JP4759545B2 - Heavy oil-fired gas turbine power generation system - Google Patents

Description

  The present invention relates to a power generation system for a heavy oil-fired gas turbine.

  Heavy oil and water are mixed under reaction conditions in which water is at or near the supercritical region, and the reformed oil generated by decomposing the heavy oil is used as gas turbine fuel to generate power, and the gas turbine There is known a combined power generation system that recovers retained heat of exhaust heat gas from an engine to produce steam and drive a steam turbine (for example, see Patent Document 1).

JP 2006-045308 A (summary)

  When reforming heavy oil using water, it is generally desirable to heat a mixed fluid of heavy oil and water to a temperature of about 350 to 550 ° C. In Patent Document 1, a heavy oil heat exchanger that heats heavy oil and a mixed fluid heat exchanger that heats a mixed fluid of heavy oil and water perform heat exchange with steam for heating, which is necessary for the reforming reaction. A combined power generation system that heats a fluid to about 350 to 550 ° C. is shown.

  Here, the steam generated in the boiler is used as a heating medium in the heavy oil heat exchanger and the mixed fluid heat exchanger, and becomes wet steam partially condensed at the outlet of the heat exchanger. When this wet steam is applied to a simple cycle, in order to ensure the soundness of the water pump that recirculates water to the boiler, it was necessary to condense the wet steam with a condenser to make the whole amount water. As a result, the condenser water cooling system becomes a large-scale system, and if there is no facility that uses the latent heat from the condenser, the heat energy of the wet steam is discharged outside the system, and the There was a problem that the thermal energy of steam could not be used efficiently.

  Therefore, an object of the present invention is to efficiently use the thermal energy of wet steam containing heavy oil and water after heat exchange in a power generation system of a heavy oil-fired gas turbine.

  The present invention provides a gas-liquid separator that separates wet steam after heating heavy oil with the heavy oil heat exchanger into dry steam and water, and dry steam separated by the gas-liquid separator. A steam compressor and a system for supplying again dry steam pressurized by the steam compressor to the heavy oil heat exchanger are provided.

  ADVANTAGE OF THE INVENTION According to this invention, in the electric power generation system of a heavy oil-fired gas turbine, the heat energy of the wet steam containing the heavy oil and the water after heat exchange can be utilized efficiently.

  A simple cycle and combined cycle power generation system to which the present invention is applied will be described below.

  An embodiment of a simple cycle power generation system for a heavy oil-fired gas turbine according to the present invention will be described with reference to FIG. A simple cycle power generation system refers to a system that does not include a waste heat recovery boiler and generates power using only a gas turbine.

  The power generation system of this embodiment includes a gas turbine 30, a heavy oil heat exchanger 4 using steam as a heating source 4, a reformer 14 for reforming and reacting heavy oil and water, and heavy oil heat exchange. The gas-liquid separator 23 for separating the moisture of the wet steam 22 after the heavy oil is heated in the vessel 4, and the dry steam 25 separated by the gas-liquid separator are used as heat in the heavy oil heat exchanger 4 or the like. A steam compressor 20 that is recirculated to the exchanger and a steam drum 41 that supplies steam from a system different from the dry steam 25 separated by the gas-liquid separator 23 are provided.

  The heavy oil 3 is supplied from the heavy oil tank 1 to the mixer 11 via the heavy oil heat exchanger 4 by the heavy oil high pressure pump 2. On the other hand, the water 9 used for the reforming reaction is pressurized in the order of the water supply pump 6, the water circulation pump 7, and the water high-pressure pump 8 from the water tank 5, and is heated by a heat transfer tube provided in the boiler 10. To be supplied. The heavy oil 3 and water 9 supplied to the mixer 11 become a mixed fluid and are supplied to the mixed fluid heat exchanger 13. The mixed fluid is supplied through the mixed fluid heat exchanger 13 to the reformer 14 maintained at conditions of 5-30 MPa and 350-550 ° C. favorable for the reforming reaction. The reformer 14 is provided with a reforming heat exchanger 42 in order to maintain the mixed fluid inside the reformer at a desired temperature. The reforming heat exchanger 42 heats the mixed fluid with heating steam. In the reformer 14, part of the heavy oil becomes a reformed fuel lightened by a reforming reaction with water, and the remaining heavy oil becomes a residual oil containing a large amount of vanadium heavy metals. The reformed fuel 15 is depressurized to a pressure suitable for the operation of the gas turbine 30 through the pressure reducing valve 16 and supplied to the combustor 32 as the fuel 17. The fuel 17 supplied to the combustor 32 is burned using the air from the air compressor 31, and the turbine 40 is driven by the combustion gas. Then, power is generated by the generator 33 connected to the rotating shafts of the turbine 40 and the air compressor 31.

  In this embodiment, the reformed fuel after decompression is directly supplied to the combustor 32 of the gas turbine. However, after the reformed fuel is cooled, the liquid reformed oil can be supplied to the pump, and the gaseous reformed oil can be supplied to the gas compressor or the like and then supplied to the combustor of the gas turbine.

  The exhaust heat gas 34 discharged from the turbine 40 is supplied to the boiler 10. The exhaust heat gas of the gas turbine is generally at a high temperature of 450 ° C. or higher, and steam can be generated by the boiler 10. The boiler 10 is provided with a heat transfer tube, and the exhaust heat gas 34 is discharged out of the system after exchanging heat with water or steam flowing in the heat transfer tube. Further, the heat transfer tubes of the boiler 10 are divided into a plurality of systems, and in this embodiment, the heat transfer tubes 43, 44, 45, and 46 are sequentially arranged from the upstream side where the exhaust heat gas 34 flows. The arrangement of the heat transfer tubes can be changed as appropriate according to the exhaust heat gas temperature discharged from the turbine 40 and the required steam temperature.

  The steam heated by the heat transfer tube 43 provided on the upstream side of the boiler 10 is branched and supplied to the heavy oil heat exchanger 4, the mixed fluid heat exchanger 13, and the reforming heat exchanger 42. Steam generated in the boiler by the exhaust heat gas discharged from the gas turbine is used to heat heavy oil or a mixed fluid of heavy oil and water. After being used for heating heavy oil or the like, it becomes wet steam 22 in which a part of the steam is condensed. The wet steam 22 is a fluid in which steam and moisture are mixed. This wet steam has enough thermal energy to be used for power generation of the steam turbine. However, it is difficult to supply wet steam as it is to the heat transfer tube of the boiler 10 in the simple cycle as in this embodiment. Supplying wet steam to the water pump not only promotes erosion due to the generation and extinction of steam, but also causes instability in the flow and malfunction of the water pump. This is because it is necessary to condense all the steam in the water container.

  Here, since the latent heat required for condensing the steam in the wet steam is larger than the sensible heat of the cooling water, the cooling water flow rate required for the condenser is also increased. For example, the latent heat of steam at 5 MPa is 2794 kJ / kg, whereas the sensible heat for changing from 20 ° C. to 95 ° C. at 0.1 MPa is 314 kJ / kg. In order to condense 1 t / h of 5 MPa saturated steam, 9 t / h of 0.1 MPa of cooling water is required. As described above, since the flow rate of the cooling water required for the condenser increases, the condenser water cooling system becomes a large-scale system. Furthermore, if there is no facility using the cooling water that has reached about 100 ° C. due to the latent heat from the steam flowing in the condenser, the heat energy absorbed by the cooling water is discarded outside the system. That is, the heat energy of the wet steam including water after heat exchange with heavy oil or mixed fluid cannot be efficiently used.

  Therefore, in the present embodiment, the wet steam 22 after heat exchange in the heat exchanger (heavy oil heat exchanger 4, mixed fluid heat exchanger 13, reforming heat exchanger 40) is supplied to the gas-liquid separator 23. To do. The dry steam 25 separated in the gas-liquid separator 23 merges with the steam generated in the steam drum 41 and is pressurized by the steam compressor 20 driven by the electric motor 24. The dry steam 25 discharged from the steam compressor 20 is superheated by the heat transfer tube 43 of the boiler 10, and then used as the heating steam 21 for the heavy oil heat exchanger 4, the mixed fluid heat exchanger 13, and the reformer heat exchanger. It branches to 42 and is supplied respectively.

  On the other hand, the water 26 separated by the gas-liquid separator 23 is guided to the water circulation pump 7 after being cooled as necessary. The water 26 separated by the gas-liquid separator 23 is branched and supplied to the water high-pressure pump 8 and the heat transfer pipe 46 in the boiler 10 together with the water supplied from the water tank 5 by the water supply pump 6. The water supplied to the water high-pressure pump 8 is further heated by the heat transfer tube 44 and then supplied to the mixer 11. On the other hand, the steam generated by being heated by the heat transfer tube 46 flows into the steam drum 41. The water separated by the steam drum 41 is heated by the heat transfer tube 45 of the boiler 10 and circulates again to the steam drum 41 as steam. The steam separated by the steam drum 41 is combined with the dry steam 25 supplied from the gas-liquid separator 23 and then supplied to the steam compressor 20.

  In this embodiment, the heat source of the boiler 10 uses the exhaust heat gas 34 of the gas turbine. If necessary, the residual oil 19 generated in the reformer 14 can be extracted from the residual oil extraction valve 18 and used as fuel for the boiler 10.

