阅读说明：本技术 超临界二氧化碳热动力循环发电系统及其控制方法 (Supercritical carbon dioxide thermodynamic cycle power generation system and control method thereof ) 是由 宋盼盼 吴鼎 魏名山 田冉 郑思宇 于 2020-11-17 设计创作，主要内容包括：本发明公开了一种超临界二氧化碳热动力循环发电系统及其控制方法,包括电机设备、超临界二氧化碳概括性卡诺循环设备、冷却液循环设备、热流体循环设备,其中电机设备包括电动机和发电机；超临界二氧化碳概括性卡诺循环设备包括涡旋压缩机、涡旋膨胀机、回热器、高温换热器和低温换热器；冷却液循环设备包括冷却塔和冷却液循环泵,提供低温冷却液与超临界二氧化碳工质进行换热,确保涡旋压缩机进行等温压缩过程；热流体循环设备包括换热流体循环换热器和导热油循环泵,提供高温热流体与超临界二氧化碳工质进行换热,确保涡旋膨胀机进行等温膨胀过程；提供了实现超临界二氧化碳概括性卡诺循环的途径,高效地提高了循环热效率。(The invention discloses a supercritical carbon dioxide thermodynamic cycle power generation system and a control method thereof, wherein the system comprises motor equipment, supercritical carbon dioxide generalized Carnot cycle equipment, cooling liquid cycle equipment and hot fluid cycle equipment, wherein the motor equipment comprises a motor and a generator; the supercritical carbon dioxide generalized Carnot cycle equipment comprises a scroll compressor, a scroll expander, a heat regenerator, a high-temperature heat exchanger and a low-temperature heat exchanger; the cooling liquid circulating equipment comprises a cooling tower and a cooling liquid circulating pump, and provides low-temperature cooling liquid for exchanging heat with the supercritical carbon dioxide working medium to ensure that the scroll compressor performs an isothermal compression process; the hot fluid circulating equipment comprises a heat exchange fluid circulating heat exchanger and a heat conducting oil circulating pump, and provides high-temperature hot fluid for exchanging heat with a supercritical carbon dioxide working medium to ensure that the vortex expander performs an isothermal expansion process; provides a way for realizing the generalized Carnot cycle of the supercritical carbon dioxide, and efficiently improves the cycle thermal efficiency.)

1. A supercritical carbon dioxide thermodynamic cycle power generation system, comprising:

the motor equipment comprises a motor and a generator, wherein the generator is connected with a rotating shaft of the motor;

the generalized Carnot cycle equipment for supercritical carbon dioxide comprises a scroll compressor, a heat regenerator, a high-temperature heat exchanger, a scroll expander and a low-temperature heat exchanger, wherein the motor is connected with a main shaft of the scroll compressor, the generator is connected with a main shaft of the scroll expander, the outlet end of the carbon dioxide working medium side of the scroll compressor is connected with the inlet end of the heat absorption side of the heat regenerator, the outlet end of the heat absorption side of the heat regenerator is connected with the inlet end of the carbon dioxide working medium side of the high-temperature heat exchanger, the outlet end of the carbon dioxide working medium side of the high-temperature heat exchanger is connected with the inlet end of the carbon dioxide working medium side of the vortex expander, the outlet end of the carbon dioxide working medium side of the vortex expander is connected with the inlet end of the heat release side of the heat regenerator, the outlet end of the heat release side of the heat regenerator is connected with the inlet end of the carbon dioxide working medium side of the low-temperature heat exchanger, the outlet end of the carbon dioxide working medium side of the low-temperature heat exchanger is connected with the inlet end of the carbon dioxide working medium side of the scroll compressor;

the cooling liquid circulating equipment comprises a cooling tower and a cooling liquid circulating pump, wherein the outlet end of the cooling tower is connected with the inlet end of the cooling liquid circulating pump; the outlet end of the cooling liquid circulating pump is connected with the cooling liquid side inlet end of the low-temperature heat exchanger, and the cooling liquid side outlet end of the low-temperature heat exchanger is connected with the inlet end of the cooling tower; the outlet end of the cooling liquid circulating pump is connected with the cooling liquid side inlet end of the scroll compressor, and the cooling liquid side outlet end of the scroll compressor is connected with the inlet end of the cooling tower;

the hot fluid circulating equipment comprises a heat exchange fluid circulating heat exchanger and a heat conduction oil circulating pump, wherein the outlet end of the heat exchange fluid circulating heat exchanger is connected with the inlet end of the heat conduction oil circulating pump; the outlet end of the heat-conducting oil circulating pump is connected with the heat-conducting oil side inlet end of the high-temperature heat exchanger, and the heat-conducting oil side outlet end of the high-temperature heat exchanger is connected with the inlet end of the heat-exchanging fluid circulating heat exchanger; the outlet end of the heat-conducting oil circulating pump is connected with the inlet end of the heat-conducting oil side of the vortex expander, and the outlet end of the heat-conducting oil side of the vortex expander is connected with the inlet end of the heat-exchanging fluid circulating heat exchanger.

2. The system of claim 1, wherein the generator and the shaft of the motor are coupled by a coupling.

3. The system of claim 1, wherein the scroll compressor comprises a first scroll wrap heat exchange microchannel, the scroll compressor coolant side inlet end connected to the first scroll wrap heat exchange microchannel inlet end, the first scroll wrap heat exchange microchannel outlet end connected to the scroll compressor coolant side outlet end.

4. The system of claim 1, wherein the scroll expander comprises a second scroll heat exchange microchannel, the scroll expander thermally conductive oil side inlet end connected to the second scroll heat exchange microchannel inlet end, the second scroll heat exchange microchannel outlet end connected to the scroll expander thermally conductive oil side outlet end.

5. The system of claim 1, wherein the carbon dioxide working medium is isothermally compressed by the scroll compressor, enters an inlet end at a heat absorption side of the heat regenerator for preheating, enters the high-temperature heat exchanger for heat exchange with the heat exchange fluid, enters the scroll expander for isothermal expansion work, enters an inlet end at a heat release side of the heat regenerator for precooling, enters the low-temperature heat exchanger for heat exchange with the cooling liquid, and finally enters the scroll compressor to form a generalized Carnot cycle.

6. The system of claim 1, wherein the cooling liquid is cooled by the cooling tower to form a low-temperature cooling liquid, the low-temperature cooling liquid enters the cooling liquid circulating pump and then is divided into two paths, and the first path of low-temperature cooling liquid enters the low-temperature heat exchanger to exchange heat with the carbon dioxide working medium and then enters the cooling tower; and the second path of low-temperature cooling liquid enters the first vortex tooth heat exchange micro-channel of the scroll compressor to exchange heat with the carbon dioxide working medium, so that the scroll compressor performs isothermal compression and finally enters the cooling tower.

7. The system according to claim 1, wherein the hot fluid is heated by the heat exchange fluid circulating heat exchanger to form a high-temperature hot fluid which is divided into two paths after passing through the heat transfer oil circulating pump, and the first path of high-temperature hot fluid enters the high-temperature heat exchanger to exchange heat with the carbon dioxide working medium and then enters the heat exchange fluid circulating heat exchanger; and a second path of high-temperature hot fluid enters the second vortex tooth heat exchange micro-channel of the vortex expander to exchange heat with the carbon dioxide working medium, so that the vortex expander performs isothermal expansion and finally enters the heat exchange fluid circulation heat exchanger.

8. A control method for the supercritical carbon dioxide thermodynamic cycle power generation system according to claim 1, comprising:

starting the motor to drive the scroll compressor and the scroll expander to coaxially rotate;

the scroll compressor performs isothermal compression on the supercritical carbon dioxide working medium;

the heat absorption side of the heat regenerator receives the supercritical carbon dioxide working medium for preheating;

the supercritical carbon dioxide working medium enters a high-temperature heat exchanger to exchange heat with hot fluid;

the supercritical carbon dioxide working medium enters a vortex expander to do isothermal expansion work;

the heat regenerator heat release side precools the supercritical carbon dioxide working medium;

the supercritical carbon dioxide working medium enters a low-temperature heat exchanger to exchange heat with cooling liquid;

returning the supercritical carbon dioxide working medium to the scroll compressor for isothermal compression;

in the isothermal compression process, after the second path of low-temperature cooling liquid enters the first vortex tooth heat exchange microchannel connected with the cooling liquid side inlet end of the scroll compressor, the second path of low-temperature cooling liquid exchanges heat with a carbon dioxide working medium entering from the carbon dioxide working medium side inlet end of the scroll compressor in the scroll compressor;

in the isothermal expansion process, after the second path of high-temperature hot fluid enters the second vortex tooth heat exchange micro-channel connected with the inlet end of the heat conduction oil side of the vortex expander, the second path of high-temperature hot fluid exchanges heat with a carbon dioxide working medium entering from the inlet end of the carbon dioxide working medium side of the vortex expander in the vortex expander;

the scroll expander outputs expansion work, the first part of the expansion work directly drives the scroll compressor, and the second part of the expansion work generates electricity through the generator.

9. The control method according to claim 8, wherein the heat transfer oil circulating pump is controlled to be started to drive the high-temperature hot fluid to enter the scroll expander and the high-temperature heat exchanger respectively to exchange heat with the carbon dioxide working medium.

10. The control method according to claim 8, wherein the coolant circulating pump is controlled to start to drive the low-temperature coolant to enter the scroll compressor and the low-temperature heat exchanger respectively to exchange heat with the carbon dioxide working medium.

Technical Field

The disclosure relates to the technical field of thermodynamic processes and thermodynamic cycles, in particular to a supercritical carbon dioxide thermodynamic cycle power generation system and a control method thereof.

Background

The global energy crisis and the ecological environment deterioration are increasingly aggravated, and the sustainable development of the human society faces a serious challenge. The method follows a low-carbon economic development mode of low energy consumption, low pollution, low emission, high energy efficiency, high efficiency and high benefit, and is the only way for solving the energy crisis and the environmental pollution problem. In recent years, power generation using clean energy such as solar energy, tidal energy, wind energy, geothermal energy, and the like has attracted much attention. The distributed power generation and energy supply is one of important technical approaches for solving the difficult problem of clean energy utilization and realizing comprehensive and efficient cascade utilization of multi-quality energy.

In order to achieve efficient recovery of distributed waste heat, supercritical carbon dioxide (S-CO) has been used in recent years₂) The power generation technology becomes the research focus of the power generation technology in the international energy field. The traditional power generation system of a steam turbine and a gas turbine can only be used for recovering middle and high temperature waste heat, but S-CO₂The power generation technology adopts carbon dioxide as a circulating working medium, because CO₂The critical point temperature of the heat recovery system is lower (31.1 ℃, 7.39MPa), except in the field of middle-high temperature waste heat recovery, S-CO₂The power generation is also considered to have wide application prospect in the fields of low-grade heat sources such as waste heat power generation, solar thermal power generation, geothermal power generation and the like. At the same time, when CO₂When the liquid is in a supercritical state, the liquid has the special physical characteristics of low gas viscosity and high liquid density, and has the advantages of good fluidity, small specific volume, small compressibility, high heat transfer efficiency and the like. Compared with the traditional power generation system of a steam turbine and a gas turbine, the S-CO₂The circulation has the characteristics of simple system, compact structure, high heat efficiency, high safety and the like.

From the currently available S-CO₂The technical scheme of the thermodynamic cycle system is that S-CO₂The thermodynamic cycle comprises a plurality of closed Brayton power cycles including a simple regenerative cycle, a recompression cycle, a segmented expansion cycle and the like, but the net output work of the Brayton power cycle is low, so that a plurality of product-level heat source energies are generatedThe thermal cycling efficiency of the work conversion is relatively low.

In addition, the temperature of the carbon dioxide working medium is increased in the compression process, so that the working medium is inconvenient to compress, extra power consumption is increased for a compressor, and energy waste is caused. In the expansion process of the carbon dioxide working medium, the temperature of released heat is reduced, so that expansion work is inconvenient, the net output work is low, and the cycle efficiency of the whole power generation system is low.

Disclosure of Invention

The embodiment of the invention provides a supercritical carbon dioxide thermodynamic cycle power generation system and a control method thereof, which are used for solving the technical problem of low thermal cycle efficiency of multi-grade heat source energy conversion in the prior art.

The embodiment of the invention provides a supercritical carbon dioxide thermodynamic cycle power generation system, which comprises:

the motor equipment comprises a motor and a generator, wherein the generator is connected with a rotating shaft of the motor;

the generalized Carnot cycle equipment for supercritical carbon dioxide comprises a scroll compressor, a heat regenerator, a high-temperature heat exchanger, a scroll expander and a low-temperature heat exchanger, wherein the motor is connected with a main shaft of the scroll compressor, the generator is connected with a main shaft of the scroll expander, the outlet end of the carbon dioxide working medium side of the scroll compressor is connected with the inlet end of the heat absorption side of the heat regenerator, the outlet end of the heat absorption side of the heat regenerator is connected with the inlet end of the carbon dioxide working medium side of the high-temperature heat exchanger, the outlet end of the carbon dioxide working medium side of the high-temperature heat exchanger is connected with the inlet end of the carbon dioxide working medium side of the vortex expander, the outlet end of the carbon dioxide working medium side of the vortex expander is connected with the inlet end of the heat release side of the heat regenerator, the outlet end of the heat release side of the heat regenerator is connected with the inlet end of the carbon dioxide working medium side of the low-temperature heat exchanger, and the carbon dioxide working medium side air outlet end of the low-temperature heat exchanger is connected with the carbon dioxide working medium side inlet end of the scroll compressor.

The cooling liquid circulating equipment comprises a cooling tower and a cooling liquid circulating pump, wherein the outlet end of the cooling tower is connected with the inlet end of the cooling liquid circulating pump; the outlet end of the cooling liquid circulating pump is connected with the cooling liquid side inlet end of the low-temperature heat exchanger, and the cooling liquid side outlet end of the low-temperature heat exchanger is connected with the inlet end of the cooling tower; the outlet end of the cooling liquid circulating pump is connected with the cooling liquid side inlet end of the scroll compressor, and the cooling liquid side outlet end of the scroll compressor is connected with the inlet end of the cooling tower.

The hot fluid circulating equipment comprises a heat exchange fluid circulating heat exchanger and a heat conduction oil circulating pump, wherein the outlet end of the heat exchange fluid circulating heat exchanger is connected with the inlet end of the heat conduction oil circulating pump; the outlet end of the heat-conducting oil circulating pump is connected with the heat-conducting oil side inlet end of the high-temperature heat exchanger, and the heat-conducting oil side outlet end of the high-temperature heat exchanger is connected with the inlet end of the heat-exchanging fluid circulating heat exchanger; the outlet end of the heat-conducting oil circulating pump is connected with the inlet end of the heat-conducting oil side of the vortex expander, and the outlet end of the heat-conducting oil side of the vortex expander is connected with the inlet end of the heat-exchanging fluid circulating heat exchanger.

Optionally, the generator and the rotating shaft of the motor are connected through a coupling.

Optionally, the scroll compressor includes a first scroll tooth heat exchange microchannel, the scroll compressor coolant side inlet end is connected to the first scroll tooth heat exchange microchannel inlet end, the first scroll tooth heat exchange microchannel outlet end is connected to the scroll compressor coolant side outlet end.

Optionally, the scroll expander includes a second scroll heat exchange microchannel, the heat-conducting oil side inlet end of the scroll expander is connected to the second scroll heat exchange microchannel inlet end, and the second scroll heat exchange microchannel outlet end is connected to the heat-conducting oil side outlet end of the scroll expander.

The carbon dioxide working medium enters an inlet end at the heat absorption side of the heat regenerator for preheating after being subjected to isothermal compression by the scroll compressor, then enters the high-temperature heat exchanger for exchanging heat with the heat exchange fluid, then enters the scroll expander for performing isothermal expansion work, then enters an outlet end at the heat release side of the heat regenerator for precooling, then enters the low-temperature heat exchanger for exchanging heat with the cooling liquid, and finally enters the scroll compressor to form generalized Carnot cycle.

After the cooling liquid is cooled by the cooling tower, low-temperature cooling liquid is formed and enters the cooling liquid circulating pump and then is divided into two paths, and the first path of low-temperature cooling liquid enters the low-temperature heat exchanger to exchange heat with the carbon dioxide working medium and then enters the cooling tower; and the second path of low-temperature cooling liquid enters the first vortex tooth heat exchange micro-channel of the scroll compressor to exchange heat with the carbon dioxide working medium, so that the scroll compressor performs isothermal compression and finally enters the cooling tower.

The hot fluid is heated by the heat exchange fluid circulating heat exchanger to form high-temperature hot fluid, the high-temperature hot fluid is divided into two paths after passing through the heat transfer oil circulating pump, the first path of high-temperature hot fluid enters the high-temperature heat exchanger to exchange heat with the carbon dioxide working medium, and then enters the heat exchange fluid circulating heat exchanger; and a second path of high-temperature hot fluid enters the second vortex tooth heat exchange micro-channel of the vortex expander to exchange heat with the carbon dioxide working medium, so that the vortex expander performs isothermal expansion and finally enters the heat exchange fluid circulation heat exchanger.

The invention also provides a control method of the supercritical carbon dioxide thermodynamic cycle power generation system, which comprises the following steps:

starting the motor to drive the scroll compressor and the scroll expander to coaxially rotate;

the scroll compressor performs isothermal compression on the supercritical carbon dioxide working medium;

optionally, in the isothermal compression process, after the second path of low-temperature cooling liquid enters the first scroll tooth heat exchange microchannel connected to the cooling liquid side inlet end of the scroll compressor, heat exchange is performed between the second path of low-temperature cooling liquid and a carbon dioxide working medium entering from the carbon dioxide working medium side inlet end of the scroll compressor in the scroll compressor;

the heat absorption side of the heat regenerator receives the supercritical carbon dioxide working medium for preheating;

the supercritical carbon dioxide working medium enters a high-temperature heat exchanger to exchange heat with hot fluid;

the supercritical carbon dioxide working medium enters a vortex expander to do isothermal expansion work;

optionally, in the isothermal expansion process, after the second path of high-temperature hot fluid enters the second vortex tooth heat exchange microchannel connected to the inlet end of the heat conduction oil side of the scroll expander, heat exchange is performed between the second path of high-temperature hot fluid and a carbon dioxide working medium entering from the inlet end of the carbon dioxide working medium side of the scroll expander in the scroll expander;

the heat regenerator heat release side precools the supercritical carbon dioxide working medium;

the supercritical carbon dioxide working medium enters a low-temperature heat exchanger to exchange heat with cooling liquid;

returning the supercritical carbon dioxide working medium to the scroll compressor for isothermal compression;

optionally, the scroll expander outputs expansion work, a first portion of the expansion work directly drives the scroll compressor, and a second portion of the expansion work generates electricity via the generator.

Optionally, the heat transfer oil circulating pump is controlled to be started, and the high-temperature hot fluid is driven to enter the vortex expander and the high-temperature heat exchanger respectively to exchange heat with the carbon dioxide working medium.

Optionally, the cooling liquid circulating pump is controlled to be started to drive the low-temperature cooling liquid to respectively enter the scroll compressor and the low-temperature heat exchanger to exchange heat with the carbon dioxide working medium.

The supercritical carbon dioxide thermodynamic cycle power generation system and the control method thereof provided by the embodiment of the invention establish a supercritical carbon dioxide generalized Carnot cycle loop, realize an isothermal compression process through cooling liquid cycle equipment, realize an isothermal expansion process through hot fluid cycle equipment, use carbon dioxide which is environment-friendly, stable, environment-friendly, cheap and has low critical temperature as a generalized Carnot cycle system working medium, realize the approach of supercritical carbon dioxide generalized Carnot cycle, supplement and perfect the technology of small-sized supercritical carbon dioxide cycle power generation, compared with the prior art, the net output power is higher, the cycle efficiency is high, the realization is convenient, particularly, a vortex tooth heat exchange micro-channel is arranged in a vortex compressor and a vortex expander, the temperature is not increased in the compression process, the temperature is not reduced in the expansion process, the cycle heat efficiency is improved, and the high-efficiency utilization of multi-grade heat energy is realized, the performance of the conventional supercritical carbon dioxide circulating power generation system is further improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure.

In order to more clearly illustrate the embodiments or technical solutions in the prior art of the present disclosure, the drawings used in the description of the embodiments or prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.

FIG. 1 is a schematic diagram of a generalized Carnot cycle and Brayton cycle according to an embodiment of the present disclosure;

FIG. 2 is a schematic structural diagram of a first embodiment of a supercritical carbon dioxide thermodynamic cycle power generation system provided in a first embodiment of the present disclosure;

FIG. 3 is a schematic diagram illustrating specific device connections of an embodiment of a supercritical carbon dioxide thermodynamic cycle power generation system provided in accordance with an embodiment of the present disclosure;

FIG. 4 is a schematic flow chart of the method for controlling the supercritical carbon dioxide thermodynamic cycle power generation provided in the second embodiment of the present disclosure;

reference numerals indicate, among others, 21-a scroll compressor, 12-a motor, 23-a high-temperature heat exchanger, 24-a scroll expander, 15-a generator, 26-a regenerator, 27-a low-temperature heat exchanger, 48-a heat exchange fluid circulation heat exchanger, 39-a cooling tower, 42-a heat transfer oil circulation pump, 31-a coolant circulation pump, and 13-a coupling.

Detailed Description

In order that the above objects, features and advantages of the present disclosure may be more clearly understood, aspects of the present disclosure will be further described below. It should be noted that the embodiments and features of the embodiments of the present disclosure may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure, but the present disclosure may be practiced in other ways than those described herein; it is to be understood that the embodiments disclosed in the specification are only a few embodiments of the present disclosure, and not all embodiments.

FIG. 1 is a schematic diagram of a generalized Carnot cycle and Brayton cycle. Wherein, the process of the general Carnot cycle principle diagram is 1-2-3-4, and the process of the Brayton cycle principle diagram is 1-2 ' -3 ' -4 '.

As can be seen from fig. 1, comparing the cycle schematic diagrams of the brayton cycle and the generalized carnot cycle, under the same high and low temperature heat source conditions, the net output work of the generalized carnot cycle is higher than that of the brayton cycle, and the cycle thermal efficiency is also higher than that of the brayton cycle, so that the supercritical carbon dioxide generalized carnot cycle thermal power generation is realized, and the cycle efficiency can be effectively improved.

The first embodiment is as follows:

in order to solve the technical problem of low thermal power cycle efficiency in the prior art, the embodiment of the invention provides a supercritical carbon dioxide thermal power cycle power generation system. Fig. 2 is a schematic structural diagram of an embodiment of a supercritical carbon dioxide thermodynamic cycle power generation system according to an embodiment of the present disclosure. Specifically, as shown in fig. 2, the system comprises a motor device 1, a supercritical carbon dioxide generalized carnot cycle device 2, a cooling liquid cycle device 3, and a hot fluid cycle device 4, wherein:

the motor device 1 comprises a motor 12 and a generator 15, wherein the generator 15 is connected with a rotating shaft of the motor 12.

Preferably, the generator 15 and the rotating shaft of the motor 12 are connected through a coupling 13.

Specifically, in the initial stage of the start-up of the supercritical carbon dioxide thermodynamic cycle power generation system, the electric motor 2 is energized to start the cycle. After the system works stably in a circulating mode, the rotating speed of the motor 12 can be automatically adjusted according to requirements, and the circulating working condition of the system can be further adjusted conveniently.

The generalized Carnot cycle equipment 2 for supercritical carbon dioxide comprises a scroll compressor 21, a heat regenerator 26, a high-temperature heat exchanger 23, a scroll expander 24 and a low-temperature heat exchanger 27, wherein the motor 12 is connected with a main shaft of the scroll compressor 21, the generator 15 is connected with a main shaft of the scroll expander 24, a carbon dioxide working medium side outlet end 212 of the scroll compressor is connected with a heat absorption side inlet end 261 of the heat regenerator, a heat absorption side outlet end 262 of the heat regenerator is connected with a carbon dioxide working medium side inlet end 231 of the high-temperature heat exchanger, a carbon dioxide working medium side outlet end 232 of the high-temperature heat exchanger is connected with a carbon dioxide working medium side inlet end 241 of the scroll expander, a carbon dioxide working medium side outlet end 242 of the scroll expander is connected with a heat release side inlet end 263 of the heat regenerator, and a heat release side outlet, the outlet end 272 of the carbon dioxide working medium side of the low-temperature heat exchanger is connected with the inlet end 211 of the carbon dioxide working medium side of the scroll compressor;

optionally, the scroll compressor 21 includes a first scroll wrap heat exchange microchannel 215, the scroll compressor coolant side inlet end 213 being connected to the first scroll wrap heat exchange microchannel inlet end 2151, the first scroll wrap heat exchange microchannel outlet end 2152 being connected to the scroll compressor coolant side outlet end 214.

It can be understood that the scroll compressor 21 is internally provided with a first scroll tooth heat exchange micro-channel 215 with a new structure, low-temperature cooling liquid flowing through the scroll compressor 21 enters the first scroll tooth heat exchange micro-channel 215 through the cooling liquid side inlet end 213 of the scroll compressor, and exchanges heat with carbon dioxide working medium entering from the carbon dioxide working medium side inlet end of the scroll compressor in the scroll compressor, so that the temperature of the working medium is not increased, isothermal compression is performed, and extra power consumption is reduced.

Optionally, the scroll expander 24 comprises a second scroll heat exchange microchannel 245, the scroll expander thermally conductive oil side inlet end 243 connecting the second scroll heat exchange microchannel inlet end 2451, the second scroll heat exchange microchannel outlet end 2452 connecting the scroll expander thermally conductive oil side outlet end 244.

It can be understood that, a second scroll tooth heat exchange micro-channel 245 with a new structure is arranged in the scroll expander 24, and the high-temperature hot fluid flowing through the scroll expander 24 enters the second scroll tooth heat exchange micro-channel 245 through the side inlet end 243 of the heat-conducting oil of the scroll expander, and exchanges heat with the carbon dioxide working medium entering from the side inlet end 241 of the carbon dioxide working medium of the scroll compressor in the scroll expander 24, so as to ensure that the temperature of the working medium is not reduced, perform isothermal expansion, and improve output power.

Preferably, the scroll compressor 21, the regenerator 26, the high temperature heat exchanger 23, the scroll expander 24 and the low temperature heat exchanger 27 are sequentially connected by a pipeline.

It will be appreciated that the regenerator interior contains a heat-emitting channel and a heat-absorbing channel.

The cooling liquid circulating equipment 3 comprises a cooling tower 39 and a cooling liquid circulating pump 31, wherein the outlet end 391 of the cooling tower is connected with the inlet end 311 of the cooling liquid circulating pump; wherein the coolant circulation pump outlet port 312 is connected to the cryogenic heat exchanger coolant side inlet port 273 and the cryogenic heat exchanger coolant side outlet port 274 is connected to the cooling tower inlet port 392; wherein the cooling fluid circulation pump outlet port 312 is connected to the scroll compressor cooling fluid side inlet port 213, and the scroll compressor cooling fluid side outlet port 214 is connected to the cooling tower inlet port 392;

it can be understood that, the cooling liquid circulation device 3 includes 2 cooling liquid circulation loops, the cooling liquid releases heat and cools in the cooling tower 39 to form a low-temperature cooling liquid, and then flows through the cooling liquid circulation pump 31 to flow into the low-temperature heat exchanger 27 and the scroll compressor 21 respectively to exchange heat with the carbon dioxide working fluid, and then flows into the cooling tower 39 respectively to complete 2 circulation loops. The 2 cooling liquid circulation loops are respectively a heat exchange loop consisting of the low-temperature heat exchanger 27, the cooling tower 39 and the cooling liquid circulation pump 31, and an isothermal compression loop consisting of the scroll compressor 21, the cooling tower 39 and the cooling liquid circulation pump 31. The cooling tower 39 and the coolant circulation pump 31 provide low temperature coolant to the cryogenic heat exchanger 27 and the scroll compressor 21.

Preferably, the cooling liquid can select water as a working medium.

The thermal fluid circulation equipment 4 comprises a heat exchange fluid circulation heat exchanger 48 and a heat transfer oil circulation pump 42, wherein the outlet end 481 of the heat exchange fluid circulation heat exchanger is connected with the inlet end 421 of the heat transfer oil circulation pump; the outlet end 422 of the heat transfer oil circulating pump is connected with the heat transfer oil side inlet end 233 of the high-temperature heat exchanger, and the outlet end 234 of the heat transfer oil side of the high-temperature heat exchanger is connected with the inlet end 482 of the heat exchange fluid circulating heat exchanger; the outlet end 422 of the heat-conducting oil circulating pump is connected with the heat-conducting oil side inlet end 243 of the scroll expander, and the outlet end 244 of the heat-conducting oil side of the scroll expander is connected with the inlet end 482 of the heat-exchanging fluid circulating heat exchanger.

It can be understood that the thermal fluid circulation device 4 comprises 2 thermal fluid circulation loops, the thermal fluid absorbs heat from a heat source in the heat exchange fluid circulation heat exchanger 48 to form a high-temperature thermal fluid, then flows through the heat transfer oil circulation pump 42, flows into the high-temperature heat exchanger 23 and the scroll expander 24 respectively to exchange heat with a carbon dioxide working medium, and then flows into the heat exchange fluid circulation heat exchanger 48 respectively to complete 2 circulation loops respectively. The 2 thermal fluid circulation loops are respectively a heat exchange loop consisting of the high-temperature heat exchanger 23, the heat exchange fluid circulation heat exchanger 48 and the heat transfer oil circulation pump 42, and an isothermal expansion loop consisting of the scroll expander 24, the heat exchange fluid circulation heat exchanger 48 and the heat transfer oil circulation pump 42. The heat exchange fluid circulation heat exchanger 48 and the conduction oil circulation pump 42 supply high temperature thermal fluid to the high temperature heat exchanger 23 and the scroll expander 24.

Preferably, the hot fluid can select heat transfer oil as a working medium.

Optionally, the heat absorbed by the thermal fluid circulation is used as a heat source of the supercritical carbon dioxide circulation, the supercritical carbon dioxide working medium is heated by the high-temperature heat exchanger 23, and the high-temperature and high-pressure supercritical carbon dioxide working medium pushes the scroll expander 24 to do work and generate power.

It should be noted that the scroll compressor 21, the high-temperature heat exchanger 23, the scroll expander 24, the low-temperature heat exchanger 27, and the supercritical carbon dioxide generalized carnot cycle device 2, which are described in the circulation circuits related to the cooling liquid circulation device 3 and the hot fluid circulation device 4, are the same device.

The carbon dioxide working medium enters the inlet end 261 of the heat absorption side of the heat regenerator for preheating after being subjected to isothermal compression by the scroll compressor 21, then enters the high-temperature heat exchanger 23 for heat exchange with the heat exchange fluid, then enters the scroll expander 24 for isothermal expansion work, then enters the outlet end 262 of the heat release side of the heat regenerator for precooling, then enters the low-temperature heat exchanger 27 for heat exchange with the cooling liquid, and finally enters the scroll compressor 21 to form the generalized Carnot cycle.

After the cooling liquid is cooled by the cooling tower 39, low-temperature cooling liquid is formed and enters the cooling liquid circulating pump 31 and then is divided into two paths, the first path of low-temperature cooling liquid enters the low-temperature heat exchanger 27 to exchange heat with the carbon dioxide working medium, and then enters the cooling tower 39; and the second path of low-temperature cooling liquid enters the first vortex tooth heat exchange micro-channel 215 of the scroll compressor 21 to exchange heat with the carbon dioxide working medium, so that the scroll compressor 21 is subjected to isothermal compression, and finally enters the cooling tower 39.

The hot fluid is heated by the heat exchange fluid circulating heat exchanger 48 to form high-temperature hot fluid, the high-temperature hot fluid is divided into two paths after passing through the heat transfer oil circulating pump 42, the first path of high-temperature hot fluid enters the high-temperature heat exchanger 23 to exchange heat with the carbon dioxide working medium, and then enters the heat exchange fluid circulating heat exchanger 48; and the second path of high-temperature hot fluid enters the second vortex tooth heat exchange micro-channel 245 of the vortex expander 24 to exchange heat with the carbon dioxide working medium, so that the vortex expander 24 performs isothermal expansion, and finally enters the heat exchange fluid circulation heat exchanger 48.

The embodiment provides a supercritical carbon dioxide thermodynamic cycle power generation system, which comprises motor equipment, supercritical carbon dioxide generalized Carnot cycle equipment, cooling liquid cycle equipment and thermal fluid cycle equipment, and realizes a way of supercritical carbon dioxide generalized Carnot cycle, realizes multi-grade heat source function conversion with higher cycle efficiency, and supplements and perfects a microminiature supercritical carbon dioxide cycle power generation technology. Compared with the prior art, the method improves S-CO₂The circulation efficiency and the output power of the circulation system, particularly the vortex tooth heat exchange micro-channel arranged in the vortex compressor and the vortex expander, ensure that the temperature is not increased in the compression process and not reduced in the expansion process, effectively avoid the generation of extra power consumption, save energy,the high-efficiency utilization of multi-grade heat energy is realized, the waste heat recovery is carried out, and the performance of the supercritical carbon dioxide circulating power generation system is further improved.

Example two:

based on the same inventive concept as that of the first embodiment of the present invention, the second embodiment of the present invention provides a control method for a supercritical carbon dioxide thermodynamic cycle power generation system, which is applicable to the supercritical carbon dioxide thermodynamic cycle power generation system described in the first embodiment, and the same contents will not be described in detail. Fig. 4 is a schematic flow chart of the supercritical carbon dioxide thermodynamic cycle power generation control method provided in the second embodiment of the present invention. The specific control method comprises the following steps:

step 1101: starting the motor to drive the scroll compressor and the scroll expander to coaxially rotate;

step 1102: the scroll compressor performs isothermal compression on the supercritical carbon dioxide working medium;

step 1103: the heat absorption side of the heat regenerator receives the supercritical carbon dioxide working medium for preheating;

step 1104: the supercritical carbon dioxide working medium enters a high-temperature heat exchanger to exchange heat with hot fluid;

step 1105: the supercritical carbon dioxide working medium enters a vortex expander to do isothermal expansion work;

step 1106: the heat regenerator heat release side precools the supercritical carbon dioxide working medium;

step 1107: the supercritical carbon dioxide working medium enters a low-temperature heat exchanger to exchange heat with cooling liquid;

step 1108: and returning the supercritical carbon dioxide working medium to the scroll compressor for isothermal compression.

That is, the motor is controlled to start to drive the scroll compressor and the scroll expander to coaxially rotate, the supercritical carbon dioxide working medium starts to circularly flow, the carbon dioxide working medium is isothermally compressed after the scroll compressor is started, enters the heat absorption inlet end of the heat regenerator from the outlet end of the carbon dioxide working medium side of the scroll compressor for preheating, enters the inlet end of the carbon dioxide working medium side of the high-temperature heat exchanger from the outlet end of the heat absorption side of the heat regenerator for heat exchange with the hot fluid, enters the scroll expander from the outlet end of the carbon dioxide working medium side of the high-temperature heat exchanger for isothermal expansion work, enters the inlet end of the heat release side of the heat regenerator from the outlet end of the carbon dioxide working medium side of the scroll expander for precooling, enters the inlet end of the carbon dioxide working medium side of the low-temperature heat exchanger from the outlet end of the, and finally, the carbon dioxide working medium side outlet end of the low-temperature heat exchanger enters the carbon dioxide working medium side inlet end of the scroll compressor.

Optionally, in the step 1101, performing an isothermal compression process, after the second path of low-temperature cooling liquid enters the first scroll heat exchange microchannel connected to the cooling liquid side inlet end of the scroll compressor, performing heat exchange with a carbon dioxide working medium entering from the carbon dioxide working medium side inlet end of the scroll compressor in the scroll compressor;

optionally, in the step 1105, an isothermal expansion process is performed, that is, after the second path of high-temperature hot fluid enters the second scroll heat exchange microchannel connected to the inlet end of the heat conduction oil side of the scroll expander, heat exchange is performed between the second path of high-temperature hot fluid and the carbon dioxide working fluid entering from the inlet end of the carbon dioxide working fluid side of the scroll expander in the scroll expander;

optionally, the step 1105 allows the scroll expander to output expansion work, a first portion of the expansion work directly drives the scroll compressor, and a second portion of the expansion work generates electricity via the generator.

Optionally, in the step 1104, the hot fluid is started by controlling the heat transfer oil circulating pump to drive the high-temperature hot fluid to enter the scroll expander and the high-temperature heat exchanger respectively to exchange heat with a carbon dioxide working medium.

Optionally, in step 1107, the cooling fluid is started by controlling the cooling fluid circulation pump to drive the low-temperature cooling fluid to enter the scroll compressor and the low-temperature heat exchanger respectively to exchange heat with the carbon dioxide working medium.

The second embodiment of the invention provides a control method of a supercritical carbon dioxide thermodynamic cycle power generation system, which comprises the steps of starting a motor and then driving a scroll compressor and a scroll expander cylinder shaft to rotate;

then the scroll compressor performs isothermal compression on the supercritical carbon dioxide working medium; the heat regenerator receives the supercritical carbon dioxide working medium for preheating; the supercritical carbon dioxide working medium enters a high-temperature heat exchanger to exchange heat with hot fluid; then, the supercritical carbon dioxide working medium enters a vortex expander to do isothermal expansion work; precooling the supercritical carbon dioxide working medium by a heat regenerator; the supercritical carbon dioxide working medium enters a low-temperature heat exchanger to exchange heat with cooling liquid; and returning the supercritical carbon dioxide working medium to the scroll compressor for isothermal compression. The method has the advantages that the generalized Carnot circulation approach of the supercritical carbon dioxide is realized, the microminiature supercritical carbon dioxide circulation power generation technology is supplemented and perfected, compared with the prior art, the net output power is higher, the circulation efficiency is high, the realization is convenient, particularly, vortex tooth heat exchange microchannels are arranged in a vortex compressor and a vortex expander, the temperature is not increased in the compression process, the temperature is not reduced in the expansion process, the generation of extra power consumption is effectively avoided, the energy is saved, the high-efficiency utilization of multi-grade heat energy is realized, the waste heat recovery is carried out, and the performance of the conventional supercritical carbon dioxide power generation system is further improved.

It is noted that, in this document, relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The foregoing are merely exemplary embodiments of the present disclosure, which enable those skilled in the art to understand or practice the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the present disclosure 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.