JP2003004332A - Multiple gas heat pump type air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multiple gas heat pump air conditioner capable of providing a desired overheating for a gas refrigerant sucked into a compressor even in a heating operation at low fresh air temperature. SOLUTION: The multiple gas heat pump air conditioner is adapted such that is comprises: a plurality of indoor machine units 10A to D; and outdoor machine unit 30 composed of a compressor 31 and an outdoor heat exchanger 32; and a shunt control unit 20 for selecting and changing over cooling and heating operations by controlling the direction of a flow of indoor machine units 10A to D. Further, the outdoor heat exchanger 32 is divided into a plurality of subunits, which are connected with each other in parallel, and further four way valves 38A to C are provided for controlling the flow of a refrigerant for each divided subunit of the outdoor heat exchanger 32. In the air conditioner, a water heat exchanger 33 is disposed on the outdoor machine unit 30 in parallel to the outdoor heat exchanger 32 for obtaining waste heat from engine cooling water for cooling a gas engine to heat the refrigerant, whereby the amount of circulation of the engine cooling water introduced into the water heat exchanger 33 is controlled to keep the degree of overheating of the refrigerant on the suction side of the compressor within a predetermined range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas heat pump type air conditioner for driving a refrigerant compressor by a gas engine and utilizing exhaust gas of the gas engine as a heating source for liquid refrigerant during heating operation. In particular, the present invention relates to a multi-type gas heat pump type air conditioner that is equipped with a plurality of indoor units and can be selectively switched from an exhaustive cooling operation, an exhaustive heating operation, and a simultaneous cooling and heating operation.

[0002]

2. Description of the Related Art An air conditioner that uses a heat pump to perform air conditioning such as heating and cooling is provided with a refrigerant circuit including elements such as an indoor heat exchanger, a compressor, an outdoor heat exchanger, and a throttle mechanism. The cooling and heating of the room is done while the refrigerant goes around this circuit.
It is realized by exchanging heat with indoor air (hereinafter referred to as "indoor air") and outside air in the indoor heat exchanger and the outdoor heat exchanger, respectively. Also, in this refrigerant circuit,
In some cases, a refrigerant heater for directly heating the refrigerant itself may be installed instead of relying only on the receipt of heat of the refrigerant by the outdoor heat exchanger (during heating operation).

By the way, in recent years, as a power source for a compressor provided in the above-mentioned refrigerant circuit, a gas engine has been developed in place of a normally used electric motor. The air conditioner using this gas engine is
Generally, a gas heat pump type air conditioner (hereinafter referred to as "GH
Abbreviated as "P"). According to this GHP, since city gas or the like, which is relatively inexpensive, can be used as fuel, running costs are high like an air conditioner (hereinafter abbreviated as “EHP”) equipped with a compressor that uses an electric motor. Therefore, the cost can be reduced for consumers.

Further, in the GHP, for example, during heating operation, if the heat (so-called waste heat) of the high temperature exhaust gas discharged from the gas engine or the engine cooling water is used as the heat source of the refrigerant, an excellent heating effect is obtained. In addition to being able to obtain it, it is possible to improve the energy utilization efficiency as compared with EHP. By the way, in this case, GHP
The energy utilization efficiency of 1.2 to 1.
5 times higher. Further, if such a mechanism is introduced, it is not necessary to specially install a device such as the above-described refrigerant heater in the refrigerant circuit.

In addition, in the GHP, the defrosting operation of the outdoor heat exchanger required during heating operation, so-called defrosting operation, can be carried out by utilizing the waste heat of the gas engine. Generally, the defrosting operation in the EHP is such that the heating operation is stopped and the cooling operation is temporarily performed to remove the frost from the outdoor heat exchanger. In this case, cool air is blown into the room, which impairs the comfort of the indoor environment. In the GHP, continuous heating operation is possible due to the above-mentioned circumstances, and there is no problem such as the concern in the EHP.

