KR20070009871A - Electric generation air condition system and the control method for the same - Google Patents

Abstract

A cogeneration system and a method for controlling the same are provided to maintain the heating efficiency of an air conditioner constantly by supplying the wasted heat of a drive source to the air conditioner. A cogeneration system includes a generator(50), a drive source(52), a wasted heat recovering unit, a wasted heat supplying heat exchanger(80), an air conditioner, and a control unit. The drive source drives the generator. The wasted heat recovering unit recovers the wasted heat of the drive source. The wasted heat recovered by the wasted heat recovering unit is transferred to the wasted heat supplying heat exchanger. The air conditioner includes an outdoor unit and an indoor unit. The outdoor unit includes a compressor, a four-way valve, an outdoor heat exchanger, and an outdoor expansion valve. The indoor unit includes an indoor expansion valve and an indoor heat exchanger. After the refrigerant in the air conditioner is evaporated by the wasted heat of the drive source in the wasted heat supplying heat exchanger, the control unit determines an error according to a suction pressure.

Description

Cogeneration system and control method {Electric generation air condition system and the Control method for the Same}

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

2 is a configuration diagram when the cogeneration system according to the present invention is a power generation output, the air conditioner is in the cooling operation mode,

3 is a configuration diagram when the cogeneration system according to the present invention is a power generation output, the air conditioner is the outdoor high temperature heating operation mode,

4 is a configuration diagram when the cogeneration system according to the present invention is a power generation output, the air conditioner is the outdoor low temperature heating operation mode,

5 is a configuration when the cogeneration system according to the present invention is a commercial power output, the air conditioner in the cooling operation mode,

6 is a commercial power output of the cogeneration system according to the present invention, the configuration when the air conditioner in the heating operation mode,

Figure 7 is a block diagram according to the valve failure determination algorithm for heating operation of the cogeneration system according to the present invention,

8 is a flowchart according to a failure determination algorithm of the valve for heating operation of the cogeneration system according to the present invention.

<Explanation of symbols on main parts of the drawings>

50: generator 51: power switching device

52: drive source 55: engine cooling device

60: waste heat recovery device 70: compressor

73: four-way valve 74: indoor heat exchanger

75: outdoor heat exchanger 76: indoor expansion valve

77: outdoor expansion valve 80: waste heat supply heat exchanger

85: waste heat radiator 94: three-way

100: first damper 104: second damper

The present invention relates to a cogeneration system and a control method thereof, and more particularly, to a cogeneration system capable of knowing whether a valve for a heating operation for allowing a refrigerant of an air conditioner to pass through a waste heat supply heat exchanger during an outdoor low temperature heating operation mode and a cogeneration system thereof It relates to a control method.

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

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

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

In the conventional cogeneration system, as shown in FIG. 1, a generator 2 for generating electric power and a driving source 10 such as a gas engine for driving heat of the generator 2 and generating heat, hereinafter referred to as a 'gas engine' ), A waste heat recovery apparatus 20 for recovering waste heat generated by the gas engine 10, and a heat demand unit 30 for utilizing waste heat of the waste heat recovery apparatus 20 to supply hot water or the like to radiate heat to the outside. It is configured to include).

The generated electric power generated by the generator 2 is supplied to a power consuming device such as various lighting fixtures or an air conditioner 4 in the home.

The generator 2 and the gas engine 10 are installed in an engine room E of a chassis (not shown) formed separately from the heat demand 30.

The air conditioner 4 includes an indoor unit 3 and an outdoor unit 5.

The waste heat recovery device 20 includes an exhaust gas heat exchanger 22 that takes heat of exhaust gas discharged from the gas engine 10, and a cooling water heat exchanger that takes heat of cooling water cooling the gas engine 10 ( 24).

The exhaust gas heat exchanger 22 is connected to the heat demand 30 and the first heat supply line 23, and the waste heat taken from the exhaust gas of the gas engine 10 is the first heat supply line 23. It is transmitted to the heat demand 30 through.

The cooling water heat exchanger 24 is connected to the heat demand 30 and the second heat supply line 25, and the heat taken away from the cooling water rotor cooling the gas engine 10 is the second heat supply line 25. It is transmitted to the heat demand 30 through.

However, the cogeneration system according to the prior art configured as described above, the waste heat of the engine 10 is not used in the air conditioner 4 is used only in hot water, etc., there is a problem that the efficiency is not maximized. .

The present invention has been made to solve the problems of the prior art, the waste heat of the drive source for driving the generator is utilized to increase the heating performance of the air conditioner in the heating operation mode of the air conditioner to maximize its efficiency Its purpose is to provide a cogeneration system and a control method thereof.

