KR20020002411A - Integrated gasification combined cycle power plant with kalina bottoming cycle - Google Patents

Abstract

The vaporization combination cycle generator is combined with a kalina bottoming cycle. The thermal energy streams 31, 69, 169 from the vaporization systems 48, 50, 52 are provided in heat exchange relationship with the working fluid mixture of the Kalina cycle, thereby heating the gas turbine exhaust gas 28 for heating the working fluid for the steam turbine. Replenishes the heat energy from The heat recovery fluid from the cold portion 50b flows through the heat exchanger 27 with the condensed working fluid from the evaporation / condensation system to preheat the working fluid for the steam generator 12 and from the hot portion 50a. The heat recovery fluid of is passed through the heat exchanger (23, 65) with the working fluid in the middle.

Description

INTEGRATED GASIFICATION COMBINED CYCLE POWER PLANT WITH KALINA BOTTOMING CYCLE}

The integrated vaporization combination cycle generator has obvious low cost, improved reliability and improved efficiency. The integrated vaporization combination cycle process consists of two stages of combustion, including clean-up between stages. The first stage has a vaporizer for partial oxidation of fossil fuels such as coal or heavy oil, while the second stage utilizes a gas turbine combustor for fuel gas combustion produced by the vaporizer to complete the combustion process. For example, inherent fuel processing losses associated with the vaporization of fossil fuels with respect to combined cycles have proven to yield excellent cycle efficiency. A simple combined cycle power generation system includes one gas turbine, one or more steam turbines, one or more. Further generators and heat recovery steam generators (HRSG) are provided. Gas turbines and steam turbines can be combined in tandem arrangement to form a single generator or one or more gas turbines, generators and heat recovery for supplying steam through a common header to separate steam turbine generator units. Multi-shaft combination cycle systems with steam generators may be provided. In the combined cycle, the heat from the gas turbine exhaust gas powers the steam turbine and is thus provided in a heat exchange relationship with the working fluid in the heat recovery steam generator to generate power and mechanical work.

Recently, using a combination of multi-component working fluids and absorption, condensation, evaporation and recuperative heat exchange operations, the irreversible losses typical of conventional Rankine cycles There was a significant improvement in the thermodynamic cycle by reducing In general, the improved thermodynamic cycles are known as Kalina cycles and provide a demonstrable and significant improvement in thermodynamic cycle efficiency. Kalina cycles use two subsystems that interact. The first subsystem includes a process for obtaining heat of a multi-component working fluid, including, for example, preheating, evaporating, superheating, generating feed heating and generating power. The second subsystem consists of a distillation / condensation subsystem (DCSS). An improvement in the efficiency of the Kalina cycle over the Rankine cycle is achieved using a component working fluid, preferably ammonia / water mixture, via a boiling point at the same pressure. The composition of the vapor stream and the liquid stream varies from point to point across each other throughout the cycle, and the subsystem is comprised of a heat sink used to condense the working fluid and the heat source and working fluid used to evaporate the working fluid. The enthalpy-temperature characteristics can be made more similar.

In the heat acquisition subsystem, the difference between the heat source as the working fluid passes through the boiler and the enthalpy temperature characteristic of the working fluid is reduced. This energy loss typical in the Rankine cycle is reduced by taking advantage of the varying temperature enthalpy properties of the multicomponent working fluid upon evaporation.

In the second subsystem, the evaporation / condensation subsystem of the Kalina cycle, the spent working fluid after expansion through the turbine is too low in pressure and too high in ammonia concentration to condense directly at the temperature of the useful coolant. Thus, the working fluid is only partially condensed, and the lean solution is mixed with the precondensed two-phase flow from the recuperative heat exchanger, whereby a low condensation can be achieved at a useful refrigerant temperature. Form a concentration of ammonia / water mixture. Thus, the lean condensate is recovered evaporatively to the turbine exhaust, regenerating the working composition for the heat acquisition subsystem. Kalina cycles are disclosed in US Pat. Nos. 4,586,340, 4,604,867, 5,095,708, and 4,732,005, which are incorporated herein by reference. Ongoing exploration for increased efficiency in power plants has resulted in incorporating kaliona bottoming into the integrated vaporization combination cycle power generation system according to the present invention.

Summary of the Invention

The present invention combines an integrated vaporization combined cycle power generation system with a kalina bottoming cycle to provide increased power production and system efficiency. In particular, the present system uses a vaporization system having a vaporizer having a gas cooling device and a cleanup device. The power unit of the system includes a gas turbine, a heat recovery steam generator device with a kalina cycle bottoming device, and an optional air separation unit. Basically, the present invention utilizes a thermal energy stream discharged from a vaporization system and / or an optional air separation unit to heat the working fluid in a kali na bottoming cycle apparatus at a suitable location to supplement the thermal energy supplied from the gas turbine exhaust. This maximizes the overall benefit of the heat stream, which in turn improves the net power yield and thermal efficiency of the power plant. In an embodiment of the present invention, heat useful from the high temperature cooling portion of the vaporization system is recovered and located in a heat exchange relationship with the multi-component working fluid of the combined cycle, thereby increasing the thermal energy supplied to the working fluid by the gas turbine exhaust gas. Let's do it. It is also used to preheat the condensed multi-component working fluid prior to feeding the low temperature cooling working fluid of the vaporization system to the heat recovery steam generator.

In a preferred embodiment according to the invention, the integrated vaporization combined cycle power generation system comprises a plurality of gas turbines for driving the first and second steam turbines and one or more generators for generating power and mechanical work. A method of operating an integrated vaporization combined cycle power generation system comprising a gas turbine and a fuel vaporizer for producing fuel gas for a gas turbine, the method comprising: (a) generating fuel with the fuel vaporizer; Supplying a heat recovery fluid from a vaporizer, (c) supplying the fuel gas from the fuel vaporizer to the combustor for the gas turbine to drive the gas turbine, and (d) operating the first steam turbine; Expanding the working fluid passing through it, (e) reheating the expanded working fluid from the first steam turbine, and (f) the second steam Expanding the reheated working fluid passing through the turbine, (g) condensing the working fluid discharged from the second steam turbine, and (h) from the steam turbine for flowing a heated working fluid; Passing the condensed working fluid to a gas turbine in a heat exchange relationship with a hot exhaust gas, and (i) passing the working fluid in a heat exchange relationship with a recovery fluid to further heat the working fluid supplied to the steam turbine. Steps.

In a preferred embodiment according to the invention, the integrated vaporization combined cycle power generation system comprises a plurality of gas turbines for driving the first and second steam turbines and one or more generators for generating power and mechanical work. A method of driving an integrated gasification combined cycle power generation system, comprising: (a) generating fuel with the fuel vaporizer; Supplying a heat recovery fluid from a fuel vaporizer, (c) supplying the fuel gas from the fuel vaporizer to the combustor for the gas turbine to drive the gas turbine, and (d) the first steam turbine Expanding the working fluid passing through it; (e) reheating the expanded working fluid from the first steam turbine; and (f) the Expanding the reheated working fluid passing through the second steam turbine; (g) condensing the working fluid discharged from the second steam turbine; and (h) steam for flowing the heated working fluid. Passing the condensed working fluid from the turbine to the gas turbine in a heat exchange relationship with a hot exhaust gas, and (i) passing the used working fluid in a heat exchange relationship with the heat recovery fluid, thereby providing the first and second vapors. Heating the used working fluid discharged from one of the turbines.

In yet another preferred embodiment according to the invention, the integrated vaporization combined cycle power generation system comprises (i) a gas turbine operatively coupled with a first steam turbine and one or more generators for generating power and mechanical work. A method of operating an integrated vaporization combined cycle power generation system, comprising: a plurality of turbines; (ii) an evaporation / condensation subsystem; and (iii) a fuel vaporizer for producing fuel gas for a gas turbine. Generating fuel to a fuel vaporizer; (b) supplying a heat recovery fluid from the fuel vaporizer; and (c) supplying the fuel gas from the fuel vaporizer to the combustor for the gas turbine to supply the gas turbine. And (d) expanding the working fluid consisting of a mixture of multiple components having a boiling point through the first steam turbine at the same pressure. Generating a spent stream of the mixture of the other components, (e) condensing the used stream in the subsystem, and (f) flowing the heated working fluid from the first steam turbine. Supplying the condensed working fluid to the gas turbine in a heat exchange relationship with the hot gas, and (g) heating the working fluid by passing the working fluid in a heat exchange relationship with the heat recovery fluid.

Accordingly, the main object of the present invention is to provide an integrated vaporization combined cycle power generation system using a kaliona bottoming cycle to increase power production and efficiency.

The present invention relates to a generator, and more particularly to a method of using a Kalina bottoning cycle in an integrated gasification combined cycle (IGCC) generator.

1 illustrates a method using a thermal energy flow of a vaporization system using a thermal energy stream from a vaporization system to heat a working fluid of a kalina bottoming cycle and supplement the thermal energy provided to the working fluid by a gas turbine exhaust gas. Schematic of an integrated vaporization combined cycle power generation system using a Kalina-type botoming cycle.

Referring to FIG. 1, an integrated vaporization combined cycle power generation system using a kalina bottoming cycle is shown. The system has a generator (G), a gas turbine (GT) and a steam turbine of the first high pressure (HP), the second medium pressure (IP) and the third low pressure, all of which are coupled to one or more generators (G). To generate electrical power or, optionally, mechanical work. A kalina bottoming cycle, or thermodynamic cycle, comprises the high pressure (HP), medium pressure (IP) and low pressure (LP) steam turbines, preheater 14, evaporator 16, reheater 18, and superheater 20. A heat recovery vapor generator (HRVG), such as boiler 12, and a distillation / condensation sub-system (DCSS). A power generator preheater 21 and / or heater 23 is provided that heats the auxiliary components via a combination cycle, described below, as well as working fluid in the HRGV using work from fuel gas. As can be appreciated from the references above for the Kalina cycle, the multicomponent working fluid mixture utilizes one comprising a lower boiling point fluid and a relatively higher boiling point fluid. For example, an ammonia / water mixture may be used, but the mixture may be used by those skilled in the art.

As shown, the fully condensed multi-component working fluid passes through preheater 14 from evaporation / condensation subsystem 24 through heat exchanger 27 in line 26. As indicated by line 28, heat is supplied from the exhaust gas of the gas turbine to the boiler 12 but this heat may be increased as much as useful from the system. The preheated working fluid is split into a first stream via a line 30 passing through a generator preheater 21 for recovering heat from the exhaust gas of the low pressure turbine IP. The working fluid is heat exchanged through the heat exchanger 23 via a line 33 to combine with a second stream of working fluid from the boiler 12 and to return to the outlet of the evaporator 16. As described below, the stream 29 exiting the heater 23 to return to the evaporator outlet is heated by heat exchange with the hot gas in the gas cooler 50. Heat exchange may be accomplished by placing the heat exchanger 23 directly in the gas cooler 50 or indirectly through an intermediate working fluid, if economical or desirable. The returned stream 29 and the stream in HRVG 12 are recombined in HRVG 12. The recombined stream of working fluid passes through the superheater 20, in which the recombined stream is exchanged with the gas turbine exhaust stream 28 for flow to the inlet of the high pressure (HP) steam turbine. Finally overheated, the recombined stream in the high pressure steam turbine is expanded and converted from thermal energy to mechanical energy to drive the turbine. The expanded working fluid stream from the high pressure (HP) turbine is returned via the 36 to the boiler 12 and via 28 which is reheated by the reheater 18 in heat exchange with the gas turbine exhaust. The reheated working fluid flows through line 40 to the inlet of the medium pressure (IP) turbine. The working fluid expanded through the medium pressure (IP) turbine is passed through the line 34 to the heat generating preheater 21 in a heat exchange relationship, the working fluid stream passing through the line 30 from the preheater of the boiler 12. It is supplied to the preheater 21. Thus, the working fluid vapor from the medium pressure turbine is cooled and provides some of the heat required for vaporizing the working fluid in line 30. The working fluid from the preheater 21 travels through the line 42 to the inlet of the low pressure (LP) turbine, where it is expanded to the final fluid pressure level. Fluid expanded from the low pressure (LP) turbine passes through line 44 to DCSS 24 where the fluid stream is condensed, pumped to higher pressure, and sent to boiler 12 via line 26. The cycle is continuous.

According to FIG. 1, the vaporization system 46, which is generally schematically shown and sometimes considered a vaporizer, comprises a vaporizer section 48, a cooling section 50 having hot and cold cooling sections 50a, 50b, respectively, and The gas cleanup part 52 is provided. The vaporizer receives feed additives and fuel feeds such as coal or heavy oil through respective lines 49 and 51. The partially oxidized fuel gas leaves the carburettor 48 at a substantial high temperature and is cooled in the cooling section 50. After the fuel gas is cooled, the contaminants are removed from the gas cleanup unit 52. For example, the gas cleanup may be equipped with a low temperature device such as dry filtration to remove coagulum by absorbing hydrogen sulfide using a water jet washer or a solvent. After the gas is cleaned up, the fuel gas is fed from the gas cleanup unit 52 through the line 56 to the combustor 54 of the gas.

