KR101531931B1 - Combined cycle power generating system - Google Patents

Abstract

The present invention relates to a combined-cycle power generation system. Specifically, according to an embodiment of the present invention, there is provided a solar heating system, comprising: a solar heat generating unit for collecting solar heat to generate steam; an absorption type refrigerator for cooling the outside air by receiving steam generated from the solar heat generating unit; A gas turbine unit including at least one gas turbine rotating the turbine using the combustion gas, and a gas turbine generator connected to the gas turbine to produce electric power, heating the water to heat the combustion gas discharged from the gas turbine, And a steam turbine unit including at least one steam turbine for receiving the steam generated from the HRSG unit to rotate the turbine and a steam turbine generator connected to the steam turbine to generate electric power, The absorption refrigerator is selectively supplied with steam from the steam turbine unit There is a combined cycle power generation system can be provided.

Description

{COMBINED CYCLE POWER GENERATING SYSTEM}

The present invention relates to a combined-cycle power generation system.

Typical examples of the energy conversion apparatus include a gas turbine system or a steam turbine system that generates electricity using energy such as fuel. Specifically, the gas turbine supplies fuel and air to burn the fuel, thereby driving the turbine using the high-temperature, high-pressure combustion gas generated thereby. The steam turbine uses a steam generator to heat the feed water Thereby generating steam, and then supplying the generated steam to the turbine to drive the steam turbine. Efforts to improve the energy efficiency of systems have continued since the development of gas turbine power generation systems or steam turbine power generation systems that produce power through such gas turbines or generators connected to steam turbines. For reference, the liquid circulating through the system can be defined differently depending on the flow position. The liquid, which is condensed by the condenser and supplied to the steam generating means, is supplied to a plurality of condensed water and steam generating means The liquid that is converted into steam can be defined as feed water.

In particular, the combined-cycle power generation system, which uses the heat of the exhaust gas produced after producing energy from the gas turbine to heat the water supply of the steam turbine cycle by using the Heat Recovery Steam Generator (HRSG), uses only the steam turbine, The efficiency of the power generation system is improved remarkably.

On the other hand, when the temperature of the air flowing into the air compression unit of the gas turbine is high, the volume of the air increases, and the absolute amount of air flowing into the combustion chamber of the gas turbine is reduced. At the same time, energy for compressing the air is excessively consumed, The output is reduced. Therefore, the intake air cooling device for cooling the air sucked into the gas turbine can be installed on the upstream side of the air compressing part, so that the efficiency and the power reduction of the gas turbine can be prevented. As an air cooling means, an evaporative freezer or an electric engine-driven heat pump (EHP) which injects water into the air is used.

However, the method of spraying water has a problem that the blades in the compressor of the gas turbine are corroded due to the droplet, and the method using EHP has a problem in that the power consumption of the entire power plant is reduced due to the use of electric power in the power plant. Therefore, it is conceivable to apply the absorption type refrigerator as the outside air cooling means.

However, even when the absorption type refrigerator is used, it is necessary to secure an additional heat source for operating the refrigerator, thereby causing an additional energy supply cost.

An embodiment of the present invention is to provide a combined-cycle power generation system including a gas turbine and a steam turbine, which can minimize the energy supply cost required for cooling the outside air supplied to the gas turbine.

According to an embodiment of the present invention, there is provided a solar heating system comprising: a solar thermal steam generating unit for collecting solar heat to generate steam; An absorption refrigerator for receiving the steam generated by the solar heat generating unit to cool the outside air; A gas turbine unit including at least one gas turbine for rotating a turbine using combustion gas generated by burning fuel, and a gas turbine generator connected to the gas turbine to produce electric power; An HRSG unit heating the water by the heat of the combustion gas discharged from the gas turbine to generate steam; And a steam turbine unit connected to the steam turbine to generate electric power, wherein the absorption refrigerator includes a steam turbine unit, and the absorption refrigerator is connected to the steam generator, A combined-cycle power generation system that receives steam selectively from the turbine unit may be provided.

The solar heat generating unit may include a solar collector for collecting solar heat; A heat transfer fluid tank for storing a heat transfer fluid; A first pump for pumping the heat transfer fluid from the heat transfer fluid tank to the solar collector; A solar heat exchanger including at least one heat exchanger for receiving the heat transfer fluid heated by the solar collector and exchanging heat with water, and generating steam by heat exchange between the heat transfer fluid and water; A water tank for temporarily storing water supplied to the solar heat exchanging unit; And a second pump for pumping water from the water tank to the solar heat exchanger may be provided.

Also, the combined thermal power generation system may be provided in which the steam supplied from the solar heat generating unit to the absorption chiller is converted into water while being heat-exchanged in the absorption chiller, and at least a part of the converted water is transferred to the water tank.

In addition, the absorption refrigerator may be provided with a combined-cycle power generation system in which steam is selectively supplied from the HRSG unit.

A condenser for rotating the turbine and condensing steam discharged from the steam turbine; And a cooling tower for supplying cooling water for condensing steam to the condenser, wherein the absorption type refrigerator is connected to the cooling tower to supply cooling water for cooling the absorption heat generated in the absorption process, Can be provided.

The steam control valve may further include a steam control valve for controlling a flow rate of steam supplied from the steam turbine to the absorption chiller, wherein the opening degree of the steam control valve monitors at least one of a temperature and a concentration of the solution in the absorption chiller A combined-cycle power generation system can be provided.

The steam control valve may further include a steam control valve for regulating a flow rate of steam supplied to the absorption refrigerator from the steam turbine, wherein the steam control valve increases the opening amount when the amount of heat of solar heat collected in the solar heat collector is reduced, If the heat of solar heat collected in the solar collector increases, a combined thermal power generation system controlled to reduce the opening amount can be provided.

According to the embodiment of the present invention, the energy supply cost required for driving the absorption type refrigerator can be reduced by using steam generated by using solar heat as a heat source necessary for the absorption type refrigerator.

In addition, there is an advantage that energy for cooling can be continuously supplied even when solar energy supply is not smooth due to weather, time, and the like.

In addition, since the temperature and the solar radiation tend to be proportional to each other, the solar energy is increased due to the increase of the solar radiation and the solar energy supplied to the solar cell. Therefore, the cooling effect is maximized when the solar heat is used as the driving heat source of the absorption refrigerator .

1 is a view illustrating a combined-cycle thermal power generation system according to an embodiment of the present invention.
FIG. 2 is a block diagram of a combined-cycle power generation system showing a state in which high-temperature steam generated by the solar-steam-generating unit of FIG. 1 is supplied to an absorption-type refrigerator.
FIG. 3 is a block diagram of a combined-cycle power generation system showing a state in which high-temperature steam generated in the solar-steam-generating unit of FIG. 1 and steam added from a steam-turbine unit are supplied to an absorption-type refrigerating machine.
Fig. 4 is a graph showing the output change of the gas turbine of Fig. 1 according to temperature.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 is a view illustrating a combined-cycle thermal power generation system according to an embodiment of the present invention.

Referring to FIG. 1, a combined thermal power generation system 10 according to an embodiment of the present invention includes a solar heat generation unit 100 for collecting solar heat to generate steam, a steam generator 100 for generating solar heat, A gas turbine unit 300 including a gas turbine unit 300 for receiving and cooling ambient air and cooling the turbine by using combustion gas generated by burning the fuel, A steam turbine unit 400 including a steam turbine 402 for rotating the steam turbine 402 to generate steam by transferring the heat of the combustion gas discharged from the gas turbine 302 to water, A heat recovery steam generator (HRSG) unit 500 for supplying steam, a condenser 600 for condensing steam discharged from the steam turbine 402, and a cooling tower 700 for supplying cooling water to the condenser 600 .

The gas turbine unit 300 may include one or more gas turbines 302 and the gas turbine 302 may comprise an air compressor and a turbine and a combustion chamber so that the compressed air in the air compressor is mixed with the fuel, As a result, the gas at high temperature and high pressure is expanded, and the turbine is driven by this force. The energy generated by the driving of the turbine is transmitted to the gas turbine generator 310 through the turbine shaft to produce electric power by rotating the rotor of the gas turbine generator 310.

For this purpose, the gas turbine 302 is supplied with fuel such as natural gas from the fuel supplier 320 and can receive ambient air from the ambient air supply device 16. At this time, the outside air supplied through the outside air supply unit 16 may be supplied to the gas turbine 302 after being cooled by the absorption type refrigerator 200. This is because, when the temperature of the air flowing into the gas turbine 302 is high, the volume of the air is increased and the absolute amount of the introduced air is reduced while energy for compressing the air is excessively consumed, thereby preventing the efficiency and output of the gas turbine from being reduced . Further, the cooled outside air passes through the water separator 18, and the moisture contained in the outside air can be removed.

The high temperature combustion gas discharged from the gas turbine 302 may be supplied to the HRSG unit 500 as a heat source for generating steam supplied to the steam turbine 402.

The HRSG unit 500 may include a superheater 502, an evaporator 504 and an economizer 506, and the superheater 502 may receive water from the condenser 600 to generate combustion The evaporator 504 reheats the heated water in the superheater 502 to the heat of the combustion gas discharged from the gas turbine 302 to generate steam and the economizer 506 heats the evaporator 504, The steam generated by the steam generator 504 may be received and heated to a proper temperature by the heat of the combustion gas discharged from the gas turbine 302. At this time, if the amount of water supplied to the HRSG unit 500 is insufficient, the water supplied through the replenishing unit 19 can be replenished. The steam generated in the HRSG unit 500 may be supplied to the steam turbine unit 400.

The HRSG unit 500 may include a superheater 502, an evaporator 504 and a plurality of heaters 506. The HRSG unit 500 may generate a high pressure steam at the upstream side based on the flow of the gas delivered from the gas turbine 302 A superheater 502, an evaporator 504 and a heat absorber 506 may be disposed downstream of the superheater 502, the evaporator 504 and the heat absorber 506 for producing steam for medium and low pressure .

The steam turbine unit 400 may include one or more steam turbines 402 and may receive high temperature steam from the HRSG unit 500 and spray the steam to the impeller wheels through nozzles to obtain rotational force. To produce electricity by rotating the rotor of the rotor 410.

To this end, the steam turbine 402 is supplied with high-temperature, high-pressure steam from the HRSG unit 500, and the steam discharged after rotating the impeller is supplied to the condenser 600 to be condensed with water, And supplied to the HRSG unit 500 to be converted into steam. For this, the condenser 600 is connected to the cooling tower 700 to receive cooling water for steam condensation, and the cooling water having a higher temperature after heat exchange with steam is transferred to the cooling tower 700 to be cooled

On the other hand, some of the steam supplied to the steam turbine 402 may be added to the absorption refrigerator 200 as a heat source. In addition, some of the steam generated in the HRSG unit 500 may also be added to the absorption refrigerator 200 as a heat source. At this time, the steam added from the steam turbine 402 and the HRSG unit 500 can be supplied to the absorption refrigerator 200 only when the steam control valve 12 is opened, and from the steam turbine 402 when it is closed The supply of steam to the absorption refrigerator 200 is cut off. The opening and closing control of the steam control valve 12 will be described later.

The solar thermal power generation unit 100 includes a solar heat collector 120 for collecting solar heat, a heat transfer fluid tank 130 for storing a heat transfer fluid, a pump 130 for pumping the heat transfer fluid from the heat transfer fluid tank 130 to the solar collector 120, 1 pump 140, a solar heat exchanger 110 for receiving the heat transfer fluid heated by the solar collector 120 and generating steam by heat-exchanging heat with water, a water storage unit 110 for temporarily storing the water supplied to the solar heat exchanger 110, And a second pump 150 for pumping water from the tank 160 and the water tank 160 to the solar heat exchanger 110.

The solar heat exchanger 110 may include one or more heat exchangers 112 and the heat exchanger 112 may be a conventional heat exchanger configured to exchange heat while indirectly contacting the two fluids in flow. The heat exchanger 112 can exchange heat between the heat transfer fluid heated by solar heat and water, and steam can be generated as a result of heat exchange.

The solar collector 120 may be configured to condense solar light and heat the heat transfer fluid passing through the solar collector 120 by solar light and may be a general solar collector composed of an endothermic plate, have. For example, the solar collector 120 may be a vacuum tube type collector, a compound parabolic collector (CPC), a linear fresnel reflector (LFR), a parabolic trough collector (PTC), or the like capable of heating a heat transfer fluid at a temperature of about 200 ° C .

The heat transfer fluid tank 130 may be a general reservoir for storing a heat transfer fluid, and a fluid having a high heat transfer rate may be used as the heat transfer fluid. For example, the heat transfer fluid tank 130 may be a thermal oil.

The water tank 160 may be a general reservoir for storing water and may further include a control valve (not shown) to control the amount of water to be supplied depending on the heat exchange capacity of the solar heat exchanging unit 110.

The solar heat exchanger 110 needs to produce steam at a temperature required for the absorption refrigerator 200 to operate normally. The temperature and flow rate of the heat transfer fluid supplied from the solar collector 120 and the temperature and flow rate of the heat transfer fluid supplied from the water tank 160 By controlling the flow rate of the water supplied according to the temperature of the water, steam of the required temperature can be generated. For this purpose, the solar heat exchanger 110 senses the temperature and the flow rate of the supplied heat transfer fluid and the temperature of the supplied water, and adjusts the opening amount of the control valve of the water tank 160 to generate steam at a required temperature according to the sensed value (Not shown) for controlling the display device.

The absorption type refrigerator 200 may include an evaporator, an absorber, a regenerator (or a generator), and a condenser. Depending on the number of regenerators, the absorption refrigerator 200 may be a single effect type (also referred to as a single effect type) And can be divided into the utility type and the multiple utility type.

Hereinafter, the operation of the absorption type refrigerator 200 will be described with reference to a case where the absorption type refrigerator 200 is the single effect type absorption type refrigerator. The vapor generated in the evaporator of the absorption type refrigerator 200 is absorbed into the lithium bromide aqueous solution as the absorbent in the absorber of the absorption type refrigerator 200 so that the lithium bromide aqueous solution changes from the high concentration solution (concentrated solution) to the low concentration solution The solution flows through a solution pump to the regenerator of the absorption chiller 200 after the temperature rises in the solution heat exchanger. At this time, the absorption heat generated in the absorption process can be cooled by receiving cooling water from the cooling tower 700. To this end, the absorption type refrigerator 200 may be connected to the cooling tower 700 to receive the cooling water, and to return the heat-exchanged cooling water back to the cooling tower 700.

Then, the regenerator of the absorption type refrigerator 200 heats the high concentration solution using a heat source, generates a refrigerant vapor using the difference between the boiling points of the absorbent and the refrigerant, and then the lithium bromide solution is made into a high concentration solution. The solution is cooled in the solution heat exchanger of the absorption chiller (200) and then returned to the absorber of the absorption chiller (200). The refrigerant vapor generated in the regenerator of the absorption type refrigerator 200 is transferred to the condenser of the absorption type refrigerator 200. The refrigerant vapor in the condenser of the absorption type refrigerator 200 is discharged into the liquid in the evaporator of the absorption type refrigerator 200 The outside air supplied from the outside air supply device 16 can be cooled while being evaporated.

On the other hand, in the dual effect absorption refrigerator, the regenerator is divided into a high temperature regenerator and a low temperature regenerator, and in the high temperature regenerator, the absorbent is heated by the medium pressure steam to generate the refrigerant vapor. The refrigerant vapor is heated again by using the heat released when the refrigerant vapor condenses in the low-temperature regenerator, and the refrigerant vapor is generated while heating the absorption liquid.

On the other hand, the steam supplied to the absorption type refrigerator 200 can be discharged as water after the heat is taken from the absorption refrigerator 200, and the discharged water is transferred to the water tank 160 or transferred to the HRSG unit 500 Can be supplied. At this time, the flow rate of the water supplied to the HRSG unit 500 can be controlled by the flow control valve 14.

Hereinafter, specific actions and effects of the combined-cycle thermal power generation system having the above-described configuration will be described with reference to FIG. 2 to FIG. FIG. 2 is a block diagram of a combined-cycle power generation system in which the high-temperature steam generated by the solar-steam-generating unit of FIG. 1 is supplied to the absorption-type refrigerator. FIG. FIG. 4 is a graph showing a change in output of the gas turbine of FIG. 1 according to temperature, showing steam and steam added from the steam turbine unit to the absorption refrigerator. FIG.

First, as shown in FIG. 2, the solar heat generating unit 100 condenses sunlight to generate steam, and the generated steam can be supplied to the absorption type refrigerator 200. The absorption refrigerator (200) can receive steam from the solar heat generating unit (100) and cool the outside air supplied from the outside air supply unit (16).

On the other hand, the sunlight to be condensed may not be sufficiently condensed enough to satisfy the required heat quantity in the case of the weather or in the evening, and thus the solar heat is intermittent and the condensation can be performed only during the time when the sun is floating. Respectively. On the other hand, since the combined-cycle power generation system 10 needs to be able to constantly operate regardless of conditions such as weather and time, if it is difficult to generate steam at a desired temperature and flow rate because the solar heat is not collected as needed, The steam control valve 12 may be opened to extract steam from the steam turbine 402 as shown in FIG. It is also possible to add steam from the HRSG unit 500 in addition to the steam turbine 402. Since the shortage of steam supplied to the absorption type refrigerator 200 can be supplemented, the cooling effect of the absorption type refrigerator 200 can be prevented from being lowered due to intermittency and periodicity of solar heat.

To this end, the amount of opening of the steam control valve 12 can be determined by monitoring the temperature and concentration of the solution in the absorption refrigerator 200. In addition to the monitoring of the absorption refrigerator 200, the amount of heat of the steam to be added is monitored by monitoring the amount of solar heat collected in the solar collector 120, and the opening amount of the steam control valve 12 is determined based on the calculated flow rate . The steam control valve 12 can be controlled so as to increase opening amount when the amount of heat of solar heat collected in the solar collector 120 is reduced and decrease amount of opening when the amount of heat of solar heat collected in the solar collector 120 increases have.

According to the above-described combined thermal power generation system 10, the energy supply cost required for driving the absorption type refrigerator 200 is reduced by using steam generated by using solar heat as a heat source necessary for the absorption type refrigerator 200 have.

In addition, there is an advantage that energy for cooling can be continuously supplied even when solar energy supply is not smooth due to weather, time, and the like.

In addition, since the temperature and the solar radiation tend to be proportional to each other, the solar energy is increased due to the increase of the solar radiation and the solar energy supplied to the solar cell. Therefore, the cooling effect is maximized when the solar heat is used as the driving heat source of the absorption refrigerator .

4, both the output of the gas turbine 302 and the energy efficiency decrease as the air temperature increases. This is because the temperature of the outside air supplied through the outside air supply unit 16 rises . Therefore, in order to maintain the output and the energy efficiency of the gas turbine 302 at a constant level even if the temperature rises, it is necessary to further cool the outside air in the absorption type refrigerator 200.

As described above, since the temperature and the solar irradiance tend to be proportional to each other as described above, the amount of solar energy to be supplied also increases, so that the temperature and flow rate of the steam, which can be generated using solar heat, The effect can be even higher. Therefore, it is possible to prevent the energy efficiency from lowering even with the temperature change.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand. For example, a person skilled in the art can change the material, size and the like of each constituent element depending on the application field or can combine or substitute the embodiments in a form not clearly disclosed in the embodiments of the present invention, Of the range. Therefore, it should be understood that the above-described embodiments are to be considered in all respects as illustrative and not restrictive, and that such modified embodiments are included in the technical idea described in the claims of the present invention.

10: Combined Cycle Power System 12: Steam control valve
14: Flow control valve 16: Outer air supply device
18: water separator 19: replenisher
100: Solar heat generating unit 110: Solar heat exchanger
112: heat exchanger 120: solar collector
130: Heat transfer fluid tank 140: First pump
150: Second pump 160: Water tank
200: Absorption refrigerator 300: Gas turbine unit
302: gas turbine 310: gas turbine generator
320: fuel supplier 400: steam turbine unit
402: Steam turbine 410: Steam turbine generator
500: HRSG unit 502: superheater
504: Evaporator 506:
600: condenser 700: cooling tower

Claims (7)

A solar steam generating unit for collecting solar heat to generate steam;
An absorption refrigerator for receiving the steam generated by the solar heat generating unit to cool the outside air;
A gas turbine unit including at least one gas turbine for rotating a turbine using combustion gas generated by burning fuel, and a gas turbine generator connected to the gas turbine to produce electric power;
An HRSG unit heating the water by the heat of the combustion gas discharged from the gas turbine to generate steam; And
A steam turbine unit including at least one steam turbine for receiving steam generated from the HRSG unit to rotate the turbine, and a steam turbine generator connected to the steam turbine to generate electric power,
Wherein the absorption refrigerator is selectively supplied with steam from the steam turbine unit. The method according to claim 1,
The solar heat generating unit includes:
A solar collector for collecting solar heat;
A heat transfer fluid tank for storing a heat transfer fluid;
A first pump for pumping the heat transfer fluid from the heat transfer fluid tank to the solar collector;
A solar heat exchanger including at least one heat exchanger for receiving the heat transfer fluid heated by the solar collector and exchanging heat with water, and generating steam by heat exchange between the heat transfer fluid and water;
A water tank for temporarily storing water supplied to the solar heat exchanging unit; And
And a second pump for pumping water from the water tank to the solar heat exchange unit. 3. The method of claim 2,
Wherein the steam supplied from the solar heat generating unit to the absorption chiller is converted into water while being heat-exchanged in the absorption chiller, and at least a part of the converted water is transferred to the water tank. The method according to claim 1,
Wherein the absorption refrigerator is selectively supplied with steam from the HRSG unit. The method according to claim 1,
A condenser for rotating the turbine and condensing the steam discharged from the steam turbine; And
Further comprising a cooling tower for supplying cooling water for condensing steam to the condenser,
Wherein the absorption chiller is connected to the cooling tower and is supplied with cooling water for cooling the absorption heat generated in the absorption process. The method according to claim 1,
Further comprising a steam control valve for regulating a flow rate of steam supplied from the steam turbine to the absorption chiller,
Wherein the amount of opening of the steam control valve is determined by monitoring at least one of the temperature and the concentration of the solution in the absorption type refrigerator. The method according to claim 1,
Further comprising a steam control valve for regulating a flow rate of steam supplied from the steam turbine to the absorption chiller,
Wherein the steam control valve is controlled so as to increase opening amount when the amount of heat of solar heat collected in the solar collector is reduced and decrease amount of opening when the amount of heat of solar heat collected in the solar collector is increased.

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