 with the outdoor heat exchanger 3 and also communicates the indoor heat exchanger 4 with the flow path switching unit 20. In the cooling operation, the refrigerant is the discharge port Pd of the compressor 1, the four-way valve 2, the outdoor heat exchanger 3, the electromagnetic expansion valve 31, the indoor heat exchanger 4, the four-way valve 2, the flow path switching unit 20, and the compressor 1. It circulates in the order of the suction port Ps.

In the heating operation, the four-way valve 2 communicates the discharge port Pd of the compressor 1 with the indoor heat exchanger 4 and also communicates the outdoor heat exchanger 3 with the flow path switching unit 20. In the heating operation, the refrigerant is the discharge port Pd of the compressor 1, the four-way valve 2, the indoor heat exchanger 4, the electromagnetic expansion valve 31, the outdoor heat exchanger 3, the four-way valve 2, the flow path switching unit 20, and the compressor 1. It circulates in the order of the suction port Ps.

With reference to FIG. 2 as well as FIG. 1, a heat storage material 10 that receives heat from the compressor 1 is arranged around the compressor 1. The heat storage material 10 covers the side surface of the compressor 1 except for the portion where the suction port Ps is formed. A metal, grease, gel-like sheet or the like having high thermal conductivity may be provided between the compressor 1 and the heat storage material 10 in order to promote heat exchange between the heat storage material 10 and the refrigerant. The heat exchange between the heat storage material 10 and the refrigerant may be promoted by tightening the outer peripheral portion of the heat storage material 10 with a belt or the like to bring it into close contact with the compressor 1.

The flow path switching unit 20 can form the flow path FP1 (first flow path) and the flow path FP2 (second flow path). At least one of the flow paths FP1 and FP2 is open. The refrigerant flowing out of the flow path FP1 reaches the suction port Ps of the compressor 1 without passing through the heat storage material 10. The refrigerant flowing out from the flow path FP2 reaches the suction port Ps of the compressor 1 via the heat storage material 10. The flow path in the heat storage material 10 may be formed to meander as shown in FIG. 3, or a plurality of flow paths may be formed in parallel as shown in FIG.

With reference to FIG. 1 again, the control device 90 acquires the temperature T11 of the refrigerant flowing between the outdoor heat exchanger 3 and the electromagnetic expansion valve 31 from the temperature sensor 11. The control device 90 acquires the temperature T12 of the refrigerant flowing through the outdoor heat exchanger 3 from the temperature sensor 12 installed in the intermediate portion of the outdoor heat exchanger 3. The control device 90 acquires the temperature T13 of the outdoor space in which the outdoor unit 110 is arranged from the temperature sensor 13.

The control device 90 acquires the temperature T14 of the heat storage material 10 from the temperature sensor 14. When the heat storage material 10 is heated, convection occurs inside the heat storage material 10, and a high-temperature fluid having a low density collects on the upper part of the heat storage material 10. As will be described later, the temperature T14 measured by the temperature sensor 14 is used to determine whether or not heating by the heat storage material 10 is possible. When the temperature sensor 14 is installed above the heat storage material 10, it can be determined that the heat storage material 10 can be heated even though sufficient heat is not accumulated in the heat storage material 10 as a whole. Therefore, the temperature measured by the temperature sensor 14 is preferably the temperature of the portion of the heat storage material 10 in which the fluid as low as possible gathers. The temperature sensor 14 is preferably installed at a position of 1/3 or less of the height of the heat storage material from the upper part of the heat storage material 10. It is more preferable that the temperature sensor 14 is installed at a position of 1/2 or less of the height of the heat storage material from the upper part of the heat storage material 10.

The refrigerant passes through a flow path formed inside the heat storage material 10. Therefore, it is preferable that the temperature sensor 14 can directly measure the temperature inside the heat storage material 10. When it is difficult to directly measure the temperature inside the heat storage material 10, the other end of the object so that one end of an object having high thermal conductivity (for example, a rod-shaped metal) is exposed to the outside of the heat storage material 10. May be inserted into the heat storage material 10 and the temperature at one end of the object may be measured by the temperature sensor 14.

The control device 90 acquires the temperature T15 of the refrigerant passing through the suction port Ps from the temperature sensor 15. The control device 90 acquires the temperature T16 of the refrigerant flowing between the indoor heat exchanger 4 and the electromagnetic expansion valve 31 from the temperature sensor 16. The control device 90 acquires the temperature T17 of the refrigerant passing through the indoor heat exchanger 4 from the temperature sensor 17 installed in the intermediate portion of the indoor heat exchanger 4. The control device 90 acquires the indoor temperature T18 of the indoor space in which the indoor unit 120 is arranged from the temperature sensor 18.

By controlling the drive frequency of the compressor 1, the control device 90 controls the amount of refrigerant discharged by the compressor 1 per unit time so that the room temperature T18 becomes the target temperature (for example, the temperature set by the user). do. The control device 90 controls the four-way valve 2 to switch the circulation direction of the refrigerant. The control device 90 controls the flow path switching unit 20 to adjust the amount of refrigerant passing through each of the flow path FP1 and the flow path FP2 per unit time.

