JP2000193327A - Air conditioner equipment and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To curtail power consumption with a miniaturization of the outdoor unit and at a lower cost by arranging the operation of a compressor and a liquid pump to carry out operation optimum for the environmental situation of any installing places. SOLUTION: This air conditioning equipment has a refrigerating cycle in which compressor 21, condenser 22, decompressing means 13 and evaporator 11 are connected sequentially with piping to circulate a refrigerant, compressor bypass piping 4 having an open-close valve 24, a liquid conveying device 23 connected between an outlet part of the condenser 22, and an inlet part of the decompressing means 13. A controller 70 controls the operation of the open- close valve 24, the compressor 21 and the liquid conveying device 23 and so, the temperature of a fluid to be cooled and the temperature of the fluid to be heated are detected by a first temperature detection means 71 and a second temperature detection means 72. When the temperature difference is below a specified value, the open-close valve 24 is closed to operate the compressor 21 and when it is larger than the specified value, the open-close valve 24 is opened to operate the liquid conveying device 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner which is operated year-round regardless of the outside air temperature, and more particularly to an operation for operating a refrigeration cycle by a compressor and an operation of a heat transport cycle by a liquid transfer device. The present invention relates to an air conditioner having an operation to be performed.

[0002]

2. Description of the Related Art In recent years, with the spread of mobile communications such as mobile phones, heat generated by electronic devices such as a computer room and a base station (shelter) containing relay electronic devices for mobile communications has been reduced. The field of removal is rapidly expanding, and these places require air conditioners that perform cooling operation throughout the year.

[0003] In these applications, when the outside air temperature is low, such as in winter or at night, air can be cooled by ventilation. However, when the outside air is taken in, fog, rain, snow, dust, and the like enter. Therefore, a stable cooling cannot be performed because the indoor temperature fluctuates due to the fluctuation of the outside air temperature. Under such conditions, an air conditioner using a heat transport cycle that uses a temperature difference between the indoor temperature and the outside air temperature to transfer heat from a room to the outside through a refrigerant by a liquid pump as a liquid transfer device through a refrigerant is used. Can be. Usually, in the summer, the outside air temperature becomes higher than the indoor temperature, so that cooling cannot be performed with the configuration in which the refrigerant is conveyed by the liquid pump, and an air conditioner that also has a configuration that cools the room with a refrigeration cycle equipped with a compressor is available. Required. The air conditioner that uses both the compressor operation and the liquid pump operation consumes about 1/10 of the power of the liquid pump compared to that of the compressor. Power consumption can be significantly reduced.

[0004] Conventionally, as an example of an air conditioner using a liquid pump, there is an air conditioner using both a compressor operation and a liquid pump operation as disclosed in JP-A-10-82566. FIG. 22 is a configuration diagram showing a conventional air conditioner having a compressor operation and a liquid pump operation. In the drawing, 1 is a base floor, 2 is a double bed, 3 is a refrigerant pipe, 4 is a compressor bypass pipe, 5 is a liquid pump bypass pipe, 10 is an indoor unit, 1
1 is an evaporator, 12 is an evaporator-side blower, 20 is an outdoor unit, 2
1 is a compressor, 22 is a condenser, 23 is a liquid pump, 24, 2
Reference numeral 5 denotes an open / close valve, and reference numeral 26 denotes a condenser-side blower.

A control device 30 is provided in the outdoor unit 20, and an outdoor air temperature sensor 31 is provided as a temperature detecting means for detecting the outdoor air temperature, and the following control is performed. That is, when the temperature detected by the outside air temperature sensor 31 becomes equal to or higher than a first predetermined value, for example, 12 ° C., the compressor 21 is operated to stop the liquid pump 23 and close the on-off valve 24 to close the on-off valve 25.
Is opened, and the cooling operation by the compressor 21 is executed. In this case, the refrigerant gas that has been adiabatically compressed by the compressor 21 and has been overheated is radiated and liquefied to the outside air by the condenser 22 to be a refrigerant liquid. Thereafter, the high-pressure refrigerant liquid flows into the indoor unit 10 through the refrigerant pipe 3, and is decompressed by the expansion valve 13 to become low-temperature low-pressure wet steam in a gas-liquid mixed state. Further, the refrigerant absorbs heat of vaporization in the evaporator 11 to become a refrigerant gas, and returns to the compressor 21 through the refrigerant pipe 3. At this time, the indoor air is cooled by the evaporator 11.

On the other hand, when the temperature detected by the outside air temperature sensor 31 falls below a second predetermined value (<first predetermined value), for example, 7 ° C. or less,
The compressor 21 is stopped, the liquid pump 23 is operated, the on-off valve 24 is opened, the on-off valve 25 is closed, and the cooling operation by the liquid pump 23 is executed. In this case, the liquid refrigerant condensed in the condenser 22 is pressurized by the liquid pump 23 and flows into the evaporator 11 through the refrigerant pipe 3. The liquid refrigerant that has flowed into the evaporator 11 receives the heat load in the room, evaporates, flows through the refrigerant pipe 3, and returns to the condenser 22 through the on-off valve 24, thereby forming a liquid pump operation cycle.

As described above, this air conditioner is provided with the two opening / closing valves 24 and 25 for bypassing the compressor 21 and the liquid pump 23, and the control device 30 receives the detected value of the outside air temperature from the control device 30. The open / close valves 24 and 25 are opened / closed in response to the above command, and the cooling operation by the compressor 21 and the cooling operation by the liquid pump 23 are switched. The operation power of the liquid pump is smaller than that of the compressor, so that the annual power consumption can be significantly reduced.

[0008]

As described above, in an air conditioner using a liquid pump operation in combination with a conventional compressor operation,
Two on-off valves 24 for switching the refrigerant circuit of both operations,
25 and a control device 30 for opening and closing them. As these open / close valves 24 and 25, for example, large and expensive valves that can be opened / closed by a command from the control device 30 such as solenoid valves are used, the outdoor unit 20 is smaller than an air conditioner only operating a compressor. There is a problem that the system becomes expensive as the size increases.

In a conventional air conditioner, both operations are switched based only on the outside air temperature. Therefore, if the room temperature is low and the temperature difference from the outside air temperature is small, the liquid pump will be operated unnecessarily, and the power consumption will increase, even if the liquid pump operation is determined based on the outside air temperature. Further, a situation may occur in which the liquid pump is operated even under the reverse condition that the room temperature becomes lower than the outside air temperature. In this case, the operation of the evaporator and the condenser is not performed normally, and there is a possibility that the liquid pump may be damaged by sucking gas into the liquid pump.

In addition, since the amount of refrigerant during the operation of the liquid pump is larger than that during operation of the compressor, an accumulator for storing the refrigerant at the inlet of the compressor is usually provided to optimize the amount of refrigerant for both operations. Install. In the case of the device having the accumulator, surplus refrigerant is accumulated in the accumulator during the operation of the compressor, and when the liquid pump operation is operated only by switching the open / close valve, the refrigerant amount becomes insufficient. The shortage of the refrigerant amount causes a situation in which the liquid pump inlet is in a two-phase state and the refrigerant circulation amount is insufficient, and a predetermined cooling capacity cannot be obtained, or cavitation occurs and the liquid pump 23 is damaged. Or cause. Here, cavitation is a phenomenon in which a gas appears in a flowing liquid to form a cavity. If cavitation is generated in the liquid pump 23, the sound and vibration generally accompany the cavitation, so that a predetermined refrigerant flow rate cannot be obtained, and the operation efficiency is reduced. For example, when the liquid pump is a rotary pump,
Corrosion progresses on members such as the rotor in the liquid pump and other parts. In extreme cases, noise and vibration make continuous operation impossible. In particular, when the size and speed of the liquid pump are reduced, the flow velocity in the rotor is further increased, and a portion with a higher vacuum appears locally, so that the possibility of cavitation is further increased. The cavity generated at the lowest pressure part of the flow causes a violent impact action when the air bubbles are crushed by moving to the high pressure part and melts back into the liquid, but the impact pressure generated at this time is extremely large, And generates noise and energy loss. As described above, in a device incorporating a liquid pump, prevention of cavitation is a major problem.

Further, when recovering the refrigerant accumulated in the accumulator in order to avoid the state of the shortage of the refrigerant amount, when the refrigerant recovery operation of completely closing the expansion valve 13 and operating the compressor 21 is performed, Since the suction pressure of the compressor 21 rapidly decreases, the refrigerant liquid sucked into the compressor 21 foams, and the refrigerating machine oil flows out into the refrigerant circuit together with the discharge gas, and the amount of the refrigerating machine oil inside the compressor decreases. There was a risk of burning due to poor lubrication. Further, there is a problem that the refrigerating machine oil flowing out into the refrigerant circuit causes an increase in pressure loss and lowers the cooling capacity during operation of the liquid pump. That is, in an air conditioner using both a compressor operation and a liquid pump operation, an apparatus provided with an accumulator for absorbing a difference in the amount of refrigerant between the two operations is capable of discharging the refrigerant stored in the accumulator during the compressor operation. It was necessary to collect the fuel when switching to the pump operation, and smooth recovery was also a major issue.

Further, when an accumulator is provided at the suction portion of the compressor 21, the inside of the accumulator has a low temperature and a low pressure during the operation of the compressor. There is a problem that the amount of refrigerant is insufficient.

Further, when the outside air temperature decreases in winter, for example, the cooling capacity obtained by the operation of the liquid pump increases, so that the compressor 21 is stopped for a long time, and the compressor 21 is stopped over time as time elapses. Drops to temperature. In such a case, since the refrigerant gas is gradually condensed from the refrigerant circuit of the liquid pump operation to the compressor 21, not only the amount of refrigerant required for the liquid pump operation is not ensured, but also liquid compression occurs when the compressor 21 starts up. There was a risk of being damaged.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described conventional problems, and includes a compressor operation and a liquid pump operation, and performs opening and closing operations of an on-off valve accompanying switching of each operation to a refrigerant circuit. An object of the present invention is to obtain an air conditioner having a simple and inexpensive configuration by simplification. further,
An object of the present invention is to provide an air conditioner capable of performing an operation suitable for an environmental condition of an installation place in each of a compressor operation and a liquid pump operation. It is another object of the present invention to provide an air conditioner capable of smoothly switching operation without rapidly reducing the suction pressure of a compressor. In addition, an air conditioner that includes a compressor operation and a liquid pump operation and has a configuration in which an accumulator is provided in a suction portion of the compressor and that can smoothly recover the refrigerant accumulated in the accumulator when the operation is switched is obtained. It is intended for that purpose. In addition, a compressor operation and a liquid pump operation are provided, and even when the compressor is in a stopped state for a long time, the refrigerant is prevented from condensing into the compressor, and the amount of refrigerant necessary for the operation of the liquid transfer device can be secured. It is an object of the present invention to provide an air conditioner that can stably operate a liquid transport device and that can prevent liquid compression at the time of restarting a compressor and improve reliability of the compressor. . It is another object of the present invention to provide an air conditioner that can prevent cavitation from occurring in a liquid pump.

[0015]

An air conditioner according to the present invention comprises a refrigeration cycle in which a compressor, a condenser, a pressure reducing means, and an evaporator are sequentially connected by piping to circulate a refrigerant, and an outlet of the evaporator. A bypass pipe connecting the inlet of the condenser via an on-off valve, and a liquid transfer device connected in series with the pressure reducing means between the outlet of the condenser and the inlet of the pressure reducing means, A control device for controlling the opening / closing operation of the on-off valve, the operation / stop operation of the compressor, and the operation / stop operation of the liquid transfer device; and a first temperature detection for detecting a temperature of the fluid to be cooled flowing into the evaporator. Means, and second temperature detecting means for detecting the temperature of the fluid to be heated flowing into the condenser, wherein the temperature of the fluid to be cooled detected by the first temperature detecting means and the temperature detected by the second temperature detecting means Temperature difference with the temperature of the heated fluid The compressor is operated with the on-off valve closed when the temperature is equal to or lower than a predetermined temperature, and the on-off valve is opened when a temperature difference between the temperature of the fluid to be heated and the temperature of the fluid to be cooled is larger than a predetermined temperature. The operation of the on-off valve, the compressor, and the liquid transfer device is controlled by the control device so that the compressor is stopped and the liquid transfer device is operated.

Further, the air conditioner according to the present invention comprises a refrigeration cycle in which a compressor, a condenser, a decompression means and an evaporator are sequentially connected by pipes to circulate a refrigerant; A bypass pipe connecting an inlet with a check valve for closing the flow of refrigerant from the condenser side to the evaporator side, and between a condenser outlet and an inlet of the decompression means. A liquid transfer device connected in series with the pressure reducing means, a control device for controlling the operation / stop operation of the compressor and the operation / stop operation of the liquid transfer device, and a temperature of the fluid to be cooled flowing into the evaporator. Temperature detecting means for detecting the temperature of the fluid to be heated flowing into the condenser, and second temperature detecting means for detecting the temperature of the fluid to be heated flowing into the condenser. Heated flow detected by the second temperature detecting means When the temperature difference between the temperature of the fluid to be cooled and the temperature of the fluid to be cooled is greater than the predetermined temperature, the compressor is operated. The control device controls the compressor and the liquid transfer device so as to operate the liquid transfer device.

Further, the air conditioner according to the present invention comprises a refrigeration cycle in which a compressor, a condenser, a decompression means and an evaporator are sequentially connected by piping to circulate a refrigerant, and an outlet of the evaporator and the condenser. A bypass pipe connecting an inlet with a first on-off valve, a liquid transporting means connected in parallel with the pressure reducing means between an outlet of the condenser and an inlet of the evaporator, A second on-off valve for opening and closing the flow path of the parallel section to which the transfer means is connected, an on-off operation of the first and second on-off valves, a start / stop operation of the compressor, and a start / stop operation of the liquid transfer device A first temperature detecting means for detecting the temperature of the fluid to be cooled flowing into the evaporator, and a second temperature detecting means for detecting the temperature of the fluid to be heated flowing into the condenser. A fluid to be cooled detected by the first temperature detecting means When the temperature difference between the temperature and the temperature of the fluid to be heated detected by the second temperature detecting means is equal to or lower than a predetermined temperature, the first and second on-off valves are closed, the liquid transfer device is stopped, and the compressor is started. Operating the liquid transfer device by opening the first and second on-off valves and stopping the compressor when the temperature difference between the temperature of the fluid to be heated and the temperature of the fluid to be cooled is greater than a predetermined temperature. The operation of the first and second on-off valves, the compressor, and the liquid transfer device is controlled by the control device so as to operate the liquid transfer device.

Further, the air conditioner according to the present invention comprises a refrigeration cycle in which a compressor, a condenser, a decompression means and an evaporator are sequentially connected by piping to circulate a refrigerant, and an outlet of the evaporator and the condenser. A bypass pipe connecting an inlet with a check valve for closing the flow of refrigerant from the condenser side to the evaporator side, and between a condenser outlet and the evaporator inlet. A liquid transfer means connected in parallel with the pressure reducing means, an on-off valve for opening and closing a flow path of a parallel portion connected to the liquid transfer means, an on-off operation of the on-off valve, and a start / stop operation of the compressor. A control device for controlling the operation / stop operation of the liquid transfer device; first temperature detecting means for detecting the temperature of the fluid to be cooled flowing into the evaporator; and detecting the temperature of the fluid to be heated flowing into the condenser. And a second temperature detecting means that performs When the temperature difference between the temperature of the fluid to be cooled detected by the temperature detecting means and the temperature of the fluid to be heated detected by the second temperature detecting means is equal to or less than a predetermined temperature, the on-off valve is closed and the liquid transfer device is stopped. Operating the compressor, and when the temperature difference between the temperature of the fluid to be heated and the temperature of the fluid to be cooled is larger than a predetermined temperature, the on-off valve is opened to stop the compressor and the liquid transfer device The operation of the on-off valve, the compressor, and the liquid transfer device is controlled by the control device so as to operate.

The air conditioner according to the present invention is characterized in that a second pressure reducing means is provided between the outlet of the liquid transfer device and the inlet of the evaporator.

Further, the air conditioner according to the present invention is characterized in that an accumulator is provided between the inlet side connection of the bypass pipe and the inlet of the compressor.

Further, the air conditioner according to the present invention is characterized in that a third on-off valve is provided between the inlet side connection of the bypass pipe and the inlet of the accumulator.

Further, the air conditioner according to the present invention is characterized in that a fourth on-off valve is provided between the outlet of the compressor and the outlet-side connection of the bypass pipe.

Further, the air conditioner according to the present invention is characterized in that the fourth on-off valve is a check valve for closing the flow of the refrigerant from the outlet side connection of the bypass pipe to the outlet of the compressor. Things.

