阅读说明：本技术 一种二氧化碳基发电制冷联合系统 (Carbon dioxide-based power generation and refrigeration combined system ) 是由 张峰 谌冰洁 廖高良 戴幸福 于 2021-10-21 设计创作，主要内容包括：本申请公开了一种二氧化碳基发电制冷联合系统,包括超临界二氧化碳发电循环、跨临界二氧化碳发电循环和跨临界二氧化碳制冷循环,高温加热器、高温透平、低温回热器、冷却器、压缩机依次连接,压缩机和第一发电机均通过高温透平输出的机械能驱动,第一发电机产生电能供给电能用户；低温加热器、低温透平、低温回热器、冷凝器、增压泵依次连接,第二发电机通过低温透平输出的机械能驱动,产生电能供给电能用户；制冷压缩机、冷凝器、节流阀、蒸发器依次连接,制冷压缩机通过低温透平输出的机械能驱动。该二氧化碳基发电制冷联合系统能够充分回收利用余热,保证尽可能高的能源转换效率,灵活提供发电量和制冷量,满足不同制冷温度需求。(The application discloses a carbon dioxide-based power generation and refrigeration combined system which comprises a supercritical carbon dioxide power generation cycle, a trans-critical carbon dioxide power generation cycle and a trans-critical carbon dioxide refrigeration cycle, wherein a high-temperature heater, a high-temperature turbine, a low-temperature heat regenerator, a cooler and a compressor are sequentially connected, the compressor and a first generator are driven by mechanical energy output by the high-temperature turbine, and the first generator generates electric energy to supply to an electric energy user; the low-temperature heater, the low-temperature turbine, the low-temperature heat regenerator, the condenser and the booster pump are sequentially connected, and the second generator is driven by mechanical energy output by the low-temperature turbine to generate electric energy for supplying to an electric energy user; the refrigeration compressor, the condenser, the throttle valve and the evaporator are connected in sequence, and the refrigeration compressor is driven by mechanical energy output by the low-temperature turbine. The carbon dioxide-based power generation and refrigeration combined system can fully recycle waste heat, ensure energy conversion efficiency as high as possible, flexibly provide generated energy and refrigerating capacity, and meet different refrigeration temperature requirements.)

1. A carbon dioxide-based power generation and refrigeration combined system is characterized by comprising a supercritical carbon dioxide power generation cycle, a transcritical carbon dioxide power generation cycle and a transcritical carbon dioxide refrigeration cycle,

the high-temperature heater (2), the high-temperature turbine (3), the low-temperature regenerator (5), the cooler (6) and the compressor (7) are sequentially connected in the supercritical carbon dioxide power generation cycle, the compressor (7) and the first generator (16) are driven by mechanical energy output by the high-temperature turbine (3), and the first generator (16) generates electric energy to supply to an electric energy user (18);

the low-temperature heater (8), the low-temperature turbine (9), the low-temperature regenerator (5), the condenser (10) and the booster pump (11) are sequentially connected in the transcritical carbon dioxide power generation cycle, the second generator (17) is driven by mechanical energy output by the low-temperature turbine (9), the second generator (17) generates electric energy to supply to an electric energy user (18), and a heat measurement inlet of the low-temperature heater (8) is connected with a heat measurement outlet of the high-temperature heater (2);

the transcritical carbon dioxide refrigeration cycle is characterized in that a refrigeration compressor (15), a condenser (10), a throttle valve (12) and an evaporator (13) are sequentially connected, the refrigeration compressor (15) is driven by mechanical energy output by a low-temperature turbine (9), and the evaporator (13) is used for cooling fluid supplied to a cold energy user (14).

2. The carbon dioxide-based power generation and refrigeration combined system is characterized by further comprising a heat source flow divider (1), wherein an inlet of the heat source flow divider (1) is connected with a heat source, an outlet of one side of the heat source flow divider (1) is connected with an inlet of a hot side of the high-temperature heater (2), and an outlet of the other side of the heat source flow divider is connected with an inlet of a hot side of the low-temperature heater (8).

3. The carbon dioxide-based power generation refrigeration combination according to claim 1, characterized in that the high temperature turbine (3), the first generator (16) and the compressor (7) are coaxially connected; the low-temperature turbine (9) and the second generator (17) are coaxially connected with the refrigeration compressor (15).

4. A carbon dioxide based power generation and refrigeration combination according to any of claims 1-3, wherein the cooler (6) inlet is connected to the refrigeration compressor (15) outlet and the hot side outlet of the low temperature regenerator (5), and the cooler (6) outlet is connected to the condenser (10) inlet and the compressor (7) inlet.

