JPWO2020026374A1 - Air conditioner - Google Patents

Abstract

The air conditioner is arranged in a refrigerating cycle circuit in which a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are sequentially connected by a refrigerant pipe, and a refrigerant pipe between the outdoor heat exchanger and the expansion valve. When a cooling device that cools the refrigerant flowing through the refrigerant piping by an external heat source and an outdoor heat exchanger functioning as a condenser for the refrigeration cycle circuit to perform cooling operation, and the refrigerant is passed from the condenser to the expansion valve, A control device configured to change the cooling capacity of the cooling device according to conditions reflecting the refrigerant state is provided.

Description

The present invention relates to an air conditioner including a cooling device arranged in a refrigerant pipe between an outdoor heat exchanger and an expansion valve.

Conventionally, in an air conditioner, in order to improve the efficiency of a refrigeration cycle circuit, the refrigerant at the outlet of the condenser is controlled to have an appropriate degree of supercooling. In order to obtain an appropriate degree of supercooling of the refrigerant at the outlet of the condenser, a method of adjusting the output of the compressor, the blower, the expansion valve and the like is practically implemented.

In Patent Documents 1 to 3, an auxiliary heat exchanger using a Peltier element is provided in the refrigerant pipe between the condenser and the expansion valve as a means for adjusting the refrigerant at the outlet of the condenser to an appropriate degree of supercooling. .. In particular, in Patent Document 3, the heat from the heat radiating surface of the Peltier element is secondarily used in the injection circuit of the compressor.

Japanese Unexamined Patent Publication No. 10-35270 Japanese Unexamined Patent Publication No. 10-38409 Japanese Unexamined Patent Publication No. 2011-202939

However, in the case of the techniques of Patent Documents 1 to 3, it is an object to improve the capacity and efficiency of the refrigeration cycle circuit. Therefore, electric power is always supplied to the Peltier element. Therefore, there is a problem that the power consumption becomes large and the energy consumption loss becomes large.

On the other hand, ensuring the degree of supercooling is a necessary condition not only in terms of performance but also in terms of quality. That is, when the degree of supercooling is appropriately controlled, the refrigerant in front of the expansion valve located at the rear stage of the condenser is in the liquid phase state. However, when the degree of supercooling is not sufficient, the refrigerant in front of the expansion valve located at the rear stage of the condenser becomes a gas-liquid two-phase state. Then, when the refrigerant in the gas-liquid two-phase state passes through the expansion valve, there is a problem that an unpleasant flow noise of the refrigerant is likely to be generated. In particular, when the cooling operation is performed when the outside air temperature is low as in the intermediate period, or when the distance between the indoor unit and the outdoor unit is long and a large pressure loss occurs in the refrigerant pipe from the outlet of the compressor to the expansion valve. , It is difficult to obtain a sufficient degree of supercooling only by adjusting the output of the compressor, blower, expansion valve, etc., and the unpleasant flow noise of the refrigerant has been a quality issue.

The present invention is for solving the above problems, and provides an air conditioner capable of appropriately suppressing the energy consumption of the cooling device and suppressing the flow noise of the refrigerant when flowing through the expansion valve to improve the quality. The purpose is to provide.

The air conditioner according to the present invention is a refrigeration cycle circuit in which a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are sequentially connected by a refrigerant pipe, and between the outdoor heat exchanger and the expansion valve. A cooling device arranged in the refrigerant pipe and cooling the refrigerant flowing through the refrigerant pipe by an external heat source and the outdoor heat exchanger functioning as a condenser for the refrigerating cycle circuit to perform cooling operation are performed from the condenser. It is provided with a control device configured to change the cooling capacity of the cooling device according to conditions reflecting the state of the refrigerant when the refrigerant is circulated through the expansion valve.

According to the air conditioner according to the present invention, the air conditioner causes the outdoor heat exchanger to function as a condenser for the cooling operation of the refrigeration cycle circuit, and the refrigerant is circulated from the condenser to the expansion valve. A control device configured to change the cooling capacity of the cooling device according to conditions reflecting the refrigerant state is provided. Therefore, the energy consumption of the cooling device can be appropriately suppressed, and the flow noise of the refrigerant when flowing through the expansion valve can be suppressed to improve the quality.

It is a refrigerant circuit diagram which shows the air conditioner which concerns on Embodiment 1 of this invention. It is a block diagram which shows the control apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the control which adjusts the output of a cooling apparatus according to the outside air temperature which concerns on Embodiment 1 of this invention. It is a figure which shows the relationship between the outside air temperature and the output of a cooling device which concerns on Embodiment 1 of this invention. It is a flowchart which shows the control which adjusts the output of a cooling apparatus according to the degree of supercooling which concerns on Embodiment 2 of this invention. It is a figure which shows the relationship between the degree of supercooling which concerns on Embodiment 2 of this invention, and the output of a cooling apparatus. It is a flowchart which shows the control which adjusts the output of a cooling apparatus according to the outside air temperature and the degree of supercooling which concerns on Embodiment 3 of this invention. It is a figure which shows the relationship between the outside air temperature and the degree of supercooling which concerns on Embodiment 3 of this invention, and the output of a cooling apparatus. It is a refrigerant circuit diagram which shows the air conditioner which concerns on Embodiment 4 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each figure, those having the same reference numerals are the same or equivalent thereof, and they are common in the entire text of the specification. Further, in the cross-sectional view, hatching is omitted as appropriate in view of visibility. Furthermore, the forms of the components shown in the full text of the specification are merely examples and are not limited to these descriptions.