In the air conditioner according to the present invention, a high-pressure pipe from the outlet of the compressor to the inlet of the pressure reducing means and a low-pressure pipe from the outlet of the pressure reducing means to the inlet of the compressor are connected to the fifth. It is characterized by being connected by a second bypass pipe via an on-off valve.

The air conditioner according to the present invention is characterized in that liquid storage means is provided between the outlet of the condenser and the inlet of the liquid transfer device.

Further, the air conditioner according to the present invention is characterized in that the air conditioner is provided with supercooling means for supercooling the refrigerant flowing between the outlet of the condenser and the inlet of the liquid transfer device.

Further, the air conditioner according to the present invention is characterized in that the latent heat of evaporation of the refrigerant liquid in the accumulator during the operation of the compressor is used as the cold heat source of the supercooling means.

Further, the air conditioner according to the present invention changes the degree of pressure reduction of at least one of the pressure reducing means and the second pressure reducing means when the operation is switched from the operation of the compressor to the operation of the liquid transfer device, so that the inside of the accumulator is changed. A refrigerant recovery operation of recovering the refrigerant stored in the refrigerant circuit into the refrigerant circuit operated by the liquid transfer device.

The air conditioner according to the present invention is characterized in that the refrigerant recovery operation is performed for a predetermined time.

Further, the air conditioner according to the present invention provides a refrigerant recovery operation time or a refrigerant recovery operation depending on the temperature of the fluid to be cooled detected by the first temperature detecting means or the temperature of the fluid to be heated detected by the second temperature detecting means. The amount of refrigerant collected from the accumulator to the refrigerant circuit in the operation of the liquid transfer device is controlled by setting the degree of pressure reduction of the pressure reducing means during the recovery operation and performing the refrigerant recovery operation.

Further, the air conditioner according to the present invention is characterized in that the pressure reducing means and the piping downstream of the means to the evaporator are arranged in a box housing the evaporator.

Further, in the air conditioner according to the present invention, the box housing one of the evaporator and the condenser is an indoor unit,
A box housing the other of the evaporator and the condenser, a compressor and a liquid transfer device is an outdoor unit, and a plurality of the indoor units are connected to one outdoor unit. Things.

Further, the method for controlling an air conditioner according to the present invention includes a refrigeration cycle in which a refrigerant is circulated through a compressor, a condenser, a pressure reducing means, and an evaporator, Detecting the temperature of the fluid to be cooled flowing into the evaporator, and detecting the temperature of the fluid to be heated flowing into the condenser in an air conditioner including a heat transport cycle that circulates a refrigerant through the condenser. And when the temperature difference between the temperature of the fluid to be heated detected in the step of detecting the temperature of the fluid to be cooled and the temperature of the fluid to be heated detected in the step of detecting the temperature of the fluid to be cooled is equal to or less than a predetermined temperature. Operating the refrigeration cycle;
When the temperature difference between the temperature of the heated fluid detected in the step of detecting the temperature of the cooled fluid and the temperature of the heated fluid detected in the step of detecting the temperature of the cooled fluid is greater than a predetermined temperature, Operating a heat transport cycle.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, for example, a cooling device will be described as an air conditioner according to Embodiment 1 of the present invention. This air conditioner is used in places requiring cooling throughout the year, and FIG. 1 is a configuration diagram showing an air conditioner according to the present embodiment. In the figure, 3
a is a gas pipe of a refrigerant pipe, 3b is a liquid pipe of a refrigerant pipe, 4
Is a compressor bypass pipe, 10 is an indoor unit, 11 is an evaporator for evaporating the refrigerant liquid into gas, 12 is an evaporator-side blower, 13
Is a pressure reducing means, for example, an electronic expansion valve, 20 is an outdoor unit, 21
Is a compressor for compressing the refrigerant gas, 22 is a condenser for cooling and liquefying the refrigerant gas, and 23 is a liquid transfer device, for example, a liquid pump, which has a function of circulating the liquid refrigerant flowing inside. Reference numeral 24 denotes an on-off valve (first on-off valve) provided in the compressor bypass pipe 4, 26 denotes a condenser-side blower, 27 denotes an accumulator for storing a refrigerant liquid, and 28 denotes an inlet of the accumulator 27 and a compressor bypass pipe. An on-off valve (third on-off valve) provided between the inlet side connection portion of the compressor 4 and a solenoid valve, for example.
The opening / closing valve (fourth opening / closing valve) provided between the outlet side connecting portion and the solenoid valve is, for example, a solenoid valve.

Reference numeral 70 denotes a control device, which is constituted by, for example, a microcomputer.
, The opening / closing operation of the expansion valve 23, the operation / stop operation of the evaporator-side blower 12 and the condenser-side blower 26, and the like. The control device 70 is attached to, for example, a side surface of the outdoor unit 20. Also, 71, 72
Denotes first and second temperature detecting means, and the first temperature detecting means 7
1 is an indoor temperature sensor for detecting the temperature of the fluid to be cooled flowing into the evaporator 11, in this case, the indoor temperature. The second temperature detecting means 72 is the temperature of the fluid to be heated flowing into the condenser 22, in this case. Is an outside air temperature sensor for detecting the outside air temperature. Note that control signal lines from the control device 70 to the evaporator-side blower 12 and the condenser-side blower 26 are omitted.

The indoor unit 10 evaporates the wet steam flowing in from the liquid pipe 3b by the air conditioning load in the space to be air-conditioned, and turns the evaporator 11 into a refrigerant gas. It comprises an evaporator-side blower 12 for blowing air to the outer surface, and a temperature sensor 71. Further, the outdoor unit 20 exits the compressor 21, the condenser 22, the condenser-side blower 26 for forcibly blowing outside air as the fluid to be heated to the outer surface of the condenser 22, the liquid pump 23, and the condenser 22. An electronic expansion valve 13 that decompresses a high-temperature and high-pressure refrigerant liquid to produce a two-phase wet vapor, and an accumulator 2 for preventing liquid from returning to the compressor 21 in the event of a transient phenomenon or refrigerant overfilling.
7. Solenoid valve 28 for preventing refrigerant from flowing into accumulator 27 during operation of liquid pump, compressor 21 during operation of liquid pump
A compressor bypass pipe 4 having an electromagnetic valve 24 for bypassing the compressor, an electromagnetic valve 29 for preventing refrigerant from flowing into the compressor 21 during operation of the liquid pump, and an outside air temperature sensor 72. The electronic expansion valve 13 is connected to a pipe between the outlet of the condenser 22 and the inlet of the evaporator 11, and the liquid pump 23 is connected between the outlet of the condenser 22 and the inlet of the electronic expansion valve 13. , Are connected in series with the electronic expansion valve 13. The opening of the electronic expansion valve 13 is variable, and the degree of pressure reduction of the refrigerant can be set by setting the opening. Although the indoor unit 10 is installed at a lower place than the outdoor unit 20 in FIG. Further, in the drawing, the indoor unit 10 and the outdoor unit 20 are provided with a refrigerant inlet and a refrigerant outlet, respectively, so that the indoor unit 10 and the outdoor unit 20 can be easily attached at the time of installation.
A gas pipe 3 is connected to the outlet of the indoor unit 10 and the inlet of the outdoor unit 20.
a, and the outlet of the outdoor unit 20 and the inlet of the indoor unit 10 are connected by the liquid pipe 3b.

As the liquid pump 23, a pump such as a rotary pump, a volute pump, or an axial flow pump is used. For example, FIG. 2 is a schematic diagram showing a configuration of a gear pump belonging to a rotary pump as an example of the liquid pump 23. Two gears 23b and 2 serving as rotors are provided inside a casing 23a.
This is a structure in which 3c is engaged and housed. Liquid pump 23
During the operation of, the gears 23b and 23c rotate while maintaining a clearance from the casing 23a, and the liquid flowing between the teeth when the rotating teeth separate at the inlet side is filled. The liquid is sent to the outlet side surrounded by the inner surface of the casing 23a and the two teeth, where the liquid between the teeth is discharged to engage the teeth again. When the liquid pump 23 is operated, two gears 23
By rotating one of b and 23c, the liquid is pushed out from the inlet side to the outlet side.

First, a compressor operation mode for operating the compressor 21 will be described. The degree of opening of the electronic expansion valve 13 is set so that the degree of supercooling at the outlet of the condenser 22 becomes a constant value, the electromagnetic valve 24 is closed, and the electromagnetic valves 28 and 29 are set.
Is opened, the compressor 21 is operated, and the liquid pump 23 is stopped. At this time, the refrigerant flows from the compressor 21 → the solenoid valve 29 → the condenser 22 → the liquid pump 23 → the electronic expansion valve 13 → the liquid pipe 3b.
→ The evaporator 11 → the gas pipe 3 a → the solenoid valve 28 → the accumulator 27 → the compressor 21 circulates in the refrigerant circuit in this order to form a refrigeration cycle. The high-temperature and high-pressure refrigerant generated by the compressor 21 is supplied to the condenser-side blower 26 in the condenser 22.
The refrigerant is condensed into a refrigerant liquid by exchanging heat with the outside air taken in at step (1). Then, the pressure is reduced by the electronic expansion valve 13 to be in a two-phase state and flows into the evaporator 11. Evaporator 11
, The refrigerant cools the indoor air and evaporates itself to become a refrigerant gas.

By circulating the refrigerant as described above, the indoor air blown to the evaporator 11 on the indoor side is cooled by exchanging heat with the refrigerant in the evaporator 11, and is again blown into the room. Cooling is performed. On the other hand, on the outdoor side, the outside air blown to the condenser 22 is:
In the condenser 22, the refrigerant gives cold heat and is heated itself and blown out of the room again.

At this time, the refrigerant is circulated in the liquid pump 23. However, the liquid pump 23 has, for example, a structure as shown in FIG. And gears 23b and 23c at the center
Pass through. Since flow resistance occurs during this passage, the opening of the electronic expansion valve 13 needs to be larger than that in the case where the liquid pump 23 is not included in the refrigerant circuit for operating the compressor. However, the casing 23a and the gears 23b, 2
The flow resistance when passing through the inside of the liquid pump 23 can be adjusted by setting the gap with 3c. Further, in this compressor operation mode, the compressor 21 and the liquid pump 23 may be operated simultaneously without stopping the liquid pump 23. In this case, even if the liquid pump 23 is included in the refrigerant circuit, the liquid pump 23
The flow resistance when the refrigerant passes through the inside can be reduced, the opening of the electronic expansion valve 13 can be made equal to the ordinary compressor operation, and the opening of the electronic expansion valve 13 is controlled by the liquid pump operation. Can be applied when not used together.

Next, the liquid pump operation mode will be described. The electromagnetic pump 24 is opened, the electromagnetic valves 28 and 29 are closed, and the opening degree of the electronic expansion valve 13 is set such that the degree of superheat at the outlet of the evaporator 11 becomes constant, for example, and the liquid pump 23 is operated. Then, the compressor 21 is stopped. At this time, the refrigerant is supplied from the liquid pump 23 → the electronic expansion valve 13 → the liquid pipe 3b → the evaporator 11 →
Gas pipe 3a → solenoid valve 24 → condenser 22 → liquid pump 23
, And a heat transport cycle is formed between the evaporator 11 and the condenser 22. The circulating refrigerant is condensed by exchanging heat with the outdoor air taken in by the condenser-side blower 26 in the condenser 22 to be condensed into a refrigerant liquid and flow into the evaporator 11. Here, the refrigerant cools the indoor air and evaporates itself to become a refrigerant gas. The indoor cooling operation is performed by such an operation. In the compressor operation mode and the liquid pump operation mode, the solenoid valve 24, the solenoid valve 28, the solenoid valve 29, the compressor 21, the liquid pump 23, the electronic expansion valve 1
Table 1 summarizes the operation states of No.3.

[0042]

[Table 1]

Switching between the compressor operation mode and the liquid pump operation mode is performed by the control device 70. The switching control procedure will be described with reference to FIG. For example, the first
The room temperature detected by the temperature sensor 71 and the second temperature sensor 7
The operation mode is switched based on the temperature difference from the outside air temperature detected in step 2. Hereinafter, the difference between the indoor temperature and the outside air temperature is Δ
Recorded as T. In ST1, the first temperature sensor 71 detects the room temperature, and compares the detected room temperature with a preset set temperature in ST2. When the room temperature is equal to or lower than the set temperature, it is not necessary to operate the air conditioner. If the air conditioner is operating, the operation is stopped (ST3, ST4). If it is determined in ST2 that the room temperature is higher than the set temperature, it is necessary to perform cooling. Therefore, in ST5, the second temperature sensor 72
, The temperature difference ΔT between the indoor temperature and the outdoor temperature is calculated. The temperature difference ΔT is compared with a first predetermined temperature, for example, 5 ° C. (ST5), and when it becomes 5 ° C. or less, switching is performed depending on the compressor operation mode to perform cooling (ST7, ST8). The temperature difference ΔT is compared with a second predetermined temperature, for example, 10 ° C. (ST9), and when it becomes 10 ° C. or more, the operation mode is switched to the liquid pump operation mode using the cool air of the outside air (ST9, ST10). Here, the threshold value of ΔT when switching between the two operation modes may be set to the same predetermined temperature in the compressor operation mode and the liquid pump operation mode, but as described above, the first predetermined temperature and the second predetermined temperature may be set. Is set differently, it is possible to prevent the compressor 21 and the liquid pump 23 from being repeatedly started and stopped frequently. Also, instead of detecting the outside air temperature as the temperature of the fluid to be heated flowing into the condenser 22, the temperature of the pipe from the outlet of the condenser 22 to the inlet of the liquid pump 23 is detected, and this pipe temperature and the indoor temperature are detected. The configuration may be such that the compressor operation mode and the liquid pump operation mode are switched based on a temperature difference from the temperature. This is because the temperature of the refrigerant flowing through this part of the pipe can be regarded as substantially equal to the temperature of the fluid to be heated flowing into the condenser 22.

By the way, comparing the compressor operation mode and the liquid pump operation mode, in the liquid pump operation mode, the liquid pipe 3b is completely filled with the liquid, and the inlet portion of the liquid pump 23 is prevented to prevent cavitation. Since it is necessary to increase the degree of subcooling of the compressor, the appropriate amount of refrigerant is larger in the liquid pump operation mode than in the compressor operation mode. Therefore, in the liquid pump operation mode, it is necessary to prevent the refrigerant from staying in the refrigerant circuit not involved in the liquid pump operation mode as much as possible. However, when the accumulator 27 is installed in the outdoor unit 20 as shown in FIG. 1, the refrigerant flows into the accumulator 27 after switching to the liquid pump operation mode because the inside of the accumulator 27 is at low temperature and low pressure during the compressor operation mode. try to. In the air conditioner of the present embodiment, the solenoid valve 2 is provided upstream of the accumulator 27.
8, which is opened in the compressor operation mode and closed in the liquid pump operation mode. The electromagnetic valve 28 can prevent the refrigerant from flowing into the accumulator 27 in the liquid pump operation mode, and can secure the required amount of refrigerant in the liquid pump operation mode, so that a stable liquid pump operation mode is always performed.

In the conventional air conditioner shown in FIG. 22, the solenoid valve 29 is not provided in a pipe between the outlet of the compressor 21 and the outlet side connection of the compressor bypass pipe 4. This is because immediately after the operation is switched from the compressor operation mode to the liquid pump operation mode, the temperature of the compressor 21 becomes lower than that of the compressor 2.
This is because the temperature of the refrigerant is maintained higher than that in the liquid pump operation mode by the heat capacity of the refrigerant itself, and the refrigerant does not flow.
However, when the outside air temperature is low, such as in winter, the temperature difference between the indoor temperature and the outside air temperature increases, and the cooling capacity obtained by the liquid pump operation mode increases. Compressor 21 over time
The temperature inside decreases to the outside temperature. In such a case, the refrigerant gradually flows into the discharge side of the compressor 21 from the outlet side connection portion of the compressor bypass pipe 4 which is the refrigerant circuit in the liquid pump operation mode, and condenses. Not only the amount of the refrigerant is not ensured, but also a phenomenon that liquid compression occurs at the time of starting the compressor when switching to the compressor operation mode to cause breakage may occur. On the other hand, in the air conditioner of the present embodiment, the solenoid valve 29 is provided between the outlet of the compressor 21 and the outlet side connection of the compressor bypass pipe 4, and is closed in the liquid pump operation mode. For this reason, even if the temperature in the compressor 21 falls as described above and drops to the outside air temperature, it is possible to prevent the refrigerant from condensing into the compressor 21 and to secure the required amount of refrigerant in the liquid pump operation mode. The reliability of the compressor 21 can be improved.