The control device 90 electromagnetically expands so that one or both of the degree of superheat of the refrigerant sucked into the compressor 1 and the degree of supercooling of the refrigerant flowing out of the heat exchanger functioning as a condenser are within a desired range. The opening degree of the valve 31 is controlled. The heat exchanger that functions as a condenser is the outdoor heat exchanger 3 in the cooling operation and the indoor heat exchanger 4 in the heating operation.

For example, when the degree of superheat of the refrigerant sucked into the compressor 1 is set to a value in a desired range, the temperature T15 of the refrigerant sucked into the compressor 1 and the temperature flowing through the heat exchanger functioning as an evaporator (temperature T12 or The opening degree of the electromagnetic expansion valve 31 is controlled based on the temperature difference from T17). The heat exchanger that functions as an evaporator is the indoor heat exchanger 4 in the cooling operation and the outdoor heat exchanger 3 in the heating operation. When the degree of supercooling of the refrigerant flowing out from the heat exchanger functioning as a condenser is set to a value in a desired range, the temperature (temperature T12 or T17) of the refrigerant flowing through the heat exchanger functioning as a condenser and the heat exchanger The opening degree of the electromagnetic expansion valve 31 is controlled based on the temperature difference from the temperature (temperature T11 or T16) of the refrigerant flowing out from.

The control device 90 controls the amount of air blown per unit time of the outdoor fan 41 and the indoor fan 42. Regarding the outdoor fan 41, for each operation mode according to the operation mode (for example, the rated mode for high-speed rotation or the intermediate mode for low-speed rotation) automatically set from the temperature difference between the indoor target temperature and the indoor temperature T18. The fan is driven at a preset rotation speed. With respect to the indoor fan 42, the fan is driven at a rotation speed according to a setting by the user (for example, a weak wind mode or a strong wind mode). Regarding the indoor fan 42, the fan is driven in the same manner as the outdoor fan when the automatic change of the fan rotation speed by the control device 90 is permitted, for example, when the automatic mode is selected by the user. You may.

A temperature sensor that detects the temperature of the refrigerant passing through the discharge port Pd of the compressor 1 may be installed. Based on the temperature difference between the detection result of the temperature sensor and the preset target discharge temperature, the drive frequency of the compressor 1, the amount of air blown per unit time of each of the outdoor fan 41 and the indoor fan 42, and the electromagnetic expansion valve. The opening degree of 31 may be controlled.

In recent years, from the viewpoint of preventing global warming, a refrigerant having a lower GWP (Global Warming Potential) has been required. Examples of the refrigerant capable of reducing GWP as compared with the conventionally used refrigerant (for example, R410A) include R32 and R290.

Since R32 has a high operating pressure, the freezing effect of the freezing cycle device can be enhanced even with a relatively small compressor. In addition, R32 is not toxic. However, the GWP of R32 is insufficient for the F-gas regulation or the regulation value of the Montreal Protocol. On the other hand, the GWP of R290 is lower than the GWP of R32. R290 is known as one of the effective refrigerants for these regulations.

Unlike R32 and R410A, R290 has a characteristic that the larger the degree of superheat of the refrigerant sucked into the compressor, the higher the theoretical COP (Coefficient of Performance) of the refrigeration cycle device (see FIG. 5). However, it is known that if the temperature of the refrigerant flowing out of the heat exchanger functioning as an evaporator is increased in order to increase the degree of superheat of the refrigerant sucked into the compressor, the performance of the heat exchanger is deteriorated. There is.

If there is almost no temperature difference between the temperature of the refrigerant flowing out of the heat exchanger functioning as a condenser and the temperature of the refrigerant flowing out of the heat exchanger functioning as an evaporator, the degree of overheating of the refrigerant sucked into the compressor It becomes difficult to secure. Such a situation can occur, for example, in a cooling operation with a low load.

FIG. 6 is a ph diagram showing the relationship between enthalpy, pressure, and temperature in the cooling operation of the refrigeration cycle apparatus according to the comparative example under a low load. In FIG. 6, the curves LC and GC represent saturated liquid lines and saturated vapor lines, respectively. The saturated liquid line and the saturated vapor line are connected at the critical point CP. The same applies to FIG. 14, which will be described later. The process of states C1 to C2 shows an adiabatic compression process by a compressor. The process from state C2 to C3 represents the process of condensation by a heat exchanger that functions as a condenser. The process from state C3 to C4 represents the decompression process by the expansion valve. The process from state C4 to C1 represents an evaporation process by a heat exchanger that functions as an evaporator. FIG. 6 shows an isotherm of outdoor temperature T1.

As shown in FIG. 6, when the temperature of the state C3 representing the state of the refrigerant flowing out from the heat exchanger functioning as the condenser is close to the outdoor temperature T1, it is sucked into the compressor through the depressurization process and the evaporation process. The state C1 representing the state of the refrigerant can be a state on the isotherm of the outdoor temperature T1. In low-load cooling operation, the degree of superheat of the refrigerant sucked into the compressor may be smaller than expected.

