JP2888688B2 - Refrigerant heating air conditioner and control method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant heating type air conditioner having a refrigerant heater provided with a combustion burner on the outdoor heat exchange side.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a refrigerant heating type air conditioner that has been conventionally proposed (for example, Japanese Patent Publication No. 60-37377).
Shown in In FIG. 3, reference numeral 41 denotes a compressor, 42 denotes a four-way valve, 43 denotes an indoor heat exchanger, 44 denotes a pressure reducing mechanism, and 45 denotes an outdoor heat exchanger, which constitutes a refrigeration cycle by connecting them annularly. . Reference numeral 46 denotes a refrigerant heater.
Is provided with a heating source 46a such as a burner for heating the refrigerant. Reference numeral 47 denotes a first solenoid valve, and one end of the refrigerant heater 46 is connected to the output side of the indoor heat exchanger 43 via the first solenoid valve 47, and the other end is connected to the suction side of the compressor 41. ing. 48 is a second solenoid valve. Reference numeral 49 denotes an electromagnetic valve that controls communication between the discharge pipe and the suction pipe of the compressor 41.

[0003]

However, the conventional refrigerant-heated air conditioner has the following problems.
That is, the normal cooling cycle is reversed and the refrigerant heater 46
Therefore, when the refrigerant heating operation is performed, power consumption increases, and there is a disadvantage that the same compressor causes inconvenience. Also,
There is a method in which the pressure reducing mechanism is omitted from the above cycle and the input of the compressor is reduced by reducing the compressor.However, when trying to obtain the heating capacity, the compression ratio does not decrease and the input of the compressor is reduced. Will not fall. Therefore, a third solenoid valve 49, which is a bypass circuit, is provided between the discharge side and the suction side of the compressor. During the refrigerant heating operation, the bypass circuit is opened to bypass a part of the medium to thereby reduce the input of the compressor. If an attempt is made to reduce the power consumption, the reduction in power consumption is not sufficient because a compressor is used to transport the refrigerant.

When a large amount of refrigerant gas is present around the refrigerant pump at the time of starting heating, there is a problem that it is difficult to immediately start circulation of the refrigerant by the refrigerant pump alone because the excluded volume of the refrigerant pump is small. Was. Further, when the refrigerant pump always sucks the refrigerant gas at the time of starting, there has been a problem that the sliding portion is worn.

During the temporary stop of the heating, the differential pressure of the control valve for switching the circuit is reduced due to a decrease in the temperature of the refrigerant heating / heating cycle, and the refrigerant does not function. There has also been a problem that the operation cannot be performed.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a refrigerant-heated air conditioner having better startup characteristics and restart characteristics and capable of reducing electric input.

[0007]

Means for Solving the Problems In order to solve the above problems, a refrigerant-heated air conditioner of the present invention comprises at least a compressor, a four-way valve, an outdoor heat exchanger, a pressure reducing mechanism, an indoor heat exchanger,
It is composed of a refrigerant pump, a refrigerant heater, and a subcooler. The operation of the compressor during heating is limited to only the refrigerant recovery operation, and the conveyance of the refrigerant to the refrigerant heater is performed by the refrigerant pump with low electric input. Things.

[0008]

According to the present invention, the operation of the compressor is limited to only the operation of recovering the refrigerant by the above configuration, and the refrigerant is conveyed to the refrigerant heater by the refrigerant pump having a low electric input. Reduced operation can be achieved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a compressor, 2 is a four-way valve, 3 is an indoor heat exchanger, 4 is a decompression mechanism, 5 is an outdoor heat exchanger, 6 is a refrigerant heater, 7 is a refrigerant pump, 8 is a subcooler, 10 , 11,13 are the first, second, third check valves, 1
Reference numerals 4 and 15 denote first and second solenoid valves, respectively.

The refrigerant pump 7, the refrigerant heater 6, the four-way valve 2, the indoor heat exchanger 3, and the subcooler 8 are sequentially connected in a circular pipe, and a first heat exchanger is provided between the indoor heat exchanger 3 and the subcooler 8. An electromagnetic valve 14 is provided, and the high pressure side of the four-way valve 2 and the refrigerant heater 6
A second check valve 11 that allows the refrigerant to flow only in the direction from the refrigerant heater 6 to the four-way valve 2 is provided in a part of the pipe connecting the two, and the low-pressure side of the four-way valve 2 and the suction of the compressor 1 Second side
The discharge side of the compressor 1 is connected to the outlet side of the second check valve 11 via the third check valve 13.
At this time, the connection direction of the third check valve 13 is set so as not to hinder the flow from the compressor 1 to the four-way valve 2.