Incidentally, the characteristics of the refrigerant used in the liquid pump operation mode include a large heat transfer coefficient in the heat exchanger of the evaporator 11 and the condenser 22, and a small pressure loss in the heat exchanger, the liquid pipe and the gas pipe. Is required. Therefore, as an HFC-based refrigerant having an ozone layer depletion coefficient (ODP) of 0 and suitable for the liquid pump operation mode, R4
10A. FIGS. 4, 5, and 6 compare the evaporative heat transfer coefficient, the condensed heat transfer coefficient, and the pressure loss of R22 and R410A in a smooth tube. 4, 5 and 6, the horizontal axis is mass velocity G (kg / m ² · S), and the vertical axis is evaporation heat transfer coefficient HTC (W / m ² · K) and condensation heat transfer coefficient HTC (W / m ² · K), the pressure loss ΔP (kPa) in the two-phase region in the evaporator. In each figure, solid circles represent measured values for R22, solid lines represent characteristic curves for R22, triangles represent measured values for R410A, and dashed lines represent R.
It is a characteristic curve in the case of 410A. In FIG. 4, the inside diameter di of the heat transfer tube of the evaporator is di = 6.8 mm, and the dryness X is 0.2 to 0.2 mm.
0.9, and in FIG. 5 the inner diameter di = 6.8 of the heat transfer tube of the condenser.
mm, superheat degree SH = 1 ° C., supercool degree SC = 1 to 3 ° C., FIG. 6 shows the characteristics under the conditions that the inner diameter of the heat transfer tube of the evaporator is di = 6.8 mm, and the length of the tube is L = 5 m. . As can be seen from these figures, the evaporation heat transfer coefficient of R410A to R22 is 1.2 to 1.5 times, and the condensation heat transfer coefficient is 0.8 to 1.
0 times and the pressure loss is 0.5 to 0.8 times. Since the rate of increase of the evaporative heat transfer rate is larger than the rate of decrease of the condensed heat transfer rate and the pressure loss is smaller, when the temperature difference between the room temperature and the outside air temperature is constant, R410A is more refrigerant than R22. The circulation amount is increased, and a large cooling capacity is obtained.
Therefore, it can be said that R410A is a refrigerant having an ozone layer destruction coefficient of 0 and more suitable for liquid pump operation.

The hydrocarbon refrigerants propane and isobutane have an ozone depletion potential of 0 and a global warming capacity (GWP) that is at least one order of magnitude lower than that of fluorocarbon refrigerants such as R22 and R410A. It is a refrigerant that is less harmful to 7, 8, and 9 show propane (R290) and isobutane (R600a), which are hydrocarbon refrigerants, and R22, which is a CFC-based refrigerant, in a smooth tube.
It shows the evaporation heat transfer coefficient, the condensation heat transfer coefficient, and the pressure loss ΔP of R407C and R410A. 7, 8, and 9
The horizontal axis of is the mass velocity G (kg / m ² · S), the vertical axis is the evaporation heat transfer coefficient (W / m ² · K), and the condensation heat transfer coefficient (W /
m ² · K), pressure loss (kPa) in the two-phase region. In FIG. 7, the inside diameter di of the smooth tube is 7 mm, and the evaporation temperature Te is 5
° C, dryness X = 0.2-0.9, pipe length L = 5 m, in FIG. 8, the pipe inner diameter di = 7 mm, and the condensation temperature Tc = 5.
9, the inner diameter di of the smooth tube is 7 mm, the evaporation temperature Te is 5 ° C., the dryness X is 0.2 to 0.9, and the pipe length L is 0 in FIG.
This is a characteristic under the condition of 5 m. As can be seen from FIGS. 7 and 8, the heat transfer coefficient of evaporation of propane (R290) with respect to R22 at the same mass velocity is about 2.3 times, the heat transfer coefficient of condensation is about 1.3 times, and isobutane (R600
As compared with a), the heat transfer coefficient of evaporation is about 1.6 times, and the heat transfer coefficient of condensation is about the same. Also,
The pressure loss at the same mass velocity is about twice as large for R22, but about 0.5 times for isobutane (R600a). This is a hydrocarbon refrigerant that can provide the same cooling performance as R22 in the mode. Here, propane (R290) was shown to be suitable for the liquid pump operation mode as a hydrocarbon refrigerant. Even when used, a similar effect is exhibited.

The liquid pump 23 is not limited to a gear pump as shown in FIG. During the operation of the liquid pump, the pressure of the liquid flowing therethrough is increased to circulate the refrigerant circuit.
Any liquid may be used as long as the liquid flowing at the time of stoppage can pass through the gap between the members in the liquid pump 23.

Also, as a valve having both the functions of the on-off valve 24 and the on-off valve 28, a multi-directional valve such as a three-way valve or a four-way valve is provided at the inlet of the compressor bypass pipe 4 to the inlet of the accumulator 27. An on-off valve capable of switching the flow path of the evaporator 11 may be provided to switch the flow path from the evaporator 11 to the accumulator 27 and the flow path from the evaporator 11 to the condenser 22. By making the functions of the two on-off valves 24 and 28 function with one on-off valve, the control device 70 can be operated by one control, so that the control device 70 can be simplified. Similarly, as a valve having the functions of the on-off valve 24 and the on-off valve 29, a multi-directional valve such as a three-way valve or a four-way valve is provided at the outlet of the compressor bypass pipe 4 to the outlet of the compressor 21. An on-off valve capable of switching the flow path may be provided to switch the flow path from the compressor bypass pipe 4 to the condenser 22 and the flow path from the compressor 21 to the condenser 22. In this case as well, by making the functions of the two on-off valves 24 and 29 function with one on-off valve, the control device 70 can be simplified because the operation can be performed by one control.

As described above, this air conditioner is provided with the compressor operation mode and the liquid pump operation mode, and switches between the two operations in accordance with the temperature difference ΔT between the room temperature and the outside air temperature. Since the power consumption in the mode is about 1/10 of that in the compressor operation mode, the annual power consumption can be significantly reduced. Further, under the condition that the room temperature is low and the temperature difference from the outside air temperature is small, or the room temperature is lower than the outside air temperature, unnecessary operation in the liquid pump operation mode can be prevented. For this reason, optimal operation can be performed according to the environmental conditions of the installation location of the air conditioner. Further, since the liquid pump 23 is connected in series with the electronic expansion valve 13 and the refrigerant circuit near the liquid pump 23 is not switched between the compressor operation mode and the liquid pump operation mode, the switching operation can be simplified. As compared with a configuration in which the liquid pump bypass pipe is provided for switching, the outdoor unit 20 can be downsized and the control device 70
Can be simplified.

Also, the solenoid valves 28 and 29 prevent the refrigerant from flowing into the compressor 21 and the accumulator 27 in the liquid pump operation mode, and can secure a necessary amount of refrigerant in the liquid pump operation mode. Can be operated in a stable liquid pump operation mode. As a refrigerant, R410
By using A or propane, it is possible to obtain an air conditioner that uses both a compressor operation mode and a liquid pump operation mode that consumes less power and is less harmful to the global environment.

Embodiment 2 Hereinafter, for example, a cooling device will be described as an air conditioner according to Embodiment 2 of the present invention. FIG. 10 is a configuration diagram showing an air conditioner according to the present embodiment. Here, non-return valves are used as the on-off valves 24 and 29, and the control device 70 constituted by a microcomputer, for example, controls the on-off operation of the on-off valve 28, the operation / stop operation of the compressor 21, and the operation / stop of the liquid pump 23. It controls the operation, the opening control operation of the electronic expansion valve 23, the operation / stop operation of the evaporator-side blower 12 and the condenser-side blower 26, and the like, and controls the on-off valves 24 and 29 performed in the first embodiment. No opening / closing operation is controlled. Other components are the same as those in FIG.

The check valve 24 is an opening / closing valve provided in the compressor bypass pipe 4 and automatically opens and closes, for example, according to a pressure difference between both ends at a place where the compressor bypass pipe 4 is installed.
That is, in the compressor bypass pipe 4, (the evaporator 1
It opens when (pressure on the side 1)> (pressure on the side of the condenser 22) and allows the flow from the evaporator 11 to the condenser 22 to pass therethrough, (pressure on the side of the evaporator 11) <(pressure on the side of the condenser 22). And the refrigerant discharged from the compressor 21 is prevented from flowing to the evaporator 11. The check valve 29 is an on-off valve provided between the outlet of the compressor 21 and the outlet-side connection of the compressor bypass pipe 4. For example, the check valve 29 automatically opens and closes due to a pressure difference between both ends of the installation location. I do. That is, the compressor 21 is connected to the condenser 22 by the same configuration as the check valve 24.
To prevent the flow in the opposite direction.

In the compressor operation mode, the controller 70
Thus, the opening degree of the electronic expansion valve 13 is controlled, for example, by the condenser 2
The supercooling degree at the outlet of Step 2 is set to a constant value, the compressor 21 is operated, and the liquid pump 23 is stopped. At this time, the check valve 24 is closed by the pressure difference between the discharge pressure and the suction pressure of the compressor 21, and the check valve 29 is opened by the discharge pressure of the compressor 21 to form a refrigerant circuit in the compressor operation mode. Is done. That is, the refrigerant flows from the compressor 21 to the check valve 29.
The refrigerant flows through the refrigerant circuit in the order of the condenser 22, the liquid pump 23, the electronic expansion valve 13, the liquid pipe 3b, the evaporator 11, the gas pipe 3a, the solenoid valve 28, the accumulator 27, and the compressor 21.

In the liquid pump operation mode, the controller 7
0, the solenoid valve 28 is closed, and the opening of the electronic expansion valve 13 is set so that the degree of superheat at the outlet of the evaporator 11 becomes constant, for example, and the liquid pump 23 is operated to operate the compressor. 21 is stopped. At this time, the check valve 24 is opened by the flow of the refrigerant, and the check valve 29 is closed, so that the refrigerant circuit in the liquid pump operation mode is formed. That is, the refrigerant flows in the refrigerant circuit in the order of the liquid pump 23 → the electronic expansion valve 13 → the liquid pipe 3b → the evaporator 11 → the gas pipe 3a → the check valve 24 → the condenser 22 → the liquid pump 23.

The main configuration and operation of the air conditioner according to the present embodiment are the same as those of the first embodiment, and have the same effects as those of the first embodiment. Further, in the present embodiment, the on-off valve 24 for connecting / disconnecting the compressor 21 to / from the refrigerant circuit is constituted by a check valve. An on-off valve 29 for preventing the refrigerant from flowing into 21 is constituted by a check valve. The check valves 24 and 29 have a simple structure by themselves,
Opening / closing is automatically performed when the compressor 21 and the liquid pump are started, so that opening / closing control by a command from the control device 70 is not required for these. Therefore, the outdoor unit 20 can be downsized and the control device 70 can be simplified.

Embodiment 3 Hereinafter, for example, a cooling device will be described as an air conditioner according to Embodiment 3 of the present invention. FIG. 11 is a configuration diagram showing an air conditioner according to the present embodiment. In the figure, reference numeral 40 denotes oil separating means for separating oil discharged from the liquid pump 23, for example, an oil separator, which is connected between the outlet of the liquid pump 23 and the inlet of the electronic expansion valve 13. Reference numeral 41 denotes oil return means for returning the oil separated by the oil separator 40 to the suction part of the liquid pump 23, for example, a lubricating oil return pipe, one end of which is connected to the oil storage part of the oil separator 40 and the other end of which is a condenser. It is connected to a pipe between the outlet of the liquid pump 22 and the inlet of the liquid pump 23. In the figure, the same reference numerals as those in FIG. 10 indicate the same or corresponding parts. The connection of the control signal line from the control device 70 to each device is the same as that in FIG. 10 and is omitted here.

The indoor unit 10 evaporates the wet steam flowing from the liquid pipe 3b by the air-conditioning load of the space to be air-conditioned, and turns the evaporator 11 into a refrigerant gas.
1 comprises an evaporator-side blower 12 for blowing air to the outer surface and an indoor temperature sensor 71. The outdoor unit 20 includes a compressor 21 for compressing the refrigerant gas, a condenser 22 for cooling and liquefying the refrigerant gas, a condenser-side blower 26 for forcibly blowing outside air to the outer surface of the condenser 22, and a liquid pump 23. An oil separator 40 for preventing oil discharged from the liquid pump 23 from flowing out to the heat exchange section of the evaporator 11 and the compressor 21; Expansion valve 1 that reduces the temperature of the high-temperature and high-pressure refrigerant liquid that has exited the condenser 22 and converts it into a two-phase wet steam
3. Compressor 21 for transient phenomena or overfilling of refrigerant
Accumulator 27 for preventing liquid from returning to tank, solenoid valve 28 for preventing refrigerant from flowing into accumulator 27 in liquid pump operation mode, check valve for bypassing compressor 21 and accumulator 27 in liquid pump operation mode 24, a check valve 29 for preventing refrigerant from flowing into the compressor 21 in the liquid pump operation mode, and an outside air temperature sensor 72. The liquid pump 23 and the electronic expansion valve 13 are connected in series to a pipe between the outlet of the condenser 22 and the inlet of the evaporator 11. In the figure, the indoor unit 10 is the outdoor unit 20
Although it is installed at a lower place than the above, there is no particular limitation on the positional relationship between the heights.

In this air conditioner, in the compressor operation mode, the opening of the electronic expansion valve 13 is set by the control device 70 so that the degree of supercooling at the outlet of the condenser 22 becomes constant. Then, the compressor 21 is operated and the liquid pump 23 is operated or stopped. At this time, the check valve 24 is closed by the pressure difference between the discharge pressure and the suction pressure of the compressor 21 to form a refrigerant circuit in the compressor operation mode. That is, the refrigerant flows from the compressor 21 → the check valve 29 → the condenser 22 → the liquid pump 2
3 → oil separator 40 → electronic expansion valve 13 → liquid pipe 3b → evaporator 11 → gas pipe 3a → electromagnetic valve 28 → accumulator 27 → compressor 21 flows in the refrigerant circuit in this order, and the cooling operation is performed. .

Further, when the liquid pump operation mode is performed, the solenoid valve 28 is closed by the control device 70, and the opening degree of the electronic expansion valve 13 becomes constant, for example, the degree of superheat at the outlet of the evaporator 11 becomes constant. Set as follows. Then, the liquid pump 23 is operated to stop the compressor 21. At this time, check valve 2
4 is opened by the flow of the refrigerant to form a refrigerant circuit in the liquid pump operation mode. That is, the refrigerant is supplied to the liquid pump 2
3 → oil separator 40 → electronic expansion valve 13 → liquid pipe 3b → evaporator 11 → gas pipe 3a → check valve 24 → condenser 22 → liquid pump 23 Done.

Table 2 shows that when the temperature was 10 ° C.
Water, R22, R410A, R407C, R404A, R
290, R600a Refrigerant saturated liquid viscosity (μPa ·
s). Generally, the inside of the liquid pump 23 does not contain the lubricating oil used for lubricating the sliding parts as in the compressor 21, and the sliding part is lubricated by the fluid to be conveyed (for example, water) itself. This lubricating effect is greater in a fluid having a large viscosity, and the viscosity of a refrigerant fluid of a chlorofluorocarbon or hydrocarbon series is smaller than that of water by about one order as shown in Table 2. Therefore, when a CFC-based or hydrocarbon-based refrigerant is used, since the lubricating effect is smaller than that of water, the progress of wear is accelerated due to poor lubrication of the sliding portion. Degradation can occur. Therefore, in the present embodiment, oil for lubricating the sliding portion of the liquid pump 23 is sealed in the oil separator 40, and this lubricating oil is circulated only around the liquid pump 23 by the lubricating oil return pipe 41. . By forming such a short circuit, the viscosity of only the liquid pump 23 can be increased, and a decrease in the flow rate when the liquid pump 23 is operated for a long time can be prevented.

[0062]

[Table 2]

Here, as the lubricating oil sealed in the oil separator 40, the same lubricating oil as the lubricating oil for the compressor is desirable. This is because when a lubricating oil other than the lubricating oil for the compressor is used as the lubricating oil for the liquid pump, the lubricating oil for the compressor and the lubricating oil for the liquid pump are mixed inside the compressor 21, and the lubricating oil for the compressor is separated. Alternatively, the lubrication is diluted and poor lubrication of the compressor 21 occurs. Further, as a method of separating the oil separator 40, when the compressor lubricating oil is a compatible oil that is mutually soluble with the refrigerant, the oil can be separated using a separation method such as membrane separation or centrifugal separation. Further, the following two types of structures are considered for the incompatible oil. That is, when the specific gravity of the lubricating oil is smaller than that of the refrigerant, for example, in the case of a combination of alkylbenzene and R410A, the lubricating oil is the upper layer of the refrigerant. Is larger than the refrigerant, for example, in the case of a combination of perfluoropolyether oil and R410A, the lubricating oil forms the lower layer of the refrigerant, so that the lubricating oil is separated from the lower layer.