On the other hand, on the indoor unit side of the EHP, an independent indoor unit is installed for each of a plurality of air-conditioning target compartments, and cooling operation for all the compartments (the total number of the indoor units) or a part of the compartments A system called a multi type has been developed which can perform heating operation for all or a part of sections and simultaneous operation for cooling / heating / pausing for each section to be air-conditioned or each indoor unit, for example, Japanese Patent Laid-Open No. 1-247967. , Japanese Patent Application Laid-Open Nos. 7-43042 and 9-60994.

[0007]

As with the EHP, it is desired to apply the multi-type system to the indoor unit of the GHP, which has many advantages as described above. Even when the multi-type system is applied to the GHP as described above, in order to ensure the stable efficiency of the compressor, an appropriate degree of superheat (generally 5 ° C. to 10 ° C.) with respect to the gas refrigerant to be sucked is required.
℃) should be given. However, since it is difficult for the outdoor heat exchanger that functions as an evaporator to absorb sufficient heat from the outside air at low outside temperatures, the refrigerant cannot be provided with the necessary degree of superheat, resulting in a gas-liquid two-phase There is a problem that the performance is deteriorated by being supplied to the compressor as it is. In such a heating operation at a low outside temperature, sufficient heating capacity cannot be obtained, and the coefficient of performance (COP) is also lowered, so a countermeasure is desired.

The present invention has been made in view of the above circumstances, and an object thereof is to give a desired superheat degree to a gas refrigerant drawn into a compressor even in a heating operation at a low outside temperature. An object of the present invention is to provide a multi-type gas heat pump type air conditioner capable of performing the above.

[0009]

The present invention adopts the following means in order to solve the above problems. The multi-type gas heat pump type air conditioner according to claim 1 comprises a plurality of indoor unit units each having an indoor heat exchanger for exchanging heat between indoor air and a refrigerant, and a compression driven by a gas engine. Unit and an outdoor unit having an outdoor heat exchanger for exchanging heat between the outdoor air and the refrigerant, and a shunt control unit for selectively switching between cooling and heating operations by controlling the refrigerant flow direction for each of the indoor unit. A multi-type in which the outdoor heat exchanger is divided into a plurality of parts and connected in parallel, and a refrigerant supply switching means for controlling the flow of the refrigerant is provided for each divided part of the outdoor heat exchanger. In the gas heat pump type air conditioner, a water heat exchanger that heats the refrigerant by obtaining waste heat from the engine cooling water for cooling the gas engine is provided in the outdoor unit. Is arranged in parallel with the compressor to control the circulation amount of the engine cooling water introduced into the water heat exchanger to maintain the refrigerant superheat degree on the suction side of the compressor within a predetermined range. .

According to such a multi-type gas heat pump type air conditioner, the heating amount of the refrigerant can be adjusted by controlling the circulation amount of the engine cooling water introduced into the water heat exchanger, so that the outside air temperature is low. It is possible to give a desired degree of superheat to the refrigerant that is vaporized by the water heat exchanger. In this case, the refrigerant superheat degree is calculated from the detection values of the low pressure detecting means for detecting the pressure on the suction side of the compressor and the temperature detecting means for detecting the refrigerant outlet temperature of the water heat exchanger, and the engine cooling is performed. It is advisable to control the amount of water circulation.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a multi-type gas heat pump type air conditioner according to the present invention will be described below with reference to FIGS. 1 to 3. The multi-type gas heat pump type air conditioner shown in FIG. 1 (hereinafter referred to as “MGH
1 is abbreviated as “P”).
A shunt control unit 20 for controlling the flow direction of the refrigerant for each indoor unit 10 to selectively switch cooling / heating operation, and an outdoor unit 30 including a gas engine driven compressor and an outdoor heat exchanger described later. And is configured. In this MGHP1, each indoor unit 10,
Shunt control unit 20 and outdoor unit 30
The refrigerant pipes 2 are connected to each other.

