CN102900528A - Self power consumption reduction method of double-working-medium combined cycle turbine - Google Patents

Abstract

The invention relates to the technical fields of gas turbines and steam turbines, namely a method for reducing the self-consumption work of a gas turbine by a dual-mass combined cycle turbine. It is to replenish the liquid working medium to the combustion chamber, so that the liquid working medium undergoes a phase change, reduces fuel consumption, replaces low-density air, reduces the compression work consumption of the compressor, and provides the remaining shaft work to the load. The compressor only needs to provide a sufficient amount of oxygen supply air for the fuel according to the "gas-fuel ratio", and only needs 20~25% of the turbine work, and the remaining 75% of the shaft work is fully provided to the load. Supplement the liquid working medium, the liquid second working medium absorbs the heat of vaporization in the dual-mass turbine, replaces the low-density air to cool the combustion chamber and impeller, the fuel consumption rate is doubled, and the oxygen supply ratio is also reduced in the same proportion , the compression work consumed by the compressor is naturally reduced in proportion, reducing self-consumption work and improving mechanical efficiency are the purposes of the present invention.

Description

Method for reducing self-consumption power of dual-mass combined cycle turbine

technical field

The invention relates to the technical fields of gas turbines and steam turbines, that is, a dual-mass combined cycle turbine method for eliminating thermal damage, improving thermal efficiency, and reducing self-consumption work for gas turbines. It is suitable for the power source of large and small walking machines and table machines on land and water.

Background technique

In the prior art, because: "'heat' cannot be directly converted into mechanical work, and must be aided by working fluid". "Heat~working medium-mechanical work", the source of "heat" is the calorific value of the fuel, which is a fixed value; "working medium" is the medium for converting heat and work, and it is precisely fixed by the "gas-fuel ratio" and the structure of the engine. A fixed value; "mechanical work" is to convert fixed "heat" with a fixed "working medium", and the result of "mechanical work" must also be a fixed value.

Therefore, the result obtained by converting a fixed value into a fixed value must be a fixed value, which is the fundamental reason why the thermal efficiency of thermomechanical machinery cannot be improved.

The engine of the closed combustion mode can only utilize the chemical energy of the first step, and the energy after the second step can only be discharged into the atmosphere as "residual heat" to do useless work.

The open combustion engine does not have the equipment conditions to utilize and transform the energy of the first step, and can only use the physical energy of the second step to discharge the heat energy after the first step and the third step for free, doing useless work.

Gas turbine: low thermal efficiency, serious thermal damage, large self-consumption, high material selection requirements, high manufacturing cost, and limited practical application. A. Thermal efficiency: 18~38%. B. Working temperature: 1340~1430℃ (gas index). C. The concept of improving thermal efficiency is: to increase the working temperature as much as possible, and to increase the flow rate of the working medium by increasing the "specific volume" of the working medium. D. The impeller and combustion chamber must be made of advanced high temperature resistant materials.

Cheng's cycle: Brayden cycle and Rankine cycle are completed in parallel in a gas turbine.

A. Thermal efficiency: ≈53%. B. The second working fluid completes the phase change in the waste heat boiler. C. The steam (and gas) is added into the combustion chamber in the state of equal pressure. D. The potential energy of phase change can only be utilized after storage and transport decay. E. The waste heat boiler and supporting facilities take up a huge space. F, waste heat recovery and reuse.

Two-machine combined cycle thermal unit: the gas turbine and the steam turbine share a fuel energy and use two different working fluids. Complete the Brayden cycle and the Rankine cycle respectively, and make output work respectively. Dual machine thermal efficiency: ≈55%. Not suitable for small machinery and walking machinery.

Internal combustion engine: "gas-fuel ratio" is to ensure the precise ratio of oxygen supply requirements for complete oxidation of hydrocarbons, rather than to ensure precise "working fluid requirements" for "thermal power conversion". A. Thermal efficiency of gasoline engine: 27~30%, thermal efficiency of diesel engine: 37~42%. B. A single working substance completes a single cycle. C. The inertia of the piston connecting rod group is large, the operation vibration is large, the noise is large, the failure rate is high, and the maintenance cycle is short. D. The forced cooling system loses 30% of the heat, and the exhaust gas carries away 30% of the heat, making useless work. How to realize the regulation of the total amount of working fluid is the key to eliminate thermal damage and improve thermal efficiency.

In order to improve thermal efficiency, the gas turbine blindly increases the working temperature, causing serious thermal damage; in order to reduce thermal damage, the compressor needs to provide a large amount of cooling air, which greatly increases the burden on the compressor. The huge compressor of the gas turbine consumes about 65% of the turbine work, and only about 30% is used as effective mechanical work. 60~70% of the compressed air provided by the compressor is used as a cooling medium, and the other 30% is used to provide oxygen for fuel combustion.

Contents of the invention

The object of the present invention is to provide a kind of gas, water as working fluid, two different working fluids are connected in series in a turbine to complete the Brayden cycle and the Rankine cycle in order to improve thermal efficiency. A method for reducing self-consumption power of a turbine.

The technical solution of the present invention is: the method of reducing the self-consumption work of the gas turbine by the dual-phase combined cycle turbine is to spray hot water at the interface temperature to the outer wall of the combustion chamber (longitudinal corrugated isolation plate) and absorb the outer wall of the combustion chamber (longitudinal corrugated isolation plate) The heat of the combustion chamber undergoes a phase change and replaces the low-density air to cool the combustion chamber; a significant reduction in fuel consumption also reduces the demand for oxygen supply in the same proportion, further reducing the compression work of the compressor. Water has 100°C water and 100°C steam under an atmospheric pressure environment, and this 100°C is the interface temperature of water under an atmospheric pressure environment, and the interface temperature of water changes with changes in the pressure environment.

The compressor only needs to provide a sufficient amount of oxygen supply air for the fuel according to the "gas-fuel ratio", and only needs 20~25% of the turbine work, and the remaining ≈75% of the turbine work is fully provided to the load.

The way to reduce the self-consumption work of gas turbines in dual-phase combined cycle turbines is to supplement high-density liquid working fluids to replace low-density gaseous working fluids, and use "residual heat" to cause phase changes in liquid working fluids to reduce the compression work of the compressor. Water with a small specific volume completely replaces air with a large specific volume to cool down the combustion chamber and turbine impeller, without compressing the cooling medium, and only providing a little delivery power.

The second working fluid is fed into the phase change chamber at the temperature of the vapor-liquid interface to cool the parts and undergo phase change at the same time.

Because the second working medium of the dual-mass turbine replaces a large amount of "gas" that consumes fuel, the fuel consumption rate is reduced and the fuel supply is reduced. Therefore, the demand for oxygen supply is also reduced in the same proportion, and the compressed gas can be further reduced. Compression power of the machine.

The two turbine engines with different combustion methods are simplified into one turbine, and two different working fluids are connected in series in one turbine to complete the Brayden cycle and the Rankine cycle.

"Combustion potential energy" is the irreversible potential energy in the chemical reaction process of fuel combustion. The energy absorbed and transformed in this chemical reaction process is set as the chemical energy of the "first step". "Phase change potential energy" uses the remaining heat of "combustion potential energy" to perform thermal work conversion, which is the "second step" reversible physical energy. The "heat" in the exhaust gas is set as "third step energy", and the emitted The energy in the dual qi is set to "fourth step energy"...

The heat energy with low heat density is gradually carried back (rather than transferred) by the second working fluid from the low-temperature heat source to the high-temperature heat source, and then absorbs the heat of the high-temperature heat source on the outer wall of the combustion chamber (corrugated partition), completes the phase change, generates phase change potential energy, and directly acts as Useful work.

The annular combustor and the phase change chamber are the complementary equipment conditions for the dual-mass turbine to convert the chemical energy of the first step and the physical energy of the second step and beyond in the fuel energy at the same time.

The working fluid of the dual-mass combined cycle turbine adopts gas and water (only water, economical, pollution-free, and low calorific value, but not absolutely limited to water, and can also be other working fluids, such as: Freon, liquid ammonia, etc. Liquid material.), gas and water enter separately in the combustion chamber; the second working medium, water, is combined with the gas as wet steam after a phase change in the phase change chamber, temperature control, and work, so that the total amount of working medium can be adjusted. The second working medium, water, is fed into the phase change chamber at the temperature of the vapor-liquid interface, and the phase change occurs while cooling the parts.

The dual-mass combined cycle turbine (abbreviation: dual-mass turbine) completes the Brayden cycle based on the structure and working principle of the gas turbine, and completes the Rankine cycle in the turbine of the gas turbine based on the working principle of the steam turbine. The two turbine engines with different combustion methods are simplified into one turbine, and two different working fluids are used in series in one turbine to complete the Brayden cycle and the Rankine cycle. In the dual-mass turbine: the adiabatic compression process and the constant pressure heating and constant pressure heat absorption process are completed separately; the adiabatic expansion process and the constant pressure heat release process are completed together in the same turbine.

"Adjustable total amount of working fluid" is a new idea to control "thermal power conversion capacity". The Brayden cycle and the Rankine cycle are completed in series in a turbine. Using a variable working medium to convert a fixed value of fuel internal energy and controlling the utilization rate of heat energy can make the thermal efficiency ≥ 60% (because: "'heat' cannot be directly converted into mechanical work, it must be used with the help of working medium." To improve the total working medium Quantity instead of increasing the specific volume of working medium,). Working temperature: the lowest can be adjusted to 480°C (water is a low-calorie substance, the latent heat of phase change is very large, and the potential energy of phase change is very strong). The impeller and combustion chamber are made of common high temperature and acid resistant materials. The second working fluid is fed into the phase change chamber at the temperature of the vapor-liquid interface. The phase change is completed in the phase change chamber with the pressure peak of the gas potential energy as its pressure starting point. No piston inertia, high speed, low failure rate, long maintenance cycle, good continuous operation characteristics.

The advantages of the present invention are:

1. The dual-mass turbine supplements the high-density liquid working medium to replace the low-density gaseous working medium, uses "residual heat" to make the liquid working medium undergo a phase change, reduces the compression work of the compressor, and completely replaces the large volume of water with small specific volume. The specific volume of air cools the combustion chamber and turbine impeller, without compressing the cooling medium, and only provides a little delivery power. The dual-mass turbine only needs the compressor to provide sufficient oxygen supply air for the fuel according to the "gas-fuel ratio".

2. Because the second working medium of the dual-mass turbine replaces a large amount of "gas" that consumes fuel, the fuel consumption rate is reduced and the fuel supply is reduced. Therefore, the demand for oxygen supply is also reduced in the same proportion, and further Reduce the compression work of the compressor.

3. Compared with gas turbines, dual-mass turbines: high thermal efficiency, eliminate thermal damage, meet the highest emission standards, easy material selection, and low manufacturing cost. Duplexes are available in Ultra Micro, Micro, Small, Neutral, Heavy, Super Heavy, Super Super Heavy. Thermal efficiency: ≥60%. Working temperature: the lowest can be adjusted to 480°C (dual gas balance index). The impeller and combustion chamber can be made of ordinary high temperature and acid resistant materials.

4. Comparison between dual-mass turbine and "Cheng's cycle": Brayden cycle and Rankine cycle are completed in series in one turbine. Thermal efficiency: ≥60%. The second working fluid is fed into the phase change chamber at the temperature of the vapor-liquid interface, and the phase change is completed in the phase change chamber. The peak of gas pressure is the starting point of phase change potential energy pressure, which reflects the strong utilization. The second working fluid supply system takes up little space. A combination of direct and recovery uses waste heat.

5. Comparison between the dual-mass turbine and the "two-machine combined cycle thermal unit": in one turbine, the combustion potential energy is used to complete the Brayden cycle, and the phase change potential energy is used to complete the Rankine cycle. Single machine output mechanical power. Stand-alone thermal efficiency: ≥60%. It is suitable for the power source of large and small walking machines and table machines on land and water.

6. Comparison between dual mass turbine and internal combustion engine: the total amount of working medium can be adjusted. Thermal efficiency: ≥60%. "Dual mass" combined cycle in one turbine. No piston inertia, high speed, low failure rate, long maintenance cycle, good continuous operation characteristics. The second working fluid is the phase change that occurs while the components are cooling. There is no forced cooling system, and the exhaust gas is not directly discharged, so that useless work becomes useful work.

7. Emissions: The combustion temperature of any heat engine is very high, and the hot spots are all above 2000°C. In a high-heat hot environment, carbon dioxide may be pyrolyzed for the second time to generate carbon monoxide and oxygen, and nitrogen can be oxidized to generate nitrogen Oxygen compounds. The dual-quality machine adopts low-temperature combustion technology, and there is always no hot spot, which is low-carbon and environmentally friendly.

8. A large amount of water vapor in the dual-mass machine replaces the gas (which needs to consume fuel), so that the fuel consumption rate is reduced, and the carbon dioxide emission is also reduced in the same proportion, which is low-carbon and environmentally friendly.

9. The dual-mass turbine greatly increases the total quality of the working medium, and the second working medium cools down the parts and undergoes a phase change at the same time. The gas temperature is suitable for regulation at 1300±50°C. Not only eliminate heat damage, but also prevent the generation of harmful gases.

Embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. the

Description of drawings

Figure 1 is a schematic diagram of the overall structure of a dual-mass combined cycle turbine.

Fig. 2 is a schematic diagram of the cross-sectional structure of the longitudinal corrugated insulation board. the

Detailed ways

The energy-saving concept of dual-mass turbines is to increase the total amount of working fluid converted from thermal work as much as possible. If you want to improve the thermal power conversion capacity of the heat engine, if it is meaningless to change the calorific value of the fuel, you must change the "working medium".

The dual-mass turbine supplements the high-density liquid working medium to replace the low-density gaseous working medium, uses "residual heat" to make the phase change of the liquid working medium, reduces the compression work of the compressor, and completely replaces the large specific volume with water of small specific volume The air cooled by the combustion chamber and the turbine impeller does not need to compress the cooling medium, but only provides a little delivery power.

The dual-mass turbine only needs the compressor to provide sufficient oxygen supply air for the fuel according to the "gas-fuel ratio".

Cancel the compression work of cooling air and reduce the compression work required for supply. The final demand for compression work is very small, accounting for only about 17% of the turbine work, plus 3~5% of the delivery work required by the second working fluid supply system , the total demand for all self-consumption power accounts for about 20-25% of the turbine work. The remaining about 75% of the shaft work can be fully provided to the load.

See Figures 1 and 2, the names of the components are as follows: Turbine and shaft 1, compressor impeller 2, compressor blade 3, compressor housing 4, lubricating oil inlet 5, fuel inlet 6, infrared grill 7, oil and water nozzle Middle body 8, fuel injection nozzle 9, exhaust port 10, water nozzle 11, water nozzle gland 12, annular combustion chamber 13, phase change chamber 27; Annular combustion chamber, phase change chamber have separating plate 14 therebetween, be separated into Combustion chamber 13 and phase change chamber 27; Annular chamber one end has annular fuel injector 9 and annular water nozzle 11, and annular injector 9 communicates with combustion chamber 13; Annular water nozzle 11 communicates with phase change chamber 27; The other end of the chamber steam and gas are combined and blown to the turbine blades 17 through the deflector.

The dual working medium combined cycle turbine includes a moving part, a fuel supply system, a second working medium supply system, an electrical system, a lubrication system, and a load. The specific experimental structure is: it includes the left turbine and the shaft 1, the right turbine, and the turbine blade 17; the left turbine and the shaft 1 have the compressor impeller 2, the compressor blade 3, and the compressor housing 4; there is an annular combustion chamber in the turbine housing 13. Phase change chamber 27; the combustion chamber and the phase change chamber include an annular chamber, and there is a separation plate 14 between the annular chambers, separating the combustion chamber 13 and the phase change chamber 27; one end of the annular chamber is provided with an annular oil nozzle 9 and an annular water spray The nozzle 11 and the annular oil nozzle 9 communicate with the combustion chamber 13; the annular water nozzle 11 communicates with the phase change chamber 27; the steam and gas at the other end of the annular chamber meet and blow to the turbine blades 17 through the blocking flow.

The isolation plate 14 is a corrugated plate (inverted cone shape) with a large contact area. The fuel injector 9 has a cone angle of 45°. In front of the fuel injection nozzle 9 at the entrance of the combustion chamber 13, an infrared grill 7 is arranged. The combustion chamber 13 is an annular conical longitudinal corrugated space. The phase change chamber 27 is an inverted cone longitudinal corrugated space between the combustion chamber wall separation plate 14 and the phase change chamber wall 25 .

Referring to FIG. 2 , the combustion chamber 13 and the phase change chamber 27 are separated by a longitudinal corrugated isolation plate 14 , and the isolation plate 14 is both the outer wall of the combustion chamber 13 and the inner wall of the phase change chamber 27 .

The compressor delivers air around the circumference. The fuel injectors are annular, with a 45° cone angle and a circular spray. The narrow annular compressed air channel is connected to the narrow annular inlet of the annular combustion chamber 13 . The combustion chamber 13 can be divided into two types: direct combustion type and infrared type. Direct combustion type: the fuel is sprayed to the narrow annular inlet of the combustion chamber 13 at a close distance with a cone angle of 45o, and the fuel starts to burn at the inlet; between burning. Combustion chamber 13 is "annulus conical longitudinal corrugation space". The phase change chamber 27 is an "inverted cone longitudinal corrugated space" between the corrugated plate on the outer wall of the combustion chamber 13 and the outer wall 25 of the cylindrical phase change chamber.

The combustion process of the gas and the phase change process of the second working substance are independently completed in the same pressure space, without directly absorbing the heat of vaporization from the gas, and not affecting the normal combustion of the fuel.

The heat energy with low heat density is gradually recovered by the second working fluid and brought back (rather than transferred) to the high-temperature heat source, and then absorbs the heat from the corrugated insulation plate 14 on the outer wall of the combustor to complete the phase change, generate phase change potential energy, and directly perform useful work.

The engine of the closed combustion mode can only utilize the chemical energy of the first step, and the energy after the second step can only be discharged into the atmosphere as "residual heat" to do useless work.

The open combustion engine does not have the equipment conditions to utilize and transform the energy of the first step, and can only use the physical energy of the second step to do useless work for the free discharge of heat energy after the first step and the third step.

The annular combustor and the phase change chamber are the complementary equipment conditions for the dual-mass turbine to convert the chemical energy of the first step and the physical energy of the second step and beyond in the fuel energy at the same time. the

Working process: 1. Start: When starting, first disconnect the load, turn on the power of the igniter, and start the turbine rotor with compressed air (or electric motor). When the rotation speed reaches 8,000~10,000 rpm, quickly open 40% of the gas (gas is replaced by liquefied gas) valve, preheat the operation, and fully open the liquefied gas valve at the right time. The gas enters the annular fuel injector 9 from the fuel inlet 6; the compressed air is supplied by the compressor, mixed at the annular injector 9, (ignited by electric spark) directly enters the annular combustion chamber 13 for combustion, and the gas heats the longitudinal corrugated isolation plate 14 ; 2. After 30 to 40 seconds of running preheating, start the second working fluid supply system, open the valve in a small amount, allow a small amount of water to enter the phase change chamber 27, and cool the combustion chamber isolation plate 14 to undergo a phase change at the same time; 3. Wet steam and The gas enters the double gas channel at the outlet of the longitudinal corrugated isolation plate 14 for mixed heat exchange: 4. The cold water previously filled in the water storage tank (heat exchanger) enters the invisible heat exchanger 19 through the cold water inlet 26 to absorb the heat of the exhaust gas, Further heating, the warm water outlet 20 enters the cooling water jacket of the combustion chamber, absorbs the heat of the inner wall of the combustion chamber, reaches the temperature of the vapor-liquid interface, and hot water enters the annular water nozzle 11 through the inlet 24, and sprays to the longitudinal corrugated isolation through the annular water nozzle 11 The plate 14 cools the annular combustion chamber 13 and undergoes a phase change at the same time, and the water vapor that undergoes a phase change enters the dual gas channel from the exhaust port 10 through the steam-water separator; 5. The wet steam mixes with the gas at the outlet of the isolation plate 14 for heat exchange , the superheated steam and gas are mixed and exchanged by the turbulent flow of the swirl guide plate 16, and after being accelerated, they are blown to the turbine blade 17 together; 17 a reaction force; 7. The turbine work drives the compressor impeller 2 to provide compression work for the compressor through the turbine, turbine and shaft 1, and at the same time drives the load to perform shaft work.

Claims (2)

1. a Double working medium combination circulate turbomachine reduces gas turbine from the wasted work method, it is characterized in that spraying to outer wall of combustion chamber the hot water of interface temperature, and the heat that absorbs outer wall of combustion chamber undergoes phase transition, and to replace low-density air be the firing chamber cooling; The decrease oil consumption rate also just reduces the oxygen supply demand in proportion, further reduces the compression work of gas compressor.

2. reduce gas turbine from the wasted work method according to claim 1 or 2 described Double working medium combination circulate turbomachines, it is characterized in that gas compressor only needs to provide capacity oxygen supply air by air-fuel ratio for fuel, only need 20 ~ 25% turbine merit, all the other turbine merits offer load fully.

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