KR101744314B1 - Electric Power Generator - Google Patents

Abstract

A power generation device is disclosed. The disclosed power generation apparatus includes a steam generator, a waste heat recovery apparatus for recovering waste heat from the exhaust gas discharged from the steam generator, a back pressure regulator for regulating the back pressure of the boiler combustion chamber or the gas turbine chamber coupled with the steam generator, A steam turbine for converting the thermal energy of the steam into mechanical energy, a generator for converting the mechanical energy of the steam turbine into electrical energy, a condenser for condensing the steam discharged from the steam turbine, And a reheater for supplying the steam to the steam generator, wherein at least a part of the heat source for reheating is the recovered column recovered in the waste heat recovering apparatus.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

A power generation device is disclosed. More specifically, a power generation apparatus is disclosed in which efficiency is improved by utilizing heat recovered from flue gas discharged into a flue via a steam generator.

The power generation device is a device which heats water to make steam of high temperature and high pressure and sends it to the steam turbine to operate the steam turbine and to generate power.

Such a power generation apparatus includes a steam generator, a steam turbine, a condenser and a reheater sequentially connected to form a steam turbine cycle. Further, the steam power generation apparatus includes a generator connected to the steam turbine. With this configuration, the water supplied to the steam generator is heated to become steam. Also, the steam produced in the steam generator flows into the steam turbine and flows. This causes the steam turbine to operate and generate electricity from the generator.

In the conventional power generation apparatus, the waste heat is recovered through the absorber and the air preheater before discharging the exhaust gas through the steam generator to the flue, and then discharged to the atmosphere. However, the flue gas remaining in the flue gas There is a problem that waste heat of up to 10% can not be recovered and utilized. In addition, when the flue gas is discharged to the atmosphere through the flue, steam and cold outside air in the flue gas come into contact with each other, resulting in a large amount of white smoke, thereby causing civil complaints.

This 10% waste heat consists of the sensible heat of the flue gas and the latent heat of the steam contained in the flue gas. The technical reason that it can not be recovered is that when the water vapor condenses, the tube gap of the shell and tube heat exchanger is closed, As the back pressure of the boiler rises very rapidly, control for controlling the back pressure can not be performed, and the operation of the combustion chamber is out of the normal condition, and the operation is stopped. Therefore, it is impossible to recover even the sensible heat to prevent clogging of the tube gap of the heat exchanger.

Accordingly, it is necessary to develop a power generation device capable of recovering and utilizing the waste heat with high efficiency while reducing the degree of back pressure of the combustion chamber to a gentle, weak and controllable level, and reducing the emission of white smoke.

One embodiment of the present invention provides a power generation apparatus improved in efficiency by utilizing heat recovered from an exhaust gas discharged from a boiler combustion chamber or a gas turbine chamber.

According to an aspect of the present invention,

A steam generator combined with a boiler combustion chamber or a gas turbine chamber;

A waste heat recovering device for recovering waste heat in the exhaust gas discharged through the steam generator;

A back pressure regulator for regulating the back pressure of the boiler combustion chamber or the gas turbine chamber;

A steam turbine for converting thermal energy of the steam generated in the steam generator into mechanical energy;

A generator for converting the mechanical energy of the steam turbine into electric energy;

A condenser for condensing the vapor discharged from the steam turbine; And

And a reheater for reheating the water discharged from the condenser and supplying the reheated water to the steam generator,

And at least a part of the heat source of the reheat is the recovered heat generated in the waste heat recovering apparatus.

The waste heat recovering apparatus is characterized in that the flue gas and the first water absorbent are brought into direct contact with each other to convert them into a process gas and a second water absorbent having a temperature higher than that of the first water absorbent and then the first heat medium and the second moisture absorbent It is possible to convert them into a second heat medium having a temperature higher than that of the first heat medium and a third moisture absorbent having a lower temperature than the second moisture absorbent.

The heating medium may include condensed water, air, water, organic substances (alcohols, glycols, etc.), commercially available heating materials, or combinations thereof, but the present invention is not limited thereto.

The process gas may have less heat and vapor than the exhaust gas.

The second moisture absorbent may have more heat and moisture than the first moisture absorbent and the third moisture absorbent.

The first water absorbent, the second water absorbent and the third water absorbent may each comprise an aqueous solution of a salt.

The salt is selected from the group consisting of calcium nitrate (Ca (NO ₃ ) ₂ ), ammonium nitrate (NH ₄ NO ₃ ), ammonium sulfate ((NH ₄ ) ₂ SO ₃ ), barium perchlorate (Ba (ClO ₄ ) ₂ ) (KHCO _3), sodium nitrate (NaNO _3), sodium chlorate (NaClO _3), potassium nitrate (KNO _3), barium nitrate _{(Ba (NO 3) 2)} , sodium perchlorate (NaClO _4), sodium chloride (NaCl), calcium chloride (CaCl ₂ ), potassium formate (CHKO ₂ ), hydrates thereof, or combinations thereof.

The waste heat recovery apparatus may receive heat from at least one of the steam generator and a separate boiler, but the present invention is not limited thereto.

The back pressure regulating device may be disposed at least one of the front end and the rear end of the waste heat recovering device and is generally disposed at a rear end of the waste heat recovering device to maintain the back pressure of the boiler room or the turbine room within a predetermined range .

The back pressure regulating device may include a blower.

The reheater includes a first reheater and a second reheater connected to each other, wherein the first reheater is connected to the condenser and the second reheater is connected to the steam generator.

The second heating medium may have a temperature of 60 ° C or higher.

The additional heat source of the reheater may be steam generated in the steam generator or condensate thereof.

The power generation device may be applied to a coal-fired power plant, a heavy oil-fired power plant, an LNG thermal power plant, an LNG combined-cycle power plant, a biomass power plant, or a waste incineration power plant.

The second heating medium generated in the waste heat recovery apparatus may be used as the reheating heat source, the coal heating and moisture removal, the water heating, the combustion air preheating heat source, the cooling and heating heat source in the greenhouse and the terrestrial fish farm, .
The power generation device may have at least one of the effects of decreasing the temperature of white smoke and decreasing the amount of generated gas, reducing the amount of dust emission, and reducing the amount of discharged acid gas.

The power generation apparatus according to an embodiment of the present invention recovers the waste heat in the exhaust gas containing steam that has been discharged to the atmosphere through the flue from the existing power generation apparatus as useful heat without increasing the back pressure of the boiler room or the gas turbine room, By using it as a reheating heat source, the power generation efficiency of about 3 ~ 4% can be increased. Therefore, the power generation apparatus can have a great effect on the improvement of economy, energy saving and greenhouse gas reduction in the thermal power plant which occupies more than 55% of the national production electric power.

In addition, the power generation apparatus has an advantage of additionally reducing the amount of white smoke, and also bringing about the cleaning effect of dust and acid gas.

1 is a schematic view of a power generating apparatus according to an embodiment of the present invention.

Hereinafter, a power generating apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

1 is a schematic view of a power generation apparatus 100 according to an embodiment of the present invention.

The power generation apparatus 100 may be a stoichiometric power generation apparatus.

1, a power generation apparatus 100 according to an embodiment of the present invention includes a gas turbine 110, a steam generator 120, a waste heat recovery apparatus 130, a back pressure regulator 131, a flue 132, A steam turbine 140, a generator 150, a condenser 160, and a reheater 170. [

The gas turbine 110 may be omitted if the steam generator 110 is combined with a boiler. The boiler may be a device for generating steam by burning fuel and heating the water-treated water (e.g., demineralized water) supplied to the steam generator 120. The gas turbine 110 is included when the power generation apparatus 100 is applied to an LNG combined cycle power plant, but may be omitted otherwise.

The steam generator 120 is a device that generates steam by contacting the hot exhaust gas discharged from the gas turbine 110 through the line L1 and the water treated by the water. The steam generator 120 is a heat recovery steam generator (HRSG) .

The temperature of the steam generated in the steam generator 120 may be 300-350 占 폚, or may be 500 占 폚 or higher.

When the steam generator 120 is a heat recovery steam generator (HRSG), the power generation apparatus 100 may be applied to an LNG combined cycle power plant. As used herein, "LNG" means liquefied natural gas.

The waste heat recovery apparatus 130 further includes at least one of an economizer (not shown) and an air preheater (not shown) after passing through the steam generator 120, To recover the waste heat in the exhaust gas flowing through the second exhaust pipe.

As a specific example, the waste heat recovering device 130 may be configured to remove exhaust gas near 100 ° C. before being drawn into the flue 132 after passing through a carbon burner and air preheater, and a first water absorbent (not shown) (For example, a low-temperature organic solvent having a temperature for heating at a temperature of 50 ° C or lower, or a second heat-absorbing agent And the second water absorbent are indirectly brought into contact with each other by heat exchange to form a second heat medium having a temperature higher than that of the first heat medium (for example, the organic solvent heated to 60 DEG C or higher And high-temperature water, or condensed water of the condenser), and a third moisture absorbent whose temperature is lower than that of the second moisture absorbent. In other words, sensible heat and latent heat (i.e., latent heat of condensation of condensed water) contained in the exhaust gas can be transferred to the first water absorbent, and water vapor contained in the exhaust gas can be absorbed into the first water absorbent in a liquid state have. As a result, the exhaust gas can be converted to the process gas having less heat and water vapor, and the first moisture absorbent can be converted to the second moisture absorbent having more heat and moisture than this.

In addition, the pollutants contained in the exhaust gas may be adsorbed on the first water absorbent, and eventually be included in the second water absorbent.

Each of the water absorbents absorbs the sensible heat, latent heat and moisture of the exhaust gas, and can also adsorb pollutants contained in the exhaust gas. Since each of the water absorbents increases the dew point of the steam by about 50K or more than the normal dew point, a large amount of moisture can be absorbed from the exhaust gas.

The salt has excellent adsorption characteristics of contaminants, has high solubility in water, and has a large difference in solubility according to temperature, so that when the temperature of the water absorbent is lowered, the salt is precipitated into a solid in solution, and recovery is easy. In addition, when the salt is dissolved in water, it causes an endothermic reaction and has an advantage of excellent latent heat recovery characteristics of the exhaust gas.

In addition, the process gas is released to the outside through the line L3 because the amount of heat and water vapor is smaller than that of the high-temperature flue gas (that is, the absolute humidity and the relative humidity are low) .

The process gas may have a temperature of 65 DEG C or less and an absolute humidity of 40 g / m < ³ > or less.

The hot exhaust gas and the first water absorbent may flow in mutually opposite directions. For example, the hot exhaust gas flows from the lower portion to the upper portion of the waste heat recovery apparatus 130, and the first water absorbent can be sprayed downward from the upper portion of the waste heat recovery apparatus 130.

The first water absorbent may be a pristine exhaust gas absorbent such as an initial state in which the water absorbed during the heat exchange process is removed or the second water absorbent may heat the first heat medium in the waste heat recovering device 130 (I. E., A third moisture absorbent). ≪ / RTI >

The first water absorbent may have a temperature of 40 ° C to 90 ° C.

The first water absorbent, the second water absorbent and the third water absorbent may each comprise an aqueous solution of a salt.

The first moisture absorbent, the second moisture absorbent and the third moisture absorbent may be essentially the same substance only in content of components such as heat, moisture, dust and acid gas, and the like. For example, the first moisture absorbent may be the same as the third moisture absorbent.

The salt is selected from the group consisting of calcium nitrate (Ca (NO ₃ ) ₂ ), ammonium nitrate (NH ₄ NO ₃ ), ammonium sulfate ((NH ₄ ) ₂ SO ₃ ), barium perchlorate (Ba (ClO ₄ ) ₂ ) (KHCO _3), sodium nitrate (NaNO _3), sodium chlorate (NaClO _3), potassium nitrate (KNO _3), barium nitrate _{(Ba (NO 3) 2)} , sodium perchlorate (NaClO _4), sodium chloride (NaCl), calcium chloride (CaCl ₂ ), potassium formate (CHKO ₂ ), hydrates thereof, or combinations thereof. For example, the salt may comprise calcium nitrate hydrate (Ca (NO ₃ ) ₂ .xH ₂ O, x = 4, 6, 8 or 10).

The concentration of the salt in the water absorbent may be 40 to 80% by weight. If the concentration of the salt is within the above range, the salt easily dissolves and the salt may precipitate as a solid to precipitate or not affect the fluidity, even though the water absorption rate is high.

There is a difference in the solubility and water absorption rate depending on the type of the salt, and the concentration of the salt can be selectively controlled in consideration of this.

The waste heat recovery apparatus 130 may or may not receive heat from at least one of the steam generator and a separate boiler (not shown) via the line 9, depending on the combination of use with existing batters or air preheaters .

The second heating medium heated by the recovery heat in the waste heat recovery apparatus 130 may have a temperature of 60 ° C or higher.

The waste heat recovery apparatus 130 can additionally perform white smoke reduction and cleaning action of dust and acid gas.

The back pressure regulating device 131 may be arranged in front of or behind the waste heat recovering device 130 or inside the device 130, respectively. In general, the back pressure regulator 131 is disposed at the rear end of the waste heat recovery device 130 to maintain the back pressure of the combustion chamber or the gas turbine chamber of the boiler within a predetermined range.

The back pressure regulator 131 may include a blower.

The steam turbine 140 is a device that converts the thermal energy of the steam generated in the steam generator 120 and supplied through the line L4 into mechanical energy.

The steam turbine 140 is a prime mover that ejects the high-pressure steam generated in the steam generator 120 through a nozzle (not shown) to form a high-speed distribution stream and to spray the steam at a turbine blade (not shown) to obtain a rotational force. The steam turbine 140 is divided into an impulse turbine that uses only the impact force generated by the distribution flow and a reaction turbine that utilizes the reaction force generated by changing the cross-sectional area between the turbine blades in addition to the distribution flow. The impulse turbine is suitable for high pressure steam. There are also multiple turbines, backpressure turbines, additional turbines, etc., depending on the state of use of the steam.

The generator 150 is a device for converting the mechanical energy of the steam turbine 140 into electrical energy.

The condenser 160 is a device for condensing the vapor discharged from the steam turbine 140. Concretely, the condenser 160 is a device for heat-exchanging and condensing the steam discharged from the steam turbine 140 through the line L5 with the cooling water supplied through the line L6 in an ocean, a river or a collective energy facility.

The cooling water heated by the heat exchange in the condenser 160 is discharged to the outside through the line L7. Further, the condensed water (about 30 DEG C) formed by condensing the steam in the condenser 160 is supplied to the reheater 170 via the line L8.

The reheater 170 is a device for reheating the condensed water discharged from the condenser 160 and supplying it to the steam generator 120. Specifically, when the steam generated in the steam generator 120 is condensed in the condenser 160 after passing through the steam turbine 140 and converted into condensed water having a lower temperature than the steam, the reheater 170 supplies the condensed water to the line L8 and reheated, and then re-supplied to the steam generator 120.

Reheater 170 may be a heat exchanger.

The heat source of the reheater 170 may be the second heat medium generated in the waste heat recovery apparatus 130.

The additional heat source of the reheater 170 may be steam generated in the steam generator 120 or condensate thereof.

The reheater 170 may include a first reheater 171 and a second reheater 172 connected to each other through a line L12.

The first reheater 171 is connected to the condenser 160 via line L8. In addition, the first reheater 171 can receive the second heat medium generated by the waste heat recoverer 130 through the line L10 and use it as a heat source.

The second reheater 172 is connected to the steam generator 120 via line L13. In addition, the second reheater 172 can receive the steam generated in the steam generator 120 through the line L11 and use it as a heat source.

The temperature of the water discharged from the second reheater 172 and supplied to the steam generator 120 through the line L13 may be 80 to 100 ° C.

The waste heat recovery apparatus 130 recovers sensible heat and latent heat in the exhaust gas discharged through the steam generator 120 and provides the sensible heat as the heat source of the reheater 170. Accordingly, the amount of steam of the steam generator 120 used as the heat source of the reheater 170 is relatively reduced, and the amount of steam of the steam generator 120 supplied to the steam turbine 140 is relatively increased. Therefore, the amount of electric energy (i.e., electric power) generated in the generator 150 increases in proportion to the amount of steam supplied thereto, so that it increases.

The power generation apparatus according to an embodiment of the present invention can increase the power generation efficiency by 3 to 4% as compared with the conventional power generation apparatus.

The power generation device may be applied to a coal-fired power plant, a heavy oil-fired power plant, an LNG thermal power plant, an LNG combined-cycle power plant, a biomass power plant, or a waste incineration power plant.

The second heating medium generated by the waste heat recovery apparatus can be used as a heat source for reheating heat after the condenser, water heating, preheating of combustion air, coal warming and moisture removal (when applied to a coal-fired power plant) . Particularly, when the second heating medium generated in the waste heat recovery apparatus is used as a heat source for the greenhouse heating and absorption type refrigerator in the winter according to the energy, agriculture and forestry complex project in the form of hot water as exemplified above, , An additional device requiring extra power to make hot water (preferably 60 ° C or higher) and cold water (preferably 10 ° C or lower) suitable for heating and cooling using power plant hot water at about 30 ° C There is an advantage that there is no need to use an electric drive type heat pump.

As shown in the following Table 1, the water content of the coal supplied to the coal-fired power plant is about 30% by weight, but actually about 40% by weight. Therefore, the moisture in the supplied coal may cause a decrease in the efficiency of the coal-fired power plant. If moisture is removed while raising the temperature of the coal supplied to the heat source recovered in the waste heat recovery apparatus, the efficiency of the coal- Can be obtained.

ingredient  unit Designed  Actual - total moisture wt% 30 10 to 40 - volatile matter wt% 31.5 20 ~ 43 - carbon wt% 33 30 to 60 - ashtray wt% 5 5 to 15 - sulfur wt% 0.5 0.3 to 1.0

While the present invention has been described with reference to the drawings, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

100: Power generator 110: Gas turbine
120: Steam generator 130: Waste heat recovery device
131: back pressure regulator 132: year
140: Steam turbine 150: Generator
160: condenser 170: re-opening
171: First Reheater 172: Second Reheater

Claims (12)

Steam generator;
A waste heat recovery device for recovering waste heat in the exhaust gas discharged from the steam generator;
A back pressure regulator for regulating the back pressure of the boiler combustion chamber or the gas turbine chamber combined with the steam generator;
A steam turbine for converting thermal energy of the steam generated in the steam generator into mechanical energy;
A generator for converting the mechanical energy of the steam turbine into electric energy;
A condenser for condensing the vapor discharged from the steam turbine; And
And a reheater for reheating the water discharged from the condenser and supplying the reheated water to the steam generator,
Wherein at least a part of the heat source of the reheating heat is recovered in the waste heat recovering apparatus,
The additional heat source of the reheater is the steam generated by the steam generator or its condensate,
The waste heat recovering apparatus is characterized in that the exhaust gas and the first water absorbent are brought into direct contact with each other to convert them into a second water absorbent having a higher temperature than that of the process gas and the first water absorbent and then the first heat medium and the second moisture absorbent are indirectly Respectively, to convert them into a second heat medium having a temperature higher than that of the first heat medium and a third moisture absorbent having a lower temperature than the second heat absorbing agent by heat exchange. delete The method according to claim 1,
Wherein the process gas has less heat and water vapor than the exhaust gas. The method according to claim 1,
Wherein the second moisture absorbent has more heat and moisture than the first moisture absorbent and the third moisture absorbent. The method according to claim 1,
Wherein the first water absorbent, the second water absorbent and the third water absorbent each comprise an aqueous solution of a salt. 6. The method of claim 5,
The salt is selected from the group consisting of calcium nitrate (Ca (NO ₃ ) ₂ ), ammonium nitrate (NH ₄ NO ₃ ), ammonium sulfate ((NH ₄ ) ₂ SO ₃ ), barium perchlorate (Ba (ClO ₄ ) ₂ ) (KHCO _3), sodium nitrate (NaNO _3), sodium chlorate (NaClO _3), potassium nitrate (KNO _3), barium nitrate _{(Ba (NO 3) 2)} , sodium perchlorate (NaClO _4), sodium chloride (NaCl), calcium chloride (CaCl ₂ ), potassium formate (CHKO ₂ ), hydrates thereof, or a combination of two or more thereof. The method according to claim 1,
Wherein the back pressure regulating device includes a blower disposed at least one of a front end, a rear end, and an interior of the waste heat recovering device to maintain the back pressure of the boiler combustion chamber or the gas turbine chamber within a predetermined range. The method according to claim 1,
Wherein the waste heat recovering device is supplied with heat from at least one of the steam generator and a separate boiler or does not receive heat from the steam generator and a separate boiler depending on whether or not the vacuum cleaner and the air preheater are present. The method according to claim 1,
Wherein the reheater includes a first reheater and a second reheater connected to each other, wherein the first reheater is connected to the condenser and the second reheater is connected to the steam generator. The method according to claim 1,
The power generation apparatus is applied to a coal-fired power plant, heavy oil-fired power plant, LNG thermal power plant, LNG combined-cycle power plant, biomass power plant, or waste incineration power plant. The method according to claim 1,
The heat recovered in the waste heat recovering device may include at least one of the reheating heat source after the condenser, the coal heating and moisture removal, the water heating, the combustion air preheating heat source, the heating and cooling heat source in the greenhouse and the terrestrial fish farm, Generator used as one. The method according to claim 1,
Wherein the power generation apparatus has at least one of a temperature drop of the white smoke production and a reduction in the amount of generation, a reduction in dust emission amount, and a reduction in the amount of acid gas emission.

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