5. The carbon dioxide-based power generation and refrigeration combined system according to any one of claims 1-3, characterized by further comprising a high-temperature regenerator (4), wherein a cold-side inlet of the high-temperature regenerator (4) is connected with a cold-side outlet of the low-temperature regenerator (5), a cold-side outlet of the high-temperature regenerator (4) is connected with a cold-side inlet of the high-temperature heater (2), a hot-side outlet of the high-temperature regenerator (4) is connected with a hot-side inlet of the low-temperature regenerator (5), and a hot-side inlet of the high-temperature regenerator (4) is connected with an outlet of the high-temperature turbine (3).

6. A carbon dioxide based power generation and refrigeration combination system as claimed in any one of claims 1 to 3, further comprising a flow divider (19), wherein the inlet of the flow divider (19) is connected with the outlet of the condenser (10), the outlet of one side of the flow divider (19) is connected with the inlet of the throttle valve (12), and the outlet of the other side of the flow divider (19) is connected with the inlet of the booster pump (11).

7. The carbon dioxide-based power generation and refrigeration integrated system according to claim 2, wherein the heat source absorbed by the heat source splitter (1) comprises engine exhaust waste heat, gas turbine exhaust gas or industrial waste heat.

Technical Field

The application relates to the technical field of waste heat recovery systems, in particular to a carbon dioxide-based power generation and refrigeration combined system.

Background

Heat recovery in heat engines and heating processes is one of the main ways to reduce fossil fuel consumption and carbon dioxide emissions in the power, transportation and heating sectors. In an industrial process, the waste heat loss of hot waste gas and heat flow is up to 20-50%, waste heat sources can be divided into low temperature (<230 ℃), medium temperature (230-.

At present, the widely applied waste heat recovery system comprises Rankine cycle, Brayton cycle and kalina cycle. The Rankine cycle takes steam as a cycle working medium, is mainly applied to the fields of thermal power generation, nuclear power generation, waste incineration power generation and the like, and has the thermal efficiency reaching 45 percent when the highest cycle temperature is 600 ℃; the Brayton cycle has higher combustion conversion efficiency and is widely applied to gas turbine power generation, space power systems, propulsion systems of airplanes, ships and the like; the kalina cycle is a power cycle which takes an ammonia/water mixture as a working medium and is improved based on Rankine cycle, and is mainly applied to low-temperature heat sources such as geothermal energy and industrial waste heat.

The supercritical carbon dioxide Brayton cycle is based on Brayton cycle and takes carbon dioxide in a supercritical state as power cycle of a working medium, and by utilizing the high density and heat transfer performance of the power cycle and special physical properties near a critical region, the power consumption of a compressor can be greatly reduced, and the heat efficiency of the cycle can be improved. Meanwhile, compared with an independent system, the cascade system can more completely utilize waste heat, improve the thermodynamic performance of the system and reduce the number of parts by sharing some equipment.

In summary, how to improve the efficiency of the waste heat recovery system and utilize the waste heat energy as much as possible is a problem to be solved urgently by those skilled in the art.

Content of application

The utility model aims at providing a carbon dioxide base electricity generation refrigeration combined system, this carbon dioxide base electricity generation refrigeration combined system unites supercritical carbon dioxide electricity generation circulation, transcritical carbon dioxide electricity generation circulation and transcritical carbon dioxide refrigeration cycle, can make full use of waste heat, guarantees energy conversion efficiency as high as possible, provides generated energy and refrigerating output in a flexible way, satisfies different refrigeration temperature demands.

In order to solve the technical problem, the application provides the following technical scheme:

a carbon dioxide-based power generation and refrigeration combined system comprises a supercritical carbon dioxide power generation cycle, a trans-critical carbon dioxide power generation cycle and a trans-critical carbon dioxide refrigeration cycle,

the high-temperature heater, the high-temperature turbine, the low-temperature regenerator, the cooler and the compressor are sequentially connected in the supercritical carbon dioxide power generation cycle, the compressor and the first generator are driven by mechanical energy output by the high-temperature turbine, and the first generator generates electric energy to supply to an electric energy user;

the low-temperature heater, the low-temperature turbine, the low-temperature regenerator, the condenser and the booster pump are sequentially connected in the transcritical carbon dioxide power generation cycle, the second generator is driven by mechanical energy output by the low-temperature turbine and generates electric energy to supply to an electric energy user, and a heat measurement inlet of the low-temperature heater is connected with a heat measurement outlet of the high-temperature heater;

the transcritical carbon dioxide refrigeration cycle is characterized in that a refrigeration compressor, a condenser, a throttle valve and an evaporator are sequentially connected, the refrigeration compressor is driven by mechanical energy output by a low-temperature turbine, and the evaporator is used for cooling fluid supplied to a cold energy user.

Preferably, the heat source device further comprises a heat source diverter, an inlet of the heat source diverter is connected with a heat source, an outlet on one side of the heat source diverter is connected with an inlet on the hot side of the high-temperature heater, and an outlet on the other side of the heat source diverter is connected with an inlet on the hot side of the low-temperature heater.

