GB2100356A - Power plant having steam and air turbines - Google Patents
Power plant having steam and air turbines Download PDFInfo
- Publication number
- GB2100356A GB2100356A GB8216646A GB8216646A GB2100356A GB 2100356 A GB2100356 A GB 2100356A GB 8216646 A GB8216646 A GB 8216646A GB 8216646 A GB8216646 A GB 8216646A GB 2100356 A GB2100356 A GB 2100356A
- Authority
- GB
- United Kingdom
- Prior art keywords
- turbine
- air
- steam
- power plant
- heat exchange
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
- F01K23/00—Plants characterised by more than one engine delivering power external to the plant, the engines being driven by different fluids
- F01K23/02—Plants characterised by more than one engine delivering power external to the plant, the engines being driven by different fluids the engine cycles being thermally coupled
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
- F01K23/00—Plants characterised by more than one engine delivering power external to the plant, the engines being driven by different fluids
- F01K23/02—Plants characterised by more than one engine delivering power external to the plant, the engines being driven by different fluids the engine cycles being thermally coupled
- F01K23/06—Plants characterised by more than one engine delivering power external to the plant, the engines being driven by different fluids the engine cycles being thermally coupled combustion heat from one cycle heating the fluid in another cycle
- F01K23/061—Plants characterised by more than one engine delivering power external to the plant, the engines being driven by different fluids the engine cycles being thermally coupled combustion heat from one cycle heating the fluid in another cycle with combustion in a fluidised bed
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
- F02C1/00—Gas-turbine plants characterised by the use of hot gases or unheated pressurised gases, as the working fluid
- F02C1/04—Gas-turbine plants characterised by the use of hot gases or unheated pressurised gases, as the working fluid the working fluid being heated indirectly
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E20/00—Combustion technologies with mitigation potential
- Y02E20/16—Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT]
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Engine Equipment That Uses Special Cycles (AREA)
Abstract
Gas produced by combustion of, e.g., low grade solid fuel in combustion chamber 10 is delivered to a heat exchanger 21. Air compressed by the compressor 23 of turbine engine 24 is passed in heat exchange relationship with the gas in the heat exchanger 21 and the compressed, heated air is used to drive the turbine 26 of the turbine engine. A second heat exchanger 32 receives the air from the turbine 26 and steam is passed in heat exchange relationship with the air in the second heat exchanger and is thereafter delivered to drive a steam turbine 40. The turbine 40 and engine 24 may drive electric generators. Alternatively, the engine 24 may drive the propellor(s) of a sea-going vessel. <IMAGE>
Description
SPECIFICATION
Power plant
This invention relates to power plant and in particular, although not so restricted, to power plant for the generation of electrical power from relatively low grade fuel.
The most efficient known way of generating electric power from liquid and/or gaseous petroleum fuels is by a combined gas turbine/steam turbine recuperative cycle.
Pressurised gasifiers have been developed to convert relatively high grade coal to gas for fuelling a power plant using the combined gas turbine/steam turbine recuperative cycle.
However, conventional combined cycle power plant cannot use relatively low grade solid fuel, such as peat, brown coal or lignite since such fuel is difficult, if not impossible. to gasify. To produce electrical power from such relatively low grade fuel the conventional steam cycle is used but this has only relatively low thermal efficiency.
The present invention seeks to provide a power plant using relatively low grade solid fuel but with a relatively high thermal efficiency.
According to the present invention there is provided a power plant comprising: a combustion chamber; first heat exchange means for receiving gas produced by combustion of fuel in the combustion chamber; a gas turbine engine having a compressor and a turbine; and means for passing air compressed by the compressor in heat exchange relationship with the said gas in the first heat exchanger means and using the air to drive the turbine of the gas turbine engine; second heat exchange means for receiving the said air after it has passed through the turbine; means for passing steam in heat exchange relationship with the air in the second heat exchange means; and a steam turbine arranged to be driven by the steam from the second heat exchange means.
Preferably the second heat exchange means is arranged to receive said air after it has passed through the turbine together with said gas from the combustion chamber.
In the preferred embodiment the combustion chamber is a fluidised bed combustion chamber.
