JPH06249541A - Gas engine heat pump device - Google Patents

Abstract

PURPOSE:To realize practicality as a cooling and heating apparatus in terms of power consumption and cost of a refrigerant by using the same propane, city gas and the like as a fuel gas and a refrigerant in a gas engine. CONSTITUTION:A gas engine heat pump device uses the same gas as a fuel gas and a refrigerant in a gas engine 15, and uses propane as the fuel gas. A fuel gas supply pipe 11 is connected to a line in a refrigerant circuit in a manner to enable communication therebetween, and a refrigerant liquid reservoir 22 is connected to an inlet side of a fuel gas pressure reducing valve 13 through a gas-liquid return pipe 40 in a manner to enable communication therebetween. A liquid level in the refrigerant liquid reservoir 22 being above or below a predetermined level is detected to cause a return liquid electromagnetic valve 41 to open a return pipe 40 or to cause a supplementary gas electromagnetic valve 52 to open a supplementary gas pipe 51. In addition, a gas outlet of an accumulator 23 is connected to the fuel gas supply pipe 11 through a return gas pipe 45 in a manner to enable communication therebetween so that a liquid level in the accumulator 23 exceeding a predetermined level is detected to cause a return gas electromagnetic valve 46 to open the return gas pipe 45.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a domestic / commercial heating / cooling device, and more particularly to a gas engine heat pump device driven by a gas engine which suppresses an increase in power demand and a refrigerant cost.

[0002]

2. Description of the Related Art In recent years, in the case of a heating / cooling dual-purpose device using a heat pump, which is popular in general, most of them use an electric motor for mechanical work required to drive a compressor. As a result, power consumption peaks in mid-summer and mid-winter, and this tends to increase every year, causing social problems such as power demand not catching up.

Recently, the problem of abolishing CFC has been raised as one of the means for suppressing the global warming phenomenon, and the prohibition of the use of the refrigerant R22, which is the mainstream in general use, has become a reality. It has become to.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
Although a low-polluting CFC has been proposed as an alternative CFC as a substitute for No. 22, it is considerably more expensive than the currently used CFCs, and there is a problem in practical use. The inventors have been working on development focusing on these social problems.

Further, as a recent tendency, in the case of a system for air conditioning a plurality of indoor spaces, a plurality of indoor units corresponding to a plurality of spaces are connected to one outdoor unit by piping, and each of these indoor units is independently controlled. The number of cases to do is increasing. In such a system, it has been reported that the difference between the maximum load and the minimum load is several times to several tens of times, and the required amount of the refrigerant varies greatly.

[0006] Furthermore, as the number of indoor units increases, the piping of the refrigerant circuit connecting these units and the outdoor unit becomes complicated and diversified, and the amount of refrigerant present inside such circuit piping also increases, and the fluctuation amount also increases. Will also increase. The increase in the amount of refrigerant is a problem that needs to be solved promptly in terms of cost in view of the adoption of alternative CFCs.

Therefore, a first object of the present invention is to suppress an increase in electric power demand by adopting a gas engine in place of a conventional electric motor which performs a mechanical work necessary for driving a compressor, and at the same time, to suppress the gas demand. It is an object of the present invention to provide a gas engine heat pump device in which the same propane or the like is used as the fuel gas and the refrigerant of the engine, thereby significantly reducing the cost of the refrigerant used in the heating / cooling dual-use device and enabling the practical use.

A second object of the present invention is to provide a gas engine heat pump device capable of efficiently distributing the required amount of refrigerant to each unit in response to changes and changes in the amount of refrigerant, especially in a system having a plurality of indoor units installed. Is to provide.

[0009]

In order to achieve this object, a gas engine heat pump device according to the present invention, in claim 1, performs a mechanical work required for driving a compressor by a gas engine, and an outdoor unit. A cooling and heating system is formed with the indoor unit, and the same gas is used as the fuel gas and the refrigerant of the gas engine.

According to a second aspect of the present invention, the fuel gas supply pipe for supplying the fuel gas from the gas supply source to the gas engine and the pipeline of the refrigerant circuit are connected so as to communicate with each other.

In the present invention, the refrigerant liquid receiving tank of the refrigerant circuit is communicably connected to the inlet side of the fuel gas pressure reducing valve provided in the fuel gas supply pipe via the gas / liquid return pipe. The return pipe is opened by the return liquid solenoid valve upon detecting that the inside of the tank has exceeded the predetermined liquid level.

According to another aspect of the present invention, the gas outlet of the accumulator of the refrigerant circuit is connected between the supply gas pressure reducing valve and the gas engine via the return gas pipe so that the inside of the accumulator exceeds the predetermined liquid level. Is detected, the return gas solenoid valve opens the return gas pipe.