Therefore, in the refrigeration cycle device 100, the heat generated in the compressor 1 is accumulated in the heat storage material 10, and the flow path FP2 is formed so that the refrigerant is sucked into the compressor 1 via the heat storage material 10. By utilizing the heat accumulated in the heat storage material 10, it is possible to increase the degree of superheat of the refrigerant sucked into the compressor 1 while suppressing an increase in the temperature of the refrigerant flowing out from the heat exchanger functioning as an evaporator. can. As a result, the theoretical COP of the refrigeration cycle apparatus 100 in which the R290 is used to reduce the GWP can be improved while suppressing the deterioration of the performance of the heat exchanger functioning as the evaporator.

FIG. 7 is a flowchart showing a flow of processing for the flow path switching unit 20 performed by the control device 90 of FIG. The process shown in FIG. 7 is called at regular time intervals by a main routine (not shown) that performs integrated control of the refrigeration cycle apparatus 100. In the following, the step is simply referred to as S.

The control device 90 determines in S101 whether or not the condition (specific condition) that the temperature T14 of the heat storage material 10 is equal to or higher than the reference temperature Tr1 is satisfied. When the temperature T14 of the heat storage material 10 is smaller than the reference temperature Tr1 (for example, 30 °) (NO in S101), the control device 90 passes the flow path FP2 with the amount of refrigerant per unit time passing through the flow path FP1 in S102. The flow path switching unit 20 is controlled so that the amount of refrigerant exceeds the amount of refrigerant per unit time, and the process is returned to the main routine. When the temperature T14 of the heat storage material 10 is equal to or higher than the reference temperature Tr1 (YES in S101), the control device 90 stores heat capable of heating the refrigerant flowing out from the heat exchanger functioning as the evaporator in the heat storage material 10. Assuming that, in S103, the flow path switching unit 20 is controlled so that the amount of refrigerant per unit time passing through the flow path FP2 is larger than the amount of refrigerant per unit time passing through the flow path FP1 to make the process the main routine. return.

The specific heat of the heat storage material 10 is preferably lower than the specific heat of water in order to shorten the time for the temperature T14 of the heat storage material 10 to reach the reference temperature Tr1. The reference temperature Tr1 is a temperature indicating that heat capable of heating the refrigerant flowing out of the heat exchanger functioning as an evaporator is accumulated in the heat storage material 10, and can be appropriately calculated by an actual machine experiment or a simulation.

FIG. 8 is a diagram showing a specific configuration of the flow path switching unit 20 of FIG. As shown in FIG. 8, the flow path switching unit 20 includes electromagnetic on-off valves 21 and 22. The electromagnetic on-off valve 21 is provided in the flow path FP1. When the electromagnetic on-off valve 21 is open, the refrigerant can pass through the flow path FP1. When the electromagnetic on-off valve 21 is closed, the refrigerant cannot pass through the flow path FP1. The electromagnetic on-off valve 22 is provided in the flow path FP2. When the electromagnetic on-off valve 22 is open, the refrigerant can pass through the flow path FP2. When the electromagnetic on-off valve 22 is closed, the refrigerant cannot pass through the flow path FP2. The control device 90 opens the electromagnetic on-off valve 21 and closes the electromagnetic on-off valve 22 in S102 of FIG. 7. The control device 90 closes the electromagnetic on-off valve 21 and opens the electromagnetic on-off valve 22 in S103 of FIG.

FIG. 9 is a diagram showing a specific configuration of the flow path switching unit 20A, which is another example of the flow path switching unit 20 of FIG. 1. As shown in FIG. 9, the flow path switching unit 20A includes electromagnetic expansion valves 21A and 22A. The electromagnetic expansion valve 21A is provided in the flow path FP1. The control device 90 adjusts the amount of refrigerant per unit time passing through the flow path FP1 by adjusting the opening degree of the electromagnetic expansion valve 21A. The electromagnetic expansion valve 22A is provided in the flow path FP2. The control device 90 adjusts the amount of refrigerant per unit time passing through the flow path FP2 by adjusting the opening degree of the electromagnetic expansion valve 22A.

When the flow path switching unit 20 in FIG. 1 is the flow rate switching unit 20A, the control device 90 adjusts the opening degree of each of the electromagnetic expansion valves 21A and 22A to adjust the opening degree of the refrigerant per unit time passing through the flow path FP1. The flow rate ratio between the amount and the amount of refrigerant per unit time passing through the flow path FP2 is controlled.

According to the refrigeration cycle device 100, since the heat generated from the compressor 1 is used for heating the refrigerant via the heat storage material 10, the energy efficiency of the refrigeration cycle device is improved. Further, by heating the refrigerant with the heat storage material 10, the degree of superheat of the refrigerant sucked into the compressor 1 can be increased even in the heating operation and the low-load cooling operation.

The amount of the refrigerant dissolved in the lubricating oil of the compressor 1 decreases as the temperature of the refrigerant increases. As the temperature of the refrigerant sucked into the compressor 1 rises, the temperature of the refrigerant discharged from the compressor 1 also rises, so that the amount of the refrigerant dissolved in the lubricating oil decreases. Since it is possible to suppress a decrease in the amount of refrigerant circulating in the refrigeration cycle device due to the dissolution of the refrigerant in the lubricating oil, it is possible to reduce the amount of refrigerant required for stable operation of the refrigeration cycle device.