Embodiment 1.
<Structure of air conditioner 100>
FIG. 1 is a refrigerant circuit diagram showing an air conditioner 100 according to a first embodiment of the present invention. The air conditioner 100 shown in FIG. 1 has a configuration in which the outdoor unit 1 and the indoor unit 10 are connected by a gas refrigerant pipe and a liquid refrigerant pipe. The air conditioner 100 includes a refrigeration cycle circuit in which the compressor 2, the outdoor heat exchanger 4, the expansion valve 12, and the indoor heat exchanger 13 are sequentially connected by a refrigerant pipe.

The outdoor unit 1 includes a compressor 2, a four-way valve 3, an outdoor heat exchanger 4, and a blower 5.

The compressor 2 compresses and discharges the sucked refrigerant. The compressor 2 may arbitrarily change the operating frequency by, for example, an inverter circuit or the like, and change the capacity for delivering the refrigerant per unit time of the compressor 2.

The four-way valve 3 is a valve that switches the flow of the refrigerant depending on, for example, the cooling operation and the heating operation.

The outdoor heat exchanger 4 exchanges heat between the refrigerant and the outdoor air. The outdoor heat exchanger 4 functions as a condenser during the cooling operation to condense and liquefy the refrigerant. The outdoor heat exchanger 4 functions as an evaporator during the heating operation to evaporate and vaporize the refrigerant.

The blower 5 blows outside air to the outdoor heat exchanger 4 in order to promote heat exchange of the outdoor heat exchanger 4.

The indoor unit 10 includes an expansion valve 12, an indoor heat exchanger 13, and a blower 14.

The expansion valve 12 is a flow rate control valve and decompresses the refrigerant to expand it. When the expansion valve 12 is composed of, for example, an electronic expansion valve, the opening degree can be adjusted based on the instruction of the control device 6.

The indoor heat exchanger 13 exchanges heat between, for example, air to be air-conditioned and a refrigerant. The indoor heat exchanger 13 functions as an evaporator during the cooling operation to evaporate and vaporize the refrigerant. The indoor heat exchanger 13 functions as a condenser during the heating operation to condense and liquefy the refrigerant.

The blower 14 blows indoor air to the indoor heat exchanger 13 in order to promote heat exchange of the indoor heat exchanger 13.

By configuring the air conditioner 100 as described above, the flow of the refrigerant can be switched by the four-way valve 3 of the outdoor unit 1 to realize a cooling operation or a heating operation.

The air conditioner 100 includes a refrigerant pressure sensor 7, a refrigerant temperature sensor 8, and an outside air temperature sensor 9. The refrigerant pressure sensor 7 detects the high pressure of the refrigerant discharged from the compressor 2. The refrigerant temperature sensor 8 detects the temperature of the refrigerant flowing out from the outlet of the outdoor heat exchanger 4. That is, when the outdoor heat exchanger 4 functions as a condenser for the refrigeration cycle circuit to operate in cooling, the refrigerant temperature sensor 8 detects the temperature of the refrigerant flowing through the refrigerant pipe at the outlet of the condenser. .. The outside air temperature sensor 9 detects the temperature of the outside air around the outdoor unit 1 with which the outdoor heat exchanger 4 exchanges heat.

The air conditioner 100 includes a cooling device 11. The cooling device 11 is provided in the refrigerant pipe between the outdoor heat exchanger 4 functioning as a condenser and the expansion valve 12, and cools the refrigerant flowing in the refrigerant pipe by an external heat source other than the refrigeration cycle circuit. The cooling device 11 has a structure in which, for example, a plurality of Peltier elements are used and the endothermic surface of the Peltier elements is brought into close contact with the refrigerant pipe. The cooling device 11 is supplied with power by a command from the control device 6 by a required number of the plurality of Peltier elements, and the auxiliary cooling capacity can be changed. The cooling device 11 does not have to be a Peltier element as long as it cools the refrigerant flowing in the refrigerant pipe by an external heat source.

<Control device 6>
FIG. 2 is a block diagram showing a control device 6 according to the first embodiment of the present invention. The air conditioner 100 includes a control device 6. The control device 6 is responsible for controlling the operation of the actuator including the compressor 2, the blower 5, the expansion valve 12, and the cooling device 11.

As shown in FIG. 2, the control device 6 is a processing circuit including a microcomputer including a memory such as a CPU, ROM and RAM, and an input / output device such as an I / O port.

The control device 6 calculates the degree of supercooling at the outlet of the outdoor heat exchanger 4 that functions as a condenser from the refrigerant pressure and the refrigerant temperature detected by the refrigerant pressure sensor 7 and the refrigerant temperature sensor 8, and sets the target value at a predetermined value. Drive the actuator to match. Under conditions where it is difficult to obtain a degree of supercooling, such as in cooling operation at low outside temperatures, the degree of supercooling may not reach the target value within the drive range of the actuator. In this case, the auxiliary cooling by the cooling device 11 functions effectively.