Further, the four-way valve 2 and the outdoor heat exchanger 5 and the pressure reducing mechanism 4 are sequentially connected to a pipe, and further connected to a pipe connecting the indoor heat exchanger 3 and the first solenoid valve 14 to constitute a cooling circuit. A first check valve 10 that allows the refrigerant to flow only in the direction from the outdoor heat exchanger 5 to the pressure reducing mechanism 4 is provided in a part of a pipe connecting the exchanger 5 and the pressure reducing mechanism 4, and the sub-cooler 8 and the outdoor The heat exchanger 5 and the heat exchanger 5 are arranged in the same ventilation circuit.

Next, the operation of the refrigerant-heated air conditioner having this configuration will be described. At the start of the heating and heating of the refrigerant, the first solenoid valve 14 is open and the second solenoid valve 15 is open. When the compressor 1 is started in this state, the refrigerant discharged from the compressor 1 is supplied to the third check valve 13, the four-way valve 2, the indoor heat exchanger 3, the subcooler 8, the refrigerant pump 7, and the refrigerant heater 6. The refrigerant in the outdoor heat exchanger 5 is also collected by the compressor 1. After performing the refrigerant recovery operation for recovering a predetermined amount of the refrigerant in the circuit for heating and heating the refrigerant,
After the electromagnetic valve 15 is closed and the refrigerant inside the compressor 1 is further discharged, the compressor 1 is stopped, the refrigerant pump is started, and the heating and heating of the refrigerant is started. At this time, a sufficient differential pressure necessary for the operation before and after each of the first check valve 10, the second check valve 11, the third check valve 13, and the four-way valve 2 is secured by the refrigerant recovery operation. Have been.

During the refrigerant heating and heating operation, the refrigerant is supplied to the refrigerant pump 7.
Refrigerant heater 6, second check valve 11, four-way valve 2, indoor heat exchanger 3, first solenoid valve 14, subcooler 8
Circulates through the circuit returning to the refrigerant pump 7.

The refrigerant heated in the refrigerant heater 6 by a burner or the like exchanges (heats) heat with indoor air in the indoor heat exchanger 3 and most of the refrigerant is condensed. The refrigerant vapor that has not been completely condensed is condensed in the subcooler 8 to become a liquid refrigerant and returns to the refrigerant heater 6 via the refrigerant pump 7. At this time, since the suction side of the refrigerant pump 7 is vertically below the subcooler 8, the liquid refrigerant is efficiently supplied to the refrigerant pump 7, and a stable refrigerant conveyance operation is realized. During the heating operation as described above, the compressor 1 is no longer operating, and the cooling and heating with low electric input is performed.

During the heating operation, when heating is temporarily stopped by a control mechanism (not shown), the pressure in the refrigerant heating / heating cycle decreases during the primary stop as the temperature of the refrigerant heating / heating cycle decreases. As the primary stop period becomes longer depending on the operating conditions, the pressure drop becomes larger. In such a case, a control mechanism (not shown) prevents the control valve for switching the circuit from functioning due to the decrease in the differential pressure, so that the refrigerant in the circuit does not move unnecessarily and has no adverse effect upon restart. Then, a burner or the like is operated for a short time to heat the refrigerant in the refrigerant heating / heating cycle to secure a necessary pressure difference.

For cooling operation, the first solenoid valve 14 is closed,
Just open the second solenoid valve 15 and switch the four-way valve 2,
The description is omitted because it is the same as the ordinary circuit configuration. Next, a second embodiment of the present invention will be described with reference to the drawings. In FIG. 2, 21 is a compressor, 22 is a four-way valve, 23 is an indoor heat exchanger, 24 is a decompression mechanism, 25 is an outdoor heat exchanger, 26 is a refrigerant heater, 27 is a refrigerant pump, 28 is a subcooler, 29 Is a gas-liquid separator, 30, 31, 33 are first, second, and third check valves, respectively, 34, 35 are first and second solenoid valves, respectively, and 36 is a second pressure reducing mechanism.

A refrigerant pump 27, a refrigerant heater 26, a four-way valve 22, an indoor heat exchanger 23, a gas-liquid separator 29, and a second pressure reducing mechanism 36 are sequentially connected in a pipe-like manner. A first solenoid valve 30 is provided between the gas-liquid separator 29, and a gas-side outlet of the gas-liquid separator 29 is connected to a second pressure reducing mechanism 36 and a refrigerant pump 27 by a pipe provided with a subcooler 28 in the middle thereof. A second check valve 31 that allows the refrigerant to flow only in the direction from the refrigerant heater 26 to the four-way valve 22 is provided on a part of the pipe connecting the high pressure side of the four-way valve 26 and the refrigerant heater 26 with the pipe. Further, the low pressure side of the four-way valve 22 and the suction side of the compressor 21 are connected via a second solenoid valve 35, and the discharge side of the compressor 21 is connected to the outlet side of the second check valve 31.
Through a non-return valve 33. At this time, the connection direction of the third check valve 33 is set so as not to hinder the flow from the compressor 21 to the four-way valve 22.

Further, a four-way valve 22, an outdoor heat exchanger 25, and a pressure reducing mechanism 24 are sequentially connected to a pipe, and further connected to a pipe connecting the indoor heat exchanger 23 and the first solenoid valve 34 to constitute a cooling circuit. A part of a pipe connecting the heat exchanger 25 and the pressure reducing mechanism 24 is provided with a first check valve 30 for allowing the refrigerant to flow only in the direction from the outdoor heat exchanger 25 to the pressure reducing mechanism 24, and further includes a subcooler. 28
And the outdoor heat exchanger 25 are installed in the same ventilation circuit.

Next, the operation of the refrigerant heating type air conditioner having this configuration will be described. At the start of refrigerant heating and heating, the first solenoid valve 34 is open and the second solenoid valve 35 is open. When the compressor 21 is started in this state, the refrigerant discharged from the compressor 21 is supplied to the third check valve 33, the four-way valve 22, the indoor heat exchanger 23, the subcooler 28, the gas-liquid separator 29, and the refrigerant pump 27. The refrigerant stays at the refrigerant heater 26 and the refrigerant inside the outdoor heat exchanger 25 is also recovered by the compressor 21. After the refrigerant recovery operation for recovering a predetermined amount of the refrigerant in the circuit for heating and heating the refrigerant in this way, the second solenoid valve 35 is closed, and the refrigerant inside the compressor 21 is also discharged. Stop 21 and refrigerant pump
Start 27 to start heating and heating the refrigerant. At this time, the first check valve 30, the second check valve 31, the third check valve 33, the four-way valve 22
Before and after each of the above, a sufficient differential pressure necessary for the operation is secured by the refrigerant recovery operation.

During the heating and heating operation of the refrigerant, the refrigerant is supplied to the refrigerant pump 27.
Discharged from the refrigerant heater 26, the second check valve 31, the four-way valve 3
2. Through the indoor heat exchanger 23, the first solenoid valve 34, and the gas-liquid separator 29, they are separated into gas and liquid here, the gas passes through the subcooler 8, and the liquid passes through the second decompression mechanism 36. The circuit which circulates and returns to the refrigerant pump 7 is circulated.

The refrigerant heated in the refrigerant heater 26 by a burner or the like exchanges heat (heats) with the indoor air in the indoor heat exchanger 23 and most of the refrigerant is condensed. The gas-liquid separator 29 mixes the refrigerant (gas) that has not been completely condensed and the condensed refrigerant (liquid) in a mixed state.
The entered refrigerant is separated here, and only the gas portion is condensed by the subcooler 28 and merges with the already condensed liquid refrigerant, and is supplied to the refrigerant pump 27. At this time, the refrigerant pump 27
Since the suction side is vertically below the subcooler 28, the liquid refrigerant is efficiently supplied to the refrigerant pump 27, and a stable refrigerant conveyance operation is realized. During the heating operation as described above, the compressor 21 is no longer operating, and the refrigerant heating and heating with a low electric input is performed.

During heating operation, when heating is temporarily stopped by a control mechanism (not shown), during the temporary stop, the pressure in the refrigerant heating and heating cycle decreases as the temperature of the cycle decreases. As the primary stop period becomes longer depending on the operating conditions, the pressure drop becomes larger. In such a case, a control mechanism (not shown) prevents the control valve for switching the circuit from functioning due to the decrease in the differential pressure, so that the refrigerant in the circuit does not move unnecessarily and has no adverse effect upon restart. The burner or the like is operated for a short time to heat the refrigerant in the refrigerant heating and heating cycle, and secure a necessary pressure difference.

For cooling operation, the first solenoid valve 34 is closed,
The circuit configuration is the same as that of a normal circuit, except that the second solenoid valve 35 is opened and the four-way valve 22 is switched. Also,
In the first and second embodiments, the subcooler and the outdoor heat exchanger are individually configured and installed in the same wind circuit. However, the subcooler and the outdoor heat exchanger are configured as an integrated heat exchanger, and a part of the heat exchanger is used as a valve. May be used as a sub-cooler by switching.

[0024]

As described above, according to the present invention, the operation of the compressor is limited to only the refrigerant recovery operation, and the conveyance of the refrigerant to the refrigerant heater is performed by the refrigerant pump with low electric input. Therefore, the power consumption can be reduced, and the suction side of the refrigerant pump is installed below the outlet of the subcooler, and the refrigerant in the circuit is prevented from moving unnecessarily during the suspension of the refrigerant heating operation. Therefore, since the combustor of the refrigerant heater is temporarily operated, stable operation can be ensured.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram showing a first embodiment of the present invention.

FIG. 2 is a refrigerant circuit diagram showing a second embodiment of the present invention.

FIG. 3 is a refrigerant circuit diagram showing a conventional example.

[Explanation of symbols]

 1,21 compressor 2,22 four-way valve 3,23 indoor heat exchanger 4,24 pressure reducing mechanism 5,25 outdoor heat exchanger 6,26 refrigerant heater 7,27 refrigerant pump 8,28 subcooler 10,30 1st Check valve 11,31 Second check valve 13,33 Third check valve 14,34 First solenoid valve 15,35 Second solenoid valve 29 Gas-liquid separator

Claims (6)

(57) [Claims] 1. At least a compressor, a four-way valve, an outdoor heat exchanger, a decompression mechanism, an indoor heat exchanger, a refrigerant pump, a refrigerant heater, and a subcooler, connecting the outdoor heat exchanger and the decompression mechanism. A first part that allows the refrigerant to flow only in a part of the pipe in a direction from the outdoor heat exchanger to the pressure reducing mechanism;
The check valve is provided, and the refrigerant pump, the refrigerant heater, the four-way valve, the indoor heat exchanger, and the subcooler are sequentially connected in a circular pipe, and the subcooler and the outdoor heat exchanger are the same. Installed in a ventilation circuit, further provided a first solenoid valve between the indoor heat exchanger and the subcooler,
A part of a pipe connecting the high-pressure side of the four-way valve and the refrigerant heater is provided with a second check valve that allows refrigerant to flow only in the direction from the refrigerant heater to the four-way valve, The low pressure side and the suction side of the compressor are connected via a second solenoid valve, and the discharge side of the compressor is connected to the outlet side of the second check valve, and the flow from the compressor to the four-way valve is controlled. Connected via a third non-return valve in an unobstructed direction, further connecting the four-way valve to the indoor heat exchanger and the first solenoid valve via the outdoor heat exchanger and the pressure reducing mechanism in order. A refrigerant-heated air conditioner that is connected to a connecting pipe to form a cooling circuit. 2. A gas-liquid separator is provided in the middle of a pipe connecting the first solenoid valve and the subcooler, and a gas-side outlet of the gas-liquid separator, a subcooler, and a refrigerant pump are sequentially connected. The air conditioner according to claim 1, wherein the liquid outlet of the separator, the second pressure reducing mechanism, and the refrigerant pump are sequentially connected. 3. The refrigerant-heated air conditioner according to claim 1, wherein a part of the outdoor heat exchanger is configured to be usable as a subcooler by switching with a valve or the like. 4. The air conditioner according to claim 1, wherein a suction side of the refrigerant pump is provided below an outlet of the subcooler. 5. The refrigerant heating type air conditioner according to claim 1, wherein the refrigerant heating operation is started.
A method for controlling a refrigerant-heated air conditioner in which a compressor is operated to recover a refrigerant in an outdoor heat exchanger and a compressor, and then the operation of a combustor of a refrigerant heater and a refrigerant pump is started. 6. The refrigerant heating type air conditioner according to claim 1, wherein, during the temporary stop of the refrigerant heating operation, the difference between the control valves for circuit switching according to the temperature decrease of the refrigerant heating operation cycle. Operates the combustor of the refrigerant heater to prevent the refrigerant in the circuit from moving unnecessarily due to the reduced pressure and not functioning, and operates the control valve for circuit switching even during the suspension of the refrigerant heating operation. Method of controlling a refrigerant heating type air conditioner to ensure the safety.