Preferably, the high temperature turbine and the first generator are coaxially connected with the compressor; the low-temperature turbine and the second generator are coaxially connected with the refrigeration compressor.

Preferably, the cooler inlet is connected to the refrigeration compressor outlet and the hot side outlet of the low temperature regenerator, and the cooler outlet is connected to the condenser inlet and the compressor inlet.

Preferably, the heat recovery system further comprises a high-temperature regenerator, a cold-side inlet of the high-temperature regenerator is connected with a cold-side outlet of the low-temperature regenerator, a cold-side outlet of the high-temperature regenerator is connected with a cold-side inlet of the high-temperature heater, a hot-side outlet of the high-temperature regenerator is connected with a hot-side inlet of the low-temperature regenerator, and a hot-side inlet of the high-temperature regenerator is connected with a high-temperature turbine outlet.

Preferably, the condenser further comprises a flow divider, an inlet of the flow divider is connected with an outlet of the condenser, an outlet of one side of the flow divider is connected with an inlet of the throttle valve, and an outlet of the other side of the flow divider is connected with an inlet of the booster pump.

Preferably, the heat source absorbed by the heat source splitter comprises engine exhaust waste heat, gas turbine exhaust gas or industrial waste heat.

The carbon dioxide-based power generation and refrigeration combined system is compactly connected with a supercritical carbon dioxide power generation cycle, a trans-critical carbon dioxide power generation cycle and a trans-critical carbon dioxide refrigeration cycle, the supercritical carbon dioxide power generation cycle comprises a high-temperature heater, a high-temperature turbine, a first generator, a low-temperature heat regenerator, a cooler and a compressor, and a circulating working medium is carbon dioxide. The transcritical carbon dioxide power generation cycle comprises a low-temperature heater, a low-temperature turbine, a second generator, a low-temperature heat regenerator, a condenser and a booster pump, wherein the circulating working medium is carbon dioxide. The transcritical carbon dioxide refrigeration cycle comprises a refrigeration compressor, a condenser, a throttle valve and an evaporator, wherein the refrigeration working medium is carbon dioxide. The supercritical carbon dioxide power generation cycle and the transcritical carbon dioxide power generation cycle share the low-temperature heat regenerator, and the transcritical carbon dioxide power generation cycle and the transcritical carbon dioxide refrigeration cycle share the condenser.

The carbon dioxide-based power generation and refrigeration combined system enables supercritical carbon dioxide power generation circulation and trans-critical carbon dioxide power generation circulation to utilize high-temperature waste heat and low-temperature waste heat in a gradient manner, and ensures that the system can fully recycle the waste heat; meanwhile, the supercritical carbon dioxide power generation cycle and the transcritical carbon dioxide power generation cycle share the low-temperature heat regenerator, so that the problem of temperature pinch of the low-temperature heat regenerator is avoided, and the heat exchange efficiency of the low-temperature heat regenerator is ensured, thereby omitting the split-flow recompression process of recompression of the supercritical carbon dioxide power generation cycle, remarkably reducing the power consumption of a compressor and improving the cycle efficiency; in addition, the low-temperature turbine exhaust gas waste heat is absorbed by the supercritical carbon dioxide power generation cycle working medium in the low-temperature heat regenerator, so that the supercritical carbon dioxide power generation cycle efficiency is improved, the cold source loss of the transcritical carbon dioxide power generation cycle is reduced, and the cycle efficiency is improved; in addition, the refrigeration cycle is driven by the power cycle of the transcritical carbon dioxide, extra high-grade electric energy is not consumed, the working medium of the refrigeration cycle is carbon dioxide, the temperature of liquid carbon dioxide can be reduced to be below 0 ℃, the evaporation temperature of the carbon dioxide can be changed by adjusting the pressure drop of the throttle valve, different refrigeration requirements such as air conditioning cold supply, food preservation, refrigeration and the like can be met, and the refrigeration capacity and the generated energy can be adjusted by changing the flow of the working medium of the refrigeration cycle. Therefore, the carbon dioxide-based power generation and refrigeration combined system provided by the invention can fully recycle waste heat, ensure the energy conversion efficiency as high as possible, flexibly provide the generated energy and the refrigeration capacity, and meet different refrigeration temperature requirements.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of a carbon dioxide based power generation and refrigeration combination system according to an embodiment of the present application;

fig. 2 is a schematic diagram of a carbon dioxide-based power generation and refrigeration combination system according to another embodiment of the present application.

Detailed Description

The core of this application provides a carbon dioxide base electricity generation refrigeration combined system, and this carbon dioxide base electricity generation refrigeration combined system unites supercritical carbon dioxide electricity generation circulation, transcritical carbon dioxide electricity generation circulation and transcritical carbon dioxide refrigeration cycle, can make full use of waste heat, guarantees energy conversion efficiency as high as possible, provides generated energy and refrigerating output in a flexible way, satisfies different refrigeration temperature demands.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Referring to fig. 1 to 2, fig. 1 is a schematic structural diagram of a carbon dioxide-based power generation and refrigeration combined system according to an embodiment of the present application; fig. 2 is a schematic diagram of a carbon dioxide-based power generation and refrigeration combination system according to another embodiment of the present application.

In one embodiment, the carbon dioxide-based power generation and refrigeration combined system provided by the application comprises a supercritical carbon dioxide power generation cycle, a transcritical carbon dioxide power generation cycle and a transcritical carbon dioxide refrigeration cycle.

The high-temperature heater 2, the high-temperature turbine 3, the low-temperature heat regenerator 5, the cooler 6 and the compressor 7 are sequentially connected in the supercritical carbon dioxide power generation cycle, the compressor 7 and the first generator 16 are driven by mechanical energy output by the high-temperature turbine 3, and the first generator 16 generates electric energy to supply to an electric energy user 18;

the low-temperature heater 8, the low-temperature turbine 9, the low-temperature heat regenerator 5, the condenser 10 and the booster pump 11 are sequentially connected in a transcritical carbon dioxide power generation cycle, the second generator 17 is driven by mechanical energy output by the low-temperature turbine 9, the second generator 17 generates electric energy to be supplied to an electric energy user 18, and a heat measurement inlet of the low-temperature heater 8 is connected with a heat measurement outlet of the high-temperature heater 2;

in the transcritical carbon dioxide refrigeration cycle, a refrigeration compressor 15, a condenser 10, a throttle valve 12 and an evaporator 13 are sequentially connected, the refrigeration compressor 15 is driven by mechanical energy output by a low-temperature turbine 9, and the evaporator 13 is used for cooling fluid supplied to a cold energy user 14.

In the structure, the high-temperature heater 2 absorbs high-temperature waste heat and is used for heating the supercritical carbon dioxide power generation circulating working medium; the inlet of the high-temperature turbine 3 is connected with the outlet of the cold side of the high-temperature heater 2; the first generator 16 is driven by part of mechanical energy output by the high-temperature turbine 3 to operate, and the generated energy of the first generator 16 is used for supplying the electric energy to an electric energy user 18; a hot side inlet of the low-temperature heat regenerator 5 is connected with an outlet of the high-temperature turbine 3 and is also connected with an outlet of the low-temperature turbine 9, and a cold side outlet of the low-temperature heat regenerator 5 is connected with a cold side inlet of the high-temperature heater 2; the inlet of the cooler 6 is connected with the hot side outlet of the low-temperature regenerator 5; the compressor 7 is driven by part of mechanical energy output by the high-temperature turbine 3 to operate, and the compressor 7 compresses the supercritical carbon dioxide power generation cycle working medium; an inlet of the compressor 7 is connected with an outlet of the cooler 6, and an outlet of the compressor 7 is connected with a cold side inlet of the low-temperature heat regenerator 5; the cold side outlet of the low-temperature regenerator 5 is connected with the cold side inlet of the high-temperature heater 2.

The low-temperature heater 8 absorbs low-temperature waste heat and is used for heating the transcritical carbon dioxide power generation circulating working medium; an inlet of the low-temperature turbine 9 is connected with a cold side outlet of the low-temperature heater 8; the second generator 17 is driven by part of mechanical energy output by the low-temperature turbine 9 to operate, and the generated energy of the second generator 17 is used for supplying an electric energy user 18; the refrigeration compressor 15 is driven by part of mechanical energy output by the low-temperature turbine 9 to operate, and the refrigeration compressor 15 compresses a transcritical carbon dioxide refrigeration cycle working medium; an inlet of the condenser 10 is connected with an outlet of the refrigeration compressor 15 and an outlet of the hot side of the low-temperature heat regenerator 5, and is used for condensing the transcritical carbon dioxide power generation cycle working medium and the transcritical carbon dioxide refrigeration cycle working medium to a liquid state; an inlet of a booster pump 11 is connected with an outlet at one side of a condenser 10, an outlet of the booster pump 11 is connected with a low-temperature heater 8, the booster pump 11 is used for boosting the transcritical carbon dioxide power generation circulating working medium, the temperature of the boosted carbon dioxide is still low, and low-temperature waste heat can be well utilized; the inlet of the throttle valve 12 is connected with the outlet of the other side of the condenser 10, the outlet of the throttle valve 12 is connected with the inlet of the evaporator 13, the outlet of the evaporator 13 is connected with the inlet of the refrigeration compressor 15, and the evaporator 13 is used for cooling the fluid supplied to the cold energy user 14.