The control device 6 supplies electric power to the cooling device 11 according to the outside air temperature T1 detected by the outside air temperature sensor 9. That is, when the cooling device 11 causes the outdoor heat exchanger 4 to function as a condenser for the refrigeration cycle circuit to perform cooling operation, and the refrigerant is circulated from the condenser to the expansion valve 12, here, it is based on the outside air temperature T1. The cooling capacity of the cooling device 11 is changed according to the conditions reflecting the refrigerant state. In particular, the control device 6 switches the magnitude of the output P1 of the cooling capacity of the cooling device 11 according to the condition reflecting the refrigerant state which is the outside air temperature T1 here. Specifically, the control device 6 cools the predetermined outside air temperature determination threshold value 1 and determination threshold value 2 and the cooling device 11 so that the cooling capacity increases as the outside air temperature T1 decreases as the power supply to the cooling device 11. Issue a command according to the relationship with the output P1 of the ability.

As a result, the power supply to the cooling device 11 is consumed as much as necessary, the liquid phase state of the refrigerant in front of the expansion valve 12 is ensured, and the quality defect of the unpleasant flow sound of the refrigerant can be avoided. In addition, a margin is created in the drive range of the actuator, and the evaporation temperature and the discharge temperature, which are the overall control targets other than the supercooling degree, can be quickly stabilized.

<Control 1 of cooling device 11>
FIG. 3 is a flowchart showing a control 1 for adjusting the cooling device output P1 according to the outside air temperature T1 according to the first embodiment of the present invention. FIG. 4 is a diagram showing the relationship between the outside air temperature T1 and the cooling device output P1 according to the first embodiment of the present invention. The control routine shown in FIG. 3 is repeatedly executed at predetermined intervals.

As shown in FIG. 3, when this routine is started, the control device 6 determines in step S1 whether or not the outside air temperature T1 detected by the outside air temperature sensor 9 is lower than the determination threshold value 1. If the outside air temperature T1 is lower than the determination threshold value 1, the process proceeds to step S2. If the outside air temperature T1 is equal to or higher than the determination threshold value 1, the process proceeds to step S3.

In step S2, the control device 6 outputs the output P1 of the cooling device 11 to a large degree. As a result, even if the outside air temperature T1 is significantly low and the heat exchange in the outdoor heat exchanger 4 is not sufficient, the liquid phase state of the refrigerant in front of the expansion valve 12 can be ensured. After the processing of this step, this routine is temporarily stopped.

In step S3, the control device 6 determines whether or not the outside air temperature T1 detected by the outside air temperature sensor 9 is lower than the determination threshold value 2. As shown in FIG. 4, the determination threshold value 2 is set to a higher temperature than the determination threshold value 1. If the outside air temperature T1 is lower than the determination threshold value 2, the process proceeds to step S4. If the outside air temperature T1 is equal to or higher than the determination threshold value 2, the process proceeds to step S5.

In step S4, the control device 6 outputs the output P1 of the cooling device 11 to a small degree. As a result, even if the outside air temperature T1 is low to some extent and the heat exchange in the outdoor heat exchanger 4 is not satisfactory, the liquid phase state of the refrigerant in front of the expansion valve 12 can be ensured. Therefore, it is possible to consume as much power as necessary for supplying power to the cooling device 11. After the processing of this step, this routine is temporarily stopped.

In step S5, the control device 6 does not output the output P1 of the cooling device 11 to a degree of 0, that is, does not output. As a result, when the outside air temperature T1 can be secured and the heat exchange in the outdoor heat exchanger 4 is satisfactory, the liquid phase state of the refrigerant in front of the expansion valve 12 can be secured even without cooling by the cooling device 11. .. Therefore, the power supply to the cooling device 11 is unnecessary and can be reduced. After the processing of this step, this routine is temporarily stopped.

As shown in FIG. 4, the relationship between the outside air temperature T1 and the cooling device output P1 becomes a correlation in which the lower the outside air temperature T1 detected by the outside air temperature sensor 9, the larger the cooling capacity of the cooling device 11 is switched to. There is. As a result, the power supply to the cooling device 11 is consumed as much as necessary, the liquid phase state of the refrigerant in front of the expansion valve 12 is secured, and the quality defect of the unpleasant flow sound of the refrigerant can be avoided.

<Effect of Embodiment 1>
According to the first embodiment, the air conditioner 100 includes a refrigeration cycle circuit in which the compressor 2, the outdoor heat exchanger 4, the expansion valve 12, and the indoor heat exchanger 13 are sequentially connected by a refrigerant pipe. The air conditioner 100 is arranged in the refrigerant pipe between the outdoor heat exchanger 4 and the expansion valve 12, and includes a cooling device 11 that cools the refrigerant flowing through the refrigerant pipe by an external heat source. In the air conditioner 100, when the outdoor heat exchanger 4 functions as a condenser for the refrigeration cycle circuit to perform the cooling operation and the refrigerant is circulated from the condenser to the expansion valve 12, the air conditioner 100 responds to the conditions reflecting the refrigerant state. A control device 6 configured to change the cooling capacity of the cooling device 11 is provided.

According to this configuration, the output of the cooling device 11 can be appropriately changed, and the energy consumption of the cooling device 11 can be appropriately suppressed. Further, even when the adjustment by the output of the components on the refrigeration cycle circuit such as the compressor 2, the blower 5, and the expansion valve 12 cannot cope with the situation, the cooling device 11 can secure a sufficient degree of supercooling. As a result, it is possible to prevent the generation of an unpleasant flow noise of the refrigerant due to the passage of the refrigerant in the gas-liquid two-phase state through the expansion valve 12. Further, the adjustment range of the degree of supercooling is expanded, and the state of the refrigerant at the inlet of the evaporator can be finely controlled. In this way, the energy consumption of the cooling device 11 can be appropriately suppressed, and the flow noise of the refrigerant when flowing through the expansion valve 12 is suppressed, so that the quality can be improved.