  According to the configuration of the present invention, it is not necessary to convert wet steam, which is a mixed fluid of steam and water after heat exchange, into water with a condenser. Therefore, the thermal energy of the steam in the wet steam can be effectively reused, and the thermal efficiency of the system is greatly improved.

  In the second embodiment of the present invention, portions common to the first embodiment are omitted, and the difference will be particularly described with reference to FIG.

  In this embodiment, a part of the driving force of the gas turbine 30 is used to drive the steam compressor 20. Therefore, in FIG. 2, the rotation shaft of the air compressor 31 is connected to the rotation shaft of the steam compressor 20. By supplying the driving source of the steam compressor 20 from the gas turbine 30, it is possible to improve the thermal power factor of the system as compared to using an electric motor.

  In this embodiment, the mixed fluid heat exchanger 13 is not installed between the mixer 11 and the reformer 14 for mixing the heavy oil 3 and the water 9. Therefore, the residence time required for the reforming reaction is ensured by the heavy oil heat exchanger 4 or the reformer 14. Further, the reformer 14 is not heated by steam but is heated by an electric heater 27. Thus, in this embodiment, since the mixed fluid heat exchanger and the reforming heat exchanger are not provided, the steam system supplied from the boiler 10 to the heat exchanger is only one system to the heavy oil heat exchanger 4. The heating steam system can be simplified.

  An embodiment of a combined cycle power generation system using a heavy oil-fired gas turbine according to the present invention will be described with reference to FIG.

  The heavy oil 3 is supplied from the heavy oil tank 1 to the mixer 11 via the heavy oil heat exchanger 4 by the heavy oil high pressure pump 2. On the other hand, the water 9 used for the reforming reaction is pressurized from the water tank 5 by the water supply pump 6, the water circulation pump 7, and the water high-pressure pump 8 and is supplied to the mixer 11 after being heated to high temperature by the boiler 10. The heavy oil 3 and water 9 supplied to the mixer 11 become a mixed fluid and are supplied to the reformer 14 maintained at 5-30 MPa and 350 to 550 ° C., which is good for the reforming reaction. By heating the reformer 14 with the electric heater 27, the temperature of the reformer 14 can be adjusted independently of the steam system, so that controllability is improved and the system can be simplified.

  In the reformer 14, a part of the heavy oil becomes a reformed fuel lightened by a reforming reaction with water, and the remaining heavy oil becomes a residual oil containing a large amount of vanadium heavy metals. The reformed fuel 15 is depressurized to a pressure suitable for the operation of the gas turbine 30 through the pressure reducing valve 16 and supplied as the fuel 17 for power generation.

  The heating steam 21 used in the heavy oil heat exchanger 4 is supplied after being heated by the boiler 10 from the steam compressor 20, and the wet steam 22 after the heat exchange is supplied to the gas-liquid separator 23. The dry steam 25 separated in the gas-liquid separator 23 is supplied to the steam compressor 20 driven by the electric motor 24 together with the steam generated in the steam drum 41 and used as the heating steam 21 of the heavy oil heat exchanger 4. Recirculate. The power source of the steam compressor 20 can be directly supplied with the power of the gas turbine 30 or the steam turbine 35 instead of the electric motor.

  A part of the steam generated in the steam drum 41 is supplied to the steam compressor 20. The remainder of the steam generated in the steam drum 41 is reheated by the heat transfer tube 47 of the boiler 10 and supplied to the steam turbine 35 as dry steam having a temperature higher than the saturation temperature. The steam flow required for the steam turbine 35 can be controlled by adjusting the flow rate of the residual oil 19 extracted from the exhaust heat gas 34 of the gas turbine and the residual oil extraction valve 18 from the reformer 14. The residual oil 19 can be burned and used as a heat source for the boiler.

  The steam supplied to the steam turbine 35 is used as a drive source for the generator 33. The steam that has lost its thermal energy in the steam turbine 35 joins the water 26 separated in the gas-liquid separator 23 and is supplied to the condenser 36. The water condensed from the steam by the cooling water 37 in the condenser 36 is guided to the water circulation pump 7. The water condensed in the condenser 36 is recirculated together with water supplied from the water tank 5 by the water supply pump 6 as water for supplying steam to the mixer 11 and the steam drum 41.

  According to the configuration of the present embodiment, the steam supplied to the steam turbine 35 can be dry steam having a temperature higher than the saturation temperature, so that the system efficiency of the combined cycle can be improved.

  The fourth embodiment of the present invention will be described with reference to FIG. 4, omitting portions common to the first embodiment and particularly focusing on the differences.

  In the present embodiment, the manufactured reformed fuel 15 is not directly supplied to the gas turbine and burned, but the manufactured reformed fuel is temporarily stored in the reformed fuel tank 39, and the reformed fuel is supplied by piping or a truck. Supply to usable gas turbine power generation facilities. In this embodiment, part of the heavy oil is supplied to the boiler 10 by the boiler fuel pump 38. However, as in the first embodiment, the residual oil 19 can be extracted from the reformer 14 by the residual oil extraction valve 18 and used as fuel for the boiler 10.

  According to the present embodiment, there is an advantage that the boiler system and the gas turbine system can be operated independently.

  According to the present invention, it is not necessary to return wet steam after heat exchange with heavy oil to water by heat exchange with cooling water in a condenser, and heat energy of the wet steam can be effectively reused. Therefore, it is optimal as a recirculation system for heating steam in a heavy oil-fired gas turbine system.

It is a figure which shows the Example regarding the simple system of a heavy oil-fired gas turbine. It is a figure which shows another Example regarding the simple system of a heavy oil-fired gas turbine. It is a figure which shows the Example regarding the combined system of a heavy oil-fired gas turbine. It is a figure which shows another Example regarding the simple system of a heavy oil-fired gas turbine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heavy oil tank 2 Heavy oil high pressure pump 3 Heavy oil 4 Heavy oil heat exchanger 5 Water tank 6 Feed water pump 7 Water circulation pump 8 Water high pressure pump 9,26 Water 10 Boiler 11 Mixer 13 Mixed fluid heat exchanger 14 Reformer 15 Reformed Fuel 16 Pressure Reducing Valve 17 Fuel 18 Residual Oil Drain Valve 19 Residual Oil 20 Steam Compressor 21 Heating Steam 22 Wet Steam 23 Gas-Liquid Separator 24 Electric Motor 25 Dry Steam 27 Electric Heater 30 Gas Turbine 31 Air compressor 32 Combustor 33 Generator 34 Waste heat gas 35 Steam turbine 36 Condenser 37 Cooling water 38 Fuel pump 39 for boiler Reformed fuel tank

Claims (6)

A heavy oil heat exchanger that heats heavy oil with steam;
A reformer that separates the mixed fluid of heated heavy oil and water into reformed fuel and residual oil;
A gas turbine driven by the reformed fuel discharged from the reformer;
A heavy oil-fired gas turbine power generation system including a boiler that generates steam by heating water with exhaust heat gas discharged from the gas turbine,
A gas-liquid separator for separating wet steam after heating heavy oil in the heavy oil heat exchanger into dry steam and water;
A steam compressor to which dry steam separated by the gas-liquid separator is supplied;
A power generation system for a heavy oil-fired gas turbine, comprising a system for supplying dry steam pressurized by the steam compressor to the heavy oil heat exchanger again. A heavy oil heat exchanger that heats heavy oil with steam;
A mixed fluid heat exchanger for heating the mixed fluid of heavy oil and water discharged from the heavy oil heat exchanger with steam;
A reformer for separating the mixed fluid discharged from the mixed fluid heat exchanger into reformed fuel and residual oil;
A gas turbine driven by the reformed fuel discharged from the reformer;
A heavy oil-fired gas turbine power generation system including a boiler that generates steam by heating water with exhaust heat gas discharged from the gas turbine,
A gas-liquid separator that separates wet steam generated after heating heavy oil with the heavy oil heat exchanger and wet steam generated after heating a mixed fluid with the mixed fluid heat exchanger into dry steam and water;
A steam compressor to which dry steam separated by the gas-liquid separator is supplied;
A power generation system for a heavy oil-fired gas turbine, comprising a system for recirculating dry steam pressurized by the steam compressor to the heavy oil heat exchanger and the mixed fluid heat exchanger. A heavy oil-fired gas turbine power generation system according to claim 1,
A power generation system for a heavy oil-fired gas turbine, wherein power of the steam compressor is supplied from the gas turbine. A heavy oil-fired gas turbine power generation system according to claim 1,
A heavy oil-fired gas turbine power generation comprising a system for supplying water separated by the gas-liquid separator to the boiler to generate steam and then recirculating it to the heavy oil heat exchanger system. A heavy oil-fired gas turbine power generation system according to claim 1,
A reforming heat exchanger that heats the mixed fluid in the reformer;
A power generation system for a heavy oil-fired gas turbine, comprising a system for supplying dry steam pressurized by the steam compressor to the reforming heat exchanger. A heavy oil-fired gas turbine power generation system according to claim 1,
A power generation system for a heavy oil-fired gas turbine, comprising a system for supplying residual oil discharged from the reformer to the boiler for combustion.

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