In this embodiment, the lubricating oil is circulated only around the liquid pump 23. However, when lubricating oil is mixed into the evaporator 11 or the condenser 22, the heat transfer performance is reduced and the pressure is reduced. This is because the loss increases and the cooling capacity decreases due to the decrease in the amount of circulating refrigerant. Therefore,
If a decrease in the cooling capacity due to the lubricating oil is allowed, the amount of the lubricating oil of the compressor 21 is filled in advance so as to be larger than a predetermined value, the amount of the lubricating oil discharged from the compressor 21 is increased, and the circulation of the entire refrigerant circuit is performed. A method such as increasing the amount of oil can also be used. Further, the on-off valves 24 and 29 are not limited to the check valves, but may be configured by electromagnetic valves and the opening and closing operations thereof are controlled by the control device 70 as in the first embodiment. As described in the first embodiment, an on-off valve such as a three-way valve, which can switch a multi-directional flow path, is provided on the inlet side and the outlet side of the compressor bypass pipe 4, and the on-off operation is controlled by the control device 70. You may comprise so that it may control.

As described above, in this embodiment, since the short circuit for circulating the lubricating oil is provided only around the liquid pump 23, it is possible to prevent the flow rate from decreasing when the liquid pump 23 is operated for a long time. . Further, the configuration other than the oil separator 40 and the lubricating oil return pipe 41 is the same as that of the second embodiment, so that the same effects as those of the second embodiment can be obtained.

Embodiment 4 Hereinafter, for example, a cooling device will be described as an air conditioner according to Embodiment 4 of the present invention. FIG. 12 is a configuration diagram showing an air conditioner according to the present embodiment. In the figure, reference numeral 5 denotes a liquid pump bypass pipe via a check valve 25 for bypassing the liquid pump 23. In the figure, the same reference numerals as those in FIG. 10 indicate the same or corresponding parts. The connection of the control signal line from the control device 70 to each device is the same as in FIG. 10 and is omitted here. In the present embodiment, the second temperature sensor 72 detects the pipe temperature at the outlet of the condenser 22. As described in the first embodiment, the temperature of the pipe from the outlet of the condenser 22 to the inlet of the liquid pump 23 is detected instead of detecting the outside air temperature as the temperature of the fluid to be heated flowing into the condenser 22. The compressor operation mode and the liquid pump operation mode can be switched based on the temperature difference between the pipe temperature and the room temperature. This is because the temperature of the refrigerant flowing through this part of the pipe can be regarded as substantially equal to the temperature of the fluid to be heated flowing into the condenser 22.

The indoor unit 10 comprises an evaporator 11 for evaporating the wet steam flowing from the liquid pipe 3b by the air conditioning load of the space to be air-conditioned and forming a refrigerant gas, and forcibly evaporating the indoor air.
1 comprises an evaporator-side blower 12 for blowing air to the outer surface and an indoor temperature sensor 71. The outdoor unit 20 includes a compressor 21 for compressing the refrigerant gas, a condenser 22 for cooling and liquefying the refrigerant gas, a condenser-side blower 26 for forcibly blowing outside air to the outer surface of the condenser 22, and a liquid pump 23. Check valve 25 that bypasses liquid pump 23 in compressor operation mode
, A liquid pump bypass pipe 5, an electronic expansion valve 13 that decompresses the high-temperature and high-pressure refrigerant liquid that has exited the condenser 22 to produce a two-phase wet vapor, in the case of a transient phenomenon or refrigerant overfilling. An accumulator 27 for storing the refrigerant liquid to prevent the liquid from returning to the compressor 21, an electromagnetic valve 28 for preventing the refrigerant from flowing into the accumulator 27 in the liquid pump operation mode, and the compressor 21 and the accumulator 27 in the liquid pump operation mode.
, A check valve 29 for preventing refrigerant from flowing into the compressor 21 in the liquid pump operation mode, and an outside air temperature sensor 72. The liquid pump 23 and the electronic expansion valve 13 are connected in series to a pipe between the outlet of the condenser 22 and the inlet of the evaporator 11, and in FIG.
Although it is installed at a position lower than 0, there is no particular limitation on the positional relationship between the heights.

In this air conditioner, when the compressor operation mode is performed, the opening of the electronic expansion valve 13 is controlled by the control device 70 so that the degree of supercooling at the outlet of the condenser 22 becomes constant. After setting, the compressor 21 is operated and the liquid pump 23 is operated.
Is stopped. At this time, the check valve 24 is closed due to the pressure difference between the discharge pressure and the suction pressure of the compressor 21, and the check valve 25 is closed.
Is opened by the flow of the refrigerant to form a refrigerant circuit for compressor operation. That is, the refrigerant flows from the compressor 21 to the check valve 2
9 → condenser 22 → check valve 25 → electronic expansion valve 13 → liquid pipe 3b → evaporator 11 → gas pipe 3a → electromagnetic valve 28 → accumulator 27 → compressor 21 Driving is performed.

When the liquid pump operation mode is performed, the control device 70 closes the solenoid valve 28 and sets the opening of the electronic expansion valve 13 to a constant value, for example, the degree of superheat at the outlet of the evaporator 11. Then, the liquid pump 23 is operated and the compressor 21 is stopped. At this time, the check valve 24 is opened by the flow of the refrigerant, and the check valve 25 is closed by the pressure difference between the discharge pressure and the suction pressure of the liquid pump 23 to form a refrigerant circuit in the liquid pump operation mode. That is, the refrigerant is supplied from the liquid pump 23 → the electronic expansion valve 13 → the liquid pipe 3b → the evaporator 11
→ gas pipe 3a → check valve 24 → condenser 22 → liquid pump 2
The refrigerant flows in the refrigerant circuit in the order of 3, and the cooling operation is performed.

The air conditioner according to the present embodiment has the structure shown in FIG.
In the prior art device, the opening / closing valve 24 and the opening / closing valve 25 are each constituted by a check valve. The check valve is connected to the compressor 21
Alternatively, the opening / closing operation is automatically performed by the pressure difference of the refrigerant generated by the operation of the liquid pump 23, and the opening / closing operation by the command from the control device 70 is not required. For this reason, when the operation mode is switched, the compressor 21 and the liquid pump 23 have a simple structure that can be opened and closed without control along with the activation thereof, and the outdoor unit can be downsized and the control device 70 can be simplified. it can. Further, the opening / closing valves 24 and 29 are not limited to those constituted by the check valves, but may be constituted by electromagnetic valves as in Embodiment 1 and the opening / closing operation thereof is controlled by the control device 70. There is an effect due to the configuration with the stop valve 25. Also, as described in the first embodiment, the compressor bypass piping 4
An opening / closing valve, such as a three-way valve, capable of switching a multidirectional flow path may be provided on the inlet side or the outlet side of the device, and the opening / closing operation thereof may be controlled by the control device 70.

In the compressor operation mode, the liquid pump 23
Since the configuration other than the liquid pump bypass pipe 5 via the check valve 25 for bypassing is the same as that of the second embodiment, the same effect as that of the second embodiment can be obtained. Furthermore, since the refrigeration cycle configured in the compressor operation mode has the same refrigerant circuit as the refrigeration cycle of the air conditioner that is currently widely used, the control method of the electronic expansion valve 13 can be used as it is. There is also an effect. For the control of the electronic expansion valve 13, it is necessary not only to open and close the on-off valve, for example, but also to control the opening degree while observing the state of the refrigerant, and to set the optimum state of the refrigerant according to the change of the refrigerant circuit. This is complicated, and the effect on the fact that the existing control method can be used is great.

Embodiment 5 Hereinafter, for example, a cooling device will be described as an air conditioner according to Embodiment 5 of the present invention. FIG. 13 is a configuration diagram showing an air conditioner according to the present embodiment. In the figure, a liquid pump 23 is connected between an outlet of a condenser 22 and an inlet of an evaporator 11 by an electronic expansion valve 1.
3 are connected in parallel. Reference numeral 42 denotes an on-off valve (second on-off valve) which is provided in a parallel portion to which the liquid pump 23 is connected and opens and closes the flow of the refrigerant from the condenser 22 to the liquid pump 23, for example, an electromagnetic valve. The opening and closing operation of the electromagnetic valve 42 is performed by the control device 70. In the figure, the same reference numerals as those in FIG. 10 indicate the same or corresponding parts.

The indoor unit 10 comprises an evaporator 11 for evaporating wet steam flowing from the liquid pipe 3b by an air-conditioning load of the space to be air-conditioned to produce a refrigerant gas, and forcibly evaporating the indoor air to the evaporator 1.
1 comprises an evaporator-side blower 12 for blowing air to the outer surface and an indoor temperature sensor 71. Further, the outdoor unit 20 includes a compressor 21 for compressing the refrigerant gas, a condenser 22 for cooling and liquefying the refrigerant gas, a condenser-side blower 26 for forcibly blowing outside air to the outer surface of the condenser 22, and a liquid pump 23. Valve 42 for opening and closing the inflow of refrigerant, liquid pump 23, condenser 22
Electronic expansion valve 13 that decompresses the high-temperature and high-pressure refrigerant liquid that has exited to produce wet vapor in a two-phase state, and an accumulator 27 that prevents liquid from returning to the compressor 21 in the event of a transient phenomenon or refrigerant overfilling. , The accumulator 27 in the liquid pump operation mode
Solenoid valve 28 for preventing refrigerant from flowing into the compressor, compressor bypass pipe 4 through check valve 24 for bypassing compressor 21 and accumulator 27 in liquid pump operation mode, and to compressor 21 in liquid pump operation mode The electronic expansion valve 13 includes a check valve 29 for preventing the refrigerant from flowing in, and an outside air temperature sensor 72.
The liquid pump 23 is connected in parallel to the pipe between the inlets of the liquid crystal device 1 and is installed in parallel with the electronic expansion valve 13. Also, the solenoid valve 4
2 is connected between the outlet of the condenser 22 and the inlet of the liquid pump 23 and closer to the liquid pump 23 than the connection with the electronic expansion valve 13. The operation of connecting / disconnecting the pump 23 to / from the refrigerant circuit is performed.

In this air conditioner, when the compressor operation mode is performed, the controller 70 opens the solenoid valve 28 and closes the solenoid valve 42, and sets the opening of the electronic expansion valve 13. The opening degree of the electronic expansion valve 13 is, for example,
The degree of supercooling at the outlet of Step 2 is set to a constant value.
Then, the compressor 21 is operated and the liquid pump 23 is stopped. At this time, the check valve 24 is closed by the pressure difference between the discharge pressure and the suction pressure of the compressor 21 to form a refrigerant circuit in the compressor operation mode. That is, the refrigerant flows from the compressor 21 → the check valve 29 → the condenser 22 → the electronic expansion valve 13 → the liquid pipe 3b.
The evaporator 11 → the gas pipe 3a → the solenoid valve 28 → the accumulator 27 → the compressor 21 flows in the refrigerant circuit in this order, and the cooling operation is performed.

When the liquid pump operation mode is performed, the control device 70 closes the electromagnetic valve 28 and sets the electromagnetic valve 42
Is opened, and the electronic expansion valve 13 is closed. Then, the liquid pump 23 is operated to stop the compressor 23. At this time, the check valve 24 is opened by the flow of the refrigerant, and a refrigerant circuit in the liquid pump operation mode is formed. That is, the refrigerant flows through the refrigerant circuit in the order of the liquid pump 23 → the liquid pipe 3b → the evaporator 11 → the gas pipe 3a → the check valve 24 → the condenser 22 → the solenoid valve 42 → the liquid pump 23; Done.

In the present embodiment, since the refrigerant does not pass through the electronic expansion valve in the liquid pump operation mode, there is no need to control the opening of the electronic expansion valve, and the control device 70 can be simplified. In the first to fourth embodiments, the control of the electronic expansion valve 13 in the liquid pump operation mode is performed by detecting the degree of superheat at the outlet of the evaporator 11 and controlling the opening thereof, which is complicated. However, in the present embodiment, it is not necessary to perform this control, and control in the liquid pump operation mode is greatly simplified.

It should be noted that the pressure loss in the refrigerant circuit is smaller than when the refrigerant circuit in the liquid pump operation mode according to the present embodiment and the electronic expansion valve of the first to fourth embodiments are passed. And the refrigerant circulation amount increases. This phenomenon will be described with reference to FIG. FIG. 14 shows the refrigerant circulation amount with respect to the pressure difference between the discharge pressure and the suction pressure of the liquid pump 23. In the figure, U0 is a characteristic curve of the liquid pump 23, U1 is a refrigerant circuit characteristic curve when the refrigerant flow path has an expansion valve as in the configurations of the first to fourth embodiments, and U2 is the present embodiment. It is a refrigerant circuit characteristic curve when there is no expansion valve in the refrigerant flow path as in the configuration of the embodiment. As shown by the curve U0, the refrigerant circulation amount of the liquid pump 23 decreases linearly as the pressure difference increases. On the other hand, the pressure loss in the refrigerant circuit increases with an increase in the amount of circulating refrigerant.
The pressure loss of 1) is larger than that of the case where no passage occurs (curve U2). In FIG. 14, the refrigerant circulation amount in the liquid pump operation mode is obtained as the intersection of the liquid pump characteristic curve U0 and the refrigerant circuit characteristic curves U1 and U2. Therefore,
The refrigerant circulation amount when the refrigerant does not pass through the electronic expansion valve 13 is point A, and is larger than the point B when the refrigerant passes.
This is represented on a pressure-enthalpy diagram as shown in FIG. In the figure, 52 is a refrigerant saturation pressure corresponding to the indoor temperature, and 53 is a refrigerant saturation pressure corresponding to the outside air temperature. In the liquid pump operation mode cycle in which the refrigerant passes through the electronic expansion valve, ignoring the pressure loss at the check valve 24, the liquid pump outlet 54 → the electronic expansion valve outlet (evaporator inlet) 55 →
A route is taken from the evaporator outlet (gas pipe inlet) 56 → gas pipe outlet (condenser inlet) 57 → condenser outlet (liquid pump inlet) 58. In the liquid pump operation mode cycle in which the refrigerant does not pass through the electronic expansion valve, the liquid pump outlet (evaporator inlet) 59 → if the pressure loss at the check valve 24 is ignored.
The evaporator outlet (gas pipe inlet) 60 → gas pipe outlet (condenser inlet) 61 → condenser outlet (liquid pump inlet) 62 takes a route, and the liquid pump operation mode in the case where the refrigerant passes through the electronic expansion valve. Compared with the cycle, the refrigerant circulation amount increases, but the enthalpy difference decreases from D to C.

Therefore, in the present embodiment, the refrigerant state at the outlet of the evaporator 22 in the liquid pump operation mode becomes two-phase due to an increase in the amount of circulating refrigerant. The amount of refrigerant at the inlet of the liquid pump 23 decreases as compared with the case. In such a case, cavitation is likely to occur due to the refrigerant gas being mixed into the inlet of the liquid pump 23. This can be avoided by taking measures such as installing a container. Further, when the accumulator 27 is provided at the outlet of the evaporator 11 as shown in FIG. 13, the accumulator 2 is not operated under the condition that the refrigerant state at the outlet of the evaporator 11 becomes two-phase in the liquid pump operation mode.
When the refrigerant liquid flows into the compressor 7 and the compressor 21, the required refrigerant amount is not ensured, and the inlet of the liquid pump 23 may be in a two-phase state to cause cavitation. However, in the present embodiment, the inlet of the accumulator 27 and the compressor 21
Since the solenoid valve 28 and the check valve 29 are respectively provided at the outlets of the above, such inflow of the refrigerant can be prevented, the required amount of refrigerant can be secured, and a stable liquid pump operation can be performed. Further, the on-off valves 24 and 29 are not limited to the check valves, but may be configured by electromagnetic valves and the opening and closing operations thereof are controlled by the control device 70 as in the first embodiment. As described in the first embodiment, an on-off valve such as a three-way valve, which can switch a multi-directional flow path, is provided on the inlet side and the outlet side of the compressor bypass pipe 4, and the on-off operation is controlled by the control device 70. You may comprise so that it may control.
Further, instead of the electromagnetic valve 42, an on-off valve such as a three-way valve capable of switching a multi-directional flow path is provided at a branch portion between the liquid pump 23 and the electronic expansion valve 13, and the on-off operation is controlled by the control device 70. You may comprise so that it may control.