According to the first embodiment, the control device 6 is configured to switch the magnitude of the output of the cooling capacity of the cooling device 11 according to the conditions reflecting the refrigerant state.

According to this configuration, the output of the cooling device 11 is appropriately changed according to the conditions reflecting the refrigerant state, and the energy consumption of the cooling device 11 can be appropriately suppressed. Further, even if the adjustment by the output of the components on the refrigeration cycle circuit such as the compressor 2, the blower 5, and the expansion valve 12 cannot cope with the problem, the cooling device 11 is sufficient according to the condition reflecting the refrigerant state. The degree of supercooling can be secured.

According to the first embodiment, the air conditioner 100 includes an outside air temperature sensor 9 that detects the temperature of the outside air that the outdoor heat exchanger 4 exchanges heat with. The condition that reflects the refrigerant state is the outside air temperature T1 detected by the outside air temperature sensor 9.

According to this configuration, the output of the cooling device 11 is appropriately changed according to the outside air temperature T1 detected by the outside air temperature sensor 9, and the energy consumption of the cooling device 11 can be appropriately suppressed. Further, even if the adjustment by the output of the components on the refrigeration cycle circuit such as the compressor 2, the blower 5, and the expansion valve 12 cannot cope with the problem, the outside air temperature T1 detected by the outside air temperature sensor 9 by the cooling device 11 is set. A sufficient degree of supercooling can be ensured accordingly.

According to the first embodiment, the control device 6 is configured to switch the cooling capacity of the cooling device 11 to a larger output as the outside air temperature T1 detected by the outside air temperature sensor 9 is lower.

According to this configuration, the output of the cooling device 11 is appropriately changed to a larger cooling capacity as the outside air temperature T1 detected by the outside air temperature sensor 9 is lower, and the energy consumption of the cooling device 11 can be appropriately suppressed. Further, even when the adjustment by the output of the components on the refrigeration cycle circuit such as the compressor 2, the blower 5, and the expansion valve 12 cannot cope with the problem, the outside air temperature T1 detected by the outside air temperature sensor 9 by the cooling device 11 is set. The lower it is, the larger the cooling capacity is appropriately changed, and a sufficient degree of supercooling can be ensured.

According to the first embodiment, a Peltier element is used in the cooling device 11.

According to this configuration, the cooling device 11 of the Peltier element that uses electric power as an external heat source can appropriately suppress the power consumption of the cooling device 11 and suppress the flow noise of the refrigerant when flowing through the expansion valve 12, so that the quality is improved. Can be improved.

Embodiment 2.
In the second embodiment, the description of the same items as those in the above embodiment will be omitted, and only the characteristic portion thereof will be described.

The control device 6 supplies electric power to the cooling device 11 according to the degree of supercooling SC1 of the refrigerant in the refrigerating cycle circuit. That is, when the cooling device 11 causes the outdoor heat exchanger 4 to function as a condenser for the refrigeration cycle circuit to perform cooling operation, and the refrigerant is circulated from the condenser to the expansion valve 12, the supercooling degree SC1 is used here. The cooling capacity of the cooling device 11 is changed according to the conditions reflecting a certain refrigerant state. In particular, the control device 6 switches the magnitude of the output P1 of the cooling capacity of the cooling device 11 according to the condition reflecting the refrigerant state, which is the supercooling degree SC1 here. Specifically, the control device 6 follows the relationship between the predetermined supercooling degree determination threshold value 3 and determination threshold value 4 and the cooling capacity output P1 so that the cooling capacity increases as the amount of supercooling degree deficiency increases. Issue a command. As a result, the same effect as that of the above-described embodiment is obtained.

<Control 2 of cooling device 11>
FIG. 5 is a flowchart showing control 2 for adjusting the cooling device output P1 according to the degree of supercooling SC1 according to the second embodiment of the present invention. FIG. 6 is a diagram showing the relationship between the supercooling degree SC1 and the cooling device output P1 according to the second embodiment of the present invention. The control routine shown in FIG. 5 is repeatedly executed at predetermined intervals.

As shown in FIG. 5, when the control device 6 starts this routine, the refrigerant calculated from the temperature of the refrigerant detected by the refrigerant temperature sensor 8 and the pressure of the refrigerant detected by the refrigerant pressure sensor 7 in step S11. It is determined whether or not the degree of supercooling SC1 of is lower than the determination threshold value 3. If the degree of supercooling SC1 is lower than the determination threshold value 3, the process proceeds to step S12. If the supercooling degree SC1 is equal to or higher than the determination threshold value 3, the process proceeds to step S13.

In step S12, the control device 6 outputs the output P1 of the cooling device 11 to a large degree. As a result, the degree of supercooling SC1 is significantly low, and even if the heat exchange in the outdoor heat exchanger 4 is not sufficient, the liquid phase state of the refrigerant in front of the expansion valve 12 can be ensured. After the processing of this step, this routine is temporarily stopped.