When the outdoor temperature is relatively low (for example, in winter), the temperature of the heat storage material 10 may be lower than the temperature of the refrigerant flowing out from the heat exchanger functioning as an evaporator. In such a case, when the refrigerant passes through the heat storage material 10, the refrigerant is cooled by the heat storage material 10. Depending on the temperature of the heat storage material 10, the refrigerant may condense into a liquid refrigerant (liquid refrigerant). When the liquid refrigerant is sucked into the compressor 1, the performance of the compressor 1 deteriorates and the possibility of failure increases. In such a case (NO in S101 of FIG. 7), in the refrigeration cycle apparatus 100, the refrigerant can be returned to the compressor 1 without passing through the heat storage material 10. As a result, deterioration of the performance of the compressor 1 can be suppressed.

The side surface of the compressor 1 covered with the heat storage material may be limited to the side surface portion around the motor in the compressor 1 having a large amount of heat generation, for example, the heat storage material 10A shown in FIG. Further, the side surface of the compressor 1 covered with the heat storage material is limited to a portion around the flow path that guides the refrigerant from the flow path FP2 to the suction port Ps of the compressor 1 as in the heat storage material 10B shown in FIG. You may be. By limiting the side surface on which the heat storage material is formed in this way, the cost of the heat storage material can be reduced.

The refrigerant used in the refrigeration cycle apparatus according to the first embodiment does not lose the characteristic that the larger the degree of superheat of the refrigerant sucked into the compressor, the greater the theoretical COP (Coefficient of Performance) of the refrigeration cycle apparatus. , R290 may contain a refrigerant other than R290.

In the first embodiment, a refrigeration cycle device including one outdoor unit and one indoor unit has been described. The refrigeration cycle device may be configured to include a plurality of indoor units, or may be configured to include a plurality of outdoor units.

In the first embodiment, a refrigeration cycle device such as a room air conditioner or a packaged air conditioner capable of switching between cooling operation and heating operation has been described. The refrigeration cycle device may have a configuration dedicated to cooling operation such as a refrigerator, which does not include a flow path switching valve such as a four-way valve.

As described above, according to the refrigeration cycle apparatus according to the first embodiment, it is possible to suppress the deterioration of the performance of the refrigeration cycle apparatus while reducing the GWP.

Embodiment 2.
In the second embodiment, a refrigeration cycle apparatus including an internal heat exchanger (third heat exchanger) will be described. In the internal heat exchanger, when the cooling operation is being performed, the refrigerant (high pressure side refrigerant) after being discharged from the compressor and before the depressurization by the expansion valve and the decompression by the expansion valve are performed. After that, heat exchange is performed with the refrigerant (low pressure side refrigerant) until it is sucked into the compressor. In the second embodiment, when the cooling operation is performed, the degree of superheat of the refrigerant sucked into the compressor is further increased among the heating of the refrigerant by the internal heat exchanger and the heating of the refrigerant by the heat storage material. The one who can do it is selected.

FIG. 12 is a functional block diagram showing the configuration of the refrigeration cycle device 200 according to the second embodiment. The configuration of the refrigeration cycle device 200 is that the internal heat exchanger 51 and the temperature sensor 19 are added to the refrigeration cycle device 100 of FIG. 1, and the control device 90 is replaced with 92. Other than these, the description is the same, so the description will not be repeated.

As shown in FIG. 12, the internal heat exchanger 51 is connected between the flow path FP1 and the suction port Ps of the compressor 1, and is between the outdoor heat exchanger 3 and the electromagnetic expansion valve 31. It is connected. The control device 92 acquires the temperature T19 of the refrigerant flowing between the internal heat exchanger 51 and the electromagnetic expansion valve 31 from the temperature sensor 19. When the cooling operation is performed, heat is exchanged between the high-pressure side refrigerant from the outdoor heat exchanger 3 functioning as a condenser and the low-pressure side refrigerant from the flow path FP1 in the internal heat exchanger 51. , The low pressure side refrigerant is heated by the high pressure side refrigerant.

FIG. 13 is a flowchart showing a flow of processing for the flow path switching unit 20 performed in the cooling operation by the control device 92 of FIG. The process shown in FIG. 13 is called at regular time intervals by a main routine (not shown) that performs integrated control of the refrigeration cycle apparatus 200. The flowchart shown in FIG. 13 is a flowchart in which S101 of the flowchart shown in FIG. 7 is replaced with S201. In the heating operation, the process shown in FIG. 7 is performed.

As shown in FIG. 13, the control device 92 satisfies the condition (specific condition) that the temperature T14 is equal to or higher than the reference temperature Tr1 and the difference between the temperatures T11 and T19 is equal to or lower than the reference value Tdr2 in S201. Determine whether or not to do so. The condition that the difference between the temperatures T11 and T19 is equal to or less than the reference value Tdr2 is a condition indicating that the amount of heat exchange in the internal heat exchanger 51 is smaller than the reference amount. The reference value Tdr2 is appropriately calculated by an actual machine experiment or a simulation.