According to a fifth aspect of the present invention, the return pipe and the liquid outlet of the accumulator are connected by a replenishment gas pipe so that they can communicate with each other, and it is detected that the inside of the refrigerant liquid receiving tank is below a predetermined liquid level, and the replenishment gas solenoid valve is connected. It is designed to open the refill gas pipe.

[0014]

In the first aspect, the same gas is used as the fuel gas and the refrigerant of the gas engine, and propane is used as the gas. The propane of this fuel gas is also used as the refrigerant of the refrigerant circuit. Therefore, when the refrigerant in each device of the refrigerant circuit is in excess or in shortage during operation, the surplus amount is supplied to the fuel gas, and conversely, the shortage amount is supplemented by the fuel gas.

According to the second to fifth aspects, as described in the first aspect, since the pipeline of the refrigerant circuit communicates with the fuel gas supply pipe, even when the refrigerant overflows in a liquid or gas state. , It can be returned to the fuel gas supply pipe. For example, when the inside of the refrigerant liquid receiving tank exceeds a predetermined liquid level, the return liquid solenoid valve opens the return pipe that also serves as gas and liquid, and the excess refrigerant liquid is returned to the fuel gas supply pipe. When the inside of the refrigerant liquid receiving tank becomes lower than a predetermined liquid level, the replenishment gas solenoid valve opens the replenishment gas pipe to replenish the fuel gas from the fuel gas supply pipe to the accumulator. Further, when the inside of the accumulator exceeds a predetermined liquid level, the return gas solenoid valve opens the return gas pipe to return the surplus gas to the fuel gas supply pipe.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a gas engine heat pump device according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a cooling operation and FIG. 2 shows a heating operation. The gas engine heat pump device of the embodiment performs mechanical work necessary for driving the compressor by the gas engine, and the outdoor unit 1 and the indoor unit. An air conditioning and heating system is formed between the two.

The outdoor unit 1 has propane, butane, city gas, a mixed gas of propane and butane, and one containing propane and butane as a main component, and a gas engine 15 that operates by using any one of these gases. The gas engine 15 performs the mechanical work required to drive the compressor 16. The gas used in the examples is propane, and the gas engine 15 uses propane sent from the propane gas cylinder 10 of the gas supply source through the fuel gas supply pipe 11 as fuel.
Works. The rotation output of the gas engine 15 is the compressor 16
Be transmitted to. This compressor 16 is one of the members constituting the outdoor unit 1 of the refrigerant circuit, and the refrigerant circuit is a four-way switching valve (hereinafter referred to as a four-way valve) 17, which is an electromagnetic valve, a double-pipe heat exchanger 18, for refrigerant. Outdoor heat exchanger 19, expansion valve 2
0, a dryer 21, a refrigerant liquid receiving tank 22, an accumulator 23 and the like, and an indoor unit 2 and the like.

As the refrigerant used in the refrigerant circuit, propane which is the fuel gas of the gas engine 15 used in the embodiment is also used in place of the conventional CFC R22 or the like. That is, the same propane is used as the fuel gas and as the refrigerant. In addition to propane, butane, city gas, a mixed gas of propane and butane, and one containing propane and butane as main components can also be used.

The indoor unit 2 is interposed between the refrigerant liquid receiving tank 22 on the outdoor unit 1 side and the four-way valve 17, and the expansion valve 2
5, the check valve 26, the indoor heat exchanger 27 for refrigerant, and the like. That is, in the indoor unit 2, cool air or warm air is discharged from the indoor fan motor 28 through the refrigerant heat exchanger 27 to cool or heat the room. Therefore, the refrigerant heat exchanger 27 is
It operates as an evaporator during cooling operation and as a condenser during heating operation.

The cooling circuit of the gas engine 15 includes a pump 31 for circulating cooling water, an exhaust gas heat exchanger 32 for exchanging heat of engine exhaust gas with the cooling water, a heat exchanger 33 for water, and a gas. Liquid separator 34, outdoor fan motor 35,
It is composed of a capillary tube 36, a water tank 37 connected to the gas-liquid separator 34, and the like. This cooling circuit is also connected to the double-tube heat exchanger 18 on the side of the outdoor unit 1 so that when the warm air supplied from the outdoor unit 1 and the indoor unit 2 is insufficient in extreme cold, it can be supplemented with heat from the engine cooling water. Has become.

On the other hand, a return conduit circuit, which is the essence of the present invention, is communicably connected to both the heating and cooling circuits of the outdoor unit 1 and the indoor unit 2 described above.