In step S13, the control device 6 has the refrigerant supercooling degree SC1 calculated from the refrigerant temperature detected by the refrigerant temperature sensor 8 and the refrigerant pressure detected by the refrigerant pressure sensor 7 lower than the determination threshold value 4. Judge whether or not. As shown in FIG. 6, the determination threshold value 4 is a degree of supercooling higher than the determination threshold value 3. If the degree of supercooling SC1 is lower than the determination threshold value 4, the process proceeds to step S14. If the supercooling degree SC1 is equal to or higher than the determination threshold value 4, the process proceeds to step S15.

In step S14, the control device 6 outputs the output P1 of the cooling device 11 to a small degree. As a result, even if the supercooling degree SC1 is low to some extent and the heat exchange in the outdoor heat exchanger 4 is not satisfactory, the liquid phase state of the refrigerant in front of the expansion valve 12 can be secured. Therefore, it is possible to consume as much power as necessary for supplying power to the cooling device 11. After the processing of this step, this routine is temporarily stopped.

In step S15, the control device 6 does not output the output P1 of the cooling device 11 to a degree of 0, that is, does not output. As a result, when the supercooling degree SC1 can be secured and the heat exchange in the outdoor heat exchanger 4 is satisfactory, the liquid phase state of the refrigerant in front of the expansion valve 12 is secured even without cooling by the cooling device 11. it can. Therefore, the power supply to the cooling device 11 is unnecessary and can be reduced. After the processing of this step, this routine is temporarily stopped.

As shown in FIG. 6, the relationship between the degree of supercooling SC1 and the cooling device output P1 is calculated from the refrigerant excess detected by the refrigerant temperature sensor 8 and the refrigerant pressure detected by the refrigerant pressure sensor 7. The lower the degree of cooling SC1, the higher the correlation is such that the cooling capacity of the cooling device 11 is switched to the larger output P1. As a result, the power supply to the cooling device 11 is consumed as much as necessary, the liquid phase state of the refrigerant in front of the expansion valve 12 is secured, and the quality defect of the unpleasant flow sound of the refrigerant can be avoided.

<Effect of Embodiment 2>
According to the second embodiment, in the air conditioner 100, when the outdoor heat exchanger 4 functions as a condenser for the refrigerating cycle circuit to operate in cooling, the refrigerant flowing through the refrigerant pipe at the outlet of the condenser The refrigerant temperature sensor 8 for detecting the temperature of the above is provided. The air conditioner 100 includes a refrigerant pressure sensor 7 that detects the pressure of the refrigerant discharged from the compressor 2. The condition that reflects the refrigerant state is the degree of refrigerant supercooling SC1 calculated from the temperature of the refrigerant detected by the refrigerant temperature sensor 8 and the pressure of the refrigerant detected by the refrigerant pressure sensor 7.

According to this configuration, the output of the cooling device 11 is appropriately changed according to the degree of supercooling SC1 of the refrigerant, and the energy consumption of the cooling device 11 can be appropriately suppressed. Further, even if the adjustment by the output of the components on the refrigeration cycle circuit such as the compressor 2, the blower 5, and the expansion valve 12 cannot cope with the problem, the cooling device 11 is sufficient according to the supercooling degree SC1 of the refrigerant. The degree of supercooling can be secured.

According to the second embodiment, the control device 6 is cooled as the degree of cooling SC1 of the refrigerant calculated from the temperature of the refrigerant detected by the refrigerant temperature sensor 8 and the pressure of the refrigerant detected by the refrigerant pressure sensor 7 is lower. It is configured to switch the cooling capacity of the device 11 to a large output.

According to this configuration, the output of the cooling device 11 is appropriately changed to a larger cooling capacity as the degree of supercooling SC1 of the refrigerant is lower, and the energy consumption of the cooling device 11 can be appropriately suppressed. Further, even if the adjustment by the output of the components on the refrigeration cycle circuit such as the compressor 2, the blower 5, and the expansion valve 12 cannot cope with the problem, the lower the supercooling degree SC1 of the refrigerant by the cooling device 11, the greater the cooling. Appropriately changed to capacity, sufficient supercooling degree can be secured.

Embodiment 3.
In the third embodiment, the description of the same matters as those in the above embodiment will be omitted, and only the characteristic portion thereof will be described.

The control device 6 supplies electric power to the cooling device 11 when the outside air temperature T1 is lower than a predetermined determination threshold value 5, for example, 10 ° C. Alternatively, power is supplied to the cooling device 11 when the degree of supercooling SC1 is lower than a predetermined determination threshold value 6, for example, 3 ° C. That is, the control device 6 switches the cooling capacity of the cooling device 11 between the output state and the stopped state according to the conditions reflecting the outside air temperature T1 or the refrigerant state having the supercooling degree SC1. In this case, the liquid phase state of the refrigerant in front of the expansion valve 12 can be ensured, the quality defect of the unpleasant flow noise of the refrigerant can be avoided, and the control can be easily performed. Further, the power supply to the cooling device 11 is limited to the case where the cooling assistance is required, and the power consumption is smaller than that in the case where the power is always energized.

<Control 3 of cooling device 11>
FIG. 7 is a flowchart showing a control 3 for adjusting the cooling device output P1 according to the outside air temperature T1 and the supercooling degree SC1 according to the third embodiment of the present invention. FIG. 8 is a diagram showing the relationship between the outside air temperature T1 and the supercooling degree SC1 and the cooling device output P1 according to the third embodiment of the present invention.