When the temperature T14 is smaller than the reference temperature Tr1 or the difference between the temperatures T11 and T19 is larger than the reference value Tdr2 (NO in S201), the control device 92 performs S102 in the same manner as in the first embodiment to perform processing. Return to the main routine. When the temperature T14 is equal to or higher than the reference temperature Tr1 and the difference between the temperatures T11 and T19 is equal to or lower than the reference value Tdr2 (YES in S201), the control device 92 performs S103 and processes as in the first embodiment. Is returned to the main routine. In S201, the condition that the temperature T14 is equal to or higher than the reference temperature Tr1 or the difference between the temperatures T11 and T19 is equal to or lower than the reference value Tdr2 may be determined.

A modified example of the second embodiment.
In the second embodiment, a case where whether or not the heat exchange amount in the internal heat exchanger 51 is smaller than the reference amount is compared between the temperature difference and the reference value Tdr2 has been described. The temperature difference, which is an index of the amount of heat exchange in the internal heat exchanger 51, can change depending on the operating environment of the refrigeration cycle device 200 (for example, the outdoor temperature T13). In the second embodiment, the accuracy of determining whether or not the heat exchange amount in the internal heat exchanger 51 is smaller than the reference amount is easily affected by the operating environment of the refrigeration cycle device 200.

Therefore, in the modified example of the second embodiment, whether or not the heat exchange amount in the internal heat exchanger 51 is smaller than the reference amount is a temperature ratio or an enthalpy ratio that is unlikely to change due to a change in the operating environment of the refrigeration cycle device 200. Judgment is made using. According to the refrigeration cycle apparatus according to the modified example of the second embodiment, the determination accuracy of whether or not the heat exchange amount in the internal heat exchanger 51 is smaller than the reference amount is maintained regardless of the operating environment of the refrigeration cycle apparatus. be able to.

The configuration of the refrigeration cycle apparatus according to the modified example of the second embodiment is a configuration in which the condition of T11-T19 ≦ Tdr2 in S201 of FIG. 13 is changed to a condition relating to a temperature ratio or a condition relating to an enthalpy ratio. Since the other parts are the same, the refrigerating cycle apparatus 200 of FIG. 13 will be described below with reference to the appropriate reference.

FIG. 14 is a ph diagram showing the relationship between enthalpy, pressure, and temperature when the cooling operation is performed in the refrigeration cycle apparatus according to the modified example of the second embodiment. The process of states C21 to C22 shows an adiabatic compression process by the compressor 1. The process from state C22 to C25 represents the condensation process by the outdoor heat exchanger 3. The process from state C25 to C26 represents a depressurization process by the electromagnetic expansion valve 31. The process from state C26 to C21 represents the evaporation process by the indoor heat exchanger 4. In FIG. 14, the isotherm of the outdoor temperature T13 is shown.

As shown in FIG. 14, the temperature of the state C23 in the condensation process is the temperature T12 detected by the temperature sensor 12. Since the temperature of the single refrigerant R290 in the gas-liquid two-phase state is almost constant, the temperature of the state C24 in the condensation process (the temperature of the saturated liquid) on the saturated liquid line is the same temperature T12 as the state C23. The temperature of the state C25 is the temperature T19 detected by the temperature sensor 19.

In the following, the temperature ratio ΔT is the ratio of the temperature difference Δ2 between the temperature T12 and the temperature T19 to the temperature difference ΔT1 between the temperature T12 (first temperature) and the outdoor temperature T13. That is, ΔT = ΔT2 / ΔT1. Further, the enthalpy ratio Δh is set to the enthalpy h12 (first enthalpy) in the saturated liquid state C24 and the enthalpy h19 (third) in the state C25 and the enthalpy h24 with respect to the enthalpy difference Δh1 of the liquid refrigerant enthalpy h13 (second enthalpy) at the outdoor temperature T13. It is assumed that the ratio of the enthalpy difference Δh2 of 3 enthalpies). That is, Δh = Δh2 / Δh1.

When the operating environment of the refrigeration cycle apparatus changes, both the temperature differences ΔT1 and ΔT2 often change at the same rate. When both the denominator and the numerator of the temperature ratio ΔT change at the same rate, the temperature ratio ΔT hardly changes. The same applies to the enthalpy ratio.

In the refrigeration cycle apparatus according to the modified example of the second embodiment, the condition of T11-T19 ≦ Tdr2 in S201 of FIG. 13 is replaced with the condition of ΔT ≧ Rr1 or Δh ≧ Rr2 using the reference ratios Rr1 and Rr2. .. By comparing the temperature ratio or enthalpy ratio with a predetermined reference ratio (for example, 0.8), the heat exchange amount in the internal heat exchanger 51 is smaller than the reference amount regardless of the operating environment of the refrigeration cycle apparatus. It is possible to maintain the determination accuracy of whether or not. The reference ratios Rr1 and Rr2 are appropriately calculated by an actual machine experiment or a simulation. The reference ratios Rr1 and Rr2 may be the same.

As described above, according to the refrigeration cycle apparatus according to the second embodiment and the first modification, even when the heat storage material cannot be used for heating in the cooling operation, the degree of superheat of the refrigerant sucked into the compressor by the internal heat exchanger can be determined. Can be raised. As a result, it is possible to further suppress the deterioration of the performance of the refrigeration cycle apparatus as compared with the first embodiment while reducing the GWP.

Embodiment 3.
In the second embodiment, when the cooling operation is performed, the degree of superheat of the refrigerant sucked into the compressor is further increased among the heating of the refrigerant by the internal heat exchanger and the heating of the refrigerant by the heat storage material. The case where the person who can do it is selected has been explained. In the third embodiment, among the heating of the refrigerant by the internal heat exchanger and the heating of the refrigerant by the heat storage material, the one capable of further increasing the degree of superheat of the refrigerant sucked into the compressor is selected even in the heating operation. The case where it is done will be described.

FIG. 15 is a functional block diagram showing the configuration of the refrigeration cycle device 300 according to the third embodiment. The refrigeration cycle device 300 is configured such that the electromagnetic expansion valve 32 (second decompression device) and the temperature sensor 19A are added to the refrigeration cycle device 200 of FIG. 12, and the control device 92 is replaced with 93. Other than these, the description is the same, so the description will not be repeated.

As shown in FIG. 15, the electromagnetic expansion valve 32 is connected between the outdoor heat exchanger 3 and the internal heat exchanger 51. The control device 93 acquires the temperature T19A of the refrigerant flowing between the electromagnetic expansion valve 32 and the internal heat exchanger 51 from the temperature sensor 19A. The control device 93 controls the opening degree of the electromagnetic expansion valve 31 by fully opening the electromagnetic expansion valve 32 that does not reduce the pressure of the refrigerant in the cooling operation. The control device 93 controls the opening degree of the electromagnetic expansion valve 32 by fully opening the electromagnetic expansion valve 31 that does not reduce the pressure of the refrigerant in the heating operation.

FIG. 16 is a flowchart showing a flow of processing for the flow path switching unit 20 performed in the heating operation by the control device 93 of FIG. The flowchart shown in FIG. 16 is a flowchart in which S201 in FIG. 13 is replaced with S301. In the cooling operation, the process shown in FIG. 13 is performed.

As shown in FIG. 16, the control device 93 satisfies the condition (specific condition) that the temperature T14 is equal to or higher than the reference temperature Tr1 and the difference between the temperatures T16 and T19A is equal to or lower than the reference value Tdr3 in S301. Determine whether or not to do so. The condition that the difference between the temperatures T16 and T19A is equal to or less than the reference value Tdr3 is a condition indicating that the amount of heat exchange in the internal heat exchanger 51 is smaller than the reference amount. The reference value Tdr3 can be appropriately calculated by an actual machine experiment or a simulation.

When the temperature T14 is smaller than the reference temperature Tr1 or the difference between the temperatures T16 and T19A is larger than the reference value Tdr3 (NO in S301), the control device 93 performs S102 in the same manner as in the first embodiment to perform processing. Return to the main routine. When the temperature T14 is equal to or higher than the reference temperature Tr1 and the difference between the temperatures T16 and T19A is equal to or lower than the reference value Tdr3 (YES in S301), the control device 93 performs S103 and processes as in the first embodiment. Is returned to the main routine.

In S301, the condition that the temperature T14 is equal to or higher than the reference temperature Tr1 or the difference between the temperatures T16 and T19A is equal to or lower than the reference value Tdr3 may be determined. Further, in S301, the condition relating to the temperature ratio or the condition relating to the enthalpy ratio may be used as in the modified example of the second embodiment. In that case, the temperatures T12, T13, and T19 of the modified example of the second embodiment are replaced with the temperatures T17, T18, and T19A, respectively.

Modification example of the third embodiment 1.
In the first modification of the third embodiment, a configuration in which the pressure loss is reduced by connecting the check valve in parallel to each of the two electromagnetic expansion valves will be described.

FIG. 17 is a functional block diagram showing the configuration of the refrigeration cycle device 300A according to the first modification of the third embodiment. The structure of the refrigeration cycle device 300A is such that the check valves 61 and 62 are added to the refrigeration cycle device 300 of FIG. 15, and the control device 93 is replaced with 93A. Other than these, the description is the same, so the description will not be repeated.

As shown in FIG. 17, the check valve 61 is connected in parallel to the electromagnetic expansion valve 31 between the indoor heat exchanger 4 and the internal heat exchanger 51. The forward direction of the check valve 61 is the direction from the indoor heat exchanger 4 to the internal heat exchanger 51. The pressure loss when the refrigerant flows in the forward direction of the check valve 61 is smaller than the pressure loss when the refrigerant flows through the fully open electromagnetic expansion valve 31.

The check valve 62 is connected in parallel to the electromagnetic expansion valve 32 between the outdoor heat exchanger 3 and the internal heat exchanger 51. The forward direction of the check valve 62 is the direction from the outdoor heat exchanger 3 to the internal heat exchanger 51. The pressure loss when the refrigerant flows in the forward direction of the check valve 62 is smaller than the pressure loss when the refrigerant flows through the fully open electromagnetic expansion valve 32.

In the cooling operation, the control device 93A closes the electromagnetic expansion valve 32. In the cooling operation, the refrigerant from the outdoor heat exchanger 3 passes through the check valve 62, the internal heat exchanger 51, and the electromagnetic expansion valve 31 in this order. In the heating operation, the control device 93A closes the electromagnetic expansion valve 31. In the heating operation, the refrigerant from the indoor heat exchanger 4 passes through the check valve 61, the internal heat exchanger 51, and the electromagnetic expansion valve 32 in this order.

In the refrigerating cycle device 300A, the electromagnetic expansion valve that does not reduce the pressure of the refrigerant is closed, and a flow path is formed so that the refrigerant passes through the check valve having a smaller pressure loss, so that the refrigerating cycle device 300A is more than the refrigerating cycle device 300. It is possible to suppress performance deterioration due to pressure loss of the electromagnetic expansion valve. The user can appropriately select the refrigeration cycle devices 300 and 300A in consideration of the cost increase and the performance improvement due to the addition of the two check valves.

Modification example of the third embodiment 2.
In the third embodiment and the first modification, in the internal heat exchanger 51, heat exchange is performed between the high-pressure side refrigerant from the heat exchanger functioning as a condenser and the low-pressure side refrigerant from the flow path FP1. The case was explained. In the second modification of the third embodiment, the case where the high-pressure side refrigerant is the refrigerant discharged from the compressor 1 will be described.

FIG. 18 is a functional block diagram showing the configuration of the refrigeration cycle device 300B according to the second modification of the third embodiment. In the configuration of the refrigeration cycle device 300B, the internal heat exchanger 51B and the temperature sensor 19B are added in place of the internal heat exchanger 51 and the temperature sensor 19 in FIG. 12, the control device 92 is replaced with 93B, and the temperature sensor 11B and the electromagnetic wave are installed. The expansion valve 32B is added. Other than these, the description is the same, so the description will not be repeated.

As shown in FIG. 18, the internal heat exchanger 51B is connected between the flow path FP1 and the suction port Ps of the compressor 1. The internal heat exchanger 51B and the electromagnetic expansion valve 32B are connected in series in this order between the discharge port Pd of the compressor 1 and the flow path between the outdoor heat exchanger 3 and the electromagnetic expansion valve 31. In the internal heat exchanger 51B, heat exchange is performed between the high-pressure side refrigerant discharged from the compressor 1 and the low-pressure side refrigerant from the flow path FP1, and the low-pressure side refrigerant is heated by the high-pressure side refrigerant.

The control device 93B controls the opening degree of the electromagnetic expansion valve 32B. The control device 93B acquires the temperature T19B of the refrigerant flowing between the internal heat exchanger 51B and the electromagnetic expansion valve 32B from the temperature sensor 19B. The control device 93B acquires the temperature T11B of the refrigerant passing through the discharge port Pd of the compressor 1 from the temperature sensor 11B.

The flow of processing for the flow path switching unit 20 performed by the control device 93B in the cooling operation and the heating operation has a configuration in which the temperatures T11, T19 and the reference value Tdr2 in FIG. 13 are replaced with the temperatures T11B, T19B and the reference value Tdr4, respectively. Is. The reference value Tdr4 is appropriately determined by an actual machine experiment or a simulation. The reference value Tdr4 may be the same as the reference value Tdr2.

As described above, according to the refrigeration cycle apparatus according to the third embodiment and the first and second modifications, even when the heat storage material cannot be used for heating in both the cooling operation and the heating operation, the internal heat exchanger is used to convert the compressor into a compressor. The degree of superheat of the sucked refrigerant can be increased. As a result, it is possible to further suppress the deterioration of the performance of the refrigeration cycle apparatus as compared with the second embodiment while reducing the GWP.

It is also planned that the embodiments disclosed this time will be appropriately combined and implemented within a consistent range. It should be considered that each embodiment disclosed this time is exemplary in all respects and is not restrictive. The scope of the present invention is shown by the claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the claims.

1 Compressor, 2 Four-way valve, 3 Outdoor heat exchanger, 4 Indoor heat exchanger, 10, 10A, 10B Heat storage material, 11-19, 11B, 19A, 19B Temperature sensor, 20, 20A Flow path switching unit, 21, 22 Electromagnetic on-off valve, 21A, 22A, 31, 32, 32B Electromagnetic expansion valve, 41 Outdoor fan, 42 Indoor fan, 51, 51B Internal heat exchanger, 61, 62 Check valve, 90, 92, 93, 93A, 93B Control device, 100, 200, 300, 300A, 300B refrigeration cycle device, 110 outdoor unit, 120 indoor unit, FP1, FP2 flow path, Pd discharge port, Ps suction port.

