The Natural Gas Co-generation electrification technique of zero carbon emission1. technical field
The present invention provides the Natural Gas Co-generation electrification technique of zero carbon emission, belongs to gas utilization field.
2. background technique
Main clean energy resource one of of the natural gas as the world, it is easy to use, particularly suitable as distributed energy and combustionGas power generation.Natural gas fuel gas is discharged almost without dust (PM2.5), SO2It discharges extremely low, is filled through low NO and denitrating flue gasIt is very low to postpone NOx emission, CO2The discharge of isothermal chamber gas is also the half or so of coal-burning power plant, and environment-friendly advantage is very prominent.
Natural gas fuel power generation is conventional all to use Gas-steam Combined Cycle mode, and combined cycle generation is followed by BrettonRing and Rankine cycle form, and current gas turbine inlet air temperature may be up to 1300 DEG C or more, and 500~600 DEG C of exhaust gas temperature, simplyThermal efficiency of cycle is up to 45%~50%；Waste heat boiler is further recovery waste heat, improves the thermal efficiency, generally double pressures or three pressuresSystem.Especially contemporary 9F grades of integrated gas-steam combined cycle power plant thermals efficiency of large size are up to 58%~60%, are much higher than coal fired power generationThe thermal efficiency.Even if 600MW grades, 1000MW grades units of Thermal generation unit thermal efficiency ultra supercritical, generally 46%~48%, twoThe class unit generation thermal efficiency differs 10~20 percentage points.
Conventional gas cogeneration process is that air is inhaled from the outside atmospheric environment in compressor, and calms the anger by axial-flow typeMachine step by step compression is allowed to be pressurized to 1.5-2.8MPa, while air themperature also correspondinglys increase；Excessive 1.5-2.8MPa compression is emptyGas is pressed to combustion chamber and the natural gas of penetrating is mixed and burned generation high temperature and high pressure flue gas；Then high temperature and high pressure flue gas enters back intoThe expansion work into turbine pushes turbine that compressor and generator is driven to rotate together at high speed, realizes the chemical energy of natural gasIt is partially converted into mechanical work, and exports electric work；High-temp combustion flue gas passes through waste heat steam boiler again and obtains high steam for vapourTurbine power generation, last flue gas pass through denitration after with minimum discharge standard outlet；It is adjusted when peak regulation by gas turbine load variationsIt is whole.In this way, the chemical energy of fuel is just converted into thermal energy by gas turbine, and partial heat energy is transformed into mechanical energy.Usually firingIn gas-turbine, compressor is driven by combustion gas turbine expansion work, it is the load of turbine.In simple cycle, turbineThe mechanical work of sending has 1/2 to 2/3 or so to be used to drive compressor, remaining 1/3 or so mechanical work is used to driven generator.When gas turbine starts, it is necessary first to which exterior power, usually starter drive compressor, until combustion gas turbine issuesMechanical work when being greater than the mechanical work of compressor consumption, extraneous starter tripping, gas turbine itself could work independently.But it is existingHaving natural gas cogeneration technology there is further increasing, compressor compression ratio is difficult, process is complicated, CO2Trapping utilizes costHigh, highly water intensive, generating efficiency needs to be further increased, high fume temperature, NOx decrement are difficult, the cogeneration amplitude of accommodation is small, throwsProvide the defects of high.
3. summary of the invention
The object of the invention is to provide zero carbon row to overcome deficiency existing for conventional natural gas cogeneration technologyThe Natural Gas Co-generation electrification technique put, had both solved that existing natural gas cogeneration technology is highly water intensive, the low problem of generating efficiency；The load of high compression ratio compressor can be greatly lowered again, realize low cost CO2Trapping utilizes, the room temperature without Nox discharges, substantiallyDegree improves generating efficiency；Can also simple flow, reduce investment, improve the adjustable range of cogeneration.
Technical solution of the present invention:
The purpose of the present invention is the liquid oxygen by air separation to be used for expansion power generation for combustion of natural gas power generation and liquid nitrogenWith refrigeration, high-temperature flue gas waste heat production vapor for heat supply and loop temperature-control power generation, flue gas classification cooled dehydrated and CO2SeparationThe series technique of recycling purification etc. couples to improve natural gas cogeneration efficiency, and simple flow reduces investment, improves combustion gas wheelMachine power realizes the clean and effective power generation without NOx pollution, without water consumption, zero carbon emission.It is characterized in that compressor is from ambient atmosphereEnvironment sucks air, and is allowed to be pressurized to 0.5-0.8MPa by axial-flow compressor step by step compression, while air themperature also phaseIt should improve for liquid oxygen or the liquid nitrogen preheating of pressurizeing；Change it is cold after 0.5-0.8MPa forced air enter air separation unit and carry out air pointFrom liquid oxygen and liquid nitrogen being obtained, after the pumping pressurization liquid oxygen of 1.5Mpa or more is by low-temperature flue gas or/and forced air heat exchange vaporizationIt generates electricity for combustion of natural gas, the pressurization liquid nitrogen of pumping pushes nitrogen by low-temperature flue gas or/and forced air heat exchange expansion vaporizationGas turbine generator power generation；High-pressure vaporization oxygen and circulation vapor are mixed with the natural gas of penetrating in the combustion chamber of gas turbineBurning, then high temperature and pressure combustion product gases enter back into expansion work in turbine, and turbine is pushed to drive compressor and generator oneSuperhigh speed rotation, the chemical energy for realizing natural gas is partially converted into mechanical work, and exports electric work；High-temp combustion flue gas passes through againWaste heat boiler generates water vapour, and part vapor is partially used for vapor heat supply as circulation vapor；Low-temperature flue gas after heat exchangeCO is separated with liquid oxygen and liquid nitrogen classification cooled dehydrated and distillation again2, part deviates from water and pressurizes to obtain high pressure water return by water pumpGenerate high-pressure water vapor, remaining water outlet.
Air separation is cryogenic air separation unit, pressure-variable adsorption separates step space division, UF membrane and the deep cooling combined with cryogenic separationSeparate combined one of step space division.
The mass ratio of oxygen and circulation vapor is 1:5-30.
In addition the heat exchange order of liquid oxygen and liquid nitrogen can be exchanged in the present invention.
The present invention carrys out embodiment to describe the features of the present invention in detail.
4. Detailed description of the invention
Attached drawing Fig. 1 is process schematic representation of the invention.
The drawing of attached drawing sets bright as follows:
1, air separation unit 2, gas pressure tank 3, compressor 4, waste heat boiler 5, generator 6, liquid oxygen heat exchanger7, liquid nitrogen-flue gas heat-exchange unit 8, high-pressure hydraulic pump 9, gas turbine 10, liquid nitrogen-air heat exchanger 11, nitrogen turbine generator12, destilling tower 13, liquid oxygen pump 14, liquid nitrogen pump
Process characteristic of the invention is described in detail with reference to the accompanying drawings and examples.
5. specific embodiment
Embodiment,
Air is inhaled from the outside atmospheric environment in the compressor (3) of gas turbine, and presses step by step by axial-flow compressor (3)Contracting is allowed to be pressurized to 0.5-0.8MPa, while air themperature also correspondinglys increase, and send after being cooled down by liquid nitrogen-air heat exchanger (10)Enter air separation unit (1) and carry out air separation, obtain liquid oxygen and liquid nitrogen, liquid oxygen pump (13) the pressurization liquid oxygen of 1.5Mpa or more is used for cigaretteThe heat exchange of gas and combustion of natural gas power generation, liquid nitrogen pump (14) pressurization liquid nitrogen pass through liquid nitrogen-air heat exchanger (10) and liquid nitrogen-cigaretteThe heat exchange of gas heat exchanger, expansion vaporization push outlet after nitrogen turbine generator (11) power generation；High-pressure vaporization oxygen and recirculated water steamThe natural gas that gas and gas pressure tank (2) spray into is mixed and burned in the combustion chamber of gas turbine (9), and then high temperature and pressure is burntFlue gas enters back into expansion work in turbine, pushes turbine that compressor (3) and generator (5) is driven to rotate together at high speed, and realizesThe chemical energy of natural gas is partially converted into mechanical work, and exports electric work；High-temp combustion flue gas passes through waste heat boiler (4) heat exchange againWater vapour is generated, part vapor is partially used for vapor heat supply as circulation vapor；Low-temperature flue gas passes through liquid again after heat exchangeOxygen heat exchanger (6) and liquid nitrogen-flue gas heat-exchange unit (7) and liquid oxygen and liquid nitrogen, which are classified cooling and are dehydrated and distill by destilling tower (12), to be dividedFrom CO2, partially deviate from water by high-pressure hydraulic pump (8) pressurization and obtain high pressure water return generation high-pressure water vapor, remaining water outlet.
Air separation is cryogenic air separation unit, pressure-variable adsorption separates step space division, UF membrane and the deep cooling combined with cryogenic separationSeparate combined one of step space division.
The mass ratio of oxygen and circulation vapor is 1:5-30.
According to Aspen analog result, the Natural Gas Co-generation electrification technique of zero carbon emission combines hair with conventional natural gasPower technology is compared, and compressor compression ratio is higher, and new process advantage is more obvious.
The Natural Gas Co-generation electrification technique of zero carbon emission provided by the present invention passes through sky by Aspen analog resultCurrent compressor compression ratio is dropped to 5-8 by 15-28 or so by separating device liquid oxygen liquid nitrogen low energy consumption pumping pressurization, makes Natural GasEnergy consumption of the turbine for compressor falls below 10% or so by 1/2-2/3；Natural gas and high-pressure steam mixing, oxygen helpCombustion power generation, flue gas specific volume increase, gas turbine power generation efficiency and the opposite raising of power；High-temperature flue gas heat exchange generates vapor and is used forCirculating temperature-regulating power generation and heat supply, exhaust gas temperature drop to 60 DEG C or so by current 140 DEG C or so, and energy recovery rate greatly improves, cigaretteGas is easy to low cost and is dehydrated isolated CO2, CO2Trapping energy consumption is greatly lowered；Burning generates water section circulation and is used for combustion gas wheelMachine temperature control and cogeneration use high pressure water closed cycle to dissolve the highly water intensive problem of natural gas power, are particularly suitable for northwest water shortageArea；Gas turbine comburant oxygen and water steam temperature control avoid the NOx emission, substantially of current Natural Gas Power Plant flue gasDegree reduces the discharge of flue dust, realizes the power generation of zero carbon emission of natural gas clean and effective；Nitrogen vaporized expanding turbine generation simultaneouslyMachine generates electricity and is used for space division air cooling, and water circulation and the pumping pressurization of liquid oxygen liquid nitrogen, considerably reduce internal system in additionEnergy consumption, system net generating efficiency are greater than 60%, and it is 0-50% that heat supply ratio, which is expanded, and investment is sent out with conventional natural gas-Steam CombinedElectric installation is compared to 20% or more reduction.