As shown in FIG. 7, when this routine is started, the control device 6 determines in step S21 whether or not the outside air temperature T1 detected by the outside air temperature sensor 9 is lower than the determination threshold value 5. If the outside air temperature T1 is lower than the determination threshold value 5, the process proceeds to step S22. If the outside air temperature T1 is equal to or higher than the determination threshold value 5, the process proceeds to step S23.

The control device 6 outputs the cooling device 11 in step S22. As a result, when the outside air temperature T1 is low and the heat exchange in the outdoor heat exchanger 4 is insufficient, the liquid phase state of the refrigerant in front of the expansion valve 12 can be ensured. After the processing of this step, this routine is temporarily stopped.

In step S23, the control device 6 calculates the degree of refrigerant supercooling SC1 from the temperature of the refrigerant detected by the refrigerant temperature sensor 8 and the pressure of the refrigerant detected by the refrigerant pressure sensor 7. After the processing of this step, the process proceeds to step S24.

In step S24, the control device 6 determines whether or not the supercooling degree SC1 calculated in step S23 is lower than the determination threshold value 6. If the degree of supercooling SC1 is lower than the determination threshold value 6, the process proceeds to step S22. If the supercooling degree SC1 is equal to or higher than the determination threshold value 6, the process proceeds to step S25.

When the control device 6 shifts from step S24 to step S22, the control device 6 outputs the cooling device 11. As a result, when the degree of supercooling SC1 is low and the heat exchange in the outdoor heat exchanger 4 is insufficient, the liquid phase state of the refrigerant in front of the expansion valve 12 can be ensured. After the processing of this step, this routine is temporarily stopped.

The control device 6 does not output the cooling device 11 in step S25. As a result, when the supercooling degree SC1 can be secured and the heat exchange in the outdoor heat exchanger 4 is satisfactory, the liquid phase state of the refrigerant in front of the expansion valve 12 is secured even without cooling by the cooling device 11. it can. Therefore, the power supply to the cooling device 11 is unnecessary and can be reduced. After the processing of this step, this routine is temporarily stopped.

As shown in FIG. 8, the relationship between the outside air temperature T1 and the supercooling degree SC1 and the cooling device output P1 is a correlation in which the cooling capacity of the cooling device 11 is exhibited when the outside air temperature T1 or the supercooling degree SC1 is low. It has become. Here, the threshold value is set to the extent that the determination threshold value 6 of the supercooling degree SC1 is more reflected in the supercooling degree than the determination threshold value 5 of the outside air temperature T1. However, it is not limited to this. The threshold value may be set to the extent that the determination threshold value 5 of the outside air temperature T1 is more reflected in the supercooling degree than the determination threshold value 6 of the supercooling degree SC1. Further, as the outside air temperature T1 or the supercooling degree SC1 of the refrigerant is lower, the correlation may be such that the cooling capacity of the cooling device 11 is switched to a larger output. As a result, the power supply to the cooling device 11 is consumed as much as necessary, the liquid phase state of the refrigerant in front of the expansion valve 12 is secured, and the quality defect of the unpleasant flow sound of the refrigerant can be avoided.

<Effect of Embodiment 3>
According to the third embodiment, the control device 6 is configured to switch the cooling capacity of the cooling device 11 between the output state and the stopped state depending on the conditions reflecting the refrigerant state.

According to this configuration, the output of the cooling device 11 can be appropriately switched between the output state and the stopped state depending on the condition reflecting the refrigerant state, and the energy consumption of the cooling device 11 can be appropriately suppressed. Further, even if the adjustment of the output of the components on the refrigeration cycle circuit such as the compressor 2, the blower 5, and the expansion valve 12 cannot cope with the problem, the cooling device 11 stops the output state and stops depending on the condition reflecting the refrigerant state. It can be appropriately switched to the state and a sufficient degree of supercooling can be secured.

According to the third embodiment, the control device 6 is configured to switch the cooling capacity of the cooling device 11 to the output state when the outside air temperature T1 detected by the outside air temperature sensor 9 is lower than the set temperature. Here, in the third embodiment, the determination threshold value 5 corresponds to the set temperature.

According to this configuration, the output of the cooling device 11 is appropriately switched between the output state and the stopped state by the outside air temperature T1 detected by the outside air temperature sensor 9, and the energy consumption of the cooling device 11 can be appropriately suppressed. Further, even when the adjustment by the output of the components on the refrigeration cycle circuit such as the compressor 2, the blower 5, and the expansion valve 12 cannot cope with the problem, the cooling device 11 uses the outside air temperature T1 detected by the outside air temperature sensor 9. It can be appropriately switched between the output state and the stopped state, and a sufficient degree of supercooling can be secured.

According to the third embodiment, the control device 6 is set by the refrigerant supercooling degree SC1 calculated from the refrigerant temperature detected by the refrigerant temperature sensor 8 and the refrigerant pressure detected by the refrigerant pressure sensor 7. When it is lower than, the cooling capacity of the cooling device 11 is configured to be switched to the output state. Here, in the third embodiment, the determination threshold value 6 corresponds to the set supercooling degree.

According to this configuration, the output of the cooling device 11 can be appropriately switched between the output state and the stopped state by the supercooling degree SC1 of the refrigerant, and the energy consumption of the cooling device 11 can be appropriately suppressed. Further, even if the adjustment by the output of the components on the refrigeration cycle circuit such as the compressor 2, the blower 5, and the expansion valve 12 cannot cope with the problem, the cooling device 11 is stopped and the output state is caused by the supercooling degree SC1 of the refrigerant. It can be appropriately switched to the state and a sufficient degree of supercooling can be secured.