That is, a main valve 12 and a fuel gas pressure reducing valve 13 are arranged in the fuel gas supply pipe 11, and propane pressure-reduced by the fuel gas pressure reducing valve 13 is predetermined by a gas pressure adjusting device 14 including a gas solenoid valve and a zero governor. After the pressure is adjusted, the gas is supplied to the gas engine 15. In the fuel gas supply pipe 11, a return pipe 40 is provided in a branched manner between the main plug 12 and the fuel gas pressure reducing valve 13, and the refrigerant liquid receiving tank 22 on the outdoor unit 1 side is connected to the fuel gas via the return pipe 40. It is connected so as to be able to communicate with the supply pipe 11.

A return liquid solenoid valve 41, a check valve 42, and preferably a gas-liquid separation filter 43 are arranged in this order from the refrigerant liquid receiving tank 22 side in the return pipe 40. The refrigerant liquid receiving tank 22 is equipped with a first liquid level sensor 44 for detecting that the internal liquid level has exceeded a predetermined position.
An operation signal from a control unit (not shown) that performs control based on the detection signal from No. 4 is sent to the return liquid solenoid valve 41. That is, the return pipe 4 is turned on by turning on the return liquid solenoid valve 41.
0 is opened so that the refrigerant liquid receiving tank 22 communicates with the fuel gas supply pipe 11. Further, the accumulator 23 of the refrigerant circuit is connected to the fuel gas supply pipe 1 via the return gas pipe 45.
The outlet side of the first pressure reducing valve 13 can communicate with the inlet side of the gas pressure adjusting device 14.

The return gas pipe 45 has an accumulator 23.
In order from the return gas solenoid valve 46, the return gas pressure reducing valve 47, the check valve 49, and preferably the gas-liquid separation filter 48.
Etc. are arranged. The accumulator 23 has a second liquid level sensor 5 for detecting that the internal liquid level has exceeded a predetermined position.
0, and an operation signal from the control unit is sent to the return gas solenoid valve 46 based on the detection signal from the second liquid level sensor 50. That is, it is possible to open the return gas pipe 45 by turning on the return gas electromagnetic valve 46 and to connect the accumulator 23 to the fuel gas supply pipe 11. Further, the return gas pressure reducing valve 47 is provided between the fuel gas supply pipe 11 and the outlet side of the return gas electromagnetic valve 46. The set pressure of the return gas pressure reducing valve 47 is set higher than that of the fuel gas pressure reducing valve 13, whereby the fuel gas supply pressure to the gas engine 15 is kept constant, and the control of the engine speed etc. is made constant. be able to.

Further, a supplementary gas pipe 51 is provided between the accumulator 23 and the return pipe 40,
The return pipe 40 can communicate with the accumulator 23 via the supplementary gas pipe 51. A replenishment gas electromagnetic valve 52, a drier 53 and the like are arranged in the replenishment gas pipe 51. An operation signal based on a detection signal of the first liquid level sensor 44 provided in the refrigerant liquid receiving tank 22 is sent to the supplementary gas electromagnetic valve 52. That is, when the liquid level in the refrigerant liquid receiving tank 22 is now "below" the predetermined position by the first liquid level sensor 44, the operation signal from the control unit is generated based on the detection signal from the first liquid level sensor 44. Are sent to the replenishment gas solenoid valve 52. That is, by turning on the replenishment gas solenoid valve 52, the replenishment gas pipe 51 is opened, and the fuel gas can be replenished to the accumulator 23 from the fuel gas supply pipe 11, and as a result, the shortage amount in the refrigerant liquid receiving tank 22 is compensated through the refrigerant circuit. Is possible.

As the first liquid level sensor 44, one can detect two upper and lower positions when the liquid level in the refrigerant liquid receiving tank 22 exceeds a predetermined position and when it falls below a predetermined position. It can be used.

Next, the operation and action of the gas engine heat pump device of the above embodiment will be described.

In FIG. 1 showing the cooling operation, propane as a fuel is supplied to the gas engine 15 from the propane gas cylinder 10 through the fuel gas supply pipe 11 by the activation of the apparatus. The rotation output of the gas engine 15 is transmitted to the compressor 16. The refrigerant circuit is also filled with propane, which is the same as the fuel, as the refrigerant. By operating the compressor 16, propane gas as a refrigerant is compressed and discharged in the direction of the arrow. The refrigerant gas due to propane, which has become high temperature and high pressure due to compression, is cooled and liquefied by contact with the outside air when the refrigerant heat exchanger 18 of the outdoor unit 1 operates as a “condenser”. The liquefied refrigerant liquid is decompressed by the expansion valve 20.

This low-pressure refrigerant liquid is then supplied to the indoor unit 2
The heat exchanger 27 for refrigerant in the indoor unit 2 operates as an “evaporator” to remove heat from the indoor air and evaporate. The heat of evaporation at this time produces a cooling effect. The evaporated refrigerant gas returns to the compressor 16 again via the four-way valve 17, and the same refrigeration cycle is repeated.

By the way, when such a cooling cycle is repeated, the first liquid level sensor 44 detects when the amount of the refrigerant liquid in the refrigerant liquid receiving tank 22 increases and exceeds a predetermined liquid level, and control is performed based on the detection signal. An operation signal is sent from the unit to the return liquid solenoid valve 41. When the return liquid solenoid valve 41 is turned on, the return pipe 40 is opened, the refrigerant liquid receiving tank 22 is communicated with the return pipe 40 and the fuel gas supply pipe 11, and excess refrigerant liquid is returned to the return pipe 4.
Return from 0 to the fuel gas supply pipe 11.

When the liquid level inside the accumulator 23 exceeds a predetermined position, the second liquid level sensor 50 detects it, and based on this detection signal, an operation signal from the control unit is returned to the return gas solenoid valve 46. Delivered and returned gas solenoid valve 4
When the switch 6 is turned on, the return gas pipe 45 is opened. Thereby, the refrigerant gas in the accumulator 23 is returned to the gas pipe 45.
Can be returned to the fuel gas supply pipe 11. Since the set pressure of the return gas pressure reducing valve 47 is set higher than that of the fuel gas pressure reducing valve 13, the fuel gas supply pressure to the gas engine 15 is always constant and the engine speed and the like are controlled to be constant.

On the other hand, when the liquid level in the refrigerant liquid receiving tank 22 is now "below" the predetermined position, the first liquid level sensor 4
An operation signal from the control unit is sent to the replenishment gas solenoid valve 52 based on the detection signal from 4. That is, the replenishment gas electromagnetic valve 52 is turned on to open the replenishment gas pipe 51, and the fuel gas supply pipe 11 is connected to the accumulator 23 through the replenishment gas pipe 51. That is, the replenishment gas solenoid valve 52 is turned on to open the replenishment gas pipe 51, replenish the high-pressure fuel gas from the fuel gas supply pipe 11 to the accumulator 23, and as a result, the shortage amount in the refrigerant liquid receiving tank 22 through the refrigerant circuit. To make up for.

Next, in the heating operation shown in FIG.
The port of the four-way valve 17 provided in the outdoor unit 1 is switched. By operating the compressor 16, propane gas as a refrigerant is compressed and discharged in the direction of the arrow. The refrigerant gas of propane, which has become high temperature and high pressure due to compression, is introduced into the indoor unit 2, the refrigerant heat exchanger 27 in the indoor unit 2 operates as a “condenser”, and is cooled and liquefied by the indoor air. At this time, the indoor air is warmed by the heat of condensation to produce a heating effect. The liquefied refrigerant is decompressed by the expansion valve 25. The depressurized refrigerant liquid uses the refrigerant heat exchanger 19 of the outdoor unit 1 as an "evaporator" to take the heat of the outside air, and the double-tube heat exchanger 18 takes the heat of the engine cooling water to evaporate it. . The evaporated refrigerant gas returns to the compressor 16 again via the four-way valve 17, and the same heating cycle is repeated.

During the repetition of this heating cycle, the excess / deficiency of the refrigerant liquid in the refrigerant liquid receiving tank 22 and the accumulator 23
When the internal liquid level exceeds a predetermined position, excess return refrigerant liquid or refrigerant gas is returned to the return pipe 4 as in the cooling cycle described above.
0 or the return gas pipe 45 is returned to the fuel gas supply pipe 11.

As is clear from the structure and operation of the embodiment, the return pipe 40 can be used not only for the circulation of the fuel gas, but also for the gas and liquid, which is the same refrigerant as the fuel gas, in the gas state or the liquid state. Has become. In such a case, it is desirable to provide means such as a pressure adjusting valve in consideration of the pressure balance with the fuel gas supply pipe 11 side at the branch point between the fuel gas supply pipe 11 and the return pipe 40.

