KR100701960B1 - Cogeneration system - Google Patents

Abstract

The cogeneration system allows the exhaust gas of the engine to pass through the exhaust gas heat exchanger through the first exhaust passage during the heating operation of the air conditioner, and bypasses the exhaust gas heat exchanger through the second exhaust passage during the cooling operation. By doing so, since the waste gas waste heat is not recovered during the cooling operation, since the heat dissipation heat exchanger is not used, the volume of the heat dissipation heat exchanger can be reduced, and the system can be made compact.

Cogeneration, Engine, Exhaust Gas, Heat Exchanger, Heat Dissipation, Recovery, Bypass

Description

Cogeneration System {Cogeneration system}

1 is a configuration diagram showing a cogeneration system according to the prior art,

2 is a block diagram showing when the air conditioner of the cogeneration system according to the present invention is a heating operation,

3 is a block diagram showing when the air conditioner of the cogeneration system according to the present invention is the cooling operation.

<Explanation of symbols on main parts of the drawings>

50: engine 51: exhaust gas heat exchanger

52: engine 53: coolant heat exchanger

60: heat medium circulation passage 61: first discharge passage

62: second discharge passage 63: third discharge passage

64: first damper 65: second damper

70: air conditioner 71: compressor

72: four-way valve 73: indoor heat exchanger

74: expansion mechanism 75: outdoor heat exchanger

76: air preheat heat exchanger 80: heat dissipation heat exchanger

81: heat radiation passage 82: first valve

83: second valve

The present invention relates to a cogeneration system, and in particular, the exhaust gas discharge passage of the engine is composed of two first and second discharge passages, so that the exhaust gas waste heat is discharged to the outside without recovering during the cooling operation of the air conditioner In addition, the present invention relates to a cogeneration system capable of reducing the volume of a heat dissipating heat exchanger, thereby making the system compact.

Cogeneration systems, commonly referred to as cogeneration systems, are systems that produce power and heat simultaneously from a single energy source.

Such a cogeneration system is capable of recovering waste heat from exhaust gas or cooling water generated by power generation by driving an engine or a turbine to increase the overall thermal efficiency by 70 to 80%. In particular, it is a high-efficiency energy utilization method that utilizes the recovered waste heat a lot in cooling, heating, and hot water supply.

1 is a block diagram showing a cogeneration system according to the prior art.

The cogeneration system according to the prior art, as shown in FIG. 1, an engine 1 to which gas is supplied, a generator 3 driven by the engine 1 to generate electricity, and the engine 1 Cooling water heat exchanger (5) for recovering the coolant heat that has cooled the engine, Exhaust gas heat exchanger (9) provided on the exhaust gas discharge passage (7) of the engine (1), and recovering exhaust gas heat, and the cooling water And a heat transfer line 11 which transfers heat and exhaust gas heat to the air conditioning and heating device 20.

The electricity generated by the generator 3 is used in various ways such as air-conditioning devices or other lighting and electronic products.

The waste heat generated by the engine 1, that is, the coolant heat generated while cooling the engine 1, and the exhaust gas heat generated by the exhaust gas discharged from the engine 1 are used during the heating operation of the air conditioner 20. When used in the cooling operation, the heat dissipation means consisting of a heat exchanger 15 and a heat dissipation fan 16 is provided to dissipate waste heat.

The heat dissipation means includes a heat dissipation heat exchanger (17) installed to dissipate heat recovered from the cooling water heat exchanger (5) and the exhaust gas heat exchanger (9) into the atmosphere, and a heat dissipation line (13) connected to the heat transfer line (11). ) Is mounted on.

The air-conditioning device 20 is a heat pump type bar, compressor 21, four-way valve 23, outdoor heat exchanger 25, outdoor fan 26, expansion device 27, indoor heat exchanger 29 ) And the like.

An air preheating heat exchanger is provided on the outdoor heat exchanger 25 side to preheat the air passing through the outdoor heat exchanger 25 by using the waste heat of the engine when the air conditioner is heated.

The air preheating heat exchanger 30 is connected to the cooling water heat exchanger 5 and the exhaust gas heat exchanger 9 and the heat transfer line 11.

In FIG. 1, reference numeral P denotes a pump for flowing the heat transfer medium of each line, and V denotes a valve for switching the flow path from the heat transfer line to the heat radiation line.

Referring to the operation of the cogeneration system according to the prior art configured as described above are as follows.

First, during the heating operation of the air conditioning and heating device 20, the heat of the exhaust gas and the cooling water discharged from the engine 1 is recovered to preheat the outdoor air through the air preheating heat exchanger 30, and the preheated air. By heat-exchanging the outdoor heat exchanger 25, it is possible to prevent a decrease in the heating capacity of the heat pump, which may occur when the outside air temperature is low.

On the other hand, since the waste heat recovered by the exhaust gas heat exchanger 9 and the cooling water heat exchanger 5 is not necessary when the air conditioner 20 is cooled, the heat dissipation line 13 changes the flow path to the heat dissipation. The waste heat recovered through the heat exchanger 17 is radiated to the outside.

However, the cogeneration system according to the prior art is configured to recover waste heat through the exhaust gas heat exchanger (9) even during cooling operation in which waste heat is not required, whereby the heat radiation heat exchanger (17) for releasing the recovered waste heat. Is required, and there is a problem in that there is a limit in reducing the size of the system due to the volume of the heat radiating heat exchanger (17).

The present invention has been made to solve the above problems of the prior art, by discharging the exhaust gas without recovering the heat of the exhaust gas during the cooling operation, it is possible to reduce the volume of the heat dissipation heat exchanger to achieve a compact system. The purpose is to provide a cogeneration system.

The cogeneration system according to the present invention for solving the above problems is a generator, a drive source for driving the generator to generate power while the generator produces power, a compressor, a four-way valve, an indoor heat exchanger and an expansion mechanism, An air conditioner including an outdoor heat exchanger, a first exhaust passage formed to discharge exhaust gas from the driving source during heating operation of the air conditioner, and installed on the first exhaust passage to recover waste heat of the driving source. And an exhaust gas heat exchanger and a second exhaust passage formed so that the exhaust gas from the driving source bypasses the exhaust gas heat exchanger and is discharged to the outside during the cooling operation of the air conditioner.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram showing when the air conditioner of the cogeneration system according to the present invention is a heating operation, Figure 3 is a block diagram showing when the air conditioner of the cogeneration system according to the present invention is a cooling operation.

In the cogeneration system according to the present invention, as shown in FIGS. 2 and 3, the generator 50 and a driving source for generating heat while driving the generator 50 so that the generator 50 generates power. And an air conditioner (70) comprising a compressor (71), a four-way valve (72), an indoor heat exchanger (73), an expansion mechanism (74), and an outdoor heat exchanger (75), and recovering waste heat from the drive source. Waste heat recovery means and waste heat supply means for supplying the heat recovered from the waste heat recovery means to the air conditioner.

The generator 51 is any one of an alternator and a direct current generator, the rotor is connected to the output shaft of the drive source to produce electric power when the output shaft rotates, the drive source is the engine 52 or the fuel cell is used The description is limited to the engine 52 here.

The waste heat recovery means includes an exhaust gas heat exchanger (51) for recovering heat of exhaust gas from the engine (52), and a cooling water heat exchanger (53) for recovering heat of cooling water for cooling the engine (52).

In addition, the waste heat supply means is an air preheat heat exchanger 76 for preheating the air passing through the outdoor heat exchanger 75 by using the waste heat recovered from the exhaust gas heat exchanger 51 and the cooling water heat exchanger 53. )to be.

The cooling water heat exchanger 53 and the exhaust gas heat exchanger 51 are connected to the air preheating heat exchanger 76 by a heat medium circulation passage 60.

The heat medium circulation passage 60 is provided with a circulation pump 66 to circulate the heat medium heated by the cooling water heat exchanger 53 and the exhaust gas heat exchanger 51.

On the other hand, the cogeneration system includes a first discharge passage 61 formed so that exhaust gas is discharged from the driving source during the heating operation of the air conditioner 70 and from the driving source during the cooling operation of the air conditioner 70. It further comprises a second discharge passage 62 formed to discharge the exhaust gas discharged.

The exhaust gas heat exchanger 51 is installed on the first exhaust passage 61, and the second exhaust passage 62 is configured to exhaust the exhaust gas heat exchanger 51 during the cooling operation of the air conditioner. It is formed to bypass.

Each outlet side of the first and second discharge passages 61 and 62 is laminated by the third discharge passage 63 to discharge the exhaust gas to the outside.

The first discharge passage 61 is opened in the first discharge passage 61 during the heating operation of the air conditioner 70, and the first discharge passage 61 during the cooling operation of the air conditioner 70. The second opening and closing means is installed.

In addition, the second discharge passage 62 blocks the second discharge passage 62 during the heating operation of the air conditioner 70 and the second discharge passage during the cooling operation of the air conditioner 70. Second opening and closing means for opening 62 is provided.

The first opening and closing means is a first damper 64 rotatably installed in the first discharge passage 61, and the second opening and closing means is a second damper rotatably installed in the second discharge passage 62. 65).

The first and second opening and closing means further include first and second motors (not shown) for rotating the first and second dampers 64 and 65, respectively.

On the other hand, the cogeneration system is provided with heat dissipation means for discharging the heat recovered from the cooling water heat exchanger 53 during the cooling operation of the air conditioner 70 or the excess heat during heating.

The heat dissipation means is connected to the heat dissipation heat exchanger 80 and the heat medium circulation passage 60 installed to dissipate heat recovered by the cooling water heat exchanger 53 and the exhaust gas heat exchanger 51 into the atmosphere, and the heat dissipation is performed. It consists of a heat dissipation flow path 81 which guides a heat medium to the heat exchanger 80.

The connection portion of the heat dissipation passage 81 and the heat medium circulation passage 60 selectively opens and closes the heat dissipation passage 81 and the heat medium circulation passage 60 according to the cooling and heating operation of the air conditioner 70. First and second valves 82 and 83 are provided.

Looking at the operation of the cogeneration system according to the present invention configured as described above are as follows.

First, when the engine 52 is driven, the generator 50 produces power, and the generated power is supplied to the air conditioner 70 and the like.

Here, in the heating operation of the air conditioner 70, as shown in FIG. 2, the second damper 65 blocks the second discharge passage 62, and the first damper 64 is The first discharge passage 61 is opened.

Therefore, the exhaust gas discharged from the engine 52 flows into the exhaust gas heat exchanger 51 through the first exhaust passage 61, and the waste gas waste heat is recovered from the exhaust gas heat exchanger 51. Will be.

And, the waste water waste heat of the engine 50 is recovered by the cooling water heat exchanger (53).

At this time, the first and second valves 83 and 84 shield the heat dissipation passage 81 and open the heat medium circulation passage 60 to exchange heat with the exhaust gas heat exchanger 51. The heated heating medium passes through the air (53) to flow into the air preheating heat exchanger (76).

That is, the heat medium on the heat medium circulation passage 60 is pumped by the heat medium circulation pump 64, and passes through the cooling water heat exchanger 53 and the exhaust gas heat exchanger 51 in turn, and then the air preheat heat exchanger. Preheating the outdoor air introduced into the 76 and entering the outdoor heat exchanger 75, and the preheated air heat exchanges the outdoor heat exchanger 75 to reduce the heating capacity that may occur when the outside air temperature is low It can be prevented.

On the other hand, during the cooling operation of the air conditioner 70, as shown in FIG. 3, the second damper 65 opens the second discharge passage 62, the first damper 64 is The first discharge passage 61 is blocked.

Therefore, the exhaust gas discharged from the engine 50 does not pass through the exhaust gas heat exchanger 51 and is immediately discharged to the outside.

In addition, the waste heat of the coolant of the engine 50 is recovered from the coolant heat exchanger 53, and the first and second valves 82 and 83 open the heat dissipation flow path 81, thereby circulating the heat medium. The heat of the heat medium on the flow path 60 is discharged to the outside through the heat radiating heat exchanger 80.

Therefore, the air conditioner 70 is configured to directly discharge to the outside without recovering heat from the exhaust gas of the engine 50 during the cooling operation of the air conditioner, the heat radiating heat exchanger 80 is the cooling water heat exchanger (53) Since only the excess heat is released during the heat or heating operation recovered in the) it is possible to reduce the volume of the heat radiating heat exchanger (80).

In the cogeneration system according to the present invention configured as described above, the exhaust gas of the engine passes through the exhaust gas heat exchanger through the first exhaust passage during the heating operation of the air conditioner, and the second exhaust passage during the cooling operation. By bypassing the exhaust gas heat exchanger through, since the waste heat is not recovered during the cooling operation, since the heat radiating heat exchanger is not used, the volume of the heat radiating heat exchanger can be reduced, thereby making the system compact. There is an advantage to that.

Claims (7)

A generator; A drive source for driving the generator so as to generate power and generating heat; An air conditioner which can be operated in a cooling operation and a heating operation; A first discharge passage configured to discharge exhaust gas from the driving source during a heating operation of the air conditioner; An exhaust gas heat exchanger installed on the first exhaust passage to recover waste heat of the driving source; And a second discharge passage configured to exhaust the exhaust gas from the driving source and discharge the exhaust gas heat exchanger to the outside during the cooling operation of the air conditioner. The method of claim 1, And each outlet side of the first and second discharge passages is laminated to a third discharge passage for discharging the exhaust gas that has passed through the first and second discharge passages to the outside. The method of claim 1, Is installed on the first discharge passage between the drive source and the exhaust gas heat exchanger, the first discharge passage is opened during the heating operation of the air conditioner, the first discharge passage during the cooling operation of the air conditioner The first opening and closing means for blocking the, A second opening and closing means installed on the second discharge passage to block the second discharge passage during the heating operation of the air conditioner and to open the second discharge passage during the cooling operation of the air conditioner; Cogeneration system including. The method of claim 3, wherein The cogeneration system of the first and second opening and closing means is a damper. The method of claim 1, And the driving source is one of an engine and a fuel cell. The method according to any one of claims 1 to 5, The air conditioner is a cogeneration system including a compressor, a four-way valve, an indoor heat exchanger, an expansion device and an outdoor heat exchanger. The method of claim 6, And a preheating heat exchanger installed at the outdoor heat exchanger and configured to preheat air passing through the outdoor heat exchanger using waste heat recovered from the driving source.

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