阅读说明：本技术 一种基于全流与三角闪蒸循环耦合的地热能发电系统 (Geothermal energy power generation system based on full flow and triangular flash cycle coupling ) 是由 王增丽 周宏洋 王青阳 袁麒镇 张泉 丁承文 朱澳 吕越 姚天宇 于 2021-02-02 设计创作，主要内容包括：本发明提供了一种基于全流与三角闪蒸循环耦合的地热能发电系统,包括全流循环系统和三角闪蒸循环系统；全流循环系统包括中高温膨胀机和换热器,地热井、中高温膨胀机、换热器和回灌井通过管道依次连接,管道近地热井一侧设置有节流阀,近中高温膨胀机进口端一侧设置有截止阀,近换热器进口端一侧设置有温度传感器；三角闪蒸循环系统包括变频工质泵、闪蒸罐、两相膨胀机和冷凝器,冷凝器的出口端与变频工质泵、换热器、闪蒸罐和两相膨胀机依次相连,两相膨胀机出口端与冷凝器进口端相连接,形成闭合回路。本发明减少了系统间的换热损失,有效解决了因地热能不稳定导致膨胀机效率波动的问题,提高了地热能利用率。(The invention provides a geothermal energy power generation system based on full flow and triangular flash evaporation cycle coupling, which comprises a full flow cycle system and a triangular flash evaporation cycle system; the full-flow circulating system comprises a medium-high temperature expander and a heat exchanger, the geothermal well, the medium-high temperature expander, the heat exchanger and the recharge well are sequentially connected through a pipeline, a throttling valve is arranged on one side of the pipeline close to the geothermal well, a stop valve is arranged on one side close to the inlet end of the medium-high temperature expander, and a temperature sensor is arranged on one side close to the inlet end of the heat exchanger; the triangular flash evaporation circulating system comprises a variable frequency working medium pump, a flash evaporation tank, a two-phase expansion machine and a condenser, wherein the outlet end of the condenser is sequentially connected with the variable frequency working medium pump, a heat exchanger, the flash evaporation tank and the two-phase expansion machine, and the outlet end of the two-phase expansion machine is connected with the inlet end of the condenser to form a closed loop. The invention reduces the heat exchange loss among systems, effectively solves the problem of the fluctuation of the efficiency of the expansion machine caused by the instability of geothermal energy, and improves the utilization rate of the geothermal energy.)

1. A geothermal energy power generation system based on full flow and triangular flash evaporation cycle coupling is characterized by comprising a full flow cycle system and a triangular flash evaporation cycle system;

the full-flow circulating system comprises a medium-high temperature expander (2) and a heat exchanger (3), wherein the inlet end of the medium-high temperature expander (2) is connected with a geothermal well through a pipeline, a throttling valve (1) is arranged on the pipeline close to one side of the geothermal well, the outlet end of the medium-high temperature expander (2) is connected with the first inlet end of the heat exchanger (3) through a pipeline, a temperature sensor (8) is arranged on the pipeline close to one side of the first inlet end of the heat exchanger (3), and the first outlet end of the heat exchanger (3) is connected with a recharge well;

the triangular flash evaporation circulating system comprises a variable frequency working medium pump (7), a flash evaporation tank (4), a two-phase expander (5) and a condenser (6), wherein the inlet end of the variable frequency working medium pump (7) is connected with the outlet end of the condenser (6), the outlet end of the variable frequency working medium pump (7) is connected with the second inlet end of the heat exchanger (3) through a pipeline, the second outlet end of the heat exchanger (3) is connected with the inlet end of the flash evaporation tank (4) through a pipeline, the outlet end of the flash evaporation tank (4) is connected with the inlet end of the two-phase expander (5), and the outlet end of the two-phase expander (5) is connected;

the medium-high temperature expander (2) and the two-phase expander (5) are used for generating electricity.

2. The geothermal power generation system based on the coupling of the full flow and the triangular flash circulation according to claim 1, wherein the full flow circulation system is provided with a first stop valve (9) on the pipeline close to the medium-high temperature expander (2), and the triangular flash circulation system is provided with a second stop valve (10) on the pipeline close to the inlet end of the flash tank (4).

3. The geothermal energy power generation system based on full-flow and triangular flash evaporation cycle coupling according to claim 1, wherein the temperature sensor (8) is used for measuring the temperature of the working medium entering the first inlet end of the heat exchanger (3), and the variable frequency working medium pump (7) is used for adjusting the pressure of the working medium entering the second inlet end of the heat exchanger (3).

4. The geothermal energy power generation system based on full-flow and triangular flash circulation coupling of claim 1, wherein in the triangular flash circulation system, the flash tank (4), the two-phase expander (5), the condenser (6) and the variable frequency working medium pump (7) are connected in sequence through pipelines.

Technical Field

The invention relates to the field of geothermal energy utilization, in particular to a geothermal energy power generation system based on full flow and triangular flash evaporation cycle coupling.

Background

At present, the situation of resource shortage in the world is more prominent, and although the utilization rate of traditional resources such as coal, petroleum, natural gas and the like is higher, the problems of environmental pollution, no regeneration and the like are also existed. As a country with large energy consumption, China needs to pay more attention to the utilization condition of resources, and in recent years, with the increasing attention to the protection of ecological environment, the sustainable development strategy is adopted as a basis, and the research on developing renewable clean energy is gradually on the way. Therefore, it is important to improve the utilization of clean energy.

Renewable energy geothermal energy belongs to a low-grade heat source and can be divided into three grades according to the temperature of geothermal energy, namely high-temperature geothermal energy ()>423.15K), intermediate-temperature geothermal energy (363.15K-423.15K) and low-temperature geothermal energy (<363.15K). The earth stores huge geothermal energy, and the total heat content of rocks and liquid with the temperature of more than 15 ℃ at the position 5km away from the earth surface is estimated to be 14.5 multiplied by 10²⁵J, equivalent to 4948 trillion tons of standard coal. Compared with other renewable energy sources, the geothermal energy has the biggest characteristics of stability and continuity. In recent years, geothermal energy has been receiving more and more attention and use from researchers due to its advantages. The utilization of geothermal energy directly reduces the use of fossil energy, and further reduces the environmental pollutants generated by using the fossil energy, thereby realizing the methodThe contradiction between the increase of energy demand and the gradual deterioration of the environment in China is relieved to a certain extent.

Although many researchers have studied the organic rankine cycle as one of the mainstream cycles for waste heat utilization in recent years, the thermal efficiency thereof is still about 20% and is not improved in a breakthrough manner, and other new power generation cycles such as flash power generation and dry steam power generation cannot greatly improve the thermal efficiency even if the geothermal energy cycle is used, and thus the organic rankine cycle is difficult to be put into commercial use. Therefore, researchers put eyes on the coupling of the circulation at present, because the working medium used by the organic Rankine cycle is the low-boiling-point organic working medium, the working medium used by the triangular flash evaporation cycle is the two-phase flow wet steam, and the temperature of the required heat source is not high, the working medium can be considered as the bottom circulation, the waste heat of the top circulation can be continuously utilized, the utilization rate of the heat source is effectively improved, and the industrial utilization value of the whole circulation is improved.

Disclosure of Invention

The invention aims to solve the problems and provides a geothermal energy power generation system based on full-flow and triangular flash evaporation cycle coupling.

In order to achieve the purpose, the invention adopts the following technical scheme:

a geothermal energy power generation system based on full flow and triangular flash circulation coupling comprises a full flow circulation system and a triangular flash circulation system;

the full-flow circulating system comprises a medium-high temperature expander and a heat exchanger, wherein the inlet end of the medium-high temperature expander is connected with the geothermal well through a pipeline, a throttling valve is arranged on the pipeline close to one side of the geothermal well, the outlet end of the medium-high temperature expander is connected with the first inlet end of the heat exchanger through a pipeline, a temperature sensor is arranged on the pipeline close to one side of the first inlet end of the heat exchanger, and the first outlet end of the heat exchanger is connected with the recharge well;

the triangular flash evaporation circulating system comprises a variable frequency working medium pump, a flash evaporation tank, a two-phase expander and a condenser, wherein the inlet end of the variable frequency working medium pump is connected with the outlet end of the condenser, the outlet end of the variable frequency working medium pump is connected with the second inlet end of the heat exchanger through a pipeline, the second outlet end of the heat exchanger is connected with the inlet end of the flash evaporation tank through a pipeline, the outlet end of the flash evaporation tank is connected with the inlet end of the two-phase expander, and the outlet end of the two-;

the medium-high temperature expander and the two-phase expander are used for generating electricity.

Preferably, in the full-flow circulation system, a first stop valve is arranged on a pipeline on one side close to the medium-high temperature expander, and in the triangular flash circulation system, a second stop valve is arranged on a pipeline on one side close to an inlet end of the flash tank.

Preferably, the temperature sensor is used for measuring the temperature of the working medium entering the first inlet end of the heat exchanger, and the variable frequency working medium pump is used for adjusting the pressure of the working medium entering the second inlet end of the heat exchanger.

Preferably, in the triangular flash circulation system, the flash tank, the two-phase expander, the condenser and the variable frequency working medium pump are sequentially connected through pipelines.

The invention has the following beneficial technical effects:

the invention utilizes the heat exchanger to couple the full-flow circulation system and the triangular flash evaporation circulation system, reduces the temperature of the geothermal water which is recharged in the full-flow circulation system, does not need to arrange a condenser in front of a recharging well, reduces the cost, utilizes the heat exchanger to heat the working medium in the triangular flash evaporation circulation system, fully utilizes the vaporization potential of the dead steam generated by the full-flow circulation system, improves the utilization rate of a heat source, and further improves the overall heat efficiency of the system.

The invention adopts the medium-high temperature expander and the two-phase expander, the operation condition is loose, the service life of the machine is long, the working medium in the full-flow circulating system adopts geothermal water, the energy is saved, the environment is protected, the corrosivity is small, the obtaining is easy, the safety is high, the special treatment on the working medium is not needed, the working medium at the inlet end of the expander is not needed to be heated into dry steam, the gas-liquid mixture can be directly used for expansion and work, meanwhile, the full-flow circulating system and the triangular flash evaporation circulating system are coupled, only one heat exchanger is needed to carry out once heat exchange, the heat efficiency of the system is ensured not to be reduced due to the increase of the number of.

According to the invention, the temperature sensor is used for monitoring the temperature of the exhaust steam at the outlet of the high-temperature expansion machine in the full-flow circulating system in real time, and the variable-frequency working medium pump in the triangular flash evaporation circulating system is matched, so that the working medium in the triangular flash evaporation circulating system is maintained in a saturated state under the pressure condition and does not generate an evaporation phase change state, the problem that the heat exchange effect of the heat exchanger cannot be kept constant due to unstable geothermal energy and small-amplitude fluctuation easily generated is solved, and a solution is provided for realizing automatic control of geothermal resource temperature fluctuation.

Drawings

FIG. 1 is a schematic structural diagram of a geothermal energy power generation system according to the present invention.

In the figure: 1. the system comprises a throttling valve, 2, a medium-high temperature expander, 3, a heat exchanger, 4, a flash tank, 5, a two-phase expander, 6, a condenser, 7, a variable frequency working medium pump, 8, a temperature sensor, 9, a first stop valve, 10 and a second stop valve.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

A geothermal energy power generation system based on full-flow and triangular flash circulation coupling is shown in figure 1 and comprises a full-flow circulation system and a triangular flash circulation system.

The full-flow circulation system comprises a medium-high temperature expansion machine 2 and a heat exchanger 3, wherein the medium-high temperature expansion machine 2 is used for generating electricity, an inlet end of the medium-high temperature expansion machine is connected with a geothermal well through a pipeline, a throttling valve 1 is arranged on one side of the pipeline close to the geothermal well, the throttling valve 1 is used for throttling and depressurizing working media in the pipeline, a first stop valve 9 is arranged on one side of the pipeline close to the inlet end of the medium-high temperature expansion machine 2, the first stop valve 9 is used for stopping the full-flow circulation system in emergency or in the troubleshooting and overhauling process, an outlet end of the medium-high temperature expansion machine 2 is connected with a first inlet end of the heat exchanger 3 through a pipeline, a temperature sensor 8 is arranged on one side of the pipeline close to the first inlet end of the heat exchanger 3, the temperature sensor 8 is used for monitoring.

The triangular flash circulation system comprises a variable frequency working medium pump 7, a flash evaporation tank 4, a two-phase expander 5 and a condenser 6, wherein the flash evaporation tank 4, the two-phase expander 5, the condenser 6 and the variable frequency working medium pump 7 are sequentially connected through a pipeline, the working medium in the triangular flash circulation system is pure water, the variable frequency working medium pump 7 is used for adjusting the pressure of the working medium entering the second inlet end of the heat exchanger 3, the inlet end of the variable frequency working medium pump 7 is connected with the outlet end of the condenser 6, the outlet end of the variable frequency working medium pump 7 is connected with the second inlet end of the heat exchanger 3 through a pipeline, the second outlet end of the heat exchanger 3 is connected with the inlet end of the flash evaporation tank 4 through a pipeline, a second stop valve 10 is arranged on one side of the pipeline close to the inlet end of the flash evaporation tank, the two-phase expander 5 is used for generating electricity, and the outlet end of the two-phase expander is connected with the inlet end of the condenser 6 to form a closed loop.

The working process of the geothermal energy power generation system based on the full flow and triangular flash cycle coupling is as follows: connecting a geothermal well with a full-flow circulating system through a pipeline, enabling medium-high temperature geothermal water and geothermal steam in the geothermal well to enter the full-flow circulating system, opening a throttle valve 1 and a first stop valve 9, throttling and depressurizing the geothermal water into wet steam by using the throttle valve 1, enabling the wet steam to enter a medium-high temperature expansion machine 2 for expansion and work, enabling the medium-high temperature expansion machine 2 to generate electricity and generate outlet exhaust steam, enabling the outlet exhaust steam to enter a heat exchanger 3 through a pipeline, exchanging heat with working media in a triangular flash evaporation circulating system to release vaporization latent heat, then changing the steam into cold water, and enabling the cold water to flow back into a recharging well; the second stop valve 10 is opened, the triangular flash circulation system is connected with the full-flow circulation system through the heat exchanger 3, the triangular flash circulation system contains pure water working medium, the pure water working medium flows into the heat exchanger 3, the pure water working medium is changed into saturated water with certain pressure after absorbing latent heat of vaporization released by the full-flow circulation system, the saturated water with pressure enters the flash tank 4, the saturated water with pressure is changed into steam after being flashed by the flash tank 4 and enters the two-phase expander 5 to be expanded and work, the two-phase expander 5 generates electricity and generates outlet exhaust steam, the outlet exhaust steam enters the condenser 6 through a pipeline to be cooled and liquefied into liquid water with lower temperature, the liquid water enters the variable frequency working medium pump 7 through a pipeline, the liquid water is kept in a state of saturation and no vaporization phase change under the pressure state after absorbing heat and raising temperature through the heat exchanger 3 according to the temperature of the exhaust steam at the outlet of the medium-high temperature expander 2 measured by the temperature sensor 8 in the, flows into the flash tank 4 to continue the circulation.

It is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art may make modifications, alterations, additions or substitutions within the spirit and scope of the present invention.