In addition, in the refrigerant circuit, when the amount of refrigerant flowing in the circuit conduit increases, or as another embodiment, the number of indoor units 2 installed is further increased and a plurality of units are connected to the outdoor unit 1. In such a case, the amount of refrigerant varies between the indoor units 2. The refrigerant liquid receiving tank 22 and the accumulator 23 absorb the increase in the amount of the refrigerant.
Is. In the case of the conventional system, the increase in the amount of the refrigerant has been taken into consideration in advance to cope with the increase in both the refrigerant liquid receiving tank 22 and the accumulator 23. In the present invention, as is apparent from the above-described embodiment, in the system that feeds back and replenishes both the refrigerant liquid receiving tank 22 and the accumulator 23 to the fuel gas supply pipe 11 with respect to the fluctuation of the refrigerant in the refrigerant circuit. Therefore, it is not necessary to enlarge both devices in advance. Therefore, it also has a great advantage that the size of the device can be suppressed, and when a plurality of indoor units are installed, it can be appropriately absorbed in excess and deficiency of the refrigerant amount between each unit, and the refrigerant It becomes possible to improve efficiency.

[0038]

As described above, the gas engine heat pump device according to the present invention uses the same gas such as propane as the fuel gas and the refrigerant of the gas engine in claim 1, so that the excess of the refrigerant is reduced. Since the shortage of the refrigerant is supplemented by the fuel gas instead of the fuel gas, the conventional troublesome replenishment work is unnecessary and the adjustment can be automatically performed, and the cost of the refrigerant can be significantly reduced.

In the second to fifth aspects, since the pipeline of the refrigerant circuit communicates with the fuel gas supply pipe, even when the refrigerant overflows in the liquid state or the gas state, it is supplied to the fuel gas supply pipe. As a result, the refrigerant liquid receiving tank of the refrigerant circuit and the accumulator can be restrained from becoming large in size and can be miniaturized, which leads to miniaturization of the outdoor unit and the indoor unit.

[Brief description of drawings]

FIG. 1 is a circuit system diagram during cooling of a gas engine heat pump device according to an embodiment of the present invention.

FIG. 2 is a circuit system diagram of the embodiment during heating.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Outdoor unit, 2 ... Indoor unit, 10 ... Propane gas cylinder, 11 ... Fuel gas supply pipe, 12 ... Main plug, 13
... Fuel gas pressure reducing valve, 14 ... Gas pressure adjusting device, 15 ... Gas engine, 16 ... Compressor, 17 ... Four-way valve, 19 ... Refrigerant outdoor heat exchanger, 20, 25 ... Expansion valve, 21, 53 ... Dryer, 22 ... Refrigerant liquid receiving tank, 23 ... Accumulator, 2
7 ... Indoor heat exchanger for refrigerant, 28 ... Indoor fan motor, 3
1 ... Cooling water circulation pump, 32 ... Exhaust gas heat exchanger, 40
... Return pipe for gas and liquid, 41 ... Return liquid solenoid valve, 44 ... First
Liquid level sensor, 45 ... Return gas pipe, 46 ... Return gas solenoid valve, 47 ... Return gas pressure reducing valve, 50 ... Second liquid level sensor, 5
1 ... Replenishment gas pipe, 52 ... Replenishment gas solenoid valve.

Claims (5)

[Claims] 1. A gas engine heat pump device for performing a mechanical work required for driving a compressor by a gas engine to form a cooling and heating system between an outdoor unit and an indoor unit, the fuel gas and the refrigerant of the gas engine. A gas engine heat pump device, characterized in that the same gas is used for both. 2. The gas engine heat pump device according to claim 1, wherein the fuel gas supply pipe for supplying the fuel gas from the gas supply source to the gas engine and the pipeline of the refrigerant circuit are connected so as to communicate with each other. 3. A refrigerant liquid receiving tank of a refrigerant circuit is communicatively connected to an inlet side of a fuel gas pressure reducing valve provided in a fuel gas supply pipe via a gas-liquid return pipe, and the inside of the refrigerant liquid receiving tank is The gas engine heat pump device according to claim 1, wherein the return pipe is opened by a return liquid solenoid valve upon detecting that the predetermined liquid level has been exceeded. 4. A gas outlet of an accumulator of a refrigerant circuit is communicably connected between a fuel gas pressure reducing valve and a gas engine via a return gas pipe to detect that the inside of the accumulator has exceeded a predetermined liquid level. The gas engine heat pump device according to claim 1, wherein the return gas pipe is opened by the return gas solenoid valve. 5. The replenishment gas pipe is connected by a replenishment gas pipe by connecting the return pipe and the liquid outlet of the accumulator so as to be able to communicate with each other, and detecting that the inside of the refrigerant liquid receiving tank is below a predetermined liquid level. The gas engine heat pump apparatus according to claim 4, wherein the gas engine heat pump apparatus is opened.