In addition, the present invention determines the failure of the valve for the heating operation to enable the waste heat of the drive source to be used in the air conditioner in the heating operation mode of the air conditioner, by determining the failure of the valve for the heating operation air Another object of the present invention is to provide a cogeneration system and a control method thereof for preventing damage to a compressor and a system of a conditioner.

Cogeneration system according to the present invention for solving the above problems is a generator; A drive source for driving the generator; A waste heat recovery apparatus for recovering waste heat of the drive source; A waste heat supply heat exchanger for receiving the waste heat recovered to the waste heat recovery apparatus; An air conditioner including an outdoor unit including a compressor, a four-way valve, an outdoor heat exchanger, and an outdoor expansion valve, and an indoor unit including an indoor expansion valve and an indoor heat exchanger; And a controller configured to determine whether an error is generated according to the suction pressure when the refrigerant of the air conditioner is evaporated by the waste heat of the driving source in the waste heat supply heat exchanger and is then sucked into the compressor. do.

The error determination of the control unit is characterized in that the failure of the valve for heating operation controlled to allow the refrigerant of the air conditioner to pass through the waste heat supply heat exchanger.

The controller may determine whether an error occurs according to the suction pressure of the compressor when a predetermined time has elapsed after the operation of the compressor.

The cogeneration system is characterized in that it comprises a warning means for informing the error through a warning sound or warning lamp when determining the error in the control unit.

The air conditioner is operated in a cooling cycle in which the refrigerant compressed by the compressor passes through the four-way valve, the outdoor heat exchanger, the indoor expansion valve, the indoor heat exchanger, and the four-way valve in order in the cooling operation mode.

When the air conditioner is a heating operation mode and does not use the waste heat of the driving source, the refrigerant compressed in the compressor passes through the four-way valve, the indoor heat exchanger, the indoor expansion valve, the outdoor expansion valve, the outdoor heat exchanger, and the four-way valve in order. It is characterized in that it is operated by an outdoor high temperature heating cycle circulated to.

The air conditioner is a heating operation mode, and when the waste heat of the driving source is used, the refrigerant compressed by the compressor passes through the four-way valve, the indoor heat exchanger, the indoor expansion valve, the outdoor expansion valve, the waste heat supply heat exchanger, and the four-way valve, and is circulated to the compressor. It is characterized in that it is operated by an outdoor low temperature heating cycle.

In addition, the control method of the cogeneration system according to the present invention for achieving the above object, the suction of the compressor when the refrigerant of the air conditioner is sucked into the compressor after evaporation by the waste heat of the driving source, during operation of the air conditioner A compressor suction pressure sensing step of sensing pressure; Characterized in that the error determination step of determining whether or not an error in accordance with the suction pressure of the compressor.

The compressor suction pressure sensing step may be performed when the operation mode of the air conditioner is an outdoor low temperature heating operation mode using waste heat of the driving source.

The compressor suction pressure sensing step may be performed when a predetermined time elapses after the compressor operation starts.

The error determining step may include determining whether a valve for a heating operation for allowing the refrigerant of the air conditioner to receive waste heat of the driving source.

The control method of the cogeneration system may further include an emergency stop step of emergency stopping the air conditioner and the driving source during the error determination in the error determination step.

The control method of the cogeneration system further comprises an error notification step of generating an error determination signal according to the error determination in the error determination step.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 2 to 8.

The cogeneration system according to the present invention includes a generator (50) for generating power, a drive source (52) for driving the generator (50), and a waste heat recovery device (60) for recovering waste heat from the drive source (52). And, the generator 50 is configured to include an air conditioner that is operated by being supplied with the commercial power (50 ') produced by the power generation company or electric power company.

The generator 50 is any one of an alternator and a direct current generator, the rotor is connected to the output shaft of the drive source 60 to produce power when the output shaft rotates.

Power generation device and commercial power (50 ') of the generator 50, the power switching device for switching the power so that any one of the generated power and commercial power (50') of the generator 50 is output to the air conditioner ( 51 may be output to the air conditioner.

The power switching device 51 is a power generation switchgear (GCB) 51a that regulates the generated power output of the generator 50, and a commercial power switchgear (MCB) 51b that controls the output of the commercial power 50 '. It consists of.

The driving source 52 may be implemented as a fuel cell or various devices such as an engine and a turbine that are operated by using a fuel such as gas or oil. ).

The engine 52 includes a fuel supply passage 53 through which fuel is supplied to a combustion chamber provided therein, and a waste heat recovery passage 54 through which exhaust gas is exhausted from the combustion chamber.

In addition, the engine 52 may be easily broken when the engine 52 is overheated, its life may be shortened, and the output of the engine may be reduced, and the reliability of the engine 52 may be degraded. The engine cooler 55 is provided to allow the engine 52 to operate within an appropriate temperature range.

The engine cooler 55 includes a coolant circulation flow path 56 for guiding the coolant to circulate between the engine 52 and the coolant heat exchanger 61, which will be described later, among the waste heat recovery device 60, and the coolant circulation flow path. And a coolant pump 57 installed on the pump 56 to pump the coolant.

The waste heat recovery device 60 is connected to the cooling water circulation passage 56 to extract the heat of the cooling water that has become a high temperature after cooling the engine 52, and the waste heat of the engine 52. The first and second exhaust gas heat exchangers 62 and 63 may be connected to the recovery passage 54 to recover the heat of the exhaust gas exhausted from the engine 52.

In particular, the waste heat recovery device 60 may be provided to selectively recover the waste gas waste heat of the engine 52 according to the operation mode of the air conditioner.

That is, the exhaust gas heat exchanger 62 is provided on the waste heat recovery passage 54 to recover the waste gas waste heat of the engine 52, and the exhaust gas heat exchanger 62 is disposed on the waste heat recovery passage 54. The first damper 100 for opening and closing the waste heat recovery passage 54 is provided at the inlet side.

In addition, in the waste heat recovery passage 54, the waste heat discharge passage 102 allows exhaust gas waste heat of the engine 52 to be directly discharged to the outside by bypassing the first and second exhaust gas heat exchangers 62 and 63. ) Is connected.

The waste heat discharge passage 102 is preferably connected to the waste heat recovery passage 54 between the first exhaust gas heat exchanger 62 and the first damper 100.

The waste heat discharge passage 102 is provided with a second damper 104 for opening and closing the waste heat discharge passage 102.

The first and second dampers 100 and 104 provided as described above are operated in the open mode or the closed mode according to the power output through the power switching device 51 and the operation mode of the air conditioner, respectively.

The waste heat recovered by the waste heat recovery device 60 may be supplied to some of the power consumer devices through the waste heat supply heat exchanger 80 or may be radiated to the atmosphere through the waste heat radiator 85.

The waste heat supply heat exchanger (80) absorbs the heat recovered in at least one of the cooling water heat exchanger (61) and the first and second exhaust gas heat exchangers (62, 63), and the cooling water heat exchanger (61). And first and second exhaust gas heat exchangers 62 and 63 and a heat medium circulation passage 64 for guiding the heat medium for waste heat recovery. That is, the heat medium circulation passage 64 is a heat medium in the heat medium circulation passage 64 is the cooling water heat exchanger 61, the second exhaust gas heat exchanger 63, the first exhaust gas heat exchanger 62, and Waste heat supply heat exchanger 80 may be provided to circulate in turn.

The heat medium circulation passage 64 is provided with a heat medium circulation pump 65 that performs a pumping function to circulate the heat medium in the heat medium circulation passage 64.

In addition, the heat medium circulation passage 64 is connected to an expansion tank 66 in which gas generated on the heat medium circulation passage 64 is stored at an inlet side of the heat medium circulation pump 65.

The waste heat radiator 85 includes a heat radiating heat exchanger 86 in which heat recovered from the cooling water heat exchanger 61 and the first and second exhaust gas heat exchangers 62 and 63 is radiated to the atmosphere, and the heat medium circulates. The heat dissipation path 87 is connected to the flow path 64 to guide the heat medium in the heat medium circulation path 64 to the heat dissipation heat exchanger 68. In addition, the waste heat radiating device 85 includes a waste heat radiating blower 88 for forcibly blowing outside air to the heat radiating heat exchanger 86 in order to maximize heat radiation.

The three-way side 94 for switching the flow of the heat medium is installed at any one of the two points of the junction where the waste heat dissipation flow path 87 and the heat medium circulation path 64 are interconnected.

The air conditioner includes a compressor (70), a four-way valve (73), an outdoor heat exchanger (75), an outdoor blower (75 '), an outdoor unit (Oa) equipped with an outdoor expansion valve (77), and the indoor heat exchanger ( 74, the indoor blower 74 ', and the indoor unit Ia provided with the indoor expansion valve 76.

The compressor 70 may be composed of one or more than two plural to each outdoor unit Oa. Hereinafter, only two compressors 70 are configured for each outdoor unit Oa.

The two compressors 70 installed in the respective outdoor units Oa are connected through a common accumulator 78 installed at a suction side on which a refrigerant, which is a heat medium of the air conditioner, is sucked.

The suction side of the two compressors 70 is provided with a compressor suction pressure sensor 72 for detecting the suction pressure of the compressor 70 sucked into the two compressors 70.

The air conditioner provided as described above may be constituted by one outdoor unit Oa and one indoor unit Ia, or may be constituted by one outdoor unit Oa and a plurality of indoor units Ia. It is also possible to be composed of three outdoor units Oa and a plurality of indoor units Ia. Hereinafter, the air conditioner according to the present embodiment will be described as being limited to a plurality of outdoor units Oa and a plurality of indoor units Ia.

The plurality of outdoor units Oa may receive power output through the power switching device 51, and the plurality of indoor units Ia may receive commercial power connected separately.

The plurality of outdoor units Oa may have different capacities, and the plurality of indoor units Ia may also have different capacities.

On the other hand, the plurality of outdoor unit (Oa) and the indoor unit (Ia), and the waste heat supply heat exchanger 80 for supplying the waste heat of the engine 52 to the air conditioner during the heating operation is the cooling / heating of the air conditioner It is connected through a refrigerant circulation passage 79 for guiding the refrigerant, which is a heat medium for circulation.

A first opening / closing valve 81 which is a valve for heating operation so that the refrigerant flows into the waste heat supply heat exchanger 80 or is blocked at the inlet side of the waste heat supply heat exchanger 80 in the refrigerant circulation passage 79. Is provided.

In addition, the refrigerant circulation passage 79 includes a first check valve 91 at the outlet side of the waste heat supply heat exchanger 80 to block the refrigerant from flowing back to the waste heat supply heat exchanger 80.

In addition, a waste heat supply heat exchanger bypass connecting the inlet side and the outlet side of the waste heat supply heat exchanger 80 to allow the refrigerant to bypass the waste heat supply heat exchanger 80 in the refrigerant circulation passage 79. The flow path 95 is provided.

The waste heat supply heat exchanger bypass passage 95 is provided with a second check valve 92 such that refrigerant flows only from the outlet side of the waste heat supply heat exchanger 80 to the inlet side of the waste heat supply heat exchanger 80. .

In addition, the refrigerant circulation passage 79 includes a second opening / closing valve 82 at one side of the outdoor heat exchanger 75 so that the refrigerant may be introduced into or blocked by the outdoor heat exchanger 75.

In addition, the refrigerant circulation passage 79 includes a third check valve 93 at the other side of the outdoor heat exchanger 75 to block the refrigerant from flowing back from the indoor unit Ia to the outdoor heat exchanger 75. do.

In addition, the refrigerant circulation passage 79 is provided with an outdoor heat exchanger bypass passage 90 connecting one side and the other side of the outdoor heat exchanger 75 so that the refrigerant bypasses the outdoor heat exchanger 75. .

At the inlet side of the outdoor heat exchanger bypass flow path 90, the outdoor expansion valve 77 is provided.

At the outlet side of the outdoor heat exchanger bypass flow path 90, a third open / close valve 83 capable of opening and closing the outdoor heat exchanger bypass flow path 90 is provided.

The outdoor heat exchanger bypass flow path 90 may be connected to the other side of the outdoor heat exchanger 75 through an outdoor heat exchanger connection flow path 96.

The outdoor heat exchanger connection flow path 96 is provided with a fourth open / close valve 84 for opening and closing the outdoor heat exchanger connection flow path 96.

The operation mode of the air conditioner configured as described above is a cooling operation mode in which the indoor unit Ia is operated in a cooling cycle for supplying cold air, and a heating operation mode in which the indoor unit Ia is operated in a heating cycle for supplying warm air. There is.

The heating operation mode of the air conditioner is an outdoor high temperature heating operation mode in which the waste heat of the engine 52 is not used through the waste heat supply heat exchanger 80 according to the outdoor temperature at which the outdoor unit Oa is installed. And, through the waste heat supply heat exchanger 80 can be divided into the outdoor low temperature heating operation mode using the waste heat of the engine 52.

Here, the air conditioner may perform a defrosting operation in which the refrigerant of the air conditioner is circulated back in a cooling cycle to defrost the outdoor heat exchanger 75 during a heating operation.

On the other hand, the cogeneration system may be divided into a cogeneration unit for generating the generator 50 and the air conditioner.

The cogeneration unit includes a main unit 110 including the generator 50, an engine 52, an engine cooling device 55, and a waste heat recovery device 60, the waste heat supply heat exchanger 80, and waste heat. The heat sink 85 may be divided into the sub unit 120 installed.

The main unit 110 is provided with a main unit controller 112 and a ventilation blower 114 for ventilation of the main unit 110.

The sub unit 120 includes a sub unit controller 122 connected to the main unit controller 112.

4 is a configuration when the cogeneration system according to the present invention is a power generation output, the air conditioner in the outdoor low-temperature heating operation mode, Figure 7 is a valve failure determination algorithm for heating operation of the cogeneration system according to the present invention It is a block diagram.

 On the other hand, if the suction pressure of the compressor 70 is too low, the scroll in the compressor 70 may be damaged due to the impact between the scroll in the compressor 70, that is, the clearance (Clearance).

In addition, if the suction pressure of the compressor 70 is too low, since the flow rate of the refrigerant in the refrigerant circulation passage 79 is reduced, oil circulated with the refrigerant in the refrigerant circulation passage 79 is transferred to the compressor 70. Since it is not smoothly recovered, the heat dissipation and lubricity of the compressor 70 are lowered, so that the compressor 70 may be damaged.

However, when the refrigerant of the air conditioner is evaporated by the waste heat of the engine 52 in the waste heat supply heat exchanger 80 and then sucked into the compressor 70, that is, the heating in the outdoor low temperature heating operation mode. If the first opening / closing valve 81, which is an operation valve, is broken and is not completely open, a pressure drop phenomenon occurs before and after the first opening / closing valve 81, which is the heating operation valve, and the suction pressure of the compressor 70 is increased. Lowers.

Accordingly, the cogeneration system according to the present invention may determine whether an error is determined according to a detection result of the compressor suction pressure sensor 72 in the heating operation mode, that is, whether the first opening / closing valve 81 which is the valve for heating operation is broken. The control unit M further determines and emergency stops the system.

In addition, the cogeneration system according to the present invention is the valve for the heating operation through the warning sound or warning lamp when determining the error due to the failure of the first opening and closing valve 81 which is the valve for heating operation in the control unit (M). One open valve 81 may further include a warning means (E) for informing a failure error.

Referring to the control method of the cogeneration system according to the present invention configured as described above, as follows.

When the operation request signal of the air conditioner is input while the engine 52 and the air conditioner are stopped, the first to the third according to the operation mode of the air conditioner for the operation of the air conditioner. The check valves 91 to 93, the three-way valve 94, the first to fourth open / close valves 81 to 84, and the first and second dampers 100 and 104 are set.

When the setting step according to the operation mode of the air conditioner is finished, one of the generated power and the commercial power 50 'of the generator 50 is output to the air conditioner through the power switching device 51.

In this case, the power switching device 51 is controlled according to the operation mode of the air conditioner and the load of the air conditioner, or the generated power of the generator 50 preset for the initial operation of the air conditioner or Commercial power 50 'can be output.

As described above, when any one of the generated electric power and the commercial power 50 'of the generator 50 is output to the air conditioner through the power switch 51, the air conditioner through the power switch 51 It operates by receiving the output power and performs cooling / heating function.

At this time, the load condition of the air conditioner may be changed while the air conditioner is operating, and thus the power output to the air conditioner may be switched.

On the other hand, when the operation stop request signal of the air conditioner is input, the engine 52 is stopped after the air conditioner is stopped.

Meanwhile, the operation of the cogeneration system configured and operated as described above will be described in detail according to the operation mode and the power of the air conditioner.

First, the operation mode of the air conditioner is a cooling operation mode, and when the generation power output is described with reference to FIG. At this time, the first opening / closing valve 81, which is the valve for heating operation, is set to an off state so that the refrigerant in the refrigerant circulation flow path 79 does not pass through the waste heat supply heat exchanger 80.

When the generator 50 is generated by the driving force of the engine 52, the engine 52 is operated at an appropriate temperature by the engine cooling device 55. That is, as the coolant on the coolant circulation passage 56 is pumped by the coolant pump 57, the heat of the engine 52 is absorbed by the coolant, and the coolant that absorbs the heat of the engine 52 is After the heat is released from the coolant heat exchanger (61), it is circulated back to the engine (52).

The coolant waste heat recovered by the coolant heat exchanger 61 is pumped into the heat medium circulation pump 65 as the heat medium on the heat medium circulation path 64 is pumped to the coolant heat exchanger 61 and the second exhaust gas heat exchanger. And after passing through the first exhaust gas heat exchanger 63, the waste heat radiator 85 is transferred through the three-way side 94.

The coolant waste heat transferred to the waste heat radiator 85 is radiated to the outside by the waste heat radiator 85.

Part of the exhaust gas waste heat of the engine 52 is immediately discharged to the outside through the waste heat discharge passage 102, and the rest is recovered through the second exhaust gas heat exchanger 63, and together with the cooling water waste heat. The heat is radiated from the waste heat radiator 85.

In the air conditioner, when the compressor 70, the outdoor blower 75 ′, and the indoor blower 74 ′ are driven, the refrigerant compressed by the compressor 70 is diverted to the four-way valve 73 and the outdoor heat exchanger. Group 75, the indoor expansion valve 76, the indoor heat exchanger 74 and the four-way valve 73 in turn and then circulated to the compressor 70.

Then, the refrigerant in the refrigerant circulation passage 79 is compressed by the compressor 70, is condensed by heat exchange with outdoor air in the outdoor heat exchanger 75, and is expanded by the indoor expansion valve 76. The indoor heat exchanger 74 exchanges heat with the indoor air and evaporates, whereby the indoor unit Ia supplies cold air.

Next, the operation mode of the air conditioner is the outdoor high temperature heating operation mode, and when described with reference to FIG. At this time, the first opening / closing valve 81 which is the valve for heating operation is set in an on state so that the refrigerant in the refrigerant circulation flow path 79 passes through the waste heat supply heat exchanger 80.

 The engine 52 is operated at an appropriate temperature by the engine cooling device 55, and the generator 50 generates power generated by the driving force of the engine 52.

After the waste water waste heat and part of the waste gas waste heat of the engine 52 are recovered by the waste heat recovery device 60, the waste heat heat dissipation device 85 is radiated, and the waste gas waste heat of the engine 52 is exhausted. A part is discharged directly through the waste heat discharge passageway 102.

In the air conditioner, the refrigerant compressed by the compressor (70) is the four-way valve 73, the indoor heat exchanger (74), the indoor expansion valve (76), the outdoor expansion valve (77), the outdoor heat exchanger (75), After passing through the waste heat supply heat exchanger (80), and the four-way valve (73), it is circulated to the compressor (70).

At this time, the outdoor expansion valve 77 is controlled according to the degree of superheat.

Since the waste heat recovered by the waste heat recovery device 60 is not transferred to the waste heat supply heat exchanger 80, the refrigerant passes through the waste heat supply heat exchanger 80 due to the design characteristics of the refrigerant circulation passage 79. However, it is not evaporated in the waste heat supply heat exchanger (80).

When the air conditioner is operated in the outdoor high temperature heating operation mode as described above, the refrigerant in the refrigerant circulation passage 79 is evaporated in the outdoor heat exchanger 75 as opposed to the cooling operation mode, and the indoor heat exchanger 74 The indoor unit Ia supplies warm air by condensing by dissipating heat into the indoor air.

Next, the air conditioner is the outdoor low-temperature heating operation mode, and when described with reference to Figure 4 when generating power output. At this time, the first opening / closing valve 81 which is the valve for heating operation is set in an on state so that the refrigerant in the refrigerant circulation flow path 79 passes through the waste heat supply heat exchanger 80.

The engine 52 is operated at an appropriate temperature by the engine cooling device 55, and the generator 50 generates power generated by the driving force of the engine 52.

The waste water waste heat of the engine 52 and the waste gas waste heat of the engine 52 are sequentially recovered through the waste heat recovery device 60. At least a part of the waste heat recovered by the waste heat recovery device 60 is transferred to the waste heat supply heat exchanger 80, and the surplus waste heat remaining after being transferred to the waste heat supply heat exchanger 80 passes through the waste heat radiator 85. Heat dissipation through.

In the air conditioner, when the compressor 70, the outdoor blower 75 ′ and the indoor blower 74 ′ are driven, the refrigerant compressed by the compressor 70 is diverted to the four-way valve 73 and the indoor heat exchanger 74. ), The indoor expansion valve 76, the outdoor expansion valve 77, the waste heat supply heat exchanger 80, and the four-way valve 73 are sequentially circulated to the compressor 70. At this time, the outdoor expansion valve 77 is controlled according to the degree of superheat.

Then, the refrigerant in the refrigerant circulation passage 79 is evaporated in the waste heat supply heat exchanger 80, and condensed by dissipating heat into the indoor air in the indoor heat exchanger 74, whereby the indoor unit Ia is warm air. Will be supplied.

In the outdoor low temperature heating operation mode as described above, since the waste heat supply heat exchanger 80 instead of the outdoor heat exchanger 75 serves as an evaporator, it is possible to always provide a constant heating capacity regardless of the outdoor temperature change. The compressor 70 can be operated without difficulty.

In addition, since the waste heat of the engine 52 is used, power consumption may be minimized when the operating capacity of the compressor 70 is reduced.

Next, when the air conditioner is in the cooling operation mode and is described with reference to FIG. 5 at the time of commercial power output, it is as follows.

At this time, the generator 50, the engine 52, the coolant pump 57, the heat medium circulation pump 65, and the waste heat radiating blower 88 are maintained in a stopped state.

The first opening / closing valve 81, which is the valve for heating operation, is set to an off state so that the refrigerant in the refrigerant circulation flow path 79 does not pass through the waste heat supply heat exchanger 80.

In the air conditioner, when the compressor 70, the outdoor blower 75 ′ and the indoor blower 74 ′ are driven, the refrigerant compressed by the compressor 70 is a four-way valve 73 and an outdoor heat exchanger 75. After passing through the indoor expansion valve 76, the indoor heat exchanger 74, and the four-way valve 73 in turn, the indoor unit Ia supplies cold air while being circulated to the compressor 70.

Next, the air conditioner is a heating operation mode, and will be described with reference to FIG. 6 when outputting commercial power.

At this time, the generator 50, the engine 52, the coolant pump 57, the heat medium circulation pump 65, and the waste heat radiating blower 88 are maintained in a stopped state.

At this time, the first opening / closing valve 81 which is the valve for heating operation is set in an on state so that the refrigerant in the refrigerant circulation flow path 79 passes through the waste heat supply heat exchanger 80.

The air conditioner, the refrigerant compressed by the compressor 70, the four-way valve 73 and the indoor heat exchanger 74, the indoor expansion valve 76, outdoor expansion valve 77, outdoor heat exchanger 75, waste heat After passing through the supply heat exchanger 80 and the four-way valve 73 in turn, the indoor unit Ia supplies warm air while being circulated to the compressor 70. At this time, the outdoor expansion valve 77 is controlled according to the degree of superheat.

Here, since the waste heat recovered by the waste heat recovery device 60 is not transmitted to the waste heat supply heat exchanger 80, the refrigerant passes through the waste heat supply heat exchanger 80 due to the design characteristics of the refrigerant circulation flow path 79. However, it is not evaporated in the waste heat supply heat exchanger (80).

On the other hand, as shown in Figures 4, 7, and 8, the cogeneration system according to the present invention, the heating operation valve by the heating operation valve failure determination algorithm as follows during the heating operation of the air conditioner It is determined whether the first opening / closing valve 81 has failed.

 The method for determining whether the first opening / closing valve 81 which is the heating operation valve according to the valve failure determination algorithm for heating operation is explained in detail as follows.

When the air conditioner is operated, a valve failure determination algorithm for heating operation is started.

When the failure determination algorithm for the heating operation is started, after the operation of the compressor 70 is stabilized, in order to determine whether the first opening / closing valve 81 which is the heating operation valve is started, the operation of the compressor 70 starts. It is then determined whether a predetermined time has elapsed (S2).

When a predetermined time (for example, 2 minutes) elapses after the operation of the compressor 70 starts, it is determined whether the operation mode of the air conditioner is the heating operation mode (S4).

If the operation mode of the air conditioner is the heating operation mode, it is determined whether the air conditioner is in defrost operation (S6).

If the dehumidification operation is not performed during the heating operation of the air conditioner, the suction pressure P of the compressor 70 is less than the preset minimum suction pressure Ps of the compressor 70 through the compressor suction pressure sensor 72. It is determined whether or not (S8).

Here, the preset minimum suction pressure Ps of the compressor 70 is a minimum suction pressure threshold of the compressor 70 in which the compressor 70 can operate without difficulty.

When the suction pressure P of the compressor 70 through the compressor suction pressure sensor 72 is less than the preset minimum suction pressure Ps of the compressor 70, the first opening / closing valve, which is the valve for heating operation ( It is determined as an error due to the failure of 81 (S10), and the operation of the compressor 70, the engine 52, and the like is emergencyly stopped (S12).

When the error determination due to the failure of the first opening / closing valve 81, which is the valve for heating operation, is notified through the warning means E (S14), the valve failure determination algorithm for heating operation is terminated.

The cogeneration system and the control method thereof according to the present invention configured as described above may generate a generator by a driving force of a driving source, supply the generated power of the generator to an air conditioner, and in the heating operation mode of the air conditioner. By recovering the waste heat of the driving source and supplying it to the air conditioner to maintain a constant heating performance of the air conditioner, there is an advantage that the efficiency can be maximized.

In addition, the present invention obtains the suction pressure information of the compressor in the outdoor low temperature heating operation mode of the air conditioner, that is, when the refrigerant of the air conditioner is sucked into the compressor after evaporated by the waste heat of the drive source, There is an advantage that it is possible to determine whether the valve for the heating operation to allow the refrigerant of the air conditioner to receive the waste heat of the driving source.

In addition, the present invention, after determining the failure of the valve for heating operation, by emergency stop of the compressor and the engine, and by notifying the error determination due to the failure of the valve for heating operation, due to the failure of the valve for heating operation The compressor and the air conditioner, cogeneration system has the advantage of preventing the operation and damage to the bunch.

In addition, according to the present invention, according to the operation mode and load conditions of the air conditioner, the system operating efficiency can be improved because the power for the operating efficiency of the cogeneration system among the generated power and commercial power is output to the air conditioner. As a result, the operating cost of the system can be reduced.

Claims (13)

A generator; A drive source for driving the generator; A waste heat recovery apparatus for recovering waste heat of the drive source; A waste heat supply heat exchanger for receiving the waste heat recovered to the waste heat recovery apparatus; An air conditioner including an outdoor unit including a compressor, a four-way valve, an outdoor heat exchanger, and an outdoor expansion valve, and an indoor unit including an indoor expansion valve and an indoor heat exchanger; And a controller configured to determine whether an error is generated according to the suction pressure when the refrigerant of the air conditioner is evaporated by the waste heat of the driving source in the waste heat supply heat exchanger and is then sucked into the compressor. Cogeneration system. The method of claim 1, The error determination of the control unit, the cogeneration system, characterized in that the failure of the valve for heating operation controlled to allow the refrigerant of the air conditioner to pass through the waste heat supply heat exchanger. The method of claim 1, The control unit, if a predetermined time elapses after the operation of the compressor, cogeneration system, characterized in that for determining whether an error according to the suction pressure of the compressor. The method of claim 1, The cogeneration system is configured to include a warning means for informing the error through a warning sound or a warning lamp when determining the error in the control unit. The method according to any one of claims 1 to 4, The air conditioner is a cogeneration system characterized in that the refrigerant compressed by the compressor is operated in a cooling cycle circulated to the compressor after passing through the four-way valve, the outdoor heat exchanger and the indoor expansion valve, the indoor heat exchanger and the four-way valve in the cooling operation mode. system. The method according to any one of claims 1 to 4, When the air conditioner is a heating operation mode and does not use the waste heat of the driving source, the refrigerant compressed in the compressor passes through the four-way valve, the indoor heat exchanger, the indoor expansion valve, the outdoor expansion valve, the outdoor heat exchanger, and the four-way valve in order. Cogeneration system characterized in that it is operated by an outdoor high temperature heating cycle circulated to. The method according to any one of claims 1 to 4, The air conditioner is a heating operation mode, and when the waste heat of the driving source is used, the refrigerant compressed in the compressor passes through the four-way valve, the indoor heat exchanger, the indoor expansion valve, the outdoor expansion valve, the waste heat supply heat exchanger, and the four-way valve, and then circulates to the compressor. Cogeneration system characterized in that it is operated by an outdoor low temperature heating cycle. A compressor suction pressure sensing step of detecting a suction pressure of the compressor when the refrigerant of the air conditioner is sucked into the compressor after evaporation by the waste heat of the driving source during operation of the air conditioner; Control method of a cogeneration system characterized in that it comprises an error determination step of determining whether or not an error in accordance with the suction pressure of the compressor. The method of claim 8, The compressor suction pressure sensing step, if the operation mode of the air conditioner is the outdoor low-temperature heating operation mode using the waste heat of the drive source, the control method of the cogeneration system. The method of claim 8, The compressor suction pressure sensing step, the control method of the cogeneration system, characterized in that is carried out when a predetermined time elapses after the start of the compressor operation. The method according to any one of claims 8 to 10, The error determining step, the control method of the cogeneration system, characterized in that for determining whether the valve for the heating operation to allow the refrigerant of the air conditioner to receive the waste heat of the drive source. The method according to any one of claims 8 to 10, The control method of the cogeneration system further comprises an emergency stop step of emergency stopping the air conditioner and the driving source when the error is determined in the error determination step. The method according to any one of claims 8 to 10, The control method of the cogeneration system further comprises an error notification step of generating an error determination signal according to the error determination in the error determination step.

Images