The gas turbine engine is preferably connected to drive an electrical power generator.
The steam turbine is preferably connected to drive an electrical power generator.
The invention is illustrated, merely by way of example, in the accompanying drawings, in which:
Figure 1 is a schematic diagram of one embodiment of a power plant according to the present invention; and
Figure 2 is a schematic diagram of a modification of the power plant of Figure 1.
Referring first to Figure 1, there is illustrated one embodiment of a power plant according to the present invention having a combustion chamber 10 which may be a fluidised bed combustion chamber producing for example, up to 50 MW of heat. Relatively low grade solid fuel, for example, peat, brown coal, lignite, waste oil or combustible refuse, is fed from a bunker 11 by means of a feeding device 1 2 to the combustion chamber. Peat, for example has a calorific value of approximately 12x106J/kg and a water content of 55%. If desired, the solid fuel may include a proportion of combustible solid or liquid waste.
Air is supplied from the atmosphere to the combustion chamber 10 by means of a fan 13.
Ash can be removed from the combustion chamber 10 through its base as indicated by reference numeral 14.
Liquid fuel, such as diesel oil, stored in a tank 15, is pumped by a pump 1 6 through a line 17 to a start-up heater 1 8 of the combustion chamber, the heater 1 8 receiving a supply of compressed air from a line 19. A conventional filter 1 7a is iocated in the line 1 7. The purpose of the heater 1 8 is to ignite solid fuel in the combustion chamber on start-up of the power plant: once ignition has been established in the combustion chamber the supply of fuel to the heater 1 8 is turned off, combustion being maintained by the supply of solid fuel to the combustion chamber.
The heater 18 can also be used to raise the temperature of flue gas leaving the combustion chamber if, for example, there is a shortage of solid fuel and it is not otherwise possible to raise the flue gas to the required temperature.
The fuel gas from the combustion chamber which may be at a temperature of 1 2500C passes via a line 20 to an air heater 21 where it passes in heat exchange relationship with atmospheric air passing through a heating coil 22. Air is drawn from atmosphere and compressed by a compressor 23 of a gas turbine engine 24 and passes through the heating coil 22. The heated air then passes through a trim combuster 25 to a turbine 26 of the gas turbine engine. For example, 183,000 kg/hr of air at a temperature of 1 SOC may be compressed by the compressor 23, the air at the outlet of the compressor having a temperature of 2500C.After passing through the heating coil 22, the air has a temperature of, for example, 8100C, and this is adjusted, if necessary, by the trim combuster 25 so that the air entering the turbine 26 is at the predetermined design temperature of, for example, 9500C. The air leaving the turbine 26 on a line 27 is at a temperature of, for example, 4900 C. The turbine 26 drives an electrical power generator (not shown), for example, an 11 kV generator producing 7700 kW of electrical power.
The trim combuster 25 receives liquid fuel from the tank 1 5 on a line 28, through which the liquid fuel is pumped by a pump 29. A filter 30 is provided in the line 28. The trim combuster 25 also has a heat release line 31 to atmosphere.
Thus if the temperature of the air leaving the heating coil 22 is less than the predetermined design temperature necessary for the turbine 26, the temperature can be raised by burning liquid fuel in the trim combuster and if the temperature of the air leaving the heating coil is greater than the predetermined design temperature its temperature can be reduced by releasing heat to the atmosphere by way of the line 31. In addition, on start-up of the power plant, liquid fuel is supplied to the trim combuster 25 to start the gas turbine engine.
The air flows from the turbine 26 via the line 27 to a heat exchanger or heat recovery boiler 32 which also receives the flue gas from the heat exchanger 21 on a line 33. The heat recovery boiler 32 includes a superheater 34, an evaporator 35 and an economiser 36. Steam flows from a boiler drum 37 through a line 38 to the superheater 34 where its temperature is raised from, for example, 2100C to 3700C.