Embodiment 4.
FIG. 9 is a refrigerant circuit diagram showing the air conditioner 100 according to the fourth embodiment of the present invention. In the fourth embodiment, the description of the same matters as those in the above embodiment will be omitted, and only the characteristic portion thereof will be described.

As shown in FIG. 9, the air conditioner 100 is a multi-type air conditioning system in which a plurality of indoor units such as the indoor unit 10a and the indoor unit 10b are connected. The indoor unit 10a includes an expansion valve 12a, an indoor heat exchanger 13a, and a blower 14a. The indoor unit 10b includes an expansion valve 12b, an indoor heat exchanger 13b, and a blower 14b.

In the air conditioner 100 of such a multi-type air conditioning system, the installation conditions such as the length of the refrigerant pipe and the height difference are different for each of the indoor unit 10a and the indoor unit 10b. Therefore, when the outdoor heat exchanger 4 functions as a condenser, the refrigerant pipe between the outdoor heat exchanger 4 serving as the condenser and the expansion valve 12a or the expansion valve 12b of each indoor unit 10a or the indoor unit 10b. The degree of supercooling in front of the expansion valve 12a or the expansion valve 12b may not be maintained due to the pressure loss of the length L1 or the length L2. Here, it is assumed that the length L2 of the refrigerant pipe is longer than the length L1 and a large pressure loss occurs in the refrigerant pipe of the indoor unit 10b. When the distance of the refrigerant pipe from the condenser to the expansion valve 12 is long, a cooling device 11 using an external heat source is provided in the middle of the refrigerant pipe having a length L2. Alternatively, a cooling device 11 using an external heat source may be provided for a path having a large height difference in the refrigerant piping from the condenser to the expansion valve 12. The cooling device 11 assists in cooling the refrigerant flowing through the refrigerant pipe of length L2, so that the gas-liquid two-phase state refrigerant does not flow into the expansion valve 12 and the liquid-phase state refrigerant flows into the expansion valve 12. It is possible to avoid the problem of generating an unpleasant flow noise of the refrigerant. In the fourth embodiment, since the cooling device 11 is provided only in the refrigerant pipe having a length L2, the cooling device 11 is installed in the indoor unit 10b.

<Effect of Embodiment 4>
According to the fourth embodiment, the air conditioner 100 includes an indoor unit 10b having an indoor heat exchanger 13b and an expansion valve 12b. The air conditioner 100 causes the outdoor heat exchanger 4 to function as a condenser for the refrigeration cycle circuit to perform cooling operation, and when the refrigerant is circulated from the condenser to the expansion valve 12, from the condenser to the expansion valve 12. The cooling device 11 is provided in a path having a path whose distance is longer than the set distance.

According to this configuration, even when the distance between the indoor unit 10b and the outdoor unit 1 is long and a large pressure loss occurs in the refrigerant pipe from the outlet of the condenser to the expansion valve 12, the cooling device 11 has a sufficient degree of supercooling. Can be secured. As a result, it is possible to prevent the generation of an unpleasant flow noise of the refrigerant due to the passage of the refrigerant in the gas-liquid two-phase state through the expansion valve 12.

According to the fourth embodiment, the air conditioner 100 includes a plurality of indoor units 10a or 10b having an indoor heat exchanger 13a or an indoor heat exchanger 13b and an expansion valve 12a or an expansion valve 12b, respectively. The air conditioner 100 causes the outdoor heat exchanger 4 to function as a condenser for the refrigeration cycle circuit to perform cooling operation, and when the refrigerant is circulated from the condenser to the expansion valve 12, the plurality of indoor units 10a and the indoor unit Of the 10b, the indoor unit 10b having a path in which the distance from the condenser to the expansion valve 12 is longer than that of the other indoor units 10a is provided with the cooling device 11.

According to this configuration, among the plurality of indoor units 10a or 10b, the indoor unit 10b has a long distance from the outdoor unit 1 and causes a large pressure loss in the refrigerant pipe from the outlet of the condenser to the expansion valve 12. Even if it exists, a sufficient degree of supercooling can be ensured by the cooling device 11. As a result, it is possible to prevent the generation of an unpleasant flow noise of the refrigerant due to the passage of the refrigerant in the gas-liquid two-phase state through the expansion valve 12.

According to the fourth embodiment, the air conditioner 100 includes an indoor unit 10b having an indoor heat exchanger 13b and an expansion valve 12b. The air conditioner 100 causes the outdoor heat exchanger 4 to function as a condenser for the refrigeration cycle circuit to perform cooling operation, and when the refrigerant is circulated from the condenser to the expansion valve 12b, from the condenser to the expansion valve 12b. The cooling device 11 is provided in a path in which the height difference of the refrigerant pipe is larger than the set difference.

According to this configuration, even when the height difference between the indoor unit 10b and the outdoor unit 1 is large and a large pressure loss occurs in the refrigerant pipe from the outlet of the condenser to the expansion valve 12b, the cooling device 11 is sufficient for supercooling. The degree can be secured. As a result, it is possible to prevent the generation of an unpleasant flow noise of the refrigerant due to the passage of the refrigerant in the gas-liquid two-phase state through the expansion valve 12b.

In addition, embodiments 1 to 4 of the present invention may be combined, or may be applied to other parts.

1 outdoor unit, 2 compressor, 3 four-way valve, 4 outdoor heat exchanger, 5 blower, 6 controller, 7 refrigerant pressure sensor, 8 refrigerant temperature sensor, 9 outside air temperature sensor, 10, 10a, 10b indoor unit, 11 cooling Equipment, 12, 12a, 12b expansion valve, 13, 13a, 13b indoor heat exchanger, 14, 14a, 14b blower, 100 air conditioner.

The air conditioner according to the present invention is a refrigeration cycle circuit in which a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are sequentially connected by a refrigerant pipe, and between the outdoor heat exchanger and the expansion valve. A cooling device arranged in the refrigerant pipe and cooling the refrigerant flowing through the refrigerant pipe by an external heat source and the outdoor heat exchanger functioning as a condenser for the refrigeration cycle circuit to perform cooling operation are performed from the condenser. When the refrigerant is circulated through the expansion valve, the control device configured to change the cooling capacity of the cooling device according to the conditions reflecting the state of the refrigerant and the outside air exchanged with heat by the outdoor heat exchanger. The outside air temperature sensor for detecting the temperature is provided , and the condition reflecting the cooling state is the outside air temperature detected by the outside air temperature sensor, and the control device has the outside air temperature detected by the outside air temperature sensor as the set temperature. When it is lower than, it is configured to switch the cooling capacity of the cooling device to the output state .

Claims (13)

A refrigeration cycle circuit in which a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are sequentially connected by a refrigerant pipe.
A cooling device arranged in the refrigerant pipe between the outdoor heat exchanger and the expansion valve and cooling the refrigerant flowing through the refrigerant pipe by an external heat source.
When the outdoor heat exchanger functions as a condenser for the refrigeration cycle circuit to perform cooling operation and the refrigerant is circulated from the condenser to the expansion valve, the cooling device depends on the conditions reflecting the refrigerant state. With a controller configured to change the cooling capacity of
An air conditioner equipped with. The air conditioner according to claim 1, wherein the control device is configured to switch the cooling capacity of the cooling device between an output state and a stopped state according to a condition reflecting the refrigerant state. The air conditioner according to claim 1 or 2, wherein the control device is configured to switch the magnitude of the output of the cooling capacity of the cooling device according to a condition reflecting the refrigerant state. The outdoor heat exchanger is provided with an outside air temperature sensor that detects the temperature of the outside air that exchanges heat.
The air conditioner according to any one of claims 1 to 3, wherein the condition reflecting the refrigerant state is the outside air temperature detected by the outside air temperature sensor. The air conditioner according to claim 4, wherein the control device is configured to switch the cooling capacity of the cooling device to an output state when the outside air temperature detected by the outside air temperature sensor is lower than the set temperature. The air conditioner according to claim 4 or 5, wherein the control device is configured to switch the cooling capacity of the cooling device to a larger output as the outside air temperature detected by the outside air temperature sensor is lower. A refrigerant temperature sensor that detects the temperature of the refrigerant flowing through the refrigerant pipe at the outlet of the condenser, and
A pressure sensor that detects the pressure of the refrigerant discharged from the compressor,
With
The condition that reflects the refrigerant state is any of claims 1 to 6, which is the degree of refrigerant supercooling calculated from the temperature of the refrigerant detected by the refrigerant temperature sensor and the pressure of the refrigerant detected by the pressure sensor. The air conditioner according to item 1. The control device is used for the cooling device when the degree of refrigerant supercooling calculated from the temperature of the refrigerant detected by the refrigerant temperature sensor and the pressure of the refrigerant detected by the pressure sensor is lower than the set degree of supercooling. The air conditioner according to claim 7, wherein the cooling capacity is configured to switch to an output state. The control device switches the cooling capacity of the cooling device to a larger output as the degree of refrigerant supercooling calculated from the temperature of the refrigerant detected by the refrigerant temperature sensor and the pressure of the refrigerant detected by the pressure sensor is lower. The air conditioner according to claim 7 or 8, which is configured as described above. The indoor heat exchanger and the indoor unit having the expansion valve are provided.
When the outdoor heat exchanger functions as a condenser for the refrigeration cycle circuit to perform cooling operation and the refrigerant is circulated from the condenser to the expansion valve, the distance from the condenser to the expansion valve is a set distance. The air conditioner according to any one of claims 1 to 9, wherein the cooling device is provided in a path having a longer path. A plurality of indoor units each having the indoor heat exchanger and the expansion valve are provided.
When the outdoor heat exchanger functions as a condenser for the refrigeration cycle circuit to perform cooling operation and the refrigerant is circulated from the condenser to the expansion valve, the condenser is used among the plurality of indoor units. The air conditioner according to any one of claims 1 to 10, wherein the indoor unit having a path in which the distance to the expansion valve is longer than that of the other indoor unit is provided with the cooling device. The indoor heat exchanger and the indoor unit having the expansion valve are provided.
When the outdoor heat exchanger functions as a condenser for the refrigeration cycle circuit to perform cooling operation and the refrigerant is circulated from the condenser to the expansion valve, the height of the refrigerant pipe from the condenser to the expansion valve is high or low. The air conditioner according to any one of claims 1 to 11, wherein the cooling device is provided in a path in which the difference is larger than the set difference. The air conditioner according to any one of claims 1 to 12, wherein a Peltier element is used as the cooling device.

Images