As shown in FIG. 2, the indoor unit 10 functions as an evaporator that evaporates the low-temperature and low-pressure liquid refrigerant to evaporate the heat from the indoor air (indoor air) during the cooling operation, and increases the temperature during the heating operation. An indoor heat exchanger 11 is provided, which functions as a condenser that condenses and liquefies a high-pressure gas refrigerant to warm indoor air. In the figure, reference numeral 12 is an electronic expansion valve provided as a throttle mechanism for cooling operation, 13 is a capillary tube functioning as a throttle mechanism for heating operation, and 14 is a check valve. In the illustrated example, four indoor units 10 (10A to 10D) described above are provided in parallel, each of which is installed in an independent air-conditioning target section, and a total number of units are set by a switching operation of a diversion control unit 20 described later. Cooling operation, total heating operation, or cooling operation / heating operation / pause (hereinafter referred to as “cooling / heating simultaneous operation”) can be selected for each indoor unit.

The diversion control unit 20 includes a refrigerant pipe line connecting the indoor unit 10 and the outdoor unit unit 30, a pipe line through which the refrigerant flows, and an on-off valve such as a solenoid valve for selectively switching the flow direction. It is composed by. In the illustrated example, four electromagnetic valves 21, 22, 23, 24 are provided for each indoor unit 10, and each electromagnetic valve 21-24 is opened and closed according to the operation of each indoor unit 10. That is, each solenoid valve 21 is selected according to the operating condition in which one of the cooling operation, the heating operation and the rest is selected.
By switching the open / closed states of 24 to 24, it is possible to selectively switch the pipe line through which the refrigerant is connected and the flow direction of the refrigerant, which is connected to the outdoor unit 30 described later. In addition, the diversion control unit 20 is one indoor unit 1
Two refrigerant pipes 2 for connecting the indoor unit, which are provided for each 0, and three refrigerant pipes 2 for connecting the outdoor unit, which are provided to connect to an outdoor unit 30 described later, are provided. .

The outdoor unit 30 is internally divided into two large components. The first component part is a part that forms a refrigerant circuit with the indoor unit 10 centering on a device such as a compressor and an outdoor heat exchanger, and will be hereinafter referred to as a refrigerant circuit part. The second component part is a part including a gas engine for driving the compressor, and devices associated therewith, which will be hereinafter referred to as a gas engine part.

In the refrigerant circuit section, a compressor 31, an outdoor heat exchanger 32, a water heat exchanger 33, an accumulator 34, a receiver 35, an oil separator 36, a throttle mechanism 37, a four-way valve 38, a solenoid valve 39 and a check valve. 40 and the like are provided. In addition, the refrigerant circuit section includes the diversion control unit 2
0 is connected to the three refrigerant pipes 2, the first operation valve 41, the second operation valve 42, and the third operation valve 4 are provided respectively.
It is provided with three refrigerant pipes 2 for connecting the diversion control unit provided with 3. The compressor 31 is operated by using a gas engine GE described below as a drive source, and the indoor heat exchanger 11 is operated.
Alternatively, a low-temperature low-pressure gas refrigerant sucked from any of the outdoor heat exchangers 32 is compressed and discharged as a high-temperature high-pressure gas refrigerant. Thus, during the cooling operation, the refrigerant can radiate heat to the outside air through the outdoor heat exchanger 32 even when the outside air temperature is high. Further, during the heating operation, it becomes possible to apply heat to the indoor air through the indoor heat exchanger 11.

The outdoor heat exchanger 32 functions as a condenser that condenses and liquefies the high-temperature and high-pressure gas refrigerant during the cooling operation to radiate heat to the outside air, and conversely evaporates the low-temperature and low-pressure liquid refrigerant during heating operation to heat the outside air It functions as an evaporator that takes away. In other words, during each operation of cooling and heating,
The outdoor heat exchanger 32 works in the opposite manner to the indoor heat exchanger 11 described above.