As described above, in this embodiment, since the electronic expansion valve is not provided at the outlet of the liquid pump 23, it is necessary to control the opening of the electronic expansion valve in the liquid pump operation mode. Therefore, the control device can be simplified.
Further, in the present embodiment, the example in which the electronic expansion valve 13 is closed in the liquid pump operation mode has been described.
When 3 is set to an appropriate opening, a short circuit that does not pass through the evaporator and the condenser, which is the liquid pump 23 → the electronic expansion valve 13 → the solenoid valve 42, is formed, and a part of the refrigerant liquid discharged from the liquid pump 23 Flows through this short circuit, the cooling capacity in the liquid pump operation mode can be controlled. For example,
If the opening degree of the electronic expansion valve 13 is changed based on the temperature difference between the room temperature and the outside air temperature to control the amount of refrigerant circulating in the short circuit, the cooling capacity in the liquid pump operation mode is reduced to the room temperature. It can be controlled based on the temperature difference between the temperature and the outside air temperature.

Embodiment 6 FIG. Hereinafter, for example, a cooling device will be described as an air conditioner according to Embodiment 6 of the present invention. FIG. 16 is a configuration diagram showing an air conditioner according to the present embodiment. In the figure, reference numeral 43 denotes a second pressure reducing means provided in a pipe between the outlet of the liquid pump 23 and the inlet of the evaporator 11, and is, for example, an electronic expansion valve. In the figure, the same reference numerals as those in FIG. 13 indicate the same or corresponding parts. Also,
The connection of the control signal lines from the control device 70 to each device is omitted here, but in addition to the control signal lines in FIG. 13, the control signal lines are controlled so that the control device 70 also controls the electronic expansion valve 43. Are connected.

The indoor unit 10 comprises an evaporator 11 which evaporates the wet steam flowing from the liquid pipe 3b by the air-conditioning load of the space to be air-conditioned and turns it into a refrigerant gas.
1 comprises an evaporator-side blower 12 for blowing air to the outer surface and an indoor temperature sensor 71. The outdoor unit 20 includes a compressor 21 for compressing the refrigerant gas, a condenser 22 for cooling and liquefying the refrigerant gas, a condenser-side blower 26 for forcibly blowing outside air to the outer surface of the condenser 22, and a liquid pump. An electromagnetic valve 42 for preventing the refrigerant from flowing into the side 23, a liquid pump 23, an electronic expansion valve 13 for reducing the temperature of the high-temperature and high-pressure refrigerant liquid that has exited the condenser 22 into two-phase wet steam, and a liquid pump 23. Electronic expansion valve 43 for reducing the pressure of the refrigerant liquid discharged from the compressor, an accumulator 27 for preventing liquid from returning to the compressor 21 in the event of a transient phenomenon or refrigerant overfilling, and an accumulator in the liquid pump operation mode. A solenoid valve 28 for preventing refrigerant from flowing into the compressor 27, a compressor bypass pipe 4 via a check valve 24 for bypassing the compressor 21 and the accumulator 27 during operation of the liquid pump, and a liquid pump operation mode The liquid pump 23 and the electronic expansion valve 13 are connected in parallel, and the liquid pump 23 and the electronic expansion valve 43 are connected in series. It is connected.

In this air conditioner, in the compressor operation mode, the control device 70 opens the solenoid valve 28 and closes the solenoid valve 42 to control the opening of the electronic expansion valve 13 and the electronic expansion valve 43. For example, the compressor 21 is operated by setting the degree of supercooling at the outlet of the condenser 22 to a constant value, and the liquid pump 23 is stopped. At this time, the check valve 24 is closed by the pressure difference between the discharge pressure and the suction pressure of the compressor 21 to form a refrigerant circuit in the compressor operation mode. That is, the refrigerant flows from the compressor 21 → the check valve 29 → the condenser 22 → the electronic expansion valve 13 → the electronic expansion valve 43 → the liquid pipe 3b → the evaporator 11
The gas flows in the refrigerant circuit in the order of the gas pipe 3a, the solenoid valve 28, the accumulator 27, and the compressor 21 to perform the cooling operation.

In the liquid pump operation mode, the controller 70 closes the solenoid valve 28 and opens the solenoid valve 42, closes the electronic expansion valve 13, and sets the electronic expansion valve 43 to an appropriate opening degree. For example, the opening degree is set such that the degree of superheat at the outlet of the evaporator 11 is about 5 ° C., and the liquid pump 23 is operated to stop the compressor 21. At this time, the check valve 24 is opened by the flow of the refrigerant, and a refrigerant circuit in the liquid pump operation mode is formed. That is, the refrigerant is supplied from the liquid pump 23 → the electronic expansion valve 43 → the liquid pipe 3b → the evaporator 11 → the gas pipe 3
a → check valve 24 → condenser 22 → solenoid valve 42 → liquid pump 2
The refrigerant flows in the refrigerant circuit in the order of 3, and the cooling operation is performed. Further, the on-off valves 24 and 29 are not limited to the check valves, but may be configured by electromagnetic valves and the opening and closing operations thereof are controlled by the control device 70 as in the first embodiment.

In this embodiment, the electronic expansion valve 43 is connected to the pipe between the outlet of the liquid pump 23 and the inlet of the evaporator 11.
Is installed, for example, the state of the refrigerant at the outlet of the evaporator 11 can be controlled, and there is an effect that the evaporator 11 can be used effectively.

Embodiment 7 FIG. Hereinafter, for example, a cooling device will be described as an air conditioner according to Embodiment 7 of the present invention. FIG. 17 is a configuration diagram showing an air conditioner according to the present embodiment. In the figure, reference numeral 44 denotes a high / low pressure bypass pipe (second bypass pipe) connecting the high pressure section and the low pressure section of the refrigerant circuit configured in the compressor operation mode. The high-pressure pipe in the compressor operation mode is a pipe from an outlet of the compressor 21 to an inlet of the electronic expansion valve 13 which is a pressure reducing means.
The low-pressure pipe is a pipe from the outlet of the electronic expansion valve 13 that is a pressure reducing means to the inlet of the compressor 21. For example, one end of the high / low pressure bypass pipe 44 is connected to a high pressure section on the outlet side of the compressor 21, and the other end is connected to a low pressure section in the accumulator 27. Further, an on-off valve (a fifth on-off valve), for example, an electromagnetic valve 45 is provided in the high / low pressure bypass pipe 44. Although connection of control signal lines from the control device 70 to each device is omitted here, in addition to each control signal line in FIG. 10, control signal lines are controlled so that the control device 70 also controls the solenoid valve 45. Are connected. In other parts, FIG.
The same reference numerals indicate the same or corresponding parts.

The indoor unit 10 includes an evaporator 11, an evaporator-side blower 12, and an indoor temperature sensor 71 for evaporating wet steam flowing from the liquid pipe 3b by an air conditioning load. Further, the outdoor unit 20 is a compressor 2 for compressing the refrigerant gas.
1. A condenser 22 for cooling and liquefying the refrigerant gas, a condenser-side blower 26 for forcibly blowing outside air to the outer surface of the condenser 22, a liquid pump 23, and a high-temperature high-pressure refrigerant liquid exiting the condenser 22. Electronic expansion valve 1 to obtain two-phase wet steam
3. Compressor 21 for transient phenomena or overfilling of refrigerant
An accumulator 27 for preventing liquid from returning to the reservoir, a solenoid valve 28 for preventing refrigerant from flowing into the accumulator 27 in the liquid pump operation mode, and a check valve 2 for bypassing the compressor 21 and the accumulator 27 in the liquid pump operation mode.
A check valve 29 for preventing refrigerant from flowing into the compressor 21 in the liquid pump operation mode;
A high / low pressure bypass pipe 4 via an electromagnetic valve 45 connecting a high pressure section at the outlet of the compressor 21 and a low pressure section of the accumulator 27.
4. An outside air temperature sensor 72 is provided.

In this air conditioner, in the compressor operation mode, the control device 70 closes the solenoid valve 45 and opens the solenoid valve 28, and adjusts the opening of the electronic expansion valve 13 by, for example, Set the degree of supercooling at the outlet to a constant value. Then, the compressor 21 is operated, and the liquid pump 23 is operated or stopped. At this time, the check valve 24 is closed by the pressure difference between the discharge pressure and the suction pressure of the compressor 21 to form a refrigerant circuit in the compressor operation mode. That is, the refrigerant flows from the compressor 21 → the check valve 29 → the condenser 22 → the liquid pump 2
3 → electronic expansion valve 13 → liquid pipe 3b → evaporator 11 → gas pipe 3a → electromagnetic valve 28 → accumulator 27 → compressor 2
The refrigerant flows in the refrigerant circuit in the order of 1, and the cooling operation is performed.

In the case of the liquid pump operation mode, the controller 70 closes the solenoid valve 28 and the solenoid valve 45 and opens the electronic expansion valve 13 at an appropriate opening degree, for example, the evaporator 11.
The liquid pump is operated by setting the opening degree so that the degree of superheat at the outlet of is about 5 ° C., and the compressor 21 is stopped. At this time, the check valve 24 is opened by the flow of the refrigerant, and a refrigerant circuit for operating the liquid pump is formed. That is, the refrigerant is supplied from the liquid pump 23 → the electronic expansion valve 13 → the liquid pipe 3b → the evaporator 11
→ gas pipe 3a → check valve 24 → condenser 22 → liquid pump 2
The refrigerant flows in the refrigerant circuit in the order of 3, and the cooling operation is performed.

By the way, comparing the compressor operation mode and the liquid pump operation mode, in the liquid pump operation mode, in addition to the liquid pipe 3b being completely filled with the liquid, the liquid pump 23 is operated in order to prevent cavitation. Since it is necessary to increase the degree of subcooling at the inlet, the appropriate refrigerant amount is larger in the liquid pump operation mode than in the compressor operation mode. However, when the accumulator 27 is installed at the suction portion of the compressor 21 as shown in FIG. 17, excess refrigerant is accumulated in the accumulator 27 in the compressor operation mode. Therefore, it is necessary to perform a refrigerant recovery operation of recovering the surplus refrigerant to the refrigerant circuit in the liquid pump operation mode when switching to the liquid pump operation mode.

In the refrigerant recovery operation, the electronic expansion valve 13
There is also a method of operating the compressor by completely closing the opening of the compressor, but in this method, since the suction pressure of the compressor 21 rapidly decreases,
The refrigerant liquid sucked into the compressor 21 foams, and the refrigerating machine oil flows out into the refrigerant circuit together with the discharged gas, and the amount of the refrigerating machine oil inside the compressor 21 decreases, which may lead to burnout due to poor lubrication. In particular, in the case of a scroll compressor, the amount of oil supplied to a sliding portion is reduced due to a decrease in suction pressure or a bubbling of a refrigerant liquid inside the compressor 21, and the sliding portion is thermally deformed due to a rise in temperature, leading to breakage. Problems arise. In addition, the refrigerating machine oil that has flowed into the refrigerant circuit causes an increase in pressure loss, which also causes a reduction in cooling capacity in the liquid pump operation mode.
Therefore, without lowering the suction pressure of the compressor 21,
It is necessary to perform a refrigerant recovery operation.

FIG. 18 shows a flow chart at the time of operation switching from the compressor operation mode to the liquid pump operation mode in the air conditioner of the present embodiment. In ST21, the compressor operation mode is performed, the solenoid valve 28 is opened, the solenoid valve 45 is closed, and the degree of opening of the electronic expansion valve 13 is such that the degree of supercooling at the outlet of the condenser 22 is constant. This is a state in which the opening is set to an appropriate opening (opening P). In ST22, when the temperature difference between the room temperature and the outside air temperature becomes a predetermined value, for example, 10 ° C. or more, an operation switching command to the liquid pump operation mode is received,
In ST23, the electromagnetic valve 45 is opened, and in ST24, the opening degree of the electronic expansion valve 13 is changed to an opening degree (opening Q) at which the superheat degree at the outlet of the evaporator 11 becomes 20 ° C., for example. The refrigerant recovery operation is performed for a predetermined time, for example, about 1 minute (ST25).
In the refrigerant recovery operation (ST25), the accumulator 2
The refrigerant liquid in the evaporator 11 and the superheated gas from the evaporator 11
Is evaporated by the superheated gas discharged from the compressor 21 flowing through the high / low pressure bypass pipe 42 through the compressor 2.
Inhaled to 1.

Next, the compressor 21 is stopped in ST26, and S
At T27, the electromagnetic valve 28 is closed to prevent the refrigerant from flowing into the accumulator 27. Then, in ST28, the solenoid valve 45
Is closed, and the opening degree of the electronic expansion valve 13 is set (opening degree R) so that the superheat degree at the outlet of the evaporator 11 becomes an appropriate value, for example, 5 ° C. (open degree R) (ST29). The operation shifts to the pump operation mode (ST30).

In the refrigerant recovery operation (ST25), the compressor 2
Since the high-temperature and high-pressure superheated gas discharged from 1 is bypassed to the suction part of the compressor 21, the refrigerant accumulated in the accumulator 27 is recovered to the refrigerant circuit in the liquid pump operation mode without lowering the low pressure of the compressor 21. can do.
In ST25, an example in which the refrigerant recovery operation is performed for a certain period of time has been described. However, the temperature and pressure of the suction or discharge pipe of the compressor 21 are detected, and the refrigerant recovery operation is performed until the detected temperature and pressure reach the set values. It may be.

Further, in ST25, an example has been shown in which the refrigerant recovery operation is performed for a fixed time in order to simplify the control device. However, based on the outside air temperature detected by the outside air temperature sensor 72, ST25
By changing the opening time of the electronic expansion valve 13 during the refrigerant recovery operation or during the refrigerant recovery operation, the amount of refrigerant recovered in the accumulator 27 may be controlled with respect to the outside air temperature. For example, when the outside air temperature is high, the recovered refrigerant amount is reduced, and when the outside air temperature is low, the recovered refrigerant amount is increased. Further, the amount of the collected refrigerant may be controlled based on the temperature difference between the outside air temperature and the room temperature using the outside air temperature detected by the outside air temperature sensor 72 and the room temperature detected by the room temperature sensor 71. For example, when the temperature difference is small, the amount of collected refrigerant is reduced, and when the temperature difference is large, the amount of collected refrigerant is increased. By performing such control, the amount of refrigerant in the liquid pump operation mode can be optimized for the outside air temperature, and the cooling capacity in the liquid pump operation mode can be used to the maximum.

By switching the operation from the compressor operation mode to the liquid pump operation mode according to the above procedure,
The refrigerant accumulated in the accumulator 27 can be recovered in the refrigerant circuit in the liquid pump operation mode without lowering the suction pressure of the compressor 21, and a stable liquid pump operation mode can be performed, and the reliability of the compressor 21 can be improved. Can be improved. The on-off valves 24 and 29 are not limited to those constituted by check valves, but may be constituted by solenoid valves and their opening and closing operations are controlled by the control device 70 as in the first embodiment.

Embodiment 8 FIG. Hereinafter, for example, a cooling device will be described as an air conditioner according to Embodiment 8 of the present invention. FIG. 19 is a configuration diagram showing an air conditioner according to the present embodiment. In the figure, reference numeral 46 denotes a liquid storage means provided in a pipe between the outlet of the condenser 22 and the inlet of the liquid pump 23, for example, a liquid receiver for storing a refrigerant liquid therein. 47 is a supercooling means for supercooling the refrigerant flowing between the outlet of the condenser 22 and the inlet of the liquid pump 23, for example, a supercooling device for obtaining a predetermined degree of subcooling at the inlet of the liquid pump 23. A cooling unit 48 is an on-off valve provided in a bypass pipe of the subcooler 47, for example, an electromagnetic valve. Although connection of control signal lines from the control device 70 to each device is omitted here, in addition to the control signal lines in FIG.
The control signal line is connected as described above. In other parts, the same reference numerals as those in FIG. 10 indicate the same or corresponding parts.

The indoor unit 10 includes an evaporator 11 for evaporating wet steam flowing from the liquid pipe 3b by an air conditioning load, an evaporator-side blower 12, and an indoor temperature sensor 71. Further, the outdoor unit 20 is a compressor 2 for compressing the refrigerant gas.
1. A condenser 22 for cooling and liquefying the refrigerant gas, a condenser-side blower 26 for forcibly blowing outside air to the outer surface of the condenser 22, and a receiver 46 for storing a refrigerant liquid flowing from an outlet of the condenser 22. A supercooler 47 for obtaining a predetermined degree of subcooling at the inlet of the liquid pump 23, an electromagnetic valve 48 provided on a bypass pipe of the subcooler 47, and an electromagnetic valve provided on a pipe passing through the inside of the subcooler 47. A valve 49, an electronic expansion valve 13 that decompresses the high-temperature and high-pressure refrigerant liquid that has exited the condenser 22 to produce a two-phase wet vapor, and supplies a liquid to the compressor 21 in the event of a transient phenomenon or refrigerant overcharge. Accumulator 27 to prevent return
A solenoid valve 28 for preventing refrigerant from flowing into the accumulator 27 in the liquid pump operation mode, a compressor bypass pipe 4 through a compressor 21 and a check valve 24 for bypassing the accumulator 27, and a compressor in the liquid pump operation mode 2
1 comprises a check valve 29 for closing the flow of refrigerant into the air conditioner 1 and an outside air temperature sensor 72.

