CN102027201A - Electricity generating system using a combined fuel - Google Patents

Abstract

The inventive electricity generating system using a combined fuel comprises a steam boiler (1), a hydrogen high-temperature steam superheater (4), which is provided with a mixing chamber (5) and is coupled, via fuel (hydrogen and oxygen) feeding pipes (15, 16) to hydrogen and oxygen producing units (2, 3), a steam turbine (6) with an electric power generator and a condenser (7), a heat-recovery boiler (8) and pipes and fittings; furthermore, heat exchangers (9, 10), to which pipes (13, 14) removing exhaust gas from the steam boiler are connected, are mounted on the pipes (15, 16) for feeding hydrogen and oxygen to the hydrogen high-temperature steam superheater (4), and a pipe (11) for supplying steam from the steam boiler (1) is connected to the mixing chamber (5).

Description

Power Generation System Using Hybrid Fuels

technical field

This system device relates to the field of power engineering and can be used to generate electricity and heat by using mixed fuels.

Background technique

A similar device is known (see: SHPILREIN EE, MALYSHENKOS.P., KULESHOV GG "Vvedenie v vodorodnuyu energetiku" (Introduction to Hydrogen Power Generation Engineering), Moscow, Energoatomizdat Publishing House, 1984, p. 203, including nuclear reactors, Oxyhydrogen fuel combustor (H ₂ O ₂ -steam generator), steam turbine with generator and condenser, electrolysis unit, hydrogen and oxygen pressure accumulators.

The disadvantages of the above-mentioned devices are that additional energy must be consumed to produce the hydrogen, and large storage tanks are required to store the explosive hydrogen.

The system that is technically closest to the protection of this patent is the power generation system described in the Russian utility model patent No. 54631 dated August 6, 2005, which includes a steam boiler and realizes the function of a hydrogen high temperature steam superheater (HHTSS) H ₂ O ₂ - steam generator, steam turbine with generator and condenser, oxygen and hydrogen production plant (natural gas to hydrogen steam conversion plant) with waste heat boiler from which steam is supplied to said steam turbine the intermediate level.

The disadvantage of the device described in patent No. 54631 is the inability to fully utilize the thermal energy of fuel combustion at the heating power of the steam boiler and the high thermal stress of the mixing chamber downstream of the H ₂ O ₂ -high temperature steam generator.

The purpose of the present invention is to improve operating efficiency, save fuel and enhance the reliability of the power generation system.

Contents of the invention

The essence of the composition of the invention consists in additionally providing a heat exchanger in the known power generation system comprising a steam boiler, a hydrogen high-temperature steam superheater (H ₂ O ₂ -steam generator) with a mixing chamber, which is passed through The supply fuel (hydrogen and oxygen) pipelines are connected to the hydrogen production unit (natural gas to hydrogen steam conversion unit) and oxygen production unit, as well as the steam turbine with generator and condenser, waste heat boiler, pipes and various joint fittings, among which The heat exchanger is installed on the pipeline for supplying fuel (hydrogen and oxygen) to the hydrogen high-temperature steam superheater, the pipeline for the gas leaving the steam boiler is connected to the above pipeline, and for supplying steam from the steam boiler A line is connected to the mixing chamber downstream of the HHTSS.

The use of a natural gas to hydrogen steam conversion system makes it possible to ensure continuous operation of the steam boiler at rated power at high initial temperature and pressure. Due to the combustion of hydrogen with oxygen and water vapor leaving the steam boiler in the HHTSS, the temperature of the water vapor at the inlet of the steam turbine is as high as 1700K-1800K, ensuring that the turbine operates in the typical mode of a gas turbine. The outlet of the steam turbine is connected to a steam condenser ensuring a pressure well below atmospheric, which is very typical for this type of turbine. This provides the possibility to have available heat drop in high temperature steam turbines which is 25%-30% higher relative to gas turbines. The preheating of the hydrogen fuel increases the efficiency of the system, and the cooling of the mixing chamber by the steam from the steam boiler increases the reliability of the system.

Regardless of the fuel type (natural gas, hydrogen, coal, etc.), it is almost impossible to heat water vapor to temperatures above 900K in modern steam boilers due to tube burnout.

Description of drawings

Figure 1 schematically shows the claimed power generation system (hereinafter referred to as "the system").

Detailed ways

The system comprises a steam boiler 1, a natural gas to hydrogen steam conversion unit 2, an oxygen production unit 3, a hydrogen high temperature steam superheater (HHTSS) 4 with a mixing chamber 5, a steam turbine 6 with a generator and a condenser 7, Waste heat boiler 8, heat exchanger 9 for oxygen heating and heat exchanger 10 for hydrogen heating.

The system also includes a line 11 for supplying steam from the steam boiler to the HHTSS 4 and the device 2, a line 12 for supplying steam from the steam boiler to the mixing chamber 5, a line 12 for supplying steam from the steam boiler 1 to the user Line 13 for supplying exhaust gas to heat exchanger 9 for oxygen heating, line 14 for supplying exhaust gas from steam boiler 1 to heat exchanger 10 for hydrogen heating. Furthermore, the HHTSS4 is also connected to the pipelines 15 and 16 for supplying oxygen and hydrogen respectively, the pipeline 17 is used to supply the hydrogen to the boiler 1, the pipeline 18 is used to supply the mixed steam to the turbine 6, and the pipeline 19 is used to supply the steam from the The plant 2 supplies the secondary combustion products to the waste heat boiler 8 from which the line 20 is used to supply steam to the intermediate stages of the steam turbine 6 . The system also includes other equipment and fittings.

The system can operate as follows.

Steam from the steam boiler 1 is supplied to the HHTSS 4 via line 11 and the natural gas to hydrogen steam conversion unit 2 is supplied to the mixing chamber 5 via line 12 and the hydrogen formed is supplied to the HHTSS 4 via line 16 . Oxygen is produced in oxygen production unit 3 , for example by an air separation process, and is fed to the HHTSS via line 15 . Part of the steam from the steam boiler 1 is supplied to the HHTSS 4, where oxygen and hydrogen are combusted in an atmosphere of water vapor. The combustion product, i.e. high temperature water vapor, is supplied to the mixing chamber 5 where it is mixed with another part of the steam from the steam boiler 1 supplied through the line 12, and this steam cools the walls of the mixing chamber 5, thus increasing the efficiency of the system. Reliability and increased steam superheat temperature (no intermediate heat exchange surface). The steam mixture is fed via line 18 to a steam turbine 6 with a generator, thus generating electrical energy. The secondary product of hydrogen production is supplied from the plant 2 via line 19 to a waste heat boiler 8 from which steam is supplied to an intermediate stage of a steam turbine 6 .

Before being supplied to HHTSS4, oxygen and hydrogen are preheated by heat exchangers 9 and 10 respectively installed on line 15 supplying oxygen from plant 3 to HHTSS4 and line 16 supplying hydrogen from plant 2 to HHTSS4. Oxygen and hydrogen are preheated in heat exchangers 9 and 10 by the gas leaving steam boiler 1 fed through lines 13 and 14 .

Utilizing the gases leaving the steam boiler 1 to preheat the oxygen and hydrogen prior to feeding to the HHTSS 4 reduces heat waste and increases overall system operating efficiency.

The steam portion after the steam boiler 1 is fed to the mixing chamber 5 through the line 12, cooling its walls, reducing thermal stress and increasing reliability. Due to the high temperature of the steam supplied from the HHTSS 4 to the steam turbine 6, the power and efficiency of the turbine plant is increased.

The claimed power generation system is capable of keeping the steam turbine running continuously at rated power at high initial temperature and pressure.

The structural features described above enable efficiencies in the production of electrical energy up to 70% relative to the calorific value of hydrogen (see MALYSHENKO S.P., NAZAROV O.V., SARUMOV Yu.A.'s article "Some Theories on Using Hydrogen as Energy Carrier in Power Engineering and Techno-Economic Viewpoints", collected in "Nuclear-Hydrogen Power Engineering and Technology", Energoatomizdat Publishing House, 1988, NO.8, pp. 16-38).

The advantage of the proposed system is also that coal, fuel oil, alternative fuels and renewable energy can be used to generate steam, its initial superheating and preheating of oxygen and hydrogen.

Claims (1)

1. A power generation system utilizing a mixed fuel, comprising: a steam boiler (1); a hydrogen high-temperature steam superheater (4) with a mixing chamber (5), which is passed through a pipeline (15, 16) Connection to means for generating hydrogen and oxygen (2, 3); steam turbine (6) with generator and condenser (7); waste heat boiler (8); piping and fittings; characterized by: Also comprising heat exchangers (9, 10) to which the lines (13, 14) for the gas leaving the steam boiler (1) are connected, said heat exchangers (9, 10) Installed on the lines (15, 16) for supplying hydrogen and oxygen to the hydrogen high temperature steam superheater (4), respectively, the line (11) is connected to the mixing chamber (5).

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