The outdoor heat exchanger 32 in this embodiment
Has a configuration in which the heat exchange part is divided into a plurality of parts and connected in parallel. In the illustrated example, the outdoor heat exchanger 32 is divided into four parts, and the reference signs 32A, 32B, 32C and 3 respectively.
Attach 2D. Further, the outdoor heat exchanger 32 is installed adjacent to a radiator 53 of a gas engine GE described later. The radiator 53 is a heat exchanger that exchanges heat with the outside air to cool the engine cooling water of the gas engine GE. Therefore, for example, when the heating operation is performed at a low outdoor temperature, by selectively switching the rotation direction of the outdoor unit fan 44, the outdoor heat exchanger 32 functioning as an evaporator passes through the radiator 53 and its temperature rises. Since it becomes possible to exchange heat with the outside air, it is possible to enhance its evaporation ability.

The water heat exchanger 33 is provided in parallel with the outdoor heat exchanger 32 because the refrigerant recovers heat from the engine cooling water of the gas engine GE which will be described later. That is, during the heating operation, the refrigerant can not only rely on the heat exchange in the outdoor heat exchanger 32 but also recover the waste heat from the engine cooling water of the gas engine GE. It is possible to further increase.
Further, since the water heat exchanger 33 is provided in parallel with the outdoor heat exchanger 32, it can be used alone as a heat exchanger (evaporator) for evaporating and evaporating the refrigerant. Incidentally, reference numeral 46 is a temperature sensor, which is provided as a temperature detecting means for detecting the refrigerant outlet temperature of the water heat exchanger 33.

The accumulator 34 is provided to store the liquid component contained in the gas refrigerant flowing into the compressor 31. The accumulator 34 has a compressor 3
A pressure sensor 45 is provided as a low pressure detecting means for detecting the suction side pressure of 1 (refrigerant saturation pressure). The receiver 35 is provided for separating the refrigerant liquefied by the heat exchanger functioning as a condenser into gas and liquid and storing the excess refrigerant in the refrigeration cycle as liquid. Oil separator 36
Is provided for separating the oil contained in the refrigerant and returning it to the compressor 31.

The throttle mechanism 37 is for decompressing and expanding the condensed high-temperature and high-pressure liquid refrigerant into a low-temperature and low-pressure liquid refrigerant. In the illustrated example, an electronic expansion valve, an expansion valve, and a capillary tube are properly used as the throttle mechanism 37 according to the purpose.

The four-way valve 38 is provided in the refrigerant pipe 2 to selectively switch the flow path and flow direction of the refrigerant, and together with the solenoid valve 39 and the check valve 40, to the outdoor heat exchanger 32 divided into a plurality of parts. Of the refrigerant supply switching means. The four-way valve 38 is provided with four ports D, C, S and E. The port D is the discharge side of the compressor 31, the port C is the outdoor heat exchanger 32, and the port S is the compressor 31. The refrigerant pipe 2 is connected to each of the suction sides, and the port E is connected to the middle of the refrigerant pipe 2 that connects the port C and the outdoor heat exchanger 32. In the illustrated configuration example, three three-way valves 38 are provided corresponding to the four-divided outdoor heat exchanger 32, and reference numerals 38A, 38B, and 38C are attached to the three four-way valves 38, respectively.

The first four-way valve 38A is connected to an outdoor heat exchanger (heat exchange section) designated by reference numeral 32A. The outdoor heat exchanger 32A can be used alone, and since the refrigerant pipe is provided with an electronic expansion valve as the throttle mechanism 37, the heat exchange capacity can be variably controlled. The second four-way valve 38B is connected to two outdoor heat exchangers (heat exchange parts) denoted by reference numerals 32B and 32C. in this case,
Both of the outdoor heat exchangers 32B and 32C are always used at the same time, and their applications are the same. Third four-way valve 38C
Is connected to an outdoor heat exchanger (heat exchange section) denoted by reference numeral 32D. This outdoor heat exchanger 32D can be used alone.