The liquid receiver 46 is arranged below the condenser 22 and above the liquid pump 23, and has a refrigerant inflow pipe and a refrigerant outflow pipe from the condenser 22. The refrigerant outflow pipe is connected to a lower part of the receiver 46, and the refrigerant inflow pipe is connected above the refrigerant outflow pipe. For this reason, the refrigerant liquid is reliably supplied to the refrigerant outflow pipe. The internal volume of the liquid receiver 46 is a volume that can store a refrigerant liquid corresponding to an appropriate refrigerant amount difference between the compressor operation mode and the liquid pump operation mode.

The supercooler 47 further cools the refrigerant liquid from the liquid receiver 46 to increase the degree of supercooling. The supercooler 47 is filled with a heat storage material, for example, water. Are installed in the heat storage material. Further, the subcooler 47
Is arranged in contact with the accumulator 27 so that the internal heat storage material can obtain cold heat from the accumulator 27 in the compressor operation mode.

In the air conditioner, when the compressor operation mode is performed, the control device 70 opens the solenoid valves 28 and 48 and closes the solenoid valve 49, and adjusts the opening of the electronic expansion valve 13 by, for example, condensing. The degree of supercooling at the outlet of the vessel 22 is set to a constant value. Then, the compressor 21 is operated, and the liquid pump 23 is operated or stopped. At this time, check valve 2
4 is closed by the pressure difference between the discharge pressure and the suction pressure of the compressor 21 to form a refrigerant circuit in the compressor operation mode. That is, the refrigerant flows from the compressor 21 → the check valve 29 → the condenser 22 →
The liquid flows in the refrigerant circuit in the order of the receiver 46 → the solenoid valve 48 → the liquid pump 23 → the electronic expansion valve 13 → the liquid pipe 3 b → the evaporator 11 → the gas pipe 3 a → the solenoid valve 28 → the accumulator 27 → the compressor 21. , A cooling operation is performed. At this time, the subcooler 4
The heat storage material inside 7 is cooled to the same temperature as the accumulator 27 by the latent heat of evaporation of the refrigerant liquid in the accumulator 27, and the heat storage material stores cold heat.

When the liquid pump operation mode is performed, the control device 70 closes the solenoid valves 28 and 48 and opens the solenoid valve 49, and adjusts the opening of the electronic expansion valve 13 by, for example, the outlet of the evaporator 11. The degree of superheat is set to 5 ° C. Then, the liquid pump 23 is operated to stop the compressor 21. At this time, the check valve 24 is opened by the flow of the refrigerant, and a refrigerant circuit in the liquid pump operation mode is formed. That is, the refrigerant is supplied from the liquid pump 23 → the electronic expansion valve 13 → the liquid pipe 3b → the evaporator 11 → the gas pipe 3a → the check valve 24 → the condenser 22 → the liquid receiver 46 → the electromagnetic valve 49 → the supercooler 47 → The liquid flows in the refrigerant circuit in the order of the liquid pump 23, and the cooling operation is performed.

In the compressor operation mode, the compressor 21 is operated, and the liquid pump 23 is operated or stopped. Further, the liquid pump 23 is operated in the liquid pump operation mode. When the liquid pump 23 is operated, a problem of cavitation occurs. However, in the air conditioner according to the present embodiment, since the liquid receiver 46 is provided at the outlet of the condenser 22, the refrigerant liquid is surely formed during the operation of the liquid pump. The liquid is supplied to the liquid pump 23. For this reason,
The occurrence of cavitation can be prevented, and the liquid pump 23 can be operated stably. Furthermore, since the supercooler 47 is provided, the degree of supercooling of the refrigerant liquid at the inlet of the liquid pump 23 can be increased, and further cavitation can be prevented. Further, the cooling source of the supercooler 47 is set to the accumulator 2 in the compressor operation mode.
7, it is not necessary to provide a separate cold heat source from the refrigerant circuit as a cold heat source for the subcooler 47, and the liquid pump 23 can be stably operated within one refrigerant circuit. In the present embodiment, the cooling source of the subcooler is obtained in one refrigerant circuit. However, if the refrigerant circuit is provided with a heat storage tank, for example, an ice heat storage tank and is capable of performing heat storage operation, the supercooling may be performed. Ice water or the like can be used as a cold heat source of the vessel 47.

The temperature of the accumulator 27 in the compressor operation mode is about 0 to 10 ° C. When water is used as the heat storage material, cold heat is stored in the form of sensible heat. Therefore, a large amount of heat storage material is required to obtain a predetermined degree of subcooling, and the volume of the supercooler 47 is accordingly increased. In such a case, 0-10
By using a substance that undergoes a phase change at a temperature of, for example, clathrate (gas hydrate), cold heat can be stored in the form of latent heat, and the size of the supercooler 47 can be reduced.

In the present embodiment, the two solenoid valves 48 and 49 are used for the flow of the refrigerant into the subcooler 47 and the bypass. However, the present invention is not limited to this.
By controlling the operation of the control device 70 using the one-way valve, it is possible to select whether or not the refrigerant liquid flowing from the liquid receiver 46 passes through the supercooler 47.

Embodiment 9 FIG. Hereinafter, for example, a cooling device will be described as an air conditioner according to Embodiment 9 of the present invention. FIG. 20 is a configuration diagram showing an air conditioner according to the present embodiment. The present embodiment shows an air conditioner having a configuration including a plurality of indoor units while showing a configuration of a supercooling unit different from that of the eighth embodiment as a supercooling unit.
Reference numeral 50 denotes a heat storage material conveying pipe through which the heat storage material, for example, water, which is filled in the supercooler 47, is wound around the accumulator 27 to obtain the cold heat thereof, and
Transport to Reference numeral 51 denotes a heat storage material transfer pump that transfers the heat storage material in the pipe 50. Although connection of control signal lines from the control device 70 to each device is omitted here, FIG.
Control signal lines are connected so that the control device 70 also controls the electromagnetic valves 48 and 49 and the heat storage material conveying pump 51 in addition to the control signal lines of 0. In other parts, FIG.
The same reference numerals as 0 indicate the same or corresponding parts.

The air conditioner according to the present embodiment has a configuration having a plurality of indoor units 10. For example, two indoor units 10 are installed vertically, and an electronic expansion valve 13 serving as a decompression unit is installed in a box housing the evaporator 11, that is, in the indoor unit. The indoor unit 10 includes, for example, a condenser 22
An electronic expansion valve 13 which decompresses the high-temperature and high-pressure refrigerant liquid that has exited into a two-phase wet vapor, an evaporator 11 for evaporating the wet vapor flowing from the liquid pipe 3b by an air conditioning load, an evaporator-side blower 12, This is a box housing the electromagnetic valve 63 and the indoor temperature sensor 71. The upper indoor unit is given a suffix a, and the lower indoor unit is given a suffix b.

The outdoor unit 20 includes a compressor 21 for compressing the refrigerant gas and a condenser 2 for cooling and liquefying the refrigerant gas.
2. A condenser-side blower 26 that forcibly blows outside air to the outer surface of the condenser 22, a supercooler 47 for obtaining a predetermined degree of subcooling at an inlet of the liquid pump 23, and a bypass pipe of the supercooler 47. , A solenoid valve 49 provided in a pipe passing through the inside of the subcooler 47, and an accumulator 2
7, a pipe 50 for transporting the heat storage material filled in the supercooler 47 to the periphery of the accumulator 27, a pump 51 for transporting the heat storage material, a liquid pump 23, transient phenomena and overfilling of the refrigerant, etc. In the case of (1), an accumulator 27 for preventing the liquid from returning to the compressor 21, a solenoid valve 28 for preventing the refrigerant from flowing into the accumulator 27 during operation of the liquid pump, and a check valve 24 for bypassing the compressor 21 and the accumulator 27. It is a box housing the bypass pipe 4 for the compressor, the check valve 29 for preventing the refrigerant from flowing into the compressor 21 when the liquid pump is operated, and the outside air temperature sensor 72.

In this air conditioner, when the compressor operation mode is performed, the controller 70 opens the solenoid valves 28 and 48 and closes the solenoid valve 49, and adjusts the opening of the electronic expansion valve 13 by, for example, a condenser. The supercooling degree at the outlet 22 is set to a constant value. Then, the compressor 21 is operated, and the liquid pump 23 is operated or stopped. At this time, check valve 2
4 is closed by the pressure difference between the discharge pressure and the suction pressure of the compressor 21 to form a refrigerant circuit in the compressor operation mode. That is, the refrigerant flows from the compressor 21 → the check valve 29 → the condenser 22 →
Solenoid valve 48 → liquid pump 23 → liquid pipe 3b → electronic expansion valves 13a and 13b → evaporators 11a and 11b → solenoid valves 63a and 63b → gas pipe 3a → solenoid valve 28 → accumulator 27 → compressor 21 in order of refrigerant. The air flows in the circuit, and the cooling operation is performed. At this time, the heat storage material, for example, water inside the subcooler 47 flows through the heat storage material transfer pipe 50 by the heat storage material transfer pump 51, exchanges heat with the accumulator 27, and is cooled to the same temperature as the accumulator 27. Conversely, the excess refrigerant in the accumulator 27 evaporates due to heat radiation from the heat storage material. However, if the compressor operation mode extends for a long time, the temperature of the heat storage material in the supercooler 47 becomes equal to the temperature of the accumulator 27, The operation returns to the same operation state as the compressor operation mode when the cooler 47 is not provided. Thus, the heat storage material inside the subcooler 47 is stored in the accumulator 27.
The cold heat from is stored. If the compressor operation mode is performed for a long time, the heat storage material transport pump 51 is stopped when the temperature of the heat storage material is detected and reaches the same temperature as that of the accumulator 27. Can be omitted.

When the compressor 21 is stopped and the liquid pump operation mode is performed, the controller 70 closes the solenoid valves 28 and 48, opens the solenoid valve 49, and opens the electronic expansion valves 13a and 13b. The degree is, for example, evaporator 11a, 1
When the degree of superheat at the outlet of 1b is set to 5 ° C., the check valve 24 is opened by the flow of the refrigerant, and a refrigerant circuit in the liquid pump operation mode is formed. That is, the refrigerant is supplied from the liquid pump 23 → the liquid pipe 3b → the electronic expansion valve 13a.
And 13b → evaporators 11a and 11b → solenoid valve 63
a and 63b → gas pipe 3a → check valve 24 → condenser 2
The coolant flows through the refrigerant circuit in the order of 2 → electromagnetic valve 49 → supercooler 47 → liquid pump 23 to perform the cooling operation.

Here, the indoor unit 10b is installed below the indoor unit 10a, and the liquid pipe 3b is completely filled with the refrigerant liquid. For this reason, the inlet pressure of the indoor unit 10b is increased by the amount corresponding to the liquid head, that is, the pressure increase corresponding to the liquid column height, as compared with the indoor unit 10a, and the refrigerant easily flows. Therefore, for example, in order to set the degree of superheat at both outlets of the evaporators 11a and 11b to 5 ° C., the opening of the electronic expansion valve 13b is set smaller than the opening of 13a, and the indoor unit 10b It is necessary to increase the flow resistance in the electronic expansion valve 13b. Therefore, in the liquid pump operation mode, the opening of the electronic expansion valve 13b is set to be smaller by the liquid head than the opening of the electronic expansion valve 13a.

When the lower indoor unit 10b of the two indoor units is stopped, the stopped indoor unit 1b is stopped.
The electronic expansion valve 13b of 0b is fully closed, and the solenoid valve 63b is closed. To fully close the electronic expansion valve 13b,
This is to prevent the liquid refrigerant from staying in the indoor unit 10b where the liquid refrigerant is stopped from the liquid pipe 3b and becoming short of the refrigerant. This is to prevent the unevaporated refrigerant liquid from flowing out from the outlet of the evaporator 11a and staying in the stopped indoor unit 10b below the gas pipe 3a to cause a shortage of the refrigerant. Further, in the present embodiment, the case where two indoor units are installed is shown, but the number of indoor units is not limited to two. Similar effects can be obtained. However, when there is no vertical difference between the installation positions of the plurality of indoor units, it is not necessary to consider the liquid head for the opening degree of the electronic expansion valve 13. It is desirable that the expansion valve 13 be fully closed and the solenoid valve 63 be closed.

In the present embodiment, the electronic expansion valve 1
3 is installed in the indoor unit 10, and the liquid pipe 3b is always filled with the refrigerant liquid in both the compressor operation mode and the liquid pump operation mode. The difference in the amount of the refrigerant can be reduced, and the size of the accumulator 27 can be reduced and the operation time of the refrigerant recovery operation can be reduced. Further, since two indoor units are provided for one outdoor unit, the space of the outdoor unit can be reduced, and the two rooms can be cooled at the same time. A supercooler 47 is provided at the outlet of the condenser 22.
Is provided, the degree of supercooling of the refrigerant liquid at the inlet of the liquid pump 23 is increased, and the occurrence of cavitation can be prevented, and a stable liquid pump operation can be performed. Further, since the cooling source of the supercooler 47 is obtained from the accumulator 27 in the compressor operation mode, a stable liquid pump operation can be performed in one refrigerant circuit.

Embodiment 10 FIG. In Embodiments 1 to 9,
Although an example of a cooling device has been shown as an air conditioner, if the condenser is an indoor unit and the evaporator is an outdoor unit, it can be used as a heating device, and the same power consumption reduction effect as that of the cooling device can be obtained. . Hereinafter, for example, a heating device will be described as an air conditioner according to Embodiment 10. This embodiment has the same configuration as the cooling device according to the first embodiment,
FIG. 21 shows a configuration of an air conditioner according to the present embodiment. In the figure, the same reference numerals as those in FIG. 1 indicate the same or corresponding parts.

The indoor unit 10 includes a condenser 22 for condensing the refrigerant by an air-conditioning load in the space to be air-conditioned, a condenser-side blower 26 for forcibly blowing indoor air to the outer surface of the condenser 22, and a condenser 22. A second temperature detecting means 72 for detecting the temperature of the inflowing fluid to be heated, in this case, an indoor temperature sensor for detecting the indoor temperature is housed. Further, the outdoor unit 20 includes a compressor 21 for compressing the refrigerant gas, an evaporator 11 for evaporating the wet steam flowing from the electronic expansion valve 13 into a refrigerant gas, and forcing the outside air out of the evaporator 11. An evaporator-side blower 12 for blowing air to the surface, an electronic expansion valve 13 that decompresses the high-temperature and high-pressure refrigerant liquid that has exited the condenser 22 to produce two-phase wet vapor, transient phenomena and overfilling of the refrigerant, etc. , An accumulator 27 for preventing liquid return to the compressor 21, a liquid pump 23, and a solenoid valve 2 for preventing refrigerant from flowing into the accumulator 27 in the liquid pump operation mode.
8, a compressor bypass pipe 4 having an electromagnetic valve 24 for bypassing the compressor 21 in the liquid pump operation mode, an electromagnetic valve 29 for preventing refrigerant from flowing into the compressor 21 in the liquid pump operation mode, and the evaporator 11 A first temperature detecting means 71 for detecting the temperature of the fluid to be cooled flowing into the air conditioner, in which case an outside air temperature sensor for detecting the outside air temperature and the like are housed, and a control device 70 composed of, for example, a microcomputer is fixed on the side surface. Have been. The electronic expansion valve 13 is connected to a pipe between the outlet of the condenser 22 and the inlet of the evaporator 11, and the liquid pump 23 is connected to a pipe between the outlet of the condenser 22 and the inlet of the electronic expansion valve 13. Is connected in series with the electronic expansion valve 13. In FIG. 21, the indoor unit 10 is installed at a higher position than the outdoor unit 20. However, there is no particular limitation on the positional relationship.