According to the carbon dioxide-based power generation and refrigeration combined system provided by the embodiment of the invention, carbon dioxide in the high-temperature heater 2 absorbs high-temperature waste heat and then is heated, high-temperature high-pressure air flow enters the high-temperature turbine 3 and expands in the high-temperature turbine 3 to do work, the heat energy of supercritical carbon dioxide is converted into mechanical energy of a rotating turbine to drive the compressor 7 to compress the carbon dioxide and the first generator 16 which is coaxially connected to generate power, and the generated energy of the first generator 16 is supplied to the electric energy user 18; the carbon dioxide expanded by the high-temperature turbine 3 flows through the low-temperature heat regenerator 5 and releases heat, and then enters the cooler 6 for cooling; the cooled carbon dioxide gas flow enters the compressor 7 for pressurization, the power consumption is reduced because the temperature is cooled to be close to the critical point of the carbon dioxide, the obtained high-pressure gas flow enters the high-temperature heater 2 after absorbing heat and raising the temperature through the low-temperature heat regenerator 5, and the heat of a heat source is absorbed in the high-temperature heater 2 so that the temperature is further raised.

After absorbing low-temperature waste heat and raising the temperature, carbon dioxide flow in the low-temperature heater 8 enters the low-temperature turbine 9 to do expansion work, mechanical energy output by the expansion work of the low-temperature turbine 9 respectively drives the second generator 17 to generate power and the refrigeration compressor 15 to compress the carbon dioxide, the carbon dioxide expanded by the low-temperature turbine 9 is converged into a hot side inlet of the low-temperature regenerator 5 to be mixed with a supercritical carbon dioxide power generation cycle working medium, so that the mass flow of the working medium at the hot side of the low-temperature regenerator 5 is larger than that at the cold side, the heat capacity difference between the cold side and the hot side fluid is reduced, the temperature pinch problem in the regenerator is avoided, the temperature matching characteristic of the working medium at the cold side and the hot side in the low-temperature regenerator 5 is improved, the heat exchange efficiency of the low-temperature regenerator 5 is improved, the mixed carbon dioxide releases heat in the low-temperature regenerator 5, and the cooled carbon dioxide flow is cooled to be in a liquid state through the condenser 10, the liquid carbon dioxide is pressurized by the pump 11 and then returns to the low-temperature heater 2 to absorb heat so as to fully utilize the low-temperature waste heat.

The pressure of the carbon dioxide flowing through the refrigeration compressor 15 is increased, the pressurized carbon dioxide flows through the condenser 10 and is cooled into liquid, the condensed carbon dioxide is throttled, cooled and depressurized through the throttle valve 12, the temperature of the condensed carbon dioxide is reduced to the evaporation temperature, and then the condensed carbon dioxide enters the evaporator 13 to absorb heat and evaporate into gas, so that the liquid carbon dioxide is refrigerated by utilizing the evaporation latent heat of the liquid carbon dioxide, the fluid on the other side of the evaporator 13 is cooled and then is supplied to users needing cold energy, the temperature of the liquid carbon dioxide can be reduced to be lower than 0 ℃, the pressure drop is realized by adjusting the throttle valve 12, the evaporation temperature of the carbon dioxide is changed to meet different refrigeration requirements, such as air conditioning cold supply, food fresh keeping and refrigeration, and the like, and finally the carbon dioxide flows back to the refrigeration compressor 15.

Namely, the carbon dioxide-based power generation and refrigeration combined system is compactly connected with a supercritical carbon dioxide power generation cycle, a transcritical carbon dioxide power generation cycle and a transcritical carbon dioxide refrigeration cycle, the supercritical carbon dioxide power generation cycle comprises a high-temperature heater 2, a high-temperature turbine 3, a first generator 16, a low-temperature heat regenerator 5, a cooler 6 and a compressor 7, and a circulating working medium is carbon dioxide. The transcritical carbon dioxide power generation cycle comprises a low-temperature heater 8, a low-temperature turbine 9, a second generator 17, a low-temperature heat regenerator 5, a condenser 10 and a booster pump 11, wherein a cycle working medium is carbon dioxide. The transcritical carbon dioxide refrigeration cycle comprises a refrigeration compressor 15, a condenser 10, a throttle valve 12 and an evaporator 13, and the refrigeration working medium is carbon dioxide. The supercritical carbon dioxide power generation cycle and the transcritical carbon dioxide power generation cycle share the low-temperature heat regenerator 5, and the transcritical carbon dioxide power generation cycle and the transcritical carbon dioxide refrigeration cycle share the condenser 10.