Therefore, if the outdoor heat exchangers 32A to 32D are evenly divided, the heat exchange capacity is 25% of the capacity of the outdoor heat exchanger 32A used alone, and the outdoor heat exchangers 32B, 32.
50% capacity to use C at the same time, outdoor heat exchangers 32B-D
It can be appropriately selected according to the usage situation from the 75% capacity of using the three divisions and the 100% capacity of using all the outdoor heat exchangers 32A to 32D. Also, the four-way valve 38
Since the flow direction of the refrigerant can be switched by opening / closing switching operations of A to D and the solenoid valve 39,
The outdoor heat exchangers 32A and 32D can be separately used, and the outdoor heat exchangers 32B and 32C can be integrally used as an evaporator or a condenser.

On the other hand, the gas engine portion is provided with a cooling water system 50, a fuel intake system 60, an exhaust gas system and an engine oil system (not shown) centered around the gas engine GE. The gas engine GE is connected to the compressor 31 installed in the refrigerant circuit section by a shaft, a belt or the like, and the driving force is transmitted from the gas engine GE to the compressor 31.

The cooling water system 50 is provided with a water pump 51, a reservoir tank 52, a radiator 53, etc., and cools the gas engine GE with the engine cooling water around a circuit (indicated by a broken line) constituted by connecting these components by piping. It is a system for doing. The water pump 51 is provided to circulate the cooling water of the gas engine GE in the circuit. The reservoir tank 52 is for temporarily storing an excess of the cooling water flowing through this circuit, or for supplying the cooling water when the cooling water is insufficient in the circuit. The radiator 53 is configured integrally with the outdoor heat exchanger 32, and is provided to release the heat taken by the engine cooling water from the gas engine GE to the outside air. In the illustrated example, the radiator 53 is similar to the outdoor heat exchanger 32.
Is also divided into four and connected in parallel, and the reference numerals 53A, 53B, 53C and 53D are attached to them. Also,
A solenoid valve 39 is provided so that the radiators 53A and 53D can be used individually or the radiators 53B and 53C can be used simultaneously.

The cooling water system 50 is provided with an exhaust gas heat exchanger 54 in addition to the above structure. This is provided in order to recover the heat of the exhaust gas discharged from the gas engine GE to the engine cooling water. Further, the cooling water system 50 is provided with the water heat exchanger 33 described above, and is arranged so as to extend over both the refrigerant circuit section and the cooling water system 50. Therefore, during the heating operation, the engine cooling water not only takes heat from the gas engine GE but also recovers heat from the exhaust gas, and the recovered heat passes through the water heat exchanger 33 from the engine cooling water. It is a mechanism that is given to the refrigerant. The cooling water system 5
The flow rate control of the engine cooling water at 0 is performed by the flow rate control valves 55A and 55B provided at two locations.

The fuel intake system 60 includes a gas regulator 6
1, a gas solenoid valve 62, a gas connection port 63, etc., and is a system for supplying city gas such as liquefied natural gas (LNG) to the gas engine GE as gas fuel. The gas regulator 61 is provided to adjust the delivery pressure of the gas fuel supplied from the outside via the gas solenoid valve 62 and the gas connection port 63. The gas fuel whose pressure is adjusted by the gas regulator 61 is mixed with air sucked from an intake port (not shown) and then supplied to the combustion chamber of the gas engine GE.