Claims (10)

A refrigeration cycle device in which the refrigerant containing R290 circulates in the first circulation direction of the compressor, the first heat exchanger, the first decompression device, and the second heat exchanger.
A heat storage material that is placed around the compressor and receives heat from the compressor,
A first flow path switching unit capable of forming a first flow path and a second flow path for guiding the refrigerant from the second heat exchanger to the compressor is provided.
When the first flow path is formed, the refrigerant flowing out of the first flow path reaches the compressor without passing through the heat storage material.
When the second flow path is formed, the refrigerant flowing out of the second flow path reaches the compressor via the heat storage material, which is a refrigeration cycle device. A control device for controlling the first flow path switching unit is further provided.
The control device is
When a specific condition is satisfied, the first flow path switching unit is controlled to close the first flow path and open the second flow path.
When the specific condition is not satisfied, the first flow path switching unit is controlled to open the first flow path and close the second flow path.
The refrigeration cycle apparatus according to claim 1, wherein the specific condition includes a condition that the temperature of the heat storage material is higher than the reference temperature. A third heat exchanger in which heat exchange is performed between the refrigerant from the first heat exchanger and the refrigerant from the first flow path.
A control device for controlling the first flow path switching unit is further provided.
The control device is
When the specific condition is satisfied, the first flow is such that the amount of the refrigerant per unit time passing through the second flow path is larger than the amount of the refrigerant per unit time passing through the first flow path. Control the road switching part,
When the specific condition is not satisfied, the first amount of the refrigerant per unit time passing through the first flow path is larger than the amount of the refrigerant per unit time passing through the second flow path. Control the flow path switching part,
The refrigeration cycle apparatus according to claim 1, wherein the specific condition includes a condition indicating that the amount of heat exchange in the third heat exchanger is smaller than the reference amount. The conditions indicating that the heat exchange amount in the third heat exchanger is smaller than the reference amount are the temperature of the refrigerant flowing between the first heat exchanger and the third heat exchanger and the third heat exchanger. The refrigeration cycle apparatus according to claim 3, further comprising a condition that the difference from the temperature of the refrigerant flowing between the first depressurizers is smaller than the reference value. The first heat exchanger is arranged outdoors and
The condition indicating that the amount of heat exchanged in the third heat exchanger is smaller than the reference amount is the first temperature with respect to the difference between the first temperature and the outdoor temperature of the saturated liquid of the refrigerant passing through the first heat exchanger. The refrigeration cycle apparatus according to claim 3, wherein the ratio of the temperature difference of the refrigerant flowing out from the third heat exchanger is larger than the reference ratio. The first heat exchanger is arranged outdoors and
The condition indicating that the amount of heat exchanged in the third heat exchanger is smaller than the reference amount is the first enthalpy of the saturated liquid of the refrigerant passing through the first heat exchanger and the first enthalpy of the liquid liquid at the outdoor temperature. 2. The refrigeration cycle apparatus according to claim 3, wherein the ratio of the difference between the first enthalpy and the third enthalpy of the refrigerant flowing out of the third heat exchanger to the difference in enthalpy is larger than the reference ratio. The refrigeration cycle apparatus according to any one of claims 3 to 6, wherein the specific condition further includes a condition that the temperature of the heat storage material is higher than the reference temperature. A second flow path switching unit that switches the circulation direction of the refrigerant between the first circulation direction and the second circulation direction opposite to the first circulation direction.
Further, a second decompression device connected between the first heat exchanger and the third heat exchanger is provided.
When the circulation direction of the refrigerant is the first circulation direction, the control device fully opens the opening degree of the second decompression device.
The refrigeration cycle device according to claim 3, wherein when the circulation direction of the refrigerant is the second circulation direction, the control device fully opens the first decompression device. A second flow path switching unit that switches the circulation direction of the refrigerant between the first circulation direction and the second circulation direction opposite to the first circulation direction.
A second decompression device connected between the first heat exchanger and the third heat exchanger,
A first check valve connected in parallel to the first decompression device between the second heat exchanger and the third heat exchanger.
A second check valve connected in parallel to the second decompression device between the first heat exchanger and the third heat exchanger is further provided.
The forward direction of the first check valve is the direction from the second heat exchanger to the third heat exchanger.
The forward direction of the second check valve is the direction from the first heat exchanger to the third heat exchanger.
When the circulation direction of the refrigerant is the first circulation direction, the control device closes the second decompression device.
The refrigeration cycle device according to claim 3, wherein when the circulation direction of the refrigerant is the second circulation direction, the control device closes the first decompression device. A third heat exchanger in which heat exchange is performed between the refrigerant from the compressor and the refrigerant from the first flow path.
A second decompression device connected between the third heat exchanger and the flow path between the first decompression device and the first heat exchanger.
A control device for controlling the first flow path switching unit is further provided.
The control device is
When a specific condition is satisfied, the amount of the refrigerant per unit time passing through the first flow path is reduced and the second flow path is opened.
When the specific condition is not satisfied, the amount of the refrigerant per unit time passing through the first flow path is increased and the second flow path is closed.
The refrigeration cycle apparatus according to claim 1, wherein the specific condition includes a condition indicating that the amount of heat exchange in the third heat exchanger is smaller than the reference amount.

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