Optionally provided air separation device 52 has injection air lines 60, 62, 64 for feeding nitrogen and oxidants to the vaporizer. Line 66 from air separation unit 58 supplies nitrogen to the gas turbine for low NO _X operation, while air from compressor discharge is directed to air separation unit via line 68. Supplied.

Kalina cycle DCSS is used to absorb, condense and regenerate working fluids and discharge them in low pressure (LP) steam turbines. The DCSS has a minimum of two pressure stages (eg, the high and low pressure sections shown) in which the working fluid mixture consisting of the composition passes through two completely. The more effective DCSS has three pressure stages (eg high pressure, medium pressure, low pressure sections) and a mixing component that causes full condensation. The mixed stream is assigned to a particular pressure section by determining the final condenser that sets the pressure of the stream (e.g., the low pressure condenser sets the pressure of the steam turbine exhaust line so that the turbine exhaust line is in the low pressure section of the DCSS). Is considered to be). The present invention can be applied to any evaporation / condensation system with two or more pressure stage condensers.

From the foregoing, the heat energy stream from the vaporizer heats the working fluid in a kalina botoming cycle at a suitable location within the fluid system, replenishing heat energy from the gas turbine exhaust, maximizing the overall benefit of the heat stream, and consequently As a result, net generator power production and thermal efficiency will be improved. In particular, the heat energy from the hot cooler 50a of the vaporizer is used in the heater 23 and optionally in the heaters 65, 165 to increase the heat supplied to the multicomponent working fluid by the gas turbine exhaust gas. In addition, useful heat from the cold cooling section 50b of the vaporizer 48 is used in the heater 27 to heat the condensed multi-component working fluid. It should be noted that the feed temperature introduced into the HRVG, ie, preheater 14 or economizer section, is maintained above the dew point of the acidic gas by the heater 27.

It will be appreciated that fuel heating for the gas turbine or additional steam production may be accomplished by heat exchanger 63 using an extract from medium pressure (IP) turbine exhaust gas from line 34. The temperature of the multi-component stream exiting the heat exchanger 63 is adjusted to be approximately equal to the temperature of the stream exiting the power generation preheater 21. The stream exiting heater 63 is recombined in line 42 prior to entering the low pressure (LP) steam turbine. The heat source of the heater 63 may be an extract of useful heat from the vaporizer, for example the cold section 50b.

In addition, if additional heat is available in the vaporizer system, the additional heater 65 may be located via line 67, for example in parallel with HRVG having preheater and evaporator sections 14, 16, respectively. The heat supplied is the heat from the vaporizer as indicated by line 69. Further reheating may be performed as an option in heat exchanger 165 by heat exchange with hot vaporized gas in the gas cooling unit. The generator preheater 21 may be omitted based on generator economics, and reheating for injecting medium pressure (IP) exhaust gas into the low pressure (LP) steam turbine may be performed by using useful high temperature heating in the vaporizer. In addition, low grade heat useful in vaporizers and optional air separators can be used to regenerate working fluid in the DCSS. This low degree of integration in DCSS improves system performance by reducing turbine back pressure, and reduces costs by generating reduction and higher temperature driving force.

Although the present invention has been described in connection with what is currently recognized as the most preferred embodiment, the invention is not limited to the above-described embodiment, but rather is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. It will be understood.

Claims (13)

An integrated unit comprising a plurality of gas turbines including first and second steam turbines and gas turbines for driving one or more generators for generating power and mechanical work, and a fuel vaporizer for producing fuel gas for the gas turbines. A method of operating a vaporization combination cycle power generation system, (a) generating fuel with the fuel vaporizer; (b) supplying a heat recovery fluid from the fuel vaporizer; (c) supplying the fuel gas from the fuel vaporizer to the combustor for the gas turbine to drive the gas turbine; (d) expanding a working fluid passing through the first steam turbine; (e) reheating the expanded working fluid from the first steam turbine; (f) expanding the reheated working fluid passing through the second steam turbine; (g) condensing the working fluid discharged from the second steam turbine; (h) passing the condensed working fluid from the steam turbine to the gas turbine for flowing a heated working fluid in a heat exchange relationship with the hot exhaust gas, (i) additionally heating the working fluid supplied to the steam turbine by passing the working fluid in a heat exchange relationship with the recovery fluid. How the system works. The method of claim 1, The condensed working fluid is heated in a heat recovery steam generator in heat exchange relationship with the exhaust gas from the gas turbine, and heat exchanges the exhausted working fluid with a portion of the condensed working fluid passing through the heat recovery steam generator. (J) cooling the working fluid discharged from the second steam turbine by passing it through. How the system works. The method of claim 1, (K) heating the condensed working fluid to form a partially condensed stream by passing the condensed working fluid in a heat exchange relationship with at least a portion of the cooled working fluid discharged from the second steam turbine. Containing How the system works. The method of claim 1, The step (h) comprises passing the condensed working fluid condensed in a heat exchange relationship with the hot exhaust gas from the gas turbine in a superheater, The step (i) is carried out before the condensed working fluid passes through the superheater. How the system works The method of claim 1, Passing the condensed working fluid in a heat exchange relationship with a second heat recovery fluid and preheating the condensed working fluid by passing the condensed working fluid in a heat exchange relationship with a second heat recovery fluid. How the system works. The method of claim 1, Said step (g) is carried out by an evaporation / condensation subsystem, and said compressed working fluid is discharged from said second steam turbine to form a partially condensed stream prior to said step (h). Heating the compressed working fluid by passing it in a heat exchange relationship with at least a portion and passing the partially condensed stream through an evaporation / condensation subsystem. How the system works. An integrated unit comprising a plurality of gas turbines including first and second steam turbines and gas turbines for driving one or more generators for generating power and mechanical work, and a fuel vaporizer for producing fuel gas for the gas turbine. A method of operating a vaporization combination cycle power generation system, (a) generating fuel with the fuel vaporizer; (b) supplying a heat recovery fluid from the fuel vaporizer; (c) supplying the fuel gas from the fuel vaporizer to the combustor for the gas turbine to drive the gas turbine; (d) expanding a working fluid passing through the first steam turbine; (e) reheating the expanded working fluid from the first steam turbine; (f) expanding the reheated working fluid passing through the second steam turbine; (g) condensing the working fluid discharged from the second steam turbine; (h) passing the condensed working fluid from the steam turbine to the gas turbine for flowing a heated working fluid in a heat exchange relationship with the hot exhaust gas, (i) heating the used working fluid discharged from one of the first and second steam turbines by passing the used working fluid in heat exchange relationship with the heat recovery fluid. How the system works. The method of claim 7, wherein The first steam turbine comprises a high pressure steam turbine, and further comprising passing the expanded working fluid through the high pressure turbine in heat exchange relationship with a heat recovery fluid. How the system works. The method of claim 7, wherein Said step (i) is carried out by passing said expanded working fluid through said second turbine in a heat exchange relationship with a heat recovery fluid. How the system works. a plurality of turbines comprising (i) a gas turbine operatively coupled to the first steam turbine and one or more generators generating power and mechanical work, (ii) an evaporation / condensation subsystem, and (iii) a gas A method of operating an integrated vaporization combined cycle power generation system comprising a fuel vaporizer that produces fuel gas for a turbine, the method comprising: (a) generating fuel with the fuel vaporizer; (b) supplying a heat recovery fluid from the fuel vaporizer; (c) supplying the fuel gas from the fuel vaporizer to the combustor for the gas turbine to drive the gas turbine; (d) expanding a working fluid consisting of the mixture of components through the first steam turbine at a same pressure and having a boiling point, thereby producing a used stream of the mixture of components, (e) condensing said used stream in said subsystem, (f) supplying the condensed working fluid in heat exchange relationship with the hot gas from the first steam turbine to the gas turbine to flow a heated working fluid; (g) heating the working fluid by passing the working fluid in a heat exchange relationship with the heat recovery fluid. How the system works. The method of claim 10, Further comprising a second steam turbine, wherein the condensed working fluid is heated in a heat recovery steam generator in heat exchange relationship with exhaust gas from the gas turbine, Cooling the working fluid discharged from the second steam turbine by passing the exhausted working fluid in a heat exchange relationship with a portion of the condensed working fluid passing through the heat recovery steam generator. How the system works. The method of claim 10, The step (f) is performed in part by passing the condensed working fluid in a heat exchange relationship with the hot gas of the gas turbine in the superheater, wherein step (g) is performed before the condensed working fluid passes through the superheater. Performed How the system works. The method of claim 10, The first steam turbine comprising the high pressure steam turbine, and passing the expanded working fluid through the high pressure turbine in heat exchange relationship with the heat recovery fluid; How the system works.