This air conditioner is used in places where heating is required throughout the year, and for example, the temperature difference between the outside air temperature detected by the first temperature detecting means 71 and the room temperature detected by the second temperature detecting means 72 ( Hereinafter, the compressor operation mode and the liquid pump operation mode are switched by a command from the control device 70 on the basis of the temperature difference between the outside air temperature and the room temperature.
That is, when ΔT is, for example, 5 ° C. or less, the compressor 21
Heating operation in the compressor operation mode using
Under the condition of 0 ° C. or more, the liquid pump operation mode using the temperature of the outside air is performed. The reason that the condition of ΔT is different between the compressor operation mode and the liquid pump operation mode is to prevent the compressor 21 and the liquid pump 23 from being repeatedly started and stopped. Also, instead of the outside air temperature, the pipe temperature from the outlet of the condenser 22 to the inlet of the electronic expansion valve 13 is detected,
The compressor operation mode and the liquid pump operation mode may be switched based on the temperature difference between the pipe temperature and the room temperature.
This is because the temperature of the refrigerant flowing through this part of the pipe can be regarded as substantially equal to the temperature of the fluid to be heated flowing into the condenser 22.

First, the compressor operation will be described. The solenoid valve 24 is closed, the solenoid valves 28 and 29 are opened according to a command from the control device 70, and the opening of the electronic expansion valve 13 is adjusted so that the degree of supercooling at the outlet of the condenser 22 becomes a constant value. After setting, the compressor 21 is operated. At this time, for example, when the liquid pump 23 stops, a refrigerant circuit in the compressor operation mode is formed. That is, the refrigerant flows from the compressor 21 → the solenoid valve 29 → the gas pipe 3a → the condenser 22 → the liquid pipe 3b → the liquid pump 23 → the electronic expansion valve 13 → the evaporator 11 → the solenoid valve 28.
The refrigerant flows through the refrigerant circuit in the order of the accumulator 27 and the compressor 21 and exchanges heat with room air in the condenser 22 to perform a heating operation. At this time, the opening degree of the electronic expansion valve 13 needs to be larger than that in the case where the liquid pump operation mode is not used because the flow resistance occurs when the refrigerant passes through the inside of the liquid pump 23. However, when the compressor 21 and the liquid pump 23 are simultaneously operated in the compressor operation mode, the flow resistance when the refrigerant passes through the inside of the liquid pump 23 is reduced, and the opening degree of the electronic expansion valve 13 is reduced to the normal compression degree. The operation of the electronic expansion valve can be applied when the liquid pump operation mode is not used together.

Next, the liquid pump operation mode will be described. The control device 70 closes the solenoid valves 28 and 29, opens the solenoid valve 24, and sets the opening of the electronic expansion valve 13 to
For example, when the superheat degree at the outlet of the evaporator 11 is set to a constant value and the liquid pump 23 is operated, a refrigerant circuit in a liquid pump operation mode is formed. That is, the refrigerant is supplied from the liquid pump 23 → the electronic expansion valve 13 → the evaporator 11 → the solenoid valve 24.
The gas flows in the refrigerant circuit in the order of the gas pipe 3a, the condenser 22, the liquid pipe 3b, and the liquid pump 23, and the heating operation is performed.

When the compressor operation mode and the liquid pump operation mode are compared, in the liquid pump operation mode, the degree of supercooling at the outlet of the condenser 22, that is, at the inlet of the liquid pump 23 is increased in order to prevent cavitation. There is a need. In addition, the inlet of the evaporator 11 is in a liquid state (dryness X = 0). On the other hand, in the compressor operation mode, the dryness X at the inlet of the evaporator 11 is in a two-phase state of about 0.2. As a result, the appropriate amount of refrigerant in the liquid pump operation mode is larger than that in the compressor operation mode.Therefore, in the liquid pump operation mode, the refrigerant is minimized from remaining in the refrigerant circuit not involved in the liquid pump operation. There is a need to. However, when the accumulator 27 is installed in the outdoor unit 20 as shown in FIG. 21, the refrigerant flows into the accumulator 27 after switching to the liquid pump operation mode because the temperature in the accumulator 27 is low and low in the compressor operation mode. try to. In the air conditioner of the present embodiment, since the electromagnetic valve 28 is provided in the upstream portion of the accumulator 27,
Such inflow of the refrigerant can be prevented. Then, since the amount of refrigerant required for the liquid pump operation mode can be ensured, a stable liquid pump operation mode is always performed.

Further, in the conventional air conditioner, the solenoid valve 29 is not provided in the pipe between the outlet of the compressor 21 and the outlet side connection of the compressor bypass pipe 4. However, when the operation pressure is switched from the compressor operation mode to the liquid pump operation mode, if the discharge pressure in the compressor operation mode before the switching is lower than the pressure in the liquid pump operation mode after the switching, the liquid pump operation mode Since the refrigerant is condensed from the circuit to the compressor 21, not only the amount of the refrigerant necessary for the operation of the liquid pump is not ensured, but also a phenomenon that liquid compression occurs at the time of starting the compressor and damage may occur. On the other hand, in the air conditioner of the present embodiment, since the solenoid valve 29 is provided between the outlet of the compressor 21 and the outlet-side connection of the compressor bypass pipe 4, the refrigerant is condensed into the compressor 21. Can be prevented, the amount of refrigerant required for the liquid pump operation mode can be secured, and the reliability of the compressor 21 can be improved.

As described above, similarly to the first embodiment, this heating device also includes the compressor operation mode and the liquid pump operation mode, and switches between the two operations according to the temperature difference ΔT between the outside air temperature and the room temperature. Since the power consumption in the liquid pump operation mode is about 1/10 of that in the compressor operation mode, annual power consumption can be significantly reduced. In addition, since both operation modes are switched based on the temperature difference between the outside air temperature and the room temperature, the temperature difference between the room temperature and the outside air temperature is small, or the room temperature is higher than the outside air temperature. Unnecessary operation in the liquid pump operation mode can be prevented. A solenoid valve 2 is provided between the inlet of the accumulator 27 and the outlet of the compressor 21.
Since the refrigerant pumps 8 and 29 are provided, it is possible to prevent the refrigerant from flowing into the compressor 21 and the accumulator 27 in the liquid pump operation mode, and to secure a necessary amount of refrigerant in the liquid pump operation mode. Mode is performed.
Further, since the liquid pump 23 is connected in series with the electronic expansion valve 13 and the refrigerant circuit near the liquid pump 23 is not switched between the compressor operation mode and the liquid pump operation mode, the switching operation can be simplified. As compared with a configuration in which a liquid pump bypass pipe is provided for switching, the outdoor unit 20 can be downsized and the control device 70 can be simplified.

Here, the embodiment in which the heating device has the same configuration as in the first embodiment has been described. However, the heating device may have the same configuration as in the second to ninth embodiments. The same effect as in the embodiment is exerted. In the first to ninth embodiments, the air conditioner is configured exclusively for the cooling device, and in the tenth embodiment, the air conditioner is configured exclusively for the heating device. However, the air conditioner may be configured as a cooling and heating device. In this case, for example, in the first embodiment, for example, a four-way valve or the like is provided to switch the flow path so that the suction side and the discharge side of the liquid pump 23 and the compressor 21 can be reversed. During cooling, the indoor heat exchanger operates as an evaporator and the outdoor heat exchanger operates as a condenser. During heating, the indoor heat exchanger operates as a condenser and the outdoor heat exchanger operates as an evaporator. Let it. Furthermore, the temperature of the fluid that exchanges heat with the heat exchanger on the outdoor unit side and the temperature of the fluid that exchanges heat with the heat exchanger on the indoor unit side are detected. The liquid pump operation is performed when the temperature difference of the outdoor unit side fluid temperature is large, and the compressor operation is performed when the temperature difference is small. In the case of a heating device, the liquid pump operation is performed when the temperature difference of (outdoor unit side fluid temperature−the indoor unit side fluid temperature) is large, and the compressor operation is performed when the temperature difference is small.
By operating in this manner, annual power consumption can be significantly reduced, and the size of the outdoor unit can be reduced.
Air conditioning for cooling and heating that can reduce the number of opening and closing operations by commands from the control device, simplify the control device, and operate the compressor and liquid transfer device optimally according to the environmental conditions of the installation location Machine.

In the first to tenth embodiments, the example in which the electronic expansion valve 13 is used as the pressure reducing means has been described. However, the pressure reducing means is not limited to this, and a capillary tube or a temperature type expansion valve may be used. . Further, in the first to tenth embodiments, the example of the air-cooled condenser that cools the condenser 22 with air has been described. It can also be used as a container, and exhibits the same effects as the present embodiment.

[0123]

As described above, according to the present invention, a refrigeration cycle in which a compressor, a condenser, a decompression means, and an evaporator are sequentially connected by piping to circulate a refrigerant, an outlet of the evaporator, A bypass pipe connecting the inlet of the condenser via an on-off valve, a liquid transfer device connected in series with the pressure reducing means between an outlet of the condenser and an inlet of the pressure reducing means, A control device for controlling the opening / closing operation of the on-off valve, the operation / stop operation of the compressor, and the operation / stop operation of the liquid transfer device; and a first temperature detecting means for detecting the temperature of the fluid to be cooled flowing into the evaporator. And second temperature detecting means for detecting the temperature of the fluid to be heated flowing into the condenser, wherein the temperature of the fluid to be cooled detected by the first temperature detecting means and the temperature detected by the second temperature detecting means are detected. The temperature difference with the temperature of the fluid to be heated When the temperature of the fluid to be heated and the temperature of the fluid to be cooled are greater than a predetermined temperature, the compressor is operated by closing the on / off valve at By controlling the operations of the on-off valve, the compressor, and the liquid transfer device by the control device so as to stop the operation of the liquid transfer device, the annual power consumption can be significantly reduced, and the outdoor unit The size of the compressor can be reduced, the opening / closing operation by commands from the control device can be reduced, the control device can be simplified, and the compressor and the liquid transfer device can be optimally adapted to the environmental conditions of the installation location. An operable air conditioner is obtained.

Further, according to the present invention, a compressor, a condenser,
A refrigeration cycle in which the pressure reducing means and the evaporator are sequentially connected by a pipe to circulate the refrigerant, and the flow of the refrigerant from the condenser side to the evaporator side is formed by an outlet of the evaporator and an inlet of the condenser. A bypass pipe connected via a check valve to be closed, a liquid transfer device connected in series with the pressure reducing means between an outlet of the condenser and an inlet of the pressure reducing means, and operation of the compressor / Stop operation and operation of the liquid transfer device /
A control device for controlling a stop operation, first temperature detecting means for detecting the temperature of the fluid to be cooled flowing into the evaporator, and second temperature detecting means for detecting the temperature of the fluid to be heated flowing into the condenser. And operating the compressor when a temperature difference between the temperature of the fluid to be cooled detected by the first temperature detecting means and the temperature of the fluid to be heated detected by the second temperature detecting means is equal to or lower than a predetermined temperature. When the temperature difference between the temperature of the fluid to be heated and the temperature of the fluid to be cooled is greater than a predetermined temperature, the compressor is stopped to operate the liquid transfer device,
By controlling the compressor and the liquid transfer device by the control device, annual power consumption can be significantly reduced, the size of the outdoor unit can be reduced, and the number of opening and closing operations in accordance with commands from the control device can be reduced. It is possible to obtain an air conditioner in which the apparatus can be simplified and the compressor and the liquid transfer device can be optimally operated according to the environmental conditions of the installation place.

Further, according to the present invention, a compressor, a condenser,
A refrigeration cycle in which a pressure reducing means and an evaporator are sequentially connected by a pipe to circulate a refrigerant; a bypass pipe connecting an outlet of the evaporator and an inlet of the condenser via a first on-off valve; A liquid transfer means connected in parallel with the pressure reducing means between an outlet of a vessel and an inlet of the evaporator, a second on-off valve for opening and closing a flow path of the connected parallel part of the liquid transfer means; A control device for controlling the opening / closing operation of the first and second on-off valves, the operation / stop operation of the compressor, and the operation / stop operation of the liquid transfer device; and controlling the temperature of the fluid to be cooled flowing into the evaporator. A first temperature detecting means for detecting the temperature of the fluid to be heated flowing into the condenser; and a second temperature detecting means for detecting a temperature of the fluid to be heated flowing into the condenser. (2) Temperature between the temperature of the fluid to be heated detected by the temperature detecting means When the difference is equal to or less than a predetermined temperature, the first and second on-off valves are closed, the liquid transfer device is stopped, the compressor is operated, and the temperature of the fluid to be heated and the temperature of the fluid to be cooled are reduced. When the difference is larger than a predetermined temperature, the first and second on-off valves are opened by the control device so that the first and second on-off valves are opened and the compressor is stopped to operate the liquid transfer device. By controlling the operation of each of the compressor and the liquid transfer device, annual power consumption can be significantly reduced, control operations by commands from the control device during operation of the liquid transfer device can be reduced, and the control device can be simplified. It is possible to obtain an air conditioner that can operate the compressor and the liquid transfer device optimally according to the environmental conditions of the installation place.

Further, according to the present invention, a compressor, a condenser,
A refrigeration cycle in which the pressure reducing means and the evaporator are sequentially connected by pipes to circulate the refrigerant, and the flow of the refrigerant from the condenser side to the evaporator side is formed by the outlet of the evaporator and the inlet of the condenser. A bypass pipe connected via a check valve to be closed, a liquid transporting means connected in parallel with the pressure reducing means between an outlet of the condenser and an inlet of the evaporator, and An on-off valve for opening and closing the flow path of the connected parallel portion, a control device for controlling the on-off operation of the on-off valve, the operation / stop operation of the compressor, and the operation / stop operation of the liquid transfer device, and the evaporator First temperature detecting means for detecting the temperature of the fluid to be cooled flowing into the condenser, and second temperature detecting means for detecting the temperature of the fluid to be heated flowing into the condenser,
When the temperature difference between the temperature of the fluid to be cooled detected by the first temperature detecting means and the temperature of the fluid to be heated detected by the second temperature detecting means is equal to or lower than a predetermined temperature, the on-off valve is closed and the liquid transfer device is closed. Stop and operate the compressor, when the temperature difference between the temperature of the fluid to be heated and the temperature of the fluid to be cooled is greater than a predetermined temperature, open the on-off valve and stop the compressor to stop the compressor. By operating each of the on-off valve, the compressor, and the liquid transfer device by the control device so as to operate the liquid transfer device, annual power consumption can be significantly reduced, and opening and closing by a command from the control device can be performed. The number of operations can be reduced, the number of control operations by commands from the control device during operation of the liquid transfer device can be reduced, and the control device can be simplified. Air conditioner can be operated optimally fit is obtained.

Further, according to the present invention, by providing the second pressure reducing means between the outlet of the liquid transfer device and the inlet of the evaporator, the state of the refrigerant in the evaporator can be controlled and the evaporator can be used effectively. Thus, an air conditioner that can be operated at a high speed is obtained.

Further, according to the present invention, by providing an accumulator between the inlet side connection of the bypass pipe and the inlet of the compressor, the difference in refrigerant amount between the operation of the compressor and the operation of the liquid transfer device is absorbed. Thus, an air conditioner that can prevent liquid from returning to the compressor in the event of a transient phenomenon, refrigerant overfilling, or the like can be obtained.

According to the present invention, the third on-off valve is provided between the inlet side connection of the bypass pipe and the inlet of the accumulator, so that the refrigerant flows into the accumulator after switching to the operation of the liquid transfer device. Thus, an air conditioner can be obtained in which the amount of refrigerant required for the operation of the liquid transfer device can be secured by preventing the operation of the liquid transfer device, and the liquid transfer device can always be operated stably.

Further, according to the present invention, the provision of the fourth on-off valve between the outlet of the compressor and the outlet-side connection of the bypass pipe prevents the refrigerant from condensing into the compressor. It is possible to secure the amount of refrigerant necessary for the operation of the liquid transfer device, to stably operate the liquid transfer device at all times, to prevent liquid compression when the compressor is restarted, and to improve the reliability of the compressor. An air conditioner that can be obtained is obtained.

According to the present invention, the fourth on-off valve is a check valve for closing the flow of the refrigerant from the outlet side connection of the bypass pipe to the outlet of the compressor. Prevents refrigerant from condensing into the compressor without requiring opening and closing operations by commands, thereby ensuring the amount of refrigerant required for operation of the liquid transfer device and preventing liquid compression when the compressor is restarted. An air conditioner that can improve the reliability of the air conditioner is obtained.

According to the present invention, the high pressure pipe from the outlet of the compressor to the inlet of the pressure reducing means and the low pressure pipe from the outlet of the pressure reducing means to the inlet of the compressor are connected to the fifth on-off valve. By connecting with the second bypass pipe via
The refrigerant accumulated in the accumulator can be smoothly recovered to the refrigerant circuit during operation of the liquid transfer device without rapidly reducing the suction pressure of the compressor, and the liquid transfer device can be operated stably. An air conditioner that can improve the reliability of the compressor can be obtained.