The steam passes through a line 39 to a steam turbine 40 which is connected to drive an electrical power generator (not shown), for example, a second 11 kV generator producing 8,300 kW of electrical power. The steam leaving the turbine 40 may have a temperature of 460C and passes to a steam condenser 42. The steam condenser 42 contains a cooling coil 43 which receives cooling water on a line 44 from a cooling tower 45, from which the water is pumped by a pump 46. The cooling water is returned to the cooling tower from the cooling coil 43 by way of a line 47. The cooling water entering the cooling coil 43 may have a temperature of 220C and the cooling water returning to the cooling tower on the line 47 may have a temperature of 320C.
The condensed steam from the condenser 42 is pumped through a line 48 by a pump 49 to the economiser 36 in the heat recovery boiler 32, where its temperature is raised to, for example, 930C. From the economiser 36 the water passes via a line 50 to a de-aerator 51 where any air entrained therein is removed.
A pump 52 pumps water from the de-aerator 51 via a line 53 to an economiser 54 in the heat exchanger 21. The water leaving the economiser 54, at a temperature of, for example, 1 600C, passes to the boiler drum 37.
Water is circulated in conventional manner from the hot boiler drum 37 through the evaporator 35 in the heat recovery boiler 32 by way of lines 55, 56.
The air entering the heat recovery boiler 32 on the line 27 and the flue gas entering on the line 33, are passed to atmosphere through a chimney 57. The temperature of the gas passing through the chimney may be 1 500C.
Feed water is supplied to the power plant through a line 58 where it is stored in a storage tank 59. The feed water is pumped, as necessary, by a pump 60 through a line 61 to the de-aerator
51. The de-aerator 51 has an overflow line 62 which connects to the storage tank 59.
A conventional blowdown flash vessel 63 is
provided having an inlet connected to the boiler
drum 37 by a line 64. When it is desired to
remove sludge or other detritus from the boiler
drum, a valve 65 on the line 64 is opened and
water, together with the sludge etc. passes to the
vessel 63. The flash steam is returned to the deaerator 51 via a line 66 and the sludge goes to waste via a line 67 which passes through the storage tank 59 where any heat remaining in the smudge is given up to the feed water in the storage tank.
A bleed line 68, including a pressure reducing valve 69, leads from the low pressure side of the turbine 40 to the line 66, to provide additional steam for de-aeration.
Figure 2 illustrates a modification of the power plant of Figure 1. Like parts in Figures 1 and 2 have been designated by the same reference numerals and only the differences between the two power plants will be described in any detail.
One difference is that, in the power plant of Figure 2, the heater 1 8 receives a supply of air solely from the fan 1 3. An additional fan 100 recycles at temperating gas from an outlet of heat recovery boiler 32 through a line 101 to the combustion chamber 10.
A second and somewhat more important difference is that condensed steam from the condenser 42 is pumped through the line 48 by the pump 49 to a low pressure feedwater heater 103 where its temperature is raised to, for example, 940C by steam flowing through the bleed line 68 from the low pressure side of the turbine 40. The steam from the low pressure feedwater heater 103 passes via a line 104 to the condenser 42. From the low pressure feedwater heater 103 the water passes via a line 105 to a boiler feed tank 106.
A pump 107 pumps water from the boiler feed tank 106 via a line 108 to a heat exchanger 109.
The water leaving the heat exchanger 109, at a temperature of, for example, 990C, passes through the economiser 36 to the boiler drum 37.
When it is desired to remove sludge or other detritus from the boiler drum, the valve 65 on the line 64 is opened and water together with the sludge etc. passes to the vessel 63, as in the power plant of Figure 1. However, flash steam is returned to the boiler feed tank 106 via the heat exchanger 109 in heat exchange relationship with the water pumped from the boiler feed tank 106 through the line 108.
Thus it will be appreciated that the boiler feed
tank 106 replaces the de-aerator 52 of the power plant of Figure 1 and the heat exchanger 109 replaces the economiser 54 in the heat exchanger 21. In the power plant of Figure 2, the electrical power generator driven by the turbine 26 may produce, for example, 9680 kW of electrical power and the electrical power generator driven by the steam turbine 40 may produce, for example, 6870 kW of electrical power.
