KR20180080048A - A combined heat and power generating and air conditioning system and A method for controlling the same - Google Patents

Abstract

A combined heat and power generating and air-conditioning system of the present invention includes: an engine using gas as fuel; a power generator driven by the engine to generate power; a waste heat recovery device for recovering waste heat generated in the engine; an air conditioning device operated to cool or heat a room after receiving generated power of the generator or commercial power; a power switching device for switching the power to supply one of the generated power and the commercial power to the air conditioning device; a charging device for supplying power for igniting the engine and charged by the generated power; and a control unit for controlling the engine, the waste heat recovery device, and the power switching device, wherein the air conditioning device includes an outdoor unit operated by receiving the generated power or the commercial power and having a compressor and a condenser and an indoor unit connected to the outdoor unit through a refrigerant tube and having an evaporator, and the control unit blocks the supply of the commercial power when a supply of the commercial power is incomplete and receives the power from the charging device to ignite and operate the engine.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cogeneration system and a control method thereof,

The present invention relates to a cogeneration system and its control method.

Generally, the cogeneration system supplies electric power produced by using fossil fuel to the power consuming place such as buildings, and supplies the heat generated in the electric power generation to use in the heat consuming place.

The cogeneration system can generate electricity by rotating the generator by operating the engine with petroleum, coal, gas, etc. as the fuel, and can utilize waste heat generated from the engine.

Recently, the cogeneration system includes an outdoor unit of an air conditioner and a cogeneration unit as an integral unit, and the electric power generated by cogeneration is supplied to an air conditioner. The outdoor unit of the air conditioner and the cogeneration unit are integrated to reduce the size of the entire system, thereby reducing the installation area and facilitating installation work.

However, when the power supply status supplied by commercial power such as power outage, power peak condition, or contracted power consumption is bad, the operation of the air conditioner itself may not be possible and the commercial temperature and humidity You may lose your ability.

Further, even when the cogeneration system supplies the generated power to the air conditioner, power is required to start the engine, but the engine can not be started at the time of power failure.

The present invention relates to a cogeneration system in which electric power generated by a cogeneration system is supplied to an air conditioning system to operate the cogeneration system by supplying power to the air conditioning system using the cogeneration system even when the commercial power supply is incomplete or in a power failure state The present invention is directed to a cogeneration system capable of operating a cogeneration system.

According to an aspect of the present invention, there is provided a cogeneration system air conditioning system including an engine using gas as fuel, a generator driven by the engine to generate electric power, a waste heat recovery device for recovering waste heat generated in the engine, A power switching device for switching power to supply either one of power generation power and commercial power to the air conditioner; and a power switching device for switching on / And a controller for controlling the engine, the waste heat recovering device, and the power switching device, wherein the air conditioner is operated by receiving the generated power or commercial power An outdoor unit having a compressor and a condenser, and an evaporator connected to the outdoor unit through a refrigerant pipe, Compared comprises an indoor unit, the control unit operates when the commercial power supply to block the incomplete commercial power supply, and start the engine when supplied with power from the charging device.

Preferably, the waste heat recovery device includes a hot water heat exchanger for taking heat of the cooling water that has cooled the engine, and an exhaust gas heat exchanger for taking heat of the exhaust gas exhausted from the engine.

Further comprising a gas switching device for switching the gas such that either the liquefied natural gas (LNG) or the liquefied petroleum gas (LPG) is supplied to the engine, wherein the control part controls the LPG to be supplied to the engine It is preferable to control the gas switching device.

Preferably, the air conditioner is a gas heater pump using gas and electric power, and the LNG or LPG is also supplied to the gas heater pump.

When the commercial power is not supplied at all, it is preferable to control the power switching device to open a relay switch connected to the commercial power supply grid.

Preferably, the charging device includes a supercapacitor, and the air conditioner is operated by receiving power from the charging device.

A control method of a cogeneration system air conditioning system according to the present invention comprises an engine using gas as fuel, a generator connected to the engine, a waste heat recovery device for recovering waste heat generated in the engine, A method of controlling a cogeneration system air conditioning system including a harmonizing device and a charging device for supplying electric power for starting an engine, the method comprising the steps of: determining whether commercial power supply is incomplete, determining whether the commercial power supply is incomplete, A step of operating the engine by supplying power to the air conditioner by operating the engine by supplying power to the engine and supplying the gaseous fuel to the air conditioner in case of a power failure, and operating the air conditioner to recover the engine waste heat And supplying hot water to the room.

If it is determined that the power failure has not occurred in the power failure determination step, it is preferable to supply commercial power to start and operate the engine.

When the power failure is determined in the power failure determination step, it is preferable to open the relay switch connected to the commercial power supply grid.

When the LNG supply is stopped after the engine is started, it is preferable to supply LPG to the engine by connecting with the LPG supply line.

Preferably, the charging device includes a supercapacitor, and the air conditioner is operated by receiving power from the charging device.

According to the cogeneration system and control method of the present invention, even when the commercial power supply is incomplete or a power failure occurs, the cogeneration system can be used to supply power to the air conditioner.

The cooling water effectively recovers waste heat generated in the engine, thereby producing hot water.

The cogeneration power generation apparatus is provided with the self-charging device, so that the engine can be started and operated even if external power is not supplied.

Even if the LNG supply is interrupted, the LPG supply line can be connected to keep the engine running.

1 is a conceptual diagram schematically showing a cogeneration system.
2 is a conceptual diagram showing that electric power and gas are supplied to the cogeneration system and the air conditioner.
3 is a flowchart showing a control method of the cogeneration system.

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

1 is a conceptual diagram schematically showing an example of a cogeneration system.

The cogeneration system 100 refers to a system that generates electricity from a generator by operating an engine with gas fuel, converts heat generated by the engine into hot water or the like, and supplies the heat to the customer.

In the cogeneration system 100, an air conditioner is connected to supply power, heat, or hot water to the air conditioner.

The gaseous fuel can be supplied by the zero governor 12 while maintaining a constant outlet pressure regardless of the shape of the inlet input or the change in flow rate. The zero governor 12 is capable of obtaining a stable outlet pressure over a wide range and has a function of adjusting the pressure of the gaseous fuel supplied to the engine to almost constant at atmospheric pressure. In addition, the zero governor 12 is provided with two solenoid valves to shut off the supplied fuel.

The air can be filtered and supplied with clean air through an air cleaner 14. The air cleaner 14 can block the mixing of moisture and oil in the form of dust and mist using external air supplied to the engine as a filter.

The gas fuel and the air supplied as described above can be sucked into the engine by a mixer having a constant mixture ratio of air and fuel by a mixer (16).

Between the zero governor 12 and the mixer 16, a fuel valve 13 for regulating the flow rate of fuel flowing into the mixer 16 may be provided.

A turbocharger 20 can compress the mixer to a high temperature and high pressure state. The turbocharger 20 is a device that rotates the turbine by the force of the exhaust gas, compresses the intake air by its rotational force, and sends the compressed air to the cylinder of the engine to increase the output.

The turbocharger 20 is a combination of a turbine and a supercharger. The turbocharger 20 is composed of a turbine and an air compressor connected directly to the turbine. The turbine wheel is rotated by the energy of the exhaust gas The air sucked by the air compressor can be compressed and sent to the cylinder.

The turbocharger 20 has a structure in which a turbine wheel in which a blade is installed and an impeller of an air compressor are connected to one shaft and each surrounds the housing, and can be disposed near the exhaust manifold of the engine.

The mixer is cooled by the intercooler 25 and then introduced into the engine 30 through the intake manifold 32 because the temperature of the mixture is compressed by the turbocharger 20. [ The intercooler 25 can cool the mixer to increase the density, thereby increasing the absolute amount of the mixer introduced into the engine and improving the engine output.

The intercooler 25 may comprise an air-cooled heat exchanger that cools with air or a water-cooled heat exchange path that cools with water. The water-cooled intercooler can use cooling water as a medium, and it has a separate heat exchanger and pump to discard the calories from the compressed mixer to the outside.

An ETC valve (Electronic Throttle Control Valve) 29 is provided at the inlet side of the intake manifold 32 to regulate the amount of the mixer introduced into the engine. When a large number of mixers are supplied, the engine output becomes large.

The control unit 110 controls the operation of the engine 30 by adjusting the opening of the fuel valve 13 and the opening of the ETC valve 29. As the opening degree of the fuel valve 13 and the opening degree of the ETC valve 29 become larger, the engine speed will increase.

The engine 30 is an internal combustion engine that operates the mixer introduced through the intake manifold 32 through four strokes of suction, compression, explosion, and exhaust.

Exhaust gas generated as the engine 30 is operated is discharged through the exhaust manifold 34, at which time the impeller of the turbocharger 20 is rotated.

The engine 30 rotates the generator 40 to produce electric power. To this end, a belt may be connected between a pulley 36 provided at one end of the rotating shaft of the engine 30 and a pulley 46 provided at one end of the rotating shaft of the generator 40.

The pulley 36 of the engine 30 and the pulley 46 of the generator 40 may be provided so that the rotation ratio thereof is approximately 1: 3. That is, when the engine 30 rotates at 1000 rpm, the generator 40 can rotate at about 3000 rpm.

The power generated by the generator 40 may be converted into a commercial power converted from a current, a voltage, a frequency, etc. in the power converter 90 and supplied to a power consumer such as a building or an air conditioner.

On the other hand, since the engine 30 generates considerable heat during operation by gas combustion, it circulates the cooling water and performs heat exchange to absorb the heat of high temperature generated in the engine.

In the automobile, the radiator is installed in the cooling water circulation flow path to discard all of the waste heat of the engine. In the cogeneration system 100, however, the heat generated by the engine can be absorbed to generate hot water.

To this end, a hot water heat exchanger (50) is provided in the cooling water circulation channel so that heat is exchanged between water supplied separately from the cooling water so that the water receives heat from the high temperature cooling water.

The hot water generated by the hot water heat exchanger (50) is stored in the hot water storage tank (51) and can be supplied to hot water consumers such as buildings.

In the case where hot water is not used in the hot water consumer, water is not supplied to the hot water heat exchanger 50, and the temperature of the cooling water rises. To prevent this, a separate heat radiator 70 is installed, You can throw away.

The radiator 70 dissipates heat by exchanging heat with the air by means of a plurality of fins, and the heat dissipating fan 72 may be provided to accelerate heat dissipation.

The cooling water flow path from the engine 30 is branched into the hot water heat exchanger 50 and the radiator 70 and a three-way valve 53 is provided at the branch point to control the flow direction of the cooling water according to the situation . The cooling water can be sent only to the hot water heat exchanger 50 or only to the radiator 70 by the three-way valve 53 or can be divided into the hot water heat exchanger 50 and the radiator 70 at a predetermined ratio depending on the situation.

Way valve 53 and radiating from the radiator 70 can be combined with the cooling water that has passed through the three-way valve 53 and passed through the hot water heat exchanger 50 and then introduced into the engine 30.

The cooling water circulating passage is provided with a cooling water pump 55 to adjust the flow rate of the cooling water. This cooling water pump 55 can be installed downstream of the hot water heat exchanger 50 and the radiator 70 and upstream of the engine 30 in the cooling water circulation flow path.

On the other hand, the exhaust gas flowing through the exhaust manifold 34 of the engine 30 operates the turbocharger 20 described above. However, the exhaust gas heat exchanger 60 may be provided to recover the waste heat of the exhaust gas. have.

The exhaust gas heat exchanger 60 is arranged between the cooling water pump 55 and the upstream side of the engine 30 in the cooling water circulating flow passage and can be configured to exchange heat between the exhaust gas discharged through the turbocharger 20 and the cooling water . The exhaust heat of the exhaust gas can be recovered through the exhaust gas heat exchanger (60).

The cooling water is heated to some extent while flowing through the exhaust gas heat exchanger 60 and flows into the engine 30 in a lukewarm state, but the cooling water can sufficiently cool the engine 30.

Exhausted gas passing through the exhaust gas heat exchanger 60 passes through the muffler 80 and the exhaust side noise of the engine can be reduced by the muffler 80. [

The exhaust gas that has passed through the muffler 80 can be discharged to the outside after passing through the drain filter 85. The drain filter 85 has a built-in hydride filter for purifying the condensed water generated in the muffler 80, the exhaust gas line, etc., so that the acidic condensed water can be purified and neutralized and flow out to the outside.

2 is a conceptual diagram showing that electric power and gas are supplied to the cogeneration system and the air conditioner.

The cogeneration power generation apparatus 100 includes an engine 30 using gas as fuel, a generator 40 driven by the engine to produce electric power, and a waste heat recovery device for recovering waste heat generated in the engine Lt; / RTI >

The air conditioner 200 may be operated to receive the commercial power from the external power source 1 or to receive the generated power generated by the generator 40 to cool or heat the room. Of course, the commercial power can be supplied not only to the air conditioner 200, but also to the cogeneration system 100 and the building 300.

To this end, the cogeneration system 100 may include a power switching device 120 for selectively connecting a power line such that either the generated power or the commercial power is supplied to the air conditioner.

In FIG. 2, the commercial power is denoted by "E1" and the generated power is denoted by "E2". That is, the commercial power E1 supplied from the power supply source 1 can be supplied to the cogeneration / generation device 100, the air conditioner 200, and the building 300, respectively, The generated electric power E2 can be supplied to the air conditioner and the building 300, respectively.

The cogeneration system 100 uses gas as fuel, and the gas supply source 2 can supply the fuel gas G.

The gas G supplied from the gas supply source 2 is generally LNG, but may be LPG or both.

Therefore, the cogeneration system 100 may include a gas switching device 130 so that LNG and LPG can be selectively supplied. The LNG is supplied from the gas supply source 2 to the building by the gas supply line, and the LPG is generally supplied while being contained in the gas container.

The air conditioner 200 may include an outdoor unit having a compressor and a condenser, which are operated by receiving generated power or commercial power, and an indoor unit connected to the outdoor unit through a refrigerant pipe and having an evaporator.

Although the cogeneration system 100 and the outdoor units of the air conditioner 200 are integrally provided in a single cabinet, the cogeneration system 100 may be a separate device in the preferred embodiment of the present invention, It is assumed that electric wires are connected to supply the generated generated electric power to the air conditioner 200.

The air conditioner 200 is preferably a heater pump capable of not only cooling but also selectively heating. In the case of a gas heater pump using gas as the heating fuel, the air conditioner 200 is supplied from the gas supply source 2 So that the gas G is supplied to the air conditioner 200 as well.

Of course, the gas G may also be supplied to the building 300 as fuel for heating, cooking, hot water, and the like.

When the air conditioner 200 is installed in a building or a building having a plurality of rooms, a plurality of indoor units 211, 212, and 213 may be installed. Each indoor unit is connected to at least one outdoor unit through a refrigerant circulation line to cool or heat the indoor unit.

The cogeneration power generation apparatus 100 may include a control unit 110 for controlling the engine 30, the waste heat recovery apparatus, the power switching apparatus 120, and the like. The control unit 110 also controls the mixer 16, the three-way valve 53, the cooling water pump 55, the power converter 90, etc., which are components of the cogeneration system 100, as well as the gas switching device 130 can do.

The cogeneration system 100 may further include a charging device 150 for supplying power required to start the engine 30. [

The engine 30 is required to be supplied with power to the starter motor when the starter is started, and if the commercial power is supplied from the power source 1, the engine 30 can be started with the commercial power.

However, when commercial power is not supplied from the outside, a charging device 150 that supplies power for starting the engine may be required.

Therefore, when the commercial power supply from the power supply source 1 is incomplete, the control unit 110 can shut off the commercial power supply and supply the power from the charging device 150 to start and operate the engine 30.

The charging device 150 is preferably chargeable by the electric power generated by the generator 40. Of course, the charging device 150 may be charged with the commercial power supplied from the power supply source 1, but it is more preferable that the charging device 150 is charged with the generated power when the engine 30 is operated to produce electric power. This is because commercial power need not be supplied at all from outside, so commercial power supply can be cut off and the system can be operated with self generated power.

When the commercial power is not supplied at all, the power switching device 120 is controlled to open the relay switch 122 connected to the commercial power supply grid to shut off the commercial power supply, Only the generated power can be supplied to the air conditioner 200 and the building 300 after the air conditioner 30 is started.

The charging device 150 may be a vehicle battery, a lithium ion battery, a supercapacitor, or the like.

Charging efficiency and capacity of the charging device 150 are better, but there is a limit in operating the air conditioner only with the charging power in a state in which the engine generating power is not supplied.

Supercapacitors are very large capacitance capacitors, Ultra capacitors, Ultra high capacity capacitors, Electrochemical capacitors, the term is mixed. The supercapacitor 301 uses a charged form by simple ion movement or surface chemical reaction to the interface between the electrode and the electrolyte and is capable of rapid charge and discharge and has a high charge / discharge efficiency and a semi-permanent cycle life. Can be used.

The power generated by the cogeneration system 100 may be stored and stored in the super capacitor. For example, a supercapacitor can use a power of 80 mW.

The air conditioner 200 can be operated for a long time by supplying electric power stored in the super capacitor even when the cogeneration device 100 is not operated.

The waste heat recovery apparatus may include the hot water heat exchanger (50) and the exhaust gas heat exchanger (60).

The hot water heat exchanger (50) can generate hot water (W) by exchanging heat between the heated cooling water and water as the engine is cooled. The generated hot water W can be stored in the hot water storage tank 51 and used when necessary.

The exhaust gas heat exchanger 60 is capable of exchanging heat between the exhaust gas and the engine coolant to desorb heat from the engine exhaust gas. In other words, the cooling water receives the heat of the engine itself and the heat of the exhaust gas to cool the engine and the exhaust gas, and is a medium for transferring heat to water.

The cooling water primarily receives the heat of the exhaust gas from the exhaust gas heat exchanger 60, and the temperature rises. The temperature of the cooling water is further increased by receiving the heat of the engine and the heat of the cooling water of high temperature is transferred to the hot water heat exchanger 50 ), And the water becomes hot water (W).

On the other hand, the gas switching device 130 supplies either the LNG or the LPG to the engine. When the LNG supply is interrupted, the controller 110 controls the gas switching device 130 to supply the LPG to the engine.

That is, when LNG is not supplied from the LNG supply line, the LPG gas can be connected to the cogeneration system to supply LPG. Therefore, even when there is a problem such as an abnormality in the LNG supply line, the cogeneration apparatus 100 can be continuously operated.

As described above, when the air conditioner 200 is a gas heater pump, LNG or LPG may be supplied to the air conditioner 200 as well.

Hereinafter, a control method of the cogeneration system will be described with reference to FIG.

First, it is determined whether or not the supply of the commercial power E1 from the power supply source 1 is incomplete (S10).

Incomplete supply of commercial power (E1) generally means not only a power failure situation, but also a blackout situation with a power use peak or a power reserve of less than 5%. However, And a case in which the value is used in excess of the target value when the value is set.

If the power supply is complete, the supplied commercial power can be supplied to the air conditioner (S100).

If the power supply is incomplete, it is determined whether or not the power is not supplied at all (S20).

In the case of the above power failure, the relay switch connected to the commercial power supply grid is opened to completely shut off the commercial power supply (S110).

Then, the power of the charging device 150 is connected to prepare to start the engine 30 (S120).

Next, it is determined whether or not the LNG supply is interrupted (S130). If LNG is supplied, maintain the LNG supply line connection.

If the LNG supply is interrupted, the LPG supply line is connected to the engine 30 so that LPG can be supplied (S140).

Then, the engine 30 is started by operating the charging device 150 to operate (S150).

On the other hand, if the power supply is incomplete but not in the power failure state, it is determined whether the LNG supply has been stopped (S30). If LNG is supplied, maintain the LNG supply line connection.

If the LNG supply is interrupted, the LPG supply line is connected to the engine 30 so that LPG can be supplied (S40).

Then, the engine 30 is started by the electric power of the charging device 150 and operated (S50).

After the engine is started, power is generated in the generator, so that the relay switch connected to the commercial power supply grid is opened to completely shut off the commercial power supply (S60).

The electric power generated by the generator is supplied to the air conditioner 200 and the building 300 while the engine is operating (S70). At this time, as described above, the power converter 90 can be converted into commercial power and supplied.

The air conditioner 200 can be supplied with generated power to cool or heat the room, and the hot water obtained by absorbing the waste heat in the cogeneration device 100 can be supplied to the building 300.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, Changes will be possible.

12: zero governor 13: fuel valve
14: air cleaner 16: mixer
20: Turbocharger 29: ETC valve
30: engine 40: generator
50: hot water heat exchanger 60: exhaust gas heat exchanger
70: Radiator 80: muffler
90: power converter 100: cogeneration device
110: control unit 120: power switching device
130: gas switching device 150: charging device
200: air conditioner 300: building

Claims (11)

An engine using gas as fuel;
A generator driven by the engine to produce electric power;
A waste heat recovery device for recovering waste heat generated in the engine;
An air conditioner which is operated to cool or heat the room by receiving generated power or commercial power of the generator;
An electric power switching device for switching electric power such that either the generated electric power or the commercial electric power is supplied to the air conditioner;
A charging device that supplies electric power for starting the engine and is chargeable by the generated electric power; And
And a control unit for controlling the engine, the waste heat recovery apparatus, and the power switching apparatus,
Wherein the air conditioner includes an outdoor unit having a compressor and a condenser, the indoor unit being connected to the outdoor unit through a refrigerant pipe and having an evaporator,
Wherein the controller cuts off the commercial power supply when the commercial power supply is incomplete and starts the engine by operating the power supply from the charging device to operate the cogeneration power generation air conditioning system. The method according to claim 1,
In the waste heat recovery device,
A hot water heat exchanger for taking heat of the cooling water that has cooled the engine,
And an exhaust gas heat exchanger for taking out the heat of the exhaust gas exhausted from the engine. 3. The method of claim 2,
Further comprising a gas switching device for switching the gas so that either the liquefied natural gas (LNG) or the liquefied petroleum gas (LPG) is supplied to the engine,
Wherein the control unit controls the gas switching device to supply LPG to the engine when the LNG supply is interrupted. The method of claim 3,
The air conditioner is a gas heater pump using gas and electric power,
Wherein the LNG or LPG is also supplied to the gas heater pump. The method according to claim 1,
Wherein the control unit controls the power switching device to open the relay switch connected to the commercial power supply grid when the commercial power is not supplied at all. The method according to claim 1,
Wherein the charging device includes a supercapacitor,
Wherein the air conditioner is operated by receiving power from the charging device. An air conditioner comprising: an engine using gas as fuel; a generator connected to the engine; a waste heat recovery device for recovering waste heat generated in the engine; an outdoor unit and an indoor unit supplied with power; A method of controlling a cogeneration system air conditioning system including a charging device that provides starting power,
Determining whether the commercial power supply is incomplete;
Determining whether a power failure occurs when the commercial power supply is incomplete;
Operating the engine with the charger power when the power failure occurs and supplying the gaseous fuel;
Supplying power generated by the generator to the air conditioner and operating the power; And
And operating the air conditioner to recover the waste heat of the engine to produce hot water to supply it to the room. 8. The method of claim 7,
If it is determined that the power failure has not occurred in the power failure determination step,
Wherein the engine is started and operated by supplying commercial power to the cogeneration system. 9. The method of claim 8,
When the power failure is determined in the step of determining the power failure,
And a relay switch connected to the commercial power supply grid is opened. 10. The method of claim 9,
When the LNG supply is stopped after the engine is started,
Wherein the LPG supply line is connected to the LPG supply line to supply LPG to the engine. 10. The method of claim 9,
Wherein the charging device includes a supercapacitor,
Wherein the air conditioner is operated by receiving power from the charging device.

Images