In the following, the operation of the MGHP 1 having the above-described structure during the heating operation for heating the room will be described.
First, a case where all the indoor units 10A to 10D are heated as usual using the outdoor heat exchanger will be described with reference to FIG.
This will be described with reference to Nos. 3 to 3. The open / closed state of each valve is closed in black, and the refrigerant flow direction is indicated by an arrow. In this case, the four-way valve 3 of the refrigerant circuit section
In all of 8A to 8C, the ports C / S are communicated with each other, and the discharge side of the compressor 31 and the indoor heat exchanger 11 are connected. In this state, the high-temperature and high-pressure gas refrigerant discharged from the compressor 31 is sent to the diversion control unit 20 through the second operation valve 42. The refrigerant guided into the diversion control unit 20 is sent through the electromagnetic valve 22 to the indoor heat exchanger 11 that functions as a condenser of each indoor unit 10A to 10D.

The high-temperature and high-pressure gas refrigerant is used for the indoor heat exchanger 11
It is condensed and liquefied by exchanging heat with the indoor air. In this process, the gas refrigerant radiates heat to warm the indoor air, and then becomes a high temperature and high pressure liquid refrigerant. This liquid refrigerant is decompressed by passing through the capillary tube 13 to become a low temperature and low pressure liquid refrigerant,
It is returned to the diversion control unit 20 via the check valve 14. The low-temperature low-pressure liquid refrigerant flowing into the flow dividing control unit 20 is sent to the refrigerant circuit section of the outdoor unit 30 through the electromagnetic valve 24 and the third operation valve 43.

The liquid refrigerant sent to the refrigerant circuit section 30 is separated into gas and liquid through the receiver 35, and only the liquid refrigerant is sent to the outdoor heat exchanger 32 which functions as an evaporator. This liquid refrigerant, before entering the outdoor heat exchanger 32, the throttling mechanism 3
After passing through a capillary tube provided as 7, the pressure is reduced again. Regarding the water heat exchanger 33 arranged in parallel with the outdoor heat exchanger 32, since the electromagnetic valve 39 provided in the refrigerant pipe 2 is closed, the low-temperature low-pressure liquid refrigerant does not flow in. In the outdoor heat exchanger 32,
The low-temperature low-pressure liquid refrigerant takes heat from the outside air and evaporates to become a low-temperature low-pressure gas refrigerant. At this time, if high-temperature engine cooling water is caused to flow through the radiator 53, the liquid waste can be efficiently evaporated and vaporized by utilizing the engine waste heat.

The refrigerant which has become the low temperature and low pressure gas in this way is
After being introduced from the port C of the four-way valve 38 to the accumulator 34 via the port S to separate the liquid component, the compressor 31
Inhaled into. The gas refrigerant sucked into the compressor 31 is compressed by the operation of the compressor 31, becomes a high-temperature and high-pressure gas refrigerant, and is sent to the indoor heat exchanger 11 again, so that the refrigerant forms a refrigeration cycle in which the state changes repeatedly. be able to.

Subsequently, the indoor unit 10A is operated when the outside temperature is low.
A case in which all of D to D are heated will be described with reference to FIG. Also in this case, the discharge side of the compressor 31 and the indoor heat exchanger 11 are connected, as in the normal heating operation described above. In this state, the high-temperature and high-pressure gas refrigerant discharged from the compressor 31 is sent to the diversion control unit 20 through the second operation valve 42. As shown in FIG. 2, the refrigerant introduced into the diversion control unit 20 is sent to the indoor heat exchanger 11 that functions as a condenser of each indoor unit 10A to 10D through the solenoid valve 22.

The high temperature and high pressure gas refrigerant is supplied to the indoor heat exchanger 11
It is condensed and liquefied by exchanging heat with the indoor air. In this process, the gas refrigerant radiates heat to warm the indoor air, and then becomes a high temperature and high pressure liquid refrigerant. This liquid refrigerant is decompressed by passing through the capillary tube 13 to become a low temperature and low pressure liquid refrigerant,
It is returned to the diversion control unit 20 via the check valve 14. The low-temperature low-pressure liquid refrigerant flowing into the flow dividing control unit 20 is sent to the refrigerant circuit section of the outdoor unit 30 through the electromagnetic valve 24 and the third operation valve 43.

The liquid refrigerant sent to the refrigerant circuit section 30 is separated into gas and liquid through the receiver 35, and only the liquid refrigerant is sent to the water heat exchanger 33. At this time, the solenoid valve 39 provided on the inlet side of the outdoor heat exchanger 32 is closed. Before entering the water heat exchanger 33, this liquid refrigerant passes through an expansion valve provided as a throttle mechanism 37 and is decompressed again. In the water heat exchanger 33, the low-temperature low-pressure liquid refrigerant is heated by the high-temperature engine cooling water and evaporates to become a low-temperature low-pressure gas refrigerant. Therefore, the water heat exchanger 33 does not have to use the outdoor heat exchanger 32, which has a low outside air temperature and cannot obtain a sufficient evaporation capacity, or on the contrary radiates heat to the outside air, which causes a decrease in COP. This allows the liquid refrigerant to be vaporized and vaporized.

The refrigerant, which has become a low-temperature and low-pressure gas in this way, is guided to the accumulator 34, where the liquid component is separated and then sucked into the compressor 31. The gas refrigerant sucked into the compressor 31 is compressed by the operation of the compressor 31, becomes a high-temperature and high-pressure gas refrigerant, and is sent to the indoor heat exchanger 11 again, so that the refrigerant forms a refrigeration cycle in which the state changes repeatedly. be able to.

When performing the heating operation using the water heat exchanger 33 described above, in order to operate the compressor 31 efficiently, it is necessary to give a proper superheat degree to the gas refrigerant to be suction-compressed. This superheat degree SH is the same as the above-mentioned water heat exchanger 3
The refrigerant outlet temperature Th detected by the temperature sensor 46 provided at the outlet of No. 3 and the refrigerant saturation temperature Ts uniquely obtained from the suction side pressure Pi detected by the pressure sensor 45 provided in the accumulator 34, SH = Th- It is calculated by the mathematical formula Ts.

Since the suction side pressure Pi detects the refrigerant saturation pressure in the accumulator 34, the refrigerant saturation temperature Ts corresponding to the refrigerant saturation pressure can be known. Suction pressure P
i is a value determined by the throttle mechanism 37 and the like of the system, and in the following description, the refrigerant saturation temperature Ts will be described as 3.7 ° C. Therefore, for example, when the superheat degree SH is set to 5 ° C., the circulation amount of the engine cooling water of the water heat exchanger 33 may be adjusted so that the refrigerant outlet temperature Th becomes 8.7 ° C. from Th = SH + Ts. . It should be noted that the actual target value of Th does not have to be the same as the above calculated value, for example, set to 9 ° C., because the appropriate degree of superheat SH varies from about 5 ° C. to 10 ° C.

Thus, the refrigerant outlet temperature T of the water heat exchanger 33
When the target value is set to h, the two detection values Ts and Th are input to a control unit (not shown), and the opening of the flow rate control valve 55B is mainly set so that the refrigerant outlet temperature Th reaches the target value by, for example, fuzzy calculation. The engine cooling water is adjusted and distributed to the water heat exchanger 33 and the radiator 53. At this time, the engine cooling water is distributed by the refrigerant outlet temperature Th of the water heat exchanger 33.
Priority is given to securing the flow rate required to keep the target value at, and the surplus is sent to the radiator 53. The flow rate adjustment valve 55A
Is mainly in the warm-up operation of the gas engine GE,
It is used for the purpose of raising the temperature in a short time by preventing the engine cooling water from flowing into the radiator 53 and the water heat exchanger 33.

With this arrangement, the gas refrigerant can be stably provided with an appropriate degree of superheat on the suction side of the compressor 31. Therefore, the gas-liquid two-phase refrigerant is not supplied to the compressor 31, and the reduction of the heating capacity and the reduction of the COP due to the reduction of the compression performance can be improved. The configuration of the present invention is not limited to the above embodiment,
Modifications can be made as appropriate without departing from the spirit of the present invention.