Through the arrangement, the supercritical carbon dioxide power generation circulation and the transcritical carbon dioxide power generation circulation use high-temperature waste heat and low-temperature waste heat in a gradient manner, and the system can fully recycle the waste heat; meanwhile, the supercritical carbon dioxide power generation cycle and the transcritical carbon dioxide power generation cycle share the low-temperature heat regenerator 5, so that the problem of temperature pinch of the low-temperature heat regenerator is avoided, and the heat exchange efficiency of the low-temperature heat regenerator 5 is ensured, thereby omitting the split-flow recompression process of recompression of the supercritical carbon dioxide power generation cycle, remarkably reducing the power consumption of a compressor and improving the cycle efficiency; in addition, the waste heat of the exhaust gas of the low-temperature turbine 9 is absorbed by the supercritical carbon dioxide power generation circulating working medium in the low-temperature heat regenerator 5, so that the supercritical carbon dioxide power generation circulating efficiency is improved, the cold source loss of the transcritical carbon dioxide power generation circulation is reduced, and the circulating efficiency is improved; in addition, the refrigeration cycle is driven by the power cycle of the transcritical carbon dioxide, extra high-grade electric energy is not consumed, the working medium of the refrigeration cycle is carbon dioxide, the temperature of liquid carbon dioxide can be reduced to be below 0 ℃, the evaporation temperature of the carbon dioxide can be changed by adjusting the pressure drop of the throttle valve, different refrigeration requirements such as air conditioning cold supply, food preservation, refrigeration and the like can be met, and the refrigeration capacity and the generated energy can be adjusted by changing the flow of the working medium of the refrigeration cycle. Therefore, the carbon dioxide-based power generation and refrigeration combined system provided by the invention can fully recycle waste heat, ensure the energy conversion efficiency as high as possible, flexibly provide the generated energy and the refrigeration capacity, and meet different refrigeration temperature requirements.

In another more reliable embodiment, on the basis of any one of the above embodiments, the heat source shunt 1 is further included, an inlet of the heat source shunt 1 is connected to a heat source, an outlet on one side of the heat source shunt 1 is connected to an inlet on the hot side of the high temperature heater 2, and an outlet on the other side of the heat source shunt 1 is connected to an outlet on the hot side of the high temperature heater 2 and an inlet on the hot side of the low temperature heater 8.

In this embodiment, the flow rate of the waste heat working medium flowing through the high temperature heater 1 and the temperature of the waste heat working medium flowing through the low temperature heater 8 can be changed by adjusting the split ratio of the heat source splitter 1, so as to change the waste heat recovery amount and the mass flow rate of the carbon dioxide working medium of the supercritical carbon dioxide power generation cycle, the waste heat recovery amount of the transcritical carbon dioxide power generation cycle, the inlet temperature of the low temperature turbine 9, and the mass flow rate of the carbon dioxide, and further adjust the output power of the supercritical carbon dioxide power generation cycle and the transcritical carbon dioxide power generation cycle, thereby achieving the purpose of adjusting the maximum generated energy and the maximum refrigerating capacity.

For convenience of arrangement, the high-temperature turbine 3 and the first generator 16 are coaxially connected with the compressor 7; the low-temperature turbine 9 and the second generator 17 are coaxially connected to the refrigeration compressor 15. Through above-mentioned setting, compact structure nature has been improved.

Of course, the high temperature turbine 3 and the first generator 16 are coaxially connected to the compressor 7; the coaxial connection of the cryogenic turbine 9 and the second generator 17 to the refrigeration compressor 15 is only a preferred embodiment and is not exclusive and it is within the scope of the present application to use a transmission to connect them non-coaxially.

In another more reliable embodiment, based on any of the above embodiments, the inlet of the cooler 6 is connected to the outlet of the refrigeration compressor 15 and the outlet of the hot side of the low temperature regenerator 5, and the outlet of the cooler 6 is connected to the inlet of the condenser 10 and the inlet of the compressor 7.

In this embodiment, the cooler 6 is disposed between the refrigeration compressor 15 and the condenser 10, and the working mediums of the supercritical carbon dioxide power generation cycle, the transcritical carbon dioxide power generation cycle and the transcritical carbon dioxide refrigeration cycle flow through the cooler 6, that is, the cooler 6 is shared by three cycles, so that the compactness of the system is enhanced. The cooler 6 is used for pre-cooling the working medium of the three cycles, reducing the temperature of the working medium to be close to a critical point, reducing the power consumption of the compressor 7 of the supercritical carbon dioxide power generation cycle, and reducing the size of the condenser 10 of the transcritical carbon dioxide power generation and refrigeration cycle.

In another more reliable embodiment, based on any of the above embodiments, a high temperature regenerator 4 is further included, a cold side inlet of the high temperature regenerator 4 is connected to a cold side outlet of the low temperature regenerator 5, the cold side outlet of the high temperature regenerator 4 is connected to a cold side inlet of the high temperature heater 2, a hot side outlet of the high temperature regenerator 4 is connected to a hot side inlet of the low temperature regenerator 5, and the hot side inlet of the high temperature regenerator 4 is connected to an outlet of the high temperature turbine 3.

In the embodiment, the high-temperature heat regenerator 4 is arranged between the hot side inlet of the low-temperature heat regenerator 5 and the outlet of the high-temperature turbine 3, and exhaust gas after the high-temperature turbine 3 expands to do work is sequentially recycled by the high-temperature heat regenerator 4 and the low-temperature heat regenerator 5, so that the mass flow of air flow at two sides of the heat regenerator at high temperature is ensured to be consistent, the heat capacity difference of fluid at two sides of the heat regenerator is reduced, the temperature matching characteristic of fluid at the cold side and the hot side of the heat regenerator at high temperature is improved, and the efficiency of the heat regenerator is further improved; meanwhile, the temperature difference of two air flows at the hot side inlet of the low-temperature heat regenerator 5 is reduced, and the mixing loss is reduced, so that the circulation efficiency is improved.

On the basis of the above embodiments, the condenser further comprises a flow divider 19, wherein an inlet of the flow divider 19 is connected with an outlet of the condenser 10, an outlet of one side of the flow divider 19 is connected with an inlet of the throttle valve 12, and an outlet of the other side of the flow divider 19 is connected with an inlet of the booster pump 11.

In this embodiment, the mass flow rate flowing through the transcritical carbon dioxide power generation cycle and the transcritical carbon dioxide refrigeration cycle can be controlled by adjusting the split ratio of the splitter 19, so as to flexibly adjust the refrigeration capacity and the power generation capacity.

On the basis of the above embodiments, the heat source absorbed by the heat source splitter 1 includes engine exhaust waste heat, gas turbine exhaust gas or industrial waste heat.

The carbon dioxide-based power generation and refrigeration combined system provided by the embodiment of the invention is a novel carbon dioxide-based power generation and refrigeration combined system based on waste heat recovery and utilization, is suitable for various heat sources, and has a good application prospect.

For ease of description, the above features are described in combination below.

The carbon dioxide-based power generation and refrigeration combined system provided by the embodiment of the invention is compactly connected with a supercritical carbon dioxide power generation cycle, a trans-critical carbon dioxide power generation cycle and a trans-critical carbon dioxide refrigeration cycle. The supercritical carbon dioxide power generation cycle comprises a high-temperature heater 2, a high-temperature turbine 3, a first generator 16, a high-temperature heat regenerator 4, a low-temperature heat regenerator 5, a cooler 6 and a compressor 7, wherein the cycle working medium is carbon dioxide. The transcritical carbon dioxide power generation cycle comprises a low-temperature heater 8, a low-temperature turbine 9, a second generator 17, a low-temperature heat regenerator 5, a cooler 6, a condenser 10, a flow divider 19 and a booster pump 11, wherein the cycle working medium is carbon dioxide. The transcritical carbon dioxide refrigeration cycle comprises a refrigeration compressor 15, a cooler 6, a condenser 10, a flow divider 19, a throttle valve 12 and an evaporator 13, wherein the refrigeration working medium is carbon dioxide. The supercritical carbon dioxide power generation cycle and the transcritical carbon dioxide power generation cycle respectively recover high-temperature waste heat and low-temperature waste heat through the high-temperature heater 2 and the low-temperature heater 8, and the two cycles also share the low-temperature heat regenerator 5 and the cooler 6; the transcritical carbon dioxide refrigeration cycle and the transcritical carbon dioxide power generation cycle share the cooler 6, the condenser 10 and the flow divider 19.

Through the arrangement, the supercritical carbon dioxide power generation cycle and the transcritical carbon dioxide power generation cycle can utilize high-temperature waste heat and low-temperature waste heat in a gradient manner, so that the system can fully recycle the waste heat; meanwhile, the supercritical carbon dioxide power generation cycle and the transcritical carbon dioxide power generation cycle share the low-temperature heat regenerator 5, so that the problem of temperature pinch of the low-temperature heat regenerator 5 is avoided, and the heat exchange efficiency of the low-temperature heat regenerator 5 is ensured, thereby omitting the split-flow recompression process of recompression of the supercritical carbon dioxide power generation cycle, remarkably reducing the power consumption of the compressor 7 and improving the cycle efficiency; in addition, the waste heat of the exhaust gas of the low-temperature turbine 9 is absorbed by the supercritical carbon dioxide power generation circulating working medium in the low-temperature heat regenerator 5, so that the supercritical carbon dioxide power generation circulating efficiency is improved, the cold source loss of the transcritical carbon dioxide power generation circulation is reduced, and the circulating efficiency is improved; the high-temperature heat regenerator 4 is arranged in the supercritical carbon dioxide power generation cycle, so that the temperature difference of two air flows at the hot side inlet of the low-temperature heat regenerator 5 can be reduced, the mixing loss is reduced, and the cycle efficiency is improved; in addition, the refrigeration cycle is driven by the power cycle of the transcritical carbon dioxide, extra high-grade electric energy is not consumed, the working medium of the refrigeration cycle is carbon dioxide, the temperature of the liquid carbon dioxide can be reduced to be below 0 ℃, the evaporation temperature of the carbon dioxide can be changed by adjusting the pressure drop of a throttle valve to meet different refrigeration requirements, such as air conditioning cold supply, food preservation, refrigeration and the like, the refrigerating capacity and the generating capacity can be adjusted by adjusting the flow of the working medium of the refrigeration cycle by adjusting a shunt 19, the flow of the waste heat working medium flowing through a high-temperature heater 1 and the temperature of the waste heat working medium flowing through a low-temperature heater 8 can be changed by adjusting the flow ratio of a heat source shunt 1, so that the output power of the power generation cycle of the supercritical carbon dioxide and the power generation cycle of the transcritical carbon dioxide can be adjusted, and the maximum refrigerating capacity and the maximum generating capacity of the system can be adjusted.

Therefore, the carbon dioxide-based power generation and refrigeration combined system provided by the invention can fully recycle waste heat, ensure the energy conversion efficiency as high as possible, flexibly provide the generated energy and the refrigeration capacity, and meet different refrigeration temperature requirements. The specific implementation scheme of the invention is as follows: the waste heat carrier is divided into two parts after passing through the heat source splitter 1, part of the waste heat carrier transfers heat to the supercritical carbon dioxide power generation cycle working medium in the high-temperature heater 2, so that the temperature of the cycle working medium is raised to the highest cycle temperature, the heated carbon dioxide enters the high-temperature turbine 3 and expands in the high-temperature turbine 3 to do work, the heat energy of the supercritical carbon dioxide is converted into mechanical energy, and the mechanical energy is used for driving the compressor 7 to compress carbon dioxide flow and a first generator 16 which is coaxially connected to generate power; the carbon dioxide expanded by the high-temperature turbine 3 flows through the high-temperature heat regenerator 4 and the low-temperature heat regenerator 5 in sequence and releases heat therein; the carbon dioxide after heat release is cooled to the temperature near the critical point through a cooler 6; the cooled carbon dioxide gas flow enters a compressor 7 for pressurization, the power consumption of the compressor 7 is reduced due to the fact that the temperature is cooled to be close to the critical point of the carbon dioxide, the obtained high-pressure gas flow enters a high-temperature heater 2 after being subjected to heat absorption and temperature rise sequentially through a low-temperature heat regenerator 5 and a high-temperature heat regenerator 4, and the heat of a heat source is absorbed in the high-temperature heater 2 to further raise the temperature, so that a complete supercritical carbon dioxide power generation cycle is formed; the transcritical carbon dioxide power generation cycle working medium absorbs the heat of a mixed working medium formed by the other part of the waste heat carrier and the waste heat carrier at the outlet of the high-temperature heater 2 in the low-temperature heater 8, then the mixed working medium is heated and enters the low-temperature turbine 9 to do expansion work, the mechanical energy output by the expansion work of the low-temperature turbine 9 respectively drives the second generator 17 to generate power and the refrigeration compressor 15 to compress carbon dioxide, the carbon dioxide expanded by the low-temperature turbine 9 is converged into the inlet at the hot side of the low-temperature regenerator 5 to be mixed with the airflow at the outlet of the high-temperature regenerator 4, the mass flow of the fluid at the hot side of the low-temperature regenerator is increased, the heat capacity difference value of the fluid at the cold side and the hot side of the low-temperature regenerator 5 is reduced, and the problem of temperature pinch is avoided; the working medium mixed with the supercritical carbon dioxide power generation cycle working medium releases heat in the low-temperature heat regenerator 5, the cooled carbon dioxide airflow is further cooled to a liquid state through the cooler 6 and the condenser 10 in sequence, and after passing through the flow divider 19, the liquid carbon dioxide is pressurized by the booster pump 11 and then returns to the low-temperature heater 2 to absorb heat and fully utilize waste heat, so that a complete transcritical carbon dioxide power generation cycle is realized; the pressure of a transcritical carbon dioxide refrigeration cycle working medium flowing through the refrigeration compressor 15 is increased, the pressurized carbon dioxide sequentially flows through the cooler 6 and the condenser 10 to be cooled into liquid, the condensed carbon dioxide passes through the flow divider 19 and then is throttled, cooled and depressurized through the throttle valve 12 to reduce the temperature to the evaporation temperature, and then enters the evaporator 13 to absorb heat and evaporate into gas, so that the liquid carbon dioxide is refrigerated by utilizing the evaporation latent heat of the liquid carbon dioxide, the carbon dioxide flows back to the refrigeration compressor 15, the fluid on the other side of the evaporator 13 is cooled and then is supplied to a user 14 needing cold energy, a transcritical carbon dioxide refrigeration cycle is formed, and a complete carbon dioxide-based power generation and refrigeration system is formed.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The carbon dioxide-based power generation and refrigeration combined system provided by the application is described in detail above. The principles and embodiments of the present application are explained herein using specific examples, which are provided only to help understand the method and the core idea of the present application. It should be noted that, for those skilled in the art, it is possible to make several improvements and modifications to the present application without departing from the principle of the present application, and such improvements and modifications also fall within the scope of the claims of the present application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.