Further, according to the present invention, the provision of the liquid storage means between the outlet of the condenser and the inlet of the liquid transfer device ensures that the refrigerant liquid flows to the liquid transfer device during operation of the liquid transfer device. Since the air conditioner is supplied, it is possible to prevent the occurrence of cavitation and obtain an air conditioner capable of stably operating the liquid transfer device.

Further, according to the present invention, by providing the supercooling means for supercooling the refrigerant flowing between the outlet of the condenser and the inlet of the liquid transfer device, it is possible to provide the supercooling means at the inlet of the liquid transfer device. An air conditioner that can increase the degree of subcooling of the refrigerant liquid, can prevent cavitation, and can operate the liquid transfer device stably can be obtained.

Further, according to the present invention, the latent heat of evaporation of the refrigerant liquid in the accumulator during the operation of the compressor is utilized as the cold heat source of the supercooling means. No need to install a cold heat source
An air conditioner that can stably operate the liquid transfer device in one refrigerant circuit is obtained.

According to the present invention, when the operation is switched from the operation of the compressor to the operation of the liquid transfer device, the degree of decompression of at least one of the decompression means and the second decompression means is changed so as to store the pressure in the accumulator. The refrigerant collected in the accumulator at the time of operation switching can be smoothly collected in the refrigerant circuit of the liquid transport device by performing the refrigerant recovery operation of recovering the cooled refrigerant into the refrigerant circuit of the liquid transport device operation. Thus, an air conditioner that can secure the required amount of refrigerant and can operate the liquid transfer device stably can be obtained.

Further, according to the present invention, an air conditioner that can stably operate the liquid transfer device with a simple control device by performing the refrigerant recovery operation for a fixed time can be obtained.

Further, according to the present invention, the time of the refrigerant recovery operation or the refrigerant recovery operation depends on the temperature of the fluid to be cooled detected by the first temperature detecting means or the temperature of the fluid to be heated detected by the second temperature detecting means. By performing the refrigerant recovery operation by setting the degree of decompression of the pressure reducing means at the time, the amount of refrigerant recovered from the accumulator to the refrigerant circuit in the operation of the liquid transfer device is controlled. An air conditioner that can be set to an optimum amount with respect to the outside air temperature and can make maximum use of the cooling capacity in the operation of the liquid transfer device is obtained.

Further, according to the present invention, since the decompression means and the pipe to the evaporator on the downstream side thereof are arranged in the box housing the evaporator, the liquid pipe can be used even when the compressor is operating. The structure is always filled with the refrigerant liquid even during the operation, so that the difference in the amount of the refrigerant between the operation of the compressor and the operation of the liquid transfer means can be reduced, and the accumulator can be downsized and the operation time of the refrigerant recovery operation can be shortened. An air conditioner is obtained.

Further, according to the present invention, the box housing either the evaporator or the condenser is an indoor unit, and the box housing the evaporator and the other of the condenser, the compressor and the liquid transfer device is provided. By using a body as an outdoor unit and connecting a plurality of the indoor units to the one outdoor unit, it is possible to save space of the outdoor unit and simultaneously perform air conditioning of the plurality of rooms. An air conditioner that can be obtained is obtained.

Further, according to the present invention, a compressor, a condenser,
In an air conditioner including a refrigeration cycle in which a refrigerant is circulated through a decompression unit and an evaporator, and a heat transport cycle in which a refrigerant is circulated between the evaporator and the condenser in a liquid transfer device, the evaporator includes: Detecting the temperature of the fluid to be cooled, detecting the temperature of the fluid to be heated flowing into the condenser, detecting the temperature of the fluid to be cooled detected in the step of detecting the temperature of the fluid to be cooled, Operating the refrigeration cycle when the temperature difference from the temperature of the fluid to be heated detected in the step of detecting the temperature of the fluid to be cooled is equal to or less than a predetermined temperature, and detecting the temperature of the fluid to be cooled. When the temperature difference between the temperature of the fluid to be heated and the temperature of the fluid to be heated detected in the step of detecting the temperature of the fluid to be cooled is greater than a predetermined temperature, By having a step of operation, the control method of an air conditioner capable of optimally switched that in context during operation of the refrigeration cycle and the heat transport cycle is obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an air conditioner according to Embodiment 1 of the present invention.

FIG. 2 is a schematic diagram showing a configuration of a liquid pump according to the first embodiment.

FIG. 3 is a flowchart showing an operation procedure of the control device according to the first embodiment.

FIG. 4 is a characteristic diagram in which the relationship between the refrigerant mass velocity and the heat transfer coefficient of evaporation according to the first embodiment is compared between R410A and R22.

FIG. 5 is a characteristic diagram comparing the relationship between the refrigerant mass velocity and the heat transfer coefficient of condensation according to the first embodiment in R410A and R22.

FIG. 6 is a characteristic diagram in which the relationship between the refrigerant mass velocity and the pressure loss according to the first embodiment is compared between R410A and R22.

FIG. 7 is a characteristic diagram showing a relationship between a refrigerant mass velocity and a heat transfer coefficient of evaporation of the hydrocarbon-based refrigerant according to the first embodiment.

FIG. 8 is a characteristic diagram showing a relationship between a refrigerant mass velocity and a condensation heat transfer coefficient of the hydrocarbon-based refrigerant according to the first embodiment.

FIG. 9 is a characteristic diagram showing a relationship between a refrigerant mass velocity and a pressure loss of the hydrocarbon-based refrigerant according to the first embodiment.

FIG. 10 is a configuration diagram showing an air conditioner according to Embodiment 2 of the present invention.

FIG. 11 is a configuration diagram showing an air conditioner according to Embodiment 3 of the present invention.

FIG. 12 is a configuration diagram showing an air conditioner according to Embodiment 4 of the present invention.

FIG. 13 is a configuration diagram showing an air conditioner according to Embodiment 5 of the present invention.

FIG. 14 is a characteristic diagram showing a relationship between a refrigerant circulation amount and a pressure difference between discharge and suction of a liquid pump according to a fifth embodiment.

FIG. 15 is a pressure-enthalpy diagram during operation of a liquid pump according to the fifth embodiment.

FIG. 16 is a configuration diagram illustrating an air conditioner according to Embodiment 6 of the present invention.

FIG. 17 is a configuration diagram showing an air conditioner according to a seventh embodiment of the present invention.

FIG. 18 is a flowchart showing an operation switching procedure from compressor operation to liquid pump operation according to the seventh embodiment.

FIG. 19 is a configuration diagram illustrating an air conditioner according to an eighth embodiment of the present invention.

FIG. 20 is a configuration diagram showing an air conditioner according to Embodiment 9 of the present invention.

FIG. 21 is a configuration diagram showing an air conditioner according to Embodiment 10 of the present invention.

FIG. 22 is a configuration diagram showing a conventional air conditioner provided with a liquid pump operation and a compressor operation.

[Explanation of symbols]

3a gas pipe, 3b liquid pipe, 10 indoor unit, 11
Evaporator, 12 Evaporator-side blower, 13 Expansion valve, 20
Outdoor unit, 21 compressor, 22 condenser, 23 liquid pump,
24, 25 check valve, 26 condenser side blower, 27 accumulator, 28 on-off valve, 40 oil separator, 41
Lubricating oil return pipe, 42 on-off valve, 43 expansion valve, 46 liquid receiver, 47 subcooler, 48, 49 on-off valve, 50 heat storage material transfer pipe, 51 heat storage material transfer pump, 63a,
63b open / close valve, 70 control device, 71, 72 temperature detecting means.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihiro Sumita 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term in Mitsubishi Electric Corporation (reference) 3L060 AA03 AA05 CC02 CC03 DD02 EE02 EE09

Claims (19)

[Claims] 1. A refrigeration cycle in which a compressor, a condenser, a decompression means, and an evaporator are sequentially connected by piping to circulate a refrigerant, and an outlet of the evaporator and an inlet of the condenser are connected via an on-off valve. A liquid transfer device connected in series with the pressure reducing means between an outlet of the condenser and an inlet of the pressure reducing means, an opening / closing operation of the on / off valve, and an operation of the compressor. A control device for controlling the start / stop operation and the operation / stop operation of the liquid transfer device; a first temperature detecting means for detecting a temperature of the fluid to be cooled flowing into the evaporator; and a fluid to be heated flowing into the condenser. A temperature difference between a temperature of the fluid to be cooled detected by the first temperature detecting means and a temperature of the fluid to be heated detected by the second temperature detecting means. When the temperature is below the temperature, the on-off valve is closed and Operate the compressor, when the temperature difference between the temperature of the fluid to be heated and the temperature of the fluid to be cooled is greater than a predetermined temperature, open the on-off valve and stop the compressor to stop the liquid transfer device. An air conditioner, wherein the control device controls the respective operations of the on-off valve, the compressor, and the liquid transfer device so as to operate. 2. A refrigeration cycle in which a compressor, a condenser, a pressure reducing means, and an evaporator are sequentially connected by piping to circulate a refrigerant, and an outlet of the evaporator and an inlet of the condenser are connected to the condenser. A bypass pipe connected via a check valve for closing the flow of the refrigerant from the evaporator to the evaporator side, and connected in series with the pressure reducing means between an outlet of the condenser and an inlet of the pressure reducing means. Liquid transfer device, a control device for controlling the operation / stop operation of the compressor and the operation / stop operation of the liquid transfer device, and first temperature detecting means for detecting the temperature of the fluid to be cooled flowing into the evaporator And second temperature detecting means for detecting the temperature of the fluid to be heated flowing into the condenser, wherein the temperature of the fluid to be cooled detected by the first temperature detecting means and the temperature detected by the second temperature detecting means are detected. The temperature difference from the temperature of the fluid to be heated is less than the specified temperature When the compressor is operated,
When the temperature difference between the temperature of the fluid to be heated and the temperature of the fluid to be cooled is greater than a predetermined temperature, the compressor is stopped to operate the liquid transport device to stop the compressor. An air conditioner characterized by controlling the liquid transfer device. 3. A refrigeration cycle in which a compressor, a condenser, a decompression means, and an evaporator are sequentially connected by piping to circulate a refrigerant, and an outlet of the evaporator and an inlet of the condenser are firstly connected.
A bypass pipe connected via an on-off valve, a liquid transfer means connected in parallel with the pressure reducing means between an outlet of the condenser and an inlet of the evaporator, and the liquid transfer means connected A second opening / closing valve for opening and closing the flow path of the parallel section, a control device for controlling opening / closing operations of the first and second opening / closing valves, operation / stop operation of the compressor, and operation / stop operation of the liquid transfer device; A first temperature detecting means for detecting a temperature of the fluid to be cooled flowing into the evaporator; and a second temperature detecting means for detecting the temperature of the fluid to be heated flowing into the condenser. When the temperature difference between the temperature of the fluid to be cooled detected by the detecting means and the temperature of the fluid to be heated detected by the second temperature detecting means is equal to or less than a predetermined temperature, the first and second on-off valves are closed and the liquid transfer is performed. The compressor is operated with the device stopped, and the temperature of the fluid to be heated is increased. The controller is configured to open the first and second on-off valves and stop the compressor when the temperature difference between the temperature of the fluid to be cooled and the temperature of the fluid to be cooled is greater than a predetermined temperature to operate the liquid transfer device. An air conditioner wherein the operations of the first and second on-off valves, the compressor, and the liquid transfer device are controlled by the first and second on-off valves. 4. A refrigeration cycle in which a compressor, a condenser, a pressure reducing means, and an evaporator are sequentially connected by piping to circulate a refrigerant, and an outlet of the evaporator and an inlet of the condenser are connected to the condenser. A bypass pipe connected via a check valve for closing the flow of refrigerant from the evaporator to the evaporator, and a bypass pipe connected between the outlet of the condenser and the inlet of the evaporator in parallel with the pressure reducing means. Liquid transfer means, an on-off valve for opening and closing a flow path of a parallel portion connected to the liquid transfer means, an opening / closing operation of the on-off valve, a start / stop operation of the compressor, and a start / stop of the liquid transfer device A control device for controlling operation, first temperature detecting means for detecting the temperature of the fluid to be cooled flowing into the evaporator, and second temperature detecting means for detecting the temperature of the fluid to be heated flowing to the condenser. A flow to be cooled detected by the first temperature detecting means. When the temperature difference between the temperature of the body and the temperature of the fluid to be heated detected by the second temperature detecting means is equal to or lower than a predetermined temperature, the on-off valve is closed and the liquid transfer device is stopped to operate the compressor; When the temperature difference between the temperature of the fluid to be heated and the temperature of the fluid to be cooled is greater than a predetermined temperature, the control is performed such that the on-off valve is opened, the compressor is stopped, and the liquid transfer device is operated. An air conditioner, wherein the operation of each of the on-off valve, the compressor, and the liquid transfer device is controlled by a device. 5. The air conditioner according to claim 3, wherein a second pressure reducing means is provided between an outlet of the liquid transfer device and an inlet of the evaporator. 6. The air conditioner according to claim 1, wherein an accumulator is provided between an inlet-side connection of the bypass pipe and an inlet of the compressor. 7. The air conditioner according to claim 6, wherein a third on-off valve is provided between an inlet-side connection of the bypass pipe and an inlet of the accumulator. 8. The air according to claim 1, wherein a fourth on-off valve is provided between an outlet of the compressor and an outlet-side connection of the bypass pipe. Harmony machine. 9. The air conditioner according to claim 8, wherein the fourth on-off valve is a check valve for closing a flow of the refrigerant from an outlet-side connection portion of the bypass pipe to an outlet portion of the compressor. . 10. A second bypass through a fifth on-off valve between a high pressure pipe from an outlet of the compressor to an inlet of the pressure reducing means and a low pressure pipe from an outlet of the pressure reducing means to an inlet of the compressor. The air conditioner according to any one of claims 6 to 9, wherein the air conditioner is connected by a pipe. 11. The air conditioner according to claim 1, wherein a liquid storage means is provided between an outlet of the condenser and an inlet of the liquid transfer device. . 12. A supercooling means for supercooling a refrigerant flowing between an outlet of the condenser and an inlet of the liquid transfer device. The air conditioner according to item 1. 13. The air conditioner according to claim 12, wherein the latent heat of evaporation of the refrigerant liquid in the accumulator during the operation of the compressor is used as a cold heat source of the supercooling means. 14. When the operation is switched from the compressor operation to the liquid transfer device operation, the degree of pressure reduction of at least one of the pressure reducing means and the second pressure reducing means is changed so that the refrigerant stored in the accumulator is transferred to the liquid transfer device. The air conditioner according to any one of claims 6 to 13, wherein a refrigerant recovery operation for recovering the refrigerant to the operating refrigerant circuit is performed. 15. The air conditioner according to claim 14, wherein the refrigerant recovery operation is performed for a predetermined time. 16. The time of the refrigerant recovery operation or the pressure reduction of the pressure reducing means during the refrigerant recovery operation according to the temperature of the fluid to be cooled detected by the first temperature detecting means or the temperature of the fluid to be heated detected by the second temperature detecting means. 15. The air conditioner according to claim 14, wherein the amount of refrigerant collected from the accumulator to the refrigerant circuit in the operation of the liquid transfer device is controlled by performing the refrigerant recovery operation by setting the degree of the refrigerant recovery. 17. The method according to claim 1, wherein the decompression means and a pipe downstream from the decompression means to the evaporator are arranged in a box housing the evaporator. Air conditioner. 18. A box containing one of an evaporator and a condenser is an indoor unit, and a box containing the other of the evaporator and the condenser, a compressor and a liquid transfer device is an outdoor unit.
The air conditioner according to any one of claims 1 to 17, wherein a plurality of the indoor units are connected to the one outdoor unit. 19. A refrigeration cycle in which a refrigerant is circulated through a compressor, a condenser, a decompression means and an evaporator, and a heat transport cycle in which a refrigerant is circulated between the evaporator and the condenser in a liquid transfer device. Detecting the temperature of the fluid to be cooled flowing into the evaporator; detecting the temperature of the fluid to be heated flowing into the condenser; and detecting the temperature of the fluid to be cooled. Operating the refrigeration cycle when a temperature difference between the temperature of the heated fluid detected in the step and the temperature of the heated fluid detected in the step of detecting the temperature of the cooled fluid is equal to or lower than a predetermined temperature; The temperature difference between the temperature of the heated fluid detected in the step of detecting the temperature of the cooling fluid and the temperature of the heated fluid detected in the step of detecting the temperature of the cooled fluid is higher than a predetermined temperature. Operating the heat transport cycle when it is large.