[0040]

According to the above-described multi-type gas heat pump type air conditioner of the present invention, the water heat exchanger for heating the refrigerant by obtaining waste heat from the engine cooling water for cooling the gas engine is used as the outdoor heat exchanger. Since they are arranged in parallel and the circulation amount of the engine cooling water introduced to the water heat exchanger is controlled to maintain the superheat degree of the refrigerant within a predetermined range, it can be used outdoors during heating operation at low outdoor temperature. By introducing the engine cooling water into the water heat exchanger instead of the heat exchanger, the refrigerant is vaporized and vaporized, and an appropriate degree of superheat can be stably given. For this reason,
It is possible to prevent the gas-liquid two-phase refrigerant from being sucked into the compressor and reduce the compression efficiency, and the gas refrigerant supplied from the water heat exchanger can circulate in the refrigeration cycle to obtain a good heating capacity. Furthermore, COP as an air conditioner can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a multi-type gas heat pump type air conditioner according to the present invention, and is an overall configuration diagram showing a normal total heating operation state using an outdoor heat exchanger as an example.

FIG. 2 is a diagram showing an internal configuration of a flow dividing control unit and an indoor unit in FIG.

FIG. 3 is a diagram showing a configuration example around an outdoor heat exchanger in FIG.

FIG. 4 is a diagram showing an embodiment of a multi-type gas heat pump type air conditioner according to the present invention, and is an overall configuration diagram showing a total heating operation state at a low outside air temperature.

[Explanation of symbols]

1 Multi-type gas heat pump type air conditioner (MGH
P) 10 indoor unit 11 indoor heat exchanger 20 diversion control unit 30 outdoor unit 31 compressor 32 outdoor heat exchanger 37 throttling mechanism 38 four-way valve 39 solenoid valve 40 check valve 41 first operating valve 42 second operating valve 43 Third Operation Valve 45 Pressure Sensor (Low Pressure Detection Means) 46 Temperature Sensor (Temperature Detection Means) GE Gas Engine

Continued front page    (72) Inventor Tsukasa Kasaki             3-1, Asahi-cho, Nishibiwajima-cho, Nishikasugai-gun, Aichi             Address Mitsubishi Heavy Industries Co., Ltd. (72) Inventor Tadahiro Kato             3-1, Asahi-cho, Nishibiwajima-cho, Nishikasugai-gun, Aichi             Address Mitsubishi Heavy Industries Co., Ltd. F term (reference) 3L060 AA03 AA06 CC02 DD02 EE23                       EE33

Claims (2)

[Claims] 1. A plurality of indoor unit units each provided with an indoor heat exchanger for exchanging heat between indoor air and a refrigerant, a compressor driven by a gas engine, and heat exchange between outside air and a refrigerant. An outdoor unit having an outdoor heat exchanger for performing, and a shunt control unit for controlling the flow direction of the refrigerant for each of the indoor units to selectively switch between heating and cooling operations, the outdoor heat exchanger In the multi-type gas heat pump type air conditioner provided with a refrigerant supply switching means for controlling the flow of the refrigerant for each of the divided parts of the outdoor heat exchanger, which is divided into a plurality of parts and connected in parallel, the outdoor unit In the unit, a water heat exchanger that heats the refrigerant by obtaining waste heat from the engine cooling water for cooling the gas engine is arranged in parallel with the outdoor heat exchanger, and is introduced into the water heat exchanger. By controlling the circulation amount of the engine cooling water, a multi-type gas heat pump type air conditioning system and maintains the refrigerant superheat of the compressor suction side within a predetermined range. 2. The refrigerant superheat degree is calculated from detected values of a low pressure detecting means for detecting a pressure on a suction side of a compressor and a temperature detecting means for detecting a refrigerant outlet temperature of the water heat exchanger. The multi-type gas heat pump type air conditioner according to claim 1.