The power plants according to the present invention and described above have the advantage that they can operate using relatively low grade solid fuel. This advantage is achieved by providing the heat exchanger 21 in which the flue gas from the combustion chamber 10 raises the temperature of air which is then used to drive the gas turbine engine 24. The remaining heat from the flue gas is then used to produce steam to drive the steam turbine 40. The power plant described above has particular advantages in areas where there is an abundant supply of relatively low grade solid fuel.
It will be appreciated that whilst the power plants described above are intended for use with relatively low grade solid fuel, they may be operated with a relatively high grade solid fuel if there is an abundant supply.
A power plant according to the present invention is not limited to the production of electrical power and it will be appreciated that a mechanical output may be taken from the gas turbine engine 26 and/or the steam turbine 40, to drive machinery for example. Thus, in one embodiment, a power plant according to the present invention is used to drive a sea-going vessel, a mechanical output from the gas turbine engine being used to drive a propellor or propellors and the steam turbine being used with an electrical power generator to provide an electrical supply to run ancillary equipment on the vessel. It will also be appreciated that the steam turbine 40 can be arranged to pass out steam at a relative low pressure, for example, 350 kPa, to provide heat for a process plant or for a factory or district heating system, all of which will further improve the overall efficiency of the power plant.
Claims (6)
1. A power plant comprising: a combustion chamber; first heat exchange means receiving gas produced by combustion of fuel in the combustion chamber; a gas turbine engine having a compressor and a turbine; and means for passing air compressed by the compressor in heat exchange relationship with the said gas in the first heat exchanger means and using the air to drive the turbine of the gas turbine engine; second heat exchange means for receiving the said air after it has passed through the turbine; means for passing steam in heat exchange relationship with the air in the second heat exchange means; and a steam turbine arranged to be driven by the steam from the second heat exchange means.
2. A power plant as claimed in claim 1 in which the second heat exchange means is arranged to receive said air after it has passed through the turbine together with said gas from the combustion chamber.
3. A power plant as claimed in claim 1 or 2 in which the combustion chamber is a fluidised bed combustion chamber.
4. A power plant as claimed in any preceding claim in which the gas turbine engine is connected to drive an electrical power generator.
5. A power plant as claimed in any preceding claim in which the steam turbine is connected to drive an electrical power generator.
6. A power plant substantially as herein described with reference to and as shown in the accompanying drawings.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB8216646A GB2100356A (en) | 1981-06-12 | 1982-06-08 | Power plant having steam and air turbines |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB8118055 | 1981-06-12 | ||
GB8216646A GB2100356A (en) | 1981-06-12 | 1982-06-08 | Power plant having steam and air turbines |
Publications (1)
Publication Number | Publication Date |
---|---|
GB2100356A true GB2100356A (en) | 1982-12-22 |
Family
ID=26279768
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB8216646A Withdrawn GB2100356A (en) | 1981-06-12 | 1982-06-08 | Power plant having steam and air turbines |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB2100356A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1989006306A1 (en) * | 1987-12-30 | 1989-07-13 | Peredi Karoly | Process and installation for performing mechanical work |
ITMI20092315A1 (en) * | 2009-12-29 | 2011-06-30 | Ansaldo Energia Spa | COMBINED CYCLE PLANT FOR THE PRODUCTION OF ELECTRICAL ENERGY AND THERMAL ENERGY AND FUNCTIONING METHOD OF SUCH SYSTEM |
-
1982
- 1982-06-08 GB GB8216646A patent/GB2100356A/en not_active Withdrawn
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1989006306A1 (en) * | 1987-12-30 | 1989-07-13 | Peredi Karoly | Process and installation for performing mechanical work |
ITMI20092315A1 (en) * | 2009-12-29 | 2011-06-30 | Ansaldo Energia Spa | COMBINED CYCLE PLANT FOR THE PRODUCTION OF ELECTRICAL ENERGY AND THERMAL ENERGY AND FUNCTIONING METHOD OF SUCH SYSTEM |
WO2011080576A3 (en) * | 2009-12-29 | 2012-01-05 | Ansaldo Energia S.P.A. | Combined-cycle plant for the production of electric and thermal energy and method for operating said plant |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |