CN114922705A - Shunting recompression supercritical carbon dioxide circulating system and method - Google Patents
Shunting recompression supercritical carbon dioxide circulating system and method Download PDFInfo
- Publication number
- CN114922705A CN114922705A CN202210421888.0A CN202210421888A CN114922705A CN 114922705 A CN114922705 A CN 114922705A CN 202210421888 A CN202210421888 A CN 202210421888A CN 114922705 A CN114922705 A CN 114922705A
- Authority
- CN
- China
- Prior art keywords
- pressure
- medium
- compressor
- pressure turbine
- regenerator
- 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.)
- Granted
Links
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 title claims abstract description 47
- 229910002092 carbon dioxide Inorganic materials 0.000 title claims abstract description 23
- 239000001569 carbon dioxide Substances 0.000 title claims abstract description 23
- 238000000034 method Methods 0.000 title claims abstract description 16
- 239000002918 waste heat Substances 0.000 claims description 13
- 239000007789 gas Substances 0.000 claims description 11
- 230000000087 stabilizing effect Effects 0.000 claims description 9
- 238000001816 cooling Methods 0.000 claims description 6
- 239000002826 coolant Substances 0.000 claims description 3
- 238000004891 communication Methods 0.000 claims description 2
- 238000004064 recycling Methods 0.000 claims description 2
- 238000005482 strain hardening Methods 0.000 claims 1
- 238000013461 design Methods 0.000 abstract description 3
- 238000010438 heat treatment Methods 0.000 description 7
- 230000002411 adverse Effects 0.000 description 3
- 230000006835 compression Effects 0.000 description 3
- 238000007906 compression Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000010248 power generation Methods 0.000 description 2
- 230000000754 repressing effect Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000001172 regenerating effect Effects 0.000 description 1
- 230000000153 supplemental effect Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Images
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
- F01K7/00—Steam engine plants characterised by the use of specific types of engine; Plants or engines characterised by their use of special steam systems, cycles or processes; Control means specially adapted for such systems, cycles or processes; Use of withdrawn or exhaust steam for feed-water heating
- F01K7/32—Steam engine plants characterised by the use of specific types of engine; Plants or engines characterised by their use of special steam systems, cycles or processes; Control means specially adapted for such systems, cycles or processes; Use of withdrawn or exhaust steam for feed-water heating the engines using steam of critical or overcritical pressure
-
- 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
- F01K11/00—Plants characterised by the engines being structurally combined with boilers or condensers
- F01K11/02—Plants characterised by the engines being structurally combined with boilers or condensers the engines being turbines
-
- 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
- F01K13/00—General layout or general methods of operation of complete plants
-
- 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
- F01K25/00—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for
- F01K25/08—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for using special vapours
- F01K25/10—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for using special vapours the vapours being cold, e.g. ammonia, carbon dioxide, ether
- F01K25/103—Carbon dioxide
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D25/00—Pumping installations or systems
- F04D25/16—Combinations of two or more pumps ; Producing two or more separate gas flows
-
- 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
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/40—Solar thermal energy, e.g. solar towers
- Y02E10/46—Conversion of thermal power into mechanical power, e.g. Rankine, Stirling or solar thermal engines
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Combustion & Propulsion (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engine Equipment That Uses Special Cycles (AREA)
Abstract
The invention provides a shunting repressurization supercritical carbon dioxide circulating system and a method, which are reasonable in design, can conveniently adjust the total circulating flow, realize quick response and reduce the total load. The system comprises an external heat source, a shunt recompression loop, a high-pressure work doing loop and a medium-pressure work doing loop which are connected in parallel; the high-pressure work doing loop comprises a high-pressure compressor, a cold side of a high-pressure primary heat regenerator, a cold side of a high-pressure secondary heat regenerator and a high-pressure turbine unit which are connected in sequence; the medium-pressure working loop comprises a medium-pressure compressor, a cold side of a medium-pressure heat regenerator, a three-way valve and a medium-pressure turbine set which are sequentially connected; the exhaust side of the medium-pressure turbine unit is sequentially connected with the hot side of the high-pressure primary regenerator and the hot side of the medium-pressure regenerator; the exhaust side of the high-pressure turbine unit is sequentially connected with the hot side of the high-pressure secondary heat regenerator and a three-way valve; the input end of the shunt recompression loop is connected with the hot side outlet of the medium-pressure heat regenerator, and the output end of the shunt recompression loop is respectively connected with the input ends of the high-pressure compressor and the medium-pressure compressor.
Description
Technical Field
The invention relates to the technical field of supercritical carbon dioxide cycle power generation, in particular to a shunting and repressing supercritical carbon dioxide cycle system and a method.
Background
With the development of power generation technology, supercritical carbon dioxide as an excellent working medium replacing water vapor enters the field of many researchers due to higher cycle efficiency, more compact equipment arrangement and more economical early investment. The split-flow repressurization type circulation mode of the main system by using the double compressors is also embodied and verified in a plurality of papers and patents.
However, in the prior art, for a small test platform only suitable for kW class, if a parameter such as MW class generated power is further realized, the conventional split-flow repressurization mode has many unreasonable places. The existing serial circulation has three problems of limitation on total flow, adverse influence on compression efficiency caused by the temperature of an inlet of a medium-pressure (re-) compressor and large fluctuation of the pressure of the inlet of the compressor under the condition of system pressure, and the circulation requirement of higher power level cannot be met.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides the shunting recompression supercritical carbon dioxide circulation system and the method, which are reasonable in design, can conveniently adjust the total circulation flow, realize quick response and reduce the total load.
The invention is realized by the following technical scheme:
a flow-dividing recompression supercritical carbon dioxide circulating system comprises an external heat source, a flow-dividing recompression loop, a high-pressure work doing loop and a medium-pressure work doing loop which are connected in parallel;
the high-pressure work doing loop comprises a high-pressure compressor, a cold side of a high-pressure primary heat regenerator, a cold side of a high-pressure secondary heat regenerator and a high-pressure turbine unit which are connected in sequence; the medium-pressure working loop comprises a medium-pressure compressor, a cold side of a medium-pressure heat regenerator, a three-way valve and a medium-pressure turbine set which are sequentially connected; the exhaust side of the medium-pressure turbine unit is sequentially connected with the hot side of the high-pressure primary regenerator and the hot side of the medium-pressure regenerator; the exhaust side of the high-pressure turbine unit is sequentially connected with the hot side of the high-pressure secondary heat regenerator and a three-way valve;
the input end of the shunt recompression loop is connected with the hot side outlet of the medium-pressure regenerator, and the output end of the shunt recompression loop is respectively connected with the input ends of the high-pressure compressor and the medium-pressure compressor;
the external heat source is arranged between the cold side of the high-pressure secondary heat regenerator and the high-pressure turbine set, and between the three-way valve and the medium-pressure turbine set.
Optionally, the three-way valve is in one-way communication with both the hot side of the high-pressure secondary regenerator and the cold side of the medium-pressure regenerator to the medium-pressure turbine set.
Optionally, the external heat source includes a superheater for performing primary heat exchange and a reheater for performing secondary heat exchange, and the superheater is disposed between a cold side of the high-pressure secondary reheater and the high-pressure turbine unit; the reheater is arranged between the three-way valve and the intermediate-pressure turbine set.
Optionally, the front of the inlet and the back of the outlet of the high-pressure turbine unit are connected with a high-pressure inlet and outlet pipeline through a high-pressure turbine bypass, and the front of the inlet and the back of the outlet of the medium-pressure turbine unit are connected with a medium-pressure inlet and outlet pipeline through a medium-pressure turbine bypass.
Optionally, the split-flow recompression loop comprises a waste heat utilization system, a cooler, a constant pressure pump, a surge tank and an air supply source arranged on a pipeline between the cooler and the constant pressure pump, wherein the waste heat utilization system, the cooler, the constant pressure pump and the surge tank are sequentially connected.
A method for recycling supercritical carbon dioxide by sub-flow recompression comprises,
before the unit is started in a cold state, filling a cold-state filling working medium into the whole pipeline of the supercritical carbon dioxide circulation system by the split-flow repressurization loop;
after the filling is finished, the highest pressure of the main system is adjusted by the high-pressure compressor, and the output of the medium-pressure compressor is adjusted by the medium-pressure compressor according to the pressure at the outlet of the hot side of the high-pressure secondary heat regenerator; controlling the inlet pressure of the high-pressure compressor and the inlet pressure of the medium-pressure compressor to be constant through the flow-dividing recompression loop;
an external heat source is thrown in to gradually raise the temperature of the system; when the back pressure of an external heat source in the medium-pressure work-applying loop is 5-7 MPa and the outlet temperature is increased to 180 ℃, the medium-pressure turbine set is switched to an operation state from a hot standby state; after the medium-pressure turbine set is connected to the grid, the high-pressure turbine set is switched to an operation state from a hot standby state;
gradually increasing the power of an external heat source, increasing the enthalpy value of the system, and controlling the working media at the inlets of the high-pressure compressor and the medium-pressure compressor to reach a stable working condition through the shunting repressurization loop by taking the temperature threshold value of the outlet at the hot side of the medium-pressure heat regenerator as reference; until the parameters of the high-pressure turbine set and the medium-pressure turbine set reach the set threshold values.
Optionally, the controlling of the split-flow recompression loop specifically includes,
a supplementary gas source is used as a cold-state working medium filling gas source;
the pressure of the pressure stabilizing tank is adjusted through the constant pressure pump, and the inlet pressure of the high-pressure compressor and the inlet pressure of the medium-pressure compressor are stabilized to be constant;
the flow of the cooling medium in the system is adjusted through the waste heat utilization system and the cooler, the temperature in front of the constant pressure pump is stabilized, and the temperature and the pressure of the working medium at the inlets of the high-pressure compressor and the medium-pressure compressor are indirectly stabilized.
Optionally, the stable working condition is that the temperature of the inlet working medium is 35 ℃ +/-3 ℃, and the pressure is 7.3MPa +/-0.2 MPa.
Optionally, during shutdown, only the output of an external heat source needs to be reduced, the total enthalpy value of the system is reduced, and the waste heat utilization system is gradually withdrawn or the flow of a cooling medium of a cooler is adjusted according to the enthalpy value change rate;
the output of the high-pressure compressor is preferentially reduced, the total flow of the system is reduced, the pressure of the medium-pressure system is stabilized by adjusting the pressure of the medium-pressure compressor tracking the hot side of the high-pressure secondary heat regenerator and the pressure of the three-way valve, and the load of the high-pressure turbine unit and the load of the medium-pressure turbine unit are gradually reduced.
Optionally, after the high-pressure turbine unit and the medium-pressure turbine unit quit operation, the system operates through the high-pressure bypass and the medium-pressure bypass, and a cooling source is provided for an external heat source under an accident condition.
Compared with the prior art, the invention has the following beneficial technical effects:
according to the invention, the traditional series connection mode of the high-pressure compressor and the medium-pressure compressor is modified into a parallel connection mode, so that the disturbance among systems is reduced; the waste heat working medium after heat exchange of the high-pressure secondary heat regenerator is directly recycled by using the three-way valve when in operation, so that the unification and coordination of the system are realized; in the operation process, the total circulation flow of the system can be adjusted by independently adjusting the output of the medium-pressure compressor, the total load can be reduced by adjusting the output of the high-pressure compressor and reducing the air intake and exhaust volume of the high-pressure turbine set, the quick response of the load adjustment is realized, and the problem of limitation of the serial connection type circulation on the total flow is solved.
Furthermore, the design of controlling the parallel connection by the method of the invention ensures that the high-pressure compressor and the medium-pressure compressor both operate at a lower temperature slightly higher than the liquid phase temperature, greatly improves the working efficiency of the medium-pressure compressor, indirectly improves the work-doing capacity of the medium-pressure turbine set, and avoids the adverse effect of the inlet temperature of the medium-pressure (re) compressor on the compression efficiency.
Furthermore, the invention stabilizes the inlet pressure of the high-pressure compressor and the medium-pressure compressor through the constant-pressure pump, the pressure stabilizing tank and the supplementary air source, reduces the influence on the system caused by the change of the medium flow at the cold side of the cooler, and avoids the problem that the inlet of the compressor is greatly fluctuated by the pressure of the system.
Drawings
FIG. 1 is a process block diagram of the system in an example of the invention.
In the figure: the system comprises a high-pressure compressor 1, a high-pressure primary regenerator 2a, a high-pressure secondary regenerator 2b, an external heat source 3, a superheater 3a, a reheater 3b, a high-pressure turbine set 4, a high-pressure turbine bypass 4By, a medium-pressure compressor 5, a medium-pressure regenerator 6, a medium-pressure turbine set 7, a medium-pressure turbine bypass 7By, an air supply source 8, a cooler 9, a constant pressure pump 10, a surge tank 11, a three-way valve 12 and a waste heat utilization system 13.
Detailed Description
The present invention will now be described in further detail with reference to specific examples, which are intended to be illustrative, but not limiting, of the invention.
The invention discloses a flow-dividing recompression supercritical carbon dioxide circulation system, which is shown in figure 1 and comprises: the system comprises a high-pressure compressor 1, a medium-pressure compressor 5, a high-pressure primary heat regenerator 2a, a high-pressure secondary heat regenerator 2b, a medium-pressure heat regenerator 6, an external heat source 3, a high-pressure turbine unit 4, a medium-pressure turbine unit 7, a cooler 9, a pressure stabilizing air storage tank 11, a constant pressure pump 10, a three-way valve 12 and a waste heat utilization system 13. The system is connected with the pipeline in a hooking way through two-stage regenerative heat, on the basis of ensuring the heat efficiency, the total circulation flow of the system is greatly increased, and a new thought is provided for megawatt-level supercritical carbon dioxide circulation. Meanwhile, disturbance of back pressure fluctuation on a system in the operation process of the supercritical carbon dioxide unit is solved to a certain extent; thereby solving the three problems of the serial circulation, such as the limitation of the total flow, the adverse effect of the inlet temperature of the medium-pressure (re) compressor on the compression efficiency and the large fluctuation of the inlet of the compressor under the system pressure.
Specifically, in the above-described configuration, the external heat source 3 includes a superheater 3a and a reheater 3b, a supplemental gas source 8 is provided on a pipe between a cooler 9 and a constant pressure pump 10, the high-pressure turbine unit 4 is connected to a high-pressure inlet/outlet pipe through a high-pressure turbine bypass 4By before an inlet and after an outlet, and the intermediate-pressure turbine unit 7 is connected to an intermediate-pressure inlet/outlet pipe through an intermediate-pressure turbine bypass 7By before an inlet and after an outlet.
The high-pressure compressor 1 is connected with the cold side of a high-pressure primary heat regenerator 2a through a pipeline and an outlet valve, the outlet of the cold side of the high-pressure primary heat regenerator 2a is connected with the cold side of a high-pressure secondary heat regenerator 2b through a pipeline, the outlet of the cold side of the high-pressure primary heat regenerator is connected with a superheater 3a in an external heat source 3 through a valve pipeline and the air inlet side of a high-pressure turbine unit 4, and the high-pressure turbine unit 4 comprises a high-pressure turbine and a high-pressure generator-transformer unit.
An outlet at the exhaust side of the high-pressure turbine unit 4 is connected with an inlet at the hot side of the high-pressure secondary heat regenerator 2b through a pipeline and is connected with an outlet pipeline at the cold side of the medium-pressure heat regenerator 6 through a three-way valve 12.
The medium-pressure compressor 5 is connected with the cold side of the medium-pressure regenerator 6 through a pipeline and an outlet valve, the outlet of the medium-pressure compressor is connected with the reheater 3b in the external heat source 3 through a valve pipeline and the air inlet side of the medium-pressure turbine unit 7, and the medium-pressure turbine unit 7 comprises a medium-pressure turbine and a medium-pressure generator-transformer unit.
An outlet at the exhaust side of the medium-pressure turbine set 7 is respectively connected with a hot side of the high-pressure primary heat regenerator 2a and a hot side of the medium-pressure heat regenerator 6 through pipelines.
And the hot side outlet of the medium-pressure regenerator 6 is connected with the cooler 9 through a valve pipeline through a waste heat utilization system 13. The outlet of the cooler 9 is connected with the inlet of a constant pressure pump 10 through a pipeline, and the outlet of the constant pressure pump 10 is connected with a gas storage tank 6 through a pipeline and then is connected with the inlets of the high pressure compressor 1 and the medium pressure compressor 5. The supplementary air source 8 is connected to the front of the inlet of the constant pressure pump 10 through a pipeline.
Aiming at a high-pressure turbine unit 4, an inlet pipeline and an outlet pipeline are connected through a high-pressure turbine bypass 4By in front of a high-pressure turbine inlet and behind a turbine outlet; similarly, for the medium-pressure turbine unit 7, the inlet and outlet pipelines are connected through the medium-pressure turbine bypass 7By in front of the medium-pressure turbine inlet and behind the turbine outlet.
In the split-flow recompression loop, the high-pressure compressor 1 and the medium-pressure compressor 5 both adopt centrifugal compressors, and the inlet pressure of the centrifugal compressors is maintained stable through a constant-pressure pump 10 and a pressure stabilizing tank 11. The constant pressure pump 10 is a high flow axial blower while ensuring a sensitive and adjustable outlet baffle or the addition of a frequency converter. The pressure-stabilizing tank 11 can be a self-operated constant pressure tank. The high-pressure compressor 1 and the medium-pressure compressor 5 are both kept at 6.5-7.5 MPa, and the inlet temperature is kept at 35-40 ℃ through the cooler 9. The carbon dioxide working medium is pressurized by the high-pressure compressor 1 to reach 22-24 MPa, and is pressurized by the medium-pressure compressor 5 to reach 16-18 MPa. After being heated by an external heat source 3, the high-pressure turbine inlet temperature is required to reach 700 ℃ before entering a high-pressure turbine unit 4; before entering the medium-pressure turbine unit 7, the temperature of the inlet of the medium-pressure turbine should reach 600 ℃, the temperature of the outlet of the hot side of the high-pressure primary heat regenerator 2a is ensured to be 450-500 ℃, the temperature of the outlet of the hot side of the high-pressure secondary heat regenerator 2b is ensured to be 450-550 ℃, and the temperature of the outlet of the hot side of the medium-pressure heat regenerator 6 is ensured to be 500-600 ℃.
The cooling mode of the cooler 5 comprises water cooling and air cooling; the external heat source 3 comprises a primary heat exchange device superheater 3a and a secondary heat exchange device reheater 3b, and the heating modes comprise coal heating, gas heating, nuclear reaction heating and photo-thermal heating.
The cold side of the waste heat utilization system 13 can use auxiliary steam and shaft seal gas as cold sources to return the residual working medium again to recover heat.
The three-way valve 12 needs to pass through the working medium in one way at the outlet side of the medium-pressure compressor 5 and the outlet side of the hot side of the high-pressure secondary heat regenerator 2 b.
And the pipeline of the supplementary air source 8 and the pipeline of the main system are arranged in front of the constant pressure pump 10, so that the disturbance of the pressure distribution and the circulation flow of the main system caused by the work of the supplementary air source 8 during the operation of the system is reduced.
A circulating method of supercritical carbon dioxide by shunting and repressing is operated as follows on the basis of the system,
the carbon dioxide working medium is divided into two paths by a constant pressure pump 10 and a pressure stabilizing tank 11. One path enters a high-pressure compressor 1, is pressurized in the high-pressure compressor 1, then exchanges heat through a high-pressure primary heat regenerator 2a and a high-pressure secondary heat regenerator 2b, and enters a superheater 3a in a boiler 3 for heating. The heated working medium enters the high-pressure turbine set 4 to do work or enters the high-pressure secondary heat regenerator 2b through the high-pressure turbine bypass 4By, and is converged into an outlet pipeline of the medium-pressure compressor 5 through the three-way valve 12 after heat exchange.
The other path of the gas enters a medium-pressure compressor 5, is pressurized in the medium-pressure compressor 5 and then exchanges heat through a medium-pressure heat regenerator 6, and forms medium-pressure main gas together with working media at the outlet of a high-pressure secondary heat regenerator 2b which is converged through a three-way valve 12. And enters a reheater 3b in the boiler 3 for heating. The heated working medium enters the medium-pressure turbine unit 7 to do work or sequentially enters the high-pressure primary heat regenerator 2a and the medium-pressure heat regenerator 6 through a medium-pressure turbine bypass 7 By.
After the heat exchange of the working medium is carried out by the medium-pressure heat regenerator 6, the enthalpy value is greatly reduced, and the working medium enters the waste heat utilization system 13 for heat recovery. And finally, the working medium enters a cooler 9, the temperature is reduced, and the working medium is used as the air source of the high-pressure compressor 1 and the medium-pressure compressor 5 after the pressure is balanced by the constant-pressure pump 10 and the pressure stabilizing tank 11. The parameters of the high-pressure compressor 1 and the medium-pressure compressor 5 are jointly controlled by the constant-pressure pump 10 through a pressure stabilizing tank.
The supplementary air source 8 is used as a cold-state filling air source and is filled in the system by matching a constant pressure pump 10, a high-pressure compressor 1 and a medium-pressure compressor 5; meanwhile, the system is used as a standby air source to ensure inlet pressure parameters of the high-pressure compressor 1 and the medium-pressure compressor 5, and the system works intermittently to maintain the circulation flow of the system.
The invention realizes the multi-stage utilization of boiler heat and turbine exhaust gas by changing the distribution mode of the supercritical carbon dioxide flow dividing and re-compressing circulation system and readjusting the system structure on the basis of ensuring the stable operation of the system.
Claims (10)
1. The split-flow recompression supercritical carbon dioxide circulating system is characterized by comprising an external heat source (3), a split-flow recompression loop, and a high-pressure working loop and a medium-pressure working loop which are connected in parallel;
the high-pressure work doing loop comprises a high-pressure compressor (1), a cold side of a high-pressure primary heat regenerator (2a), a cold side of a high-pressure secondary heat regenerator (2b) and a high-pressure turbine unit (4) which are connected in sequence; the medium-pressure work doing loop comprises a medium-pressure compressor (5), a cold side of a medium-pressure heat regenerator (6), a three-way valve (12) and a medium-pressure turbine set (7) which are connected in sequence; the exhaust side of the medium-pressure turbine unit (7) is sequentially connected with the hot side of the high-pressure primary regenerator (2a) and the hot side of the medium-pressure regenerator (6); the exhaust side of the high-pressure turbine unit (4) is sequentially connected with the hot side of the high-pressure secondary heat regenerator (2b) and a three-way valve (12);
the input end of the shunt recompression loop is connected with the hot side outlet of the medium-pressure heat regenerator (6), and the output end of the shunt recompression loop is respectively connected with the input ends of the high-pressure compressor (1) and the medium-pressure compressor (5);
the external heat source (3) is arranged between the cold side of the high-pressure secondary regenerator (2b) and the high-pressure turbine set (4) and between the three-way valve (12) and the medium-pressure turbine set (7).
2. A split-flow recompression supercritical carbon dioxide cycle system as in claim 1, characterized by the three-way valve (12) being in one-way communication in both the hot side of the high pressure secondary regenerator (2b) to the intermediate pressure turbine set (7) and the cold side of the intermediate pressure regenerator (6) to the intermediate pressure turbine set (7).
3. A split-flow recompression supercritical carbon dioxide cycle system as claimed in claim 1, characterized in that said external heat source (3) comprises a superheater (3a) for primary heat exchange and a reheater (3b) for secondary heat exchange, said superheater (3a) being arranged between the cold side of the high pressure secondary regenerator (2b) and the high pressure turbine set (4); the reheater (3b) is arranged between the three-way valve (12) and the intermediate-pressure turbine group (7).
4. The system of claim 1, wherein the high pressure turbine set (4) is connected to the high pressure inlet and outlet pipes through a high pressure turbine bypass (4By) before and after the inlet and outlet, and the intermediate pressure turbine set (7) is connected to the intermediate pressure inlet and outlet pipes through an intermediate pressure turbine bypass (7By) before and after the inlet and outlet.
5. The system for circulating the supercritical carbon dioxide through the split-flow recompression according to claim 1, wherein the split-flow recompression loop comprises a waste heat utilization system (13), a cooler (9), a constant pressure pump (10) and a pressure stabilizing tank (11) which are connected in sequence, and an air make-up source (8) arranged on a pipeline between the cooler (9) and the constant pressure pump (10).
6. A method for circulating supercritical carbon dioxide by using partial pressure and re-pressure is characterized by comprising the following steps,
before the unit is started in a cold state, filling the whole pipeline of the supercritical carbon dioxide circulation system with cold-state filling working medium through the split-flow recompression loop, wherein the pipeline is as defined in any one of claims 1-5;
after filling, the highest pressure of the main system is adjusted by the high-pressure compressor (1), and the output of the medium-pressure compressor is adjusted by the medium-pressure compressor (5) according to the pressure of the outlet of the high-pressure secondary heat regenerator (2b) at the hot side; controlling the inlet pressure of the high-pressure compressor (1) and the inlet pressure of the medium-pressure compressor (5) to be constant through the split-flow recompression loop;
an external heat source (3) is thrown in to gradually increase the temperature of the system; when the back pressure of an external heat source (3) in the medium-pressure working loop is 5-7 MPa and the outlet temperature is increased to 180 ℃, the medium-pressure turbine unit (7) is switched to an operation state from a hot standby state; after the medium-pressure turbine unit (7) is connected to the grid, the high-pressure turbine unit (4) is switched to an operation state from a hot standby state;
the power of an external heat source (3) is gradually increased, the enthalpy value of the system is increased, and meanwhile, the temperature threshold value of the hot side outlet of the medium-pressure heat regenerator (6) is taken as a reference, and the working media at the inlets of the high-pressure compressor (1) and the medium-pressure compressor (5) are controlled to reach a stable working condition through the shunting recompression loop; until the parameters of the high-pressure turbine set (4) and the medium-pressure turbine set (7) reach the set threshold values.
7. The method of claim 6, wherein the controlling of the split-flow recompression loop comprises,
a supplementary gas source (8) is used as a cold working medium filling gas source;
the pressure of the pressure stabilizing tank (11) is adjusted through the constant pressure pump (10), and the inlet pressure of the high-pressure compressor (1) and the inlet pressure of the medium-pressure compressor (5) are stabilized to be constant;
the flow of cooling media in the system is adjusted through the waste heat utilization system (13) and the cooler (9), the front temperature of the constant pressure pump (10) is stabilized, and the inlet working medium temperature and pressure of the high-pressure compressor (1) and the medium-pressure compressor (5) are indirectly stabilized.
8. The method of claim 6 or 7, wherein the stable operating condition is an inlet working medium temperature of 35 ℃ ± 3 ℃ and a pressure of 7.3MPa ± 0.2 MPa.
9. The method for recycling supercritical carbon dioxide with split-flow recompression as claimed in claim 7, wherein during shutdown, only the output of the external heat source (3) is reduced, the total enthalpy of the system is reduced, the waste heat utilization system (13) is gradually withdrawn according to the enthalpy change rate, or the flow of the cooling medium of the cooler (9) is adjusted;
the output of the high-pressure compressor (1) is preferentially reduced, the total flow of the system is reduced, the pressure of the hot side of the high-pressure secondary regenerator (2b) and the pressure of the three-way valve (12) are tracked by adjusting the medium-pressure compressor (5), the pressure of the medium-pressure system is stabilized, and the loads of the high-pressure turbine unit (4) and the medium-pressure turbine unit (7) are gradually reduced.
10. The method of claim 9, wherein after the high pressure turbine set (4) and the intermediate pressure turbine set (7) are removed from operation, the system is operated By the high pressure turbine bypass (4By) and the intermediate pressure turbine bypass (7By) to provide a cooling source for the external heat source (3) under accident conditions.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210421888.0A CN114922705B (en) | 2022-04-21 | 2022-04-21 | System and method for circulating split-flow repressing supercritical carbon dioxide |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210421888.0A CN114922705B (en) | 2022-04-21 | 2022-04-21 | System and method for circulating split-flow repressing supercritical carbon dioxide |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114922705A true CN114922705A (en) | 2022-08-19 |
| CN114922705B CN114922705B (en) | 2024-03-01 |
Family
ID=82805804
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210421888.0A Active CN114922705B (en) | 2022-04-21 | 2022-04-21 | System and method for circulating split-flow repressing supercritical carbon dioxide |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114922705B (en) |
Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20150308736A1 (en) * | 2014-04-24 | 2015-10-29 | Air Products And Chemicals, Inc. | Integrated Nitrogen Removal in the Production of Liquefied Natural Gas Using Dedicated Reinjection Circuit |
| US20160369658A1 (en) * | 2015-06-18 | 2016-12-22 | Korea Institute Of Energy Research | Supercritical carbon dioxide power generation system |
| KR20180097363A (en) * | 2017-02-23 | 2018-08-31 | 대우조선해양 주식회사 | Supercritical Carbon Dioxide Power Generation System |
| CN108661735A (en) * | 2018-04-26 | 2018-10-16 | 华北电力大学 | A kind of supercritical CO of cascade utilization smoke heat energy2Coal circulation burning electricity generation system |
| CN108915810A (en) * | 2018-08-17 | 2018-11-30 | 西安热工研究院有限公司 | The working medium displacement apparatus and method of the non-rotating environment division of supercritical carbon dioxide system |
| CN109555569A (en) * | 2018-12-25 | 2019-04-02 | 西安交通大学 | Supercritical carbon dioxide recycles cold end waste heat recovery generating system and operation method |
| CN112901297A (en) * | 2021-03-30 | 2021-06-04 | 西安热工研究院有限公司 | Sodium-cooled fast reactor supercritical carbon dioxide two-stage shunting efficient power generation system and method |
| CN113123840A (en) * | 2019-12-30 | 2021-07-16 | 上海汽轮机厂有限公司 | Supercritical carbon dioxide circulation system |
| CN113266442A (en) * | 2021-04-16 | 2021-08-17 | 上海齐耀动力技术有限公司 | Supercritical carbon dioxide recompression power generation system and operation control method thereof |
| CN113586186A (en) * | 2020-06-15 | 2021-11-02 | 浙江大学 | Supercritical carbon dioxide Brayton cycle system |
| CN113833534A (en) * | 2021-10-18 | 2021-12-24 | 西安热工研究院有限公司 | Supercritical carbon dioxide turbine shaft seal air supply and leakage recovery system and method |
| CN114001398A (en) * | 2021-10-29 | 2022-02-01 | 西安热工研究院有限公司 | Winter heat supply and power generation switching system and method under supercritical carbon dioxide power generation background |
| WO2022037711A1 (en) * | 2020-12-28 | 2022-02-24 | 中国长江三峡集团有限公司 | Flexible power station employing supercritical carbon dioxide power cycle in combination with seawater desalination and an adjustment method thereof |
-
2022
- 2022-04-21 CN CN202210421888.0A patent/CN114922705B/en active Active
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20150308736A1 (en) * | 2014-04-24 | 2015-10-29 | Air Products And Chemicals, Inc. | Integrated Nitrogen Removal in the Production of Liquefied Natural Gas Using Dedicated Reinjection Circuit |
| US20160369658A1 (en) * | 2015-06-18 | 2016-12-22 | Korea Institute Of Energy Research | Supercritical carbon dioxide power generation system |
| KR20180097363A (en) * | 2017-02-23 | 2018-08-31 | 대우조선해양 주식회사 | Supercritical Carbon Dioxide Power Generation System |
| CN108661735A (en) * | 2018-04-26 | 2018-10-16 | 华北电力大学 | A kind of supercritical CO of cascade utilization smoke heat energy2Coal circulation burning electricity generation system |
| CN108915810A (en) * | 2018-08-17 | 2018-11-30 | 西安热工研究院有限公司 | The working medium displacement apparatus and method of the non-rotating environment division of supercritical carbon dioxide system |
| CN109555569A (en) * | 2018-12-25 | 2019-04-02 | 西安交通大学 | Supercritical carbon dioxide recycles cold end waste heat recovery generating system and operation method |
| CN113123840A (en) * | 2019-12-30 | 2021-07-16 | 上海汽轮机厂有限公司 | Supercritical carbon dioxide circulation system |
| CN113586186A (en) * | 2020-06-15 | 2021-11-02 | 浙江大学 | Supercritical carbon dioxide Brayton cycle system |
| WO2022037711A1 (en) * | 2020-12-28 | 2022-02-24 | 中国长江三峡集团有限公司 | Flexible power station employing supercritical carbon dioxide power cycle in combination with seawater desalination and an adjustment method thereof |
| CN112901297A (en) * | 2021-03-30 | 2021-06-04 | 西安热工研究院有限公司 | Sodium-cooled fast reactor supercritical carbon dioxide two-stage shunting efficient power generation system and method |
| CN113266442A (en) * | 2021-04-16 | 2021-08-17 | 上海齐耀动力技术有限公司 | Supercritical carbon dioxide recompression power generation system and operation control method thereof |
| CN113833534A (en) * | 2021-10-18 | 2021-12-24 | 西安热工研究院有限公司 | Supercritical carbon dioxide turbine shaft seal air supply and leakage recovery system and method |
| CN114001398A (en) * | 2021-10-29 | 2022-02-01 | 西安热工研究院有限公司 | Winter heat supply and power generation switching system and method under supercritical carbon dioxide power generation background |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114922705B (en) | 2024-03-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111022138B (en) | Supercritical carbon dioxide power generation system based on absorption heat pump waste heat recovery | |
| CN109681279B (en) | Supercritical carbon dioxide power generation system and method containing liquid air energy storage | |
| CN113586185B (en) | Coal-fired boiler flue gas and steam combined heat storage deep peak regulation system and operation method | |
| CN111121390A (en) | Liquefied air energy storage power generation system coupled with steam-water system of coal-fired power generating unit | |
| CN111306842A (en) | Variable working condition multi-energy combined supply system and method suitable for different seasons | |
| CN209637831U (en) | A kind of system of thermal power plant's hot press in conjunction with space division system | |
| CN112412561B (en) | Coupling control method for compressed air energy storage system and thermal power plant control system | |
| CN113739516A (en) | Air separation energy storage coupling oxygen-enriched combustion system and method | |
| CN108104887B (en) | Thermodynamic system with double reheating | |
| CN114001398A (en) | Winter heat supply and power generation switching system and method under supercritical carbon dioxide power generation background | |
| CN113153462A (en) | Waste heat auxiliary heating condensed water system and method for supercritical carbon dioxide circulation cold end | |
| KR101628611B1 (en) | Supercritical CO2 generation system using multistage compressing and expanding of working fluid | |
| CN211903494U (en) | Liquefied air energy storage power generation system coupled with steam-water system of coal-fired power generating unit | |
| CN214741510U (en) | Waste heat auxiliary heating condensate system for supercritical carbon dioxide circulation cold end | |
| CN215724557U (en) | Air separation energy storage coupling oxygen-enriched combustion system | |
| WO2023226666A1 (en) | Carbon dioxide energy storage system and method coupled with coal power unit | |
| CN113294217A (en) | Back pressure type steam turbine heat regeneration system with small steam turbine and thermodynamic balance design method | |
| CN212339737U (en) | Liquefied air energy storage and power generation system of deep coupling coal-fired unit | |
| CN114991895B (en) | Coal-fired power generation unit capable of storing energy by coupling compressed air and operation method thereof | |
| CN109139147B (en) | Split-flow recompression supercritical carbon dioxide cogeneration system and operation method | |
| CN114922705A (en) | Shunting recompression supercritical carbon dioxide circulating system and method | |
| CN114483232B (en) | Compressed air energy storage system based on organic flash evaporation circulation and control method | |
| CN211950617U (en) | Organic Rankine cycle power generation system for recycling black water flash steam waste heat | |
| CN114810243B (en) | Coal-fired power generation system with boiler flue gas coupled with compressed air energy storage and operation method | |
| WO2019042021A1 (en) | Adjustable combined regeneration device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |