阅读说明：本技术 一种用于干热岩能量综合利用的发电供暖耦合系统 (Power generation and heating coupling system for comprehensive utilization of hot dry rock energy ) 是由 汪健生 牛锦涛 刘雪玲 付伟娟 于 2020-10-22 设计创作，主要内容包括：本发明涉及一种用于干热岩能量综合利用的发电供暖耦合系统,包括干热岩生产井、除沙装置、第一闪蒸器、第二闪蒸器、第一膨胀机、蒸发器、第一发电机、膨胀机、第二发电机、预热器、第二膨胀机、第三发电机、工质泵、冷凝器、土壤源热泵冷水管、土壤源热泵热水管和干热岩回灌井；干热岩生产井的热水通过除沙装置处理后首先在第一级闪蒸系统中的第一闪蒸器中进行降压降温闪蒸,温度降低,热水从饱和液体变成饱和气体和饱和液体两部分,饱和气体进入第一膨胀机中进行膨胀做功,带动第一发电机输出电能；饱和液体进入第二级闪蒸系统中的第二闪蒸器；热用户的回水管的供水在有机朗肯循环的冷凝器中温度升温,之后进入热用户进行供热。(The invention relates to a power generation and heating coupling system for comprehensive utilization of hot dry rock energy, which comprises a hot dry rock production well, a sand removal device, a first flash evaporator, a second flash evaporator, a first expander, an evaporator, a first generator, an expander, a second generator, a preheater, a second expander, a third generator, a working medium pump, a condenser, a soil source heat pump cold water pipe, a soil source heat pump hot water pipe and a hot dry rock recharge well, wherein the first flash evaporator is connected with the first generator through a pipeline; after being treated by a sand removal device, hot water of the hot dry rock production well is subjected to pressure reduction, temperature reduction and flash evaporation in a first flash evaporator in a first-stage flash evaporation system, the temperature is reduced, the hot water is changed into two parts of saturated gas and saturated liquid from saturated liquid, and the saturated gas enters a first expansion machine to perform expansion work so as to drive a first generator to output electric energy; the saturated liquid enters a second flash evaporator in the second-stage flash evaporation system; the temperature of water supplied to a water return pipe of a hot user is raised in a condenser of the organic Rankine cycle, and then the water enters the hot user for heating.)

1. The utility model provides a power generation heating coupled system for hot dry rock energy is used multipurposely, includes hot dry rock production well (1), sand removal device (2), first flash evaporator (3), second flash vessel (4), first expander (5), evaporimeter (6), first generator (7), expander (8), second generator (9), pre-heater (10), second expander (11), third generator (12), working medium pump (13), condenser (15), soil source heat pump cold water pipe (17), soil source heat pump hot water pipe (18) and hot dry rock recharge well (19).

After being treated by a sand removal device (2), hot water of a hot dry rock production well (1) is firstly subjected to pressure reduction, temperature reduction and flash evaporation in a first flash evaporator (3) in a first-stage flash evaporation system, the temperature is reduced from T1 to T3, the hot water is changed into two parts of saturated gas and saturated liquid from the saturated liquid, and the saturated gas enters a first expansion machine (5) to perform expansion work so as to drive a first generator (7) to output electric energy; the saturated liquid enters a second flash evaporator (4) in the second-stage flash evaporation system;

the saturated liquid flowing out of the first flash evaporator (3) in the first-stage flash evaporation system is further cooled and depressurized in a second flash evaporator (4) in the second-stage flash evaporation system for flash evaporation, the temperature is reduced from T3 to T4, and the saturated liquid is divided into two parts, namely saturated liquid and saturated gas; the saturated gas and the dead steam which does work from the first expansion machine (5) enter a second expansion machine (8) together for expansion and work, and a second generator (9) is driven to output electric energy;

after working, the exhaust steam flows out of the second expansion machine (8), enters the preheater (10) to preheat the organic working medium, flows into the hot dry rock recharging well (19) after flowing out of the preheater (10), and dissipates heat to the low-temperature soil layer in the process of flowing into the ground, so that the temperature of the low-temperature soil layer is reduced, and the higher heat extraction capacity is obtained;

saturated liquid in a second flash evaporator (4) in the second-stage flash evaporation system flows out and then enters an evaporator (6), and the saturated liquid releases heat in the evaporator (6) to reduce the temperature and then flows out; then flows into a hot dry rock recharging well (19) and dissipates heat to the low-temperature soil layer in the process of flowing into the underground, so that the temperature of the low-temperature soil layer is reduced to obtain higher heat extraction capacity;

the organic working medium compressed by the working medium pump (13) flows into the preheater (10) to absorb heat and raise the temperature to the evaporation temperature, and then flows into the evaporator (6) to absorb the heat released by the saturated liquid and evaporate to saturated gas; saturated gas of the organic working medium enters a second expansion machine (11) to perform expansion work, and a third generator (12) is driven to output electric energy; then the liquid flows through a condenser (15) to be condensed into saturated liquid, and finally flows into a working medium pump (13);

the temperature of the water supply of the water return pipe of the hot user (16) is increased from T14 to T14' in the condenser (15) of the organic Rankine cycle, and then the water supply enters the hot user (16) for heating.

Technical Field

The invention belongs to the field of hot dry rock energy utilization power generation systems, and particularly relates to a power generation and heating coupling system for comprehensive utilization of hot dry rock energy.

Background

Referring to fig. 1, fig. 1 shows a conventional Organic Rankine Cycle (ORC) power generation system, which includes an evaporator 1, an expander 2, a condenser 3, a working fluid pump 4, a generator 5, and cooling water 6.

The low-temperature low-pressure organic working medium (liquid) is boosted by a working medium pump 4 and then enters an evaporator 1; absorbing heat provided by a heat source into high-temperature high-pressure gas in the evaporator 1; the mixture enters an expansion machine 2 to do expansion work and drive a generator 5 to generate electricity; the organic working medium (gas) after expansion work enters a condenser 3 to be cooled into liquid; and then returns to the working medium pump 4 to complete a complete organic Rankine cycle.

For a conventional organic Rankine cycle, the thermal efficiency of the system is low, the net output work of the system is low due to the fact that the dry hot rock energy cannot be efficiently utilized, and the average cost of dry hot rock power generation is high compared with the low net output work of the system.

Referring to fig. 2, fig. 2 is a single-stage flash evaporation power generation system, which includes a dry hot rock production well 1, a sand removing device 2, a flash evaporator 3, an expander 4, a generator 5, a condenser 6, cooling water 7, and a recharging well 8.

Hot water pumped from the hot dry rock production well 1 enters a sand removal device 2, and the sand removal device 2 filters solid impurities in the hot water; hot water enters a flash evaporator 3 for flash evaporation after coming out of the sand removing device 2, and the temperature is reduced from T1 to T3; the saturated gas enters an expansion machine 4 for expansion work, and is converted into electric energy through a generator 5; the working exhaust steam and the saturated liquid from the flash evaporator 3 are merged and the temperature is reduced to T4, and the steam enters the condenser 6 for condensation; and then enters a hot dry rock recharging well 8, enters the underground and the hot dry rock to exchange heat, and flows to the position of a hot dry rock production well.

Compared with the conventional organic Rankine cycle, the single-stage flash power generation system can improve the thermal efficiency and the net output work of the system, but the T4 temperature is still high, and the waste of energy is caused by the excess heat dissipated by the condenser, so that the full and efficient utilization of the energy cannot be realized. The higher input results in higher power generation costs for the single stage flash system compared to lower net work output.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the power generation and heating coupling system for comprehensively utilizing the dry hot rock energy is provided, so that the comprehensive utilization of the dry hot rock energy is realized, the heat efficiency and the net output power of the system are improved, and the average power generation cost of the dry hot rock is reduced.

In order to solve the problems, the invention adopts the following technical scheme:

a power generation and heating coupling system for comprehensive utilization of hot dry rock energy comprises a hot dry rock production well 1, a sand removal device 2, a first flash evaporator 3, a second flash evaporator 4, a first expander 5, an evaporator 6, a first generator 7, an expander 8, a second generator 9, a preheater 10, a second expander 11, a third generator 12, a working medium pump 13, a condenser 15, a soil source heat pump cold water pipe 17, a soil source heat pump hot water pipe 18 and a hot dry rock recharging well 19;

after being treated by the sand removal device 2, hot water in the hot dry rock production well 1 is firstly subjected to pressure reduction, temperature reduction and flash evaporation in a first flash evaporator 3 in a first-stage flash evaporation system, the temperature is reduced from T1 to T3, the hot water is changed into two parts of saturated gas and saturated liquid from saturated liquid, and the saturated gas enters a first expansion machine 5 to perform expansion work so as to drive a first generator 7 to output electric energy; the saturated liquid enters a second flash evaporator 4 in a second-stage flash evaporation system;

the saturated liquid flowing out of the first flash evaporator 3 in the first-stage flash evaporation system is further cooled and depressurized in the second flash evaporator 4 in the second-stage flash evaporation system for flash evaporation, the temperature is reduced from T3 to T4, and the saturated liquid is divided into two parts, namely saturated liquid and saturated gas; the saturated gas and the dead steam which does work from the first expansion machine 5 enter the second expansion machine 8 together for expansion and work, and the second generator 9 is driven to output electric energy;

the dead steam after acting flows out of the second expander 8, enters the preheater 10 to preheat the organic working medium, flows into the hot dry rock recharging well 19 after flowing out of the preheater 10, and dissipates heat to the low-temperature soil layer in the process of flowing into the underground, so that the temperature of the dead steam is reduced to obtain higher heat extraction capacity;

saturated liquid in a second flash evaporator 4 in the second-stage flash evaporation system flows out and then enters an evaporator 6, and the saturated liquid releases heat in the evaporator 6 and flows out after the temperature is reduced; then flows into the hot dry rock recharging well 19 and dissipates heat to the low-temperature soil layer in the process of flowing into the underground, so that the temperature of the hot dry rock recharging well is reduced to obtain higher heat extraction capacity;

the organic working medium compressed by the working medium pump 13 flows into the preheater 10 to absorb heat and raise the temperature to the evaporation temperature, and then flows into the evaporator 6 to absorb the heat released by the saturated liquid and evaporate to saturated gas; saturated gas of the organic working medium enters the second expander 11 to perform expansion work, and drives the third generator 12 to output electric energy; then the liquid flows through a condenser 15 to be condensed into saturated liquid, and finally flows into a working medium pump 13;

the temperature of the water supply of the water return pipe of the hot user 16 is raised from T14 to T14' in the condenser 15 of the orc, and then the water supply enters the hot user 16 to supply heat.

In the present invention, the soil source heat pump performs heating using thermal energy stored in soil.

According to the invention, the net output power of the system can be improved by coupling two-stage flash evaporation with the organic Rankine cycle; the condenser of the organic Rankine cycle and the heat stored in shallow soil provide heat energy for heating users, so that the heat efficiency of the system is improved; the temperature of the reinjection water is reduced through soil, condenser equipment is reduced, and system investment is reduced; the variable load working condition of the heat pump is realized by utilizing the good heat storage performance of the soil; therefore, the invention realizes the high-efficiency comprehensive utilization of the energy of the hot dry rock and reduces the average cost of the power generation of the hot dry rock.

Drawings

FIG. 1 is a conventional organic Rankine cycle power generation system

FIG. 2 is a single stage flash power generation system

FIG. 3 shows a two-stage flash evaporation-organic Rankine cycle coupled power generation system

In fig. 3, 1, a hot dry rock production well, 2, a sand removal device, 3, a flash evaporator, 4, a flash evaporator, 5, an expander, 6, an evaporator, 7, a generator, 8, an expander, 9, a generator, 10, a preheater, 11, an expander, 12, a generator, 13, a working medium pump, 14, cooling water, 15, a condenser, 16, a heat consumer, 17, a soil source heat pump cold water pipe, 18, a soil source heat pump hot water pipe, 19 and a hot dry rock recharging well.

Fig. 4 is a cross-sectional view of the hot dry rock recharging well 19, and 19(a), 19(b), 19(c), 19(d) and 19(e) are single hot dry rock recharging wells.

Detailed Description

The invention is further described below with reference to fig. 3 and 4.

The invention discloses a power generation and heating coupling system for comprehensive utilization of hot dry rock energy, which mainly comprises a two-stage flash evaporation system, a one-stage organic Rankine cycle and a soil source heat pump, and is specifically shown in FIG. 3: the dry hot rock recycling system comprises a dry hot rock production well 1, a sand removing device 2, a flash evaporator 3, a flash evaporator 4, an expander 5, an evaporator 6, a generator 7, an expander 8, a generator 9, a preheater 10, an expander 11, a generator 12, a working medium pump 13, cooling water 14, a condenser 15, a heat user 16, a soil source heat pump cold water pipe 17, a soil source heat pump hot water pipe 18 and a dry hot rock recycling well 19.

In the present invention, the sand removing device 2 is to remove various solid impurities from the hot water pumped out of the hot dry rock production well 1 and prevent them from damaging the subsequent equipment. The hot water has no heat loss and pressure loss in the device.

In the invention, hot water is firstly subjected to pressure reduction, temperature reduction and flash evaporation in a flash evaporator 3 in a first-stage flash evaporation system, the temperature is reduced from T1 to T3, the hot water is changed into two parts of saturated gas and saturated liquid from saturated liquid, and the saturated gas enters an expansion machine 5 to perform expansion work to drive a generator 7 to output electric energy; the saturated liquid enters the flash vessel 4 in the second stage flash system.

In the invention, the saturated liquid flowing out of the flash evaporator 3 in the first-stage flash evaporation system is further cooled and depressurized in the flash evaporator 4 in the second-stage flash evaporation system for flash evaporation, the temperature is reduced from T3 to T4, and the saturated liquid is divided into two parts of saturated liquid and saturated gas again; the saturated gas and the dead steam which does work from the expansion machine 5 enter the expansion machine 8 together for expansion and work, and the generator 9 is driven to output electric energy;

in the invention, the dead steam after acting flows out of the expansion machine 8 and enters the preheater 10 to preheat the organic working medium, flows into the hot dry rock recharging well 19 after flowing out of the preheater 10 and dissipates heat to the low-temperature soil layer in the process of flowing into the ground, so that the self temperature is reduced to obtain higher heat taking capacity.

In the invention, saturated liquid in the flash evaporator 4 in the second-stage flash evaporation system flows out and then enters the evaporator 6, and the saturated liquid releases heat in the evaporator 6 and flows out after the temperature is reduced; then flows into the hot dry rock recharging well 19 and dissipates heat to the low-temperature soil layer in the process of flowing into the underground, so that the temperature of the hot dry rock recharging well is reduced, and the higher heat extraction capacity is obtained.

In the invention, the organic working medium compressed by the working medium pump 13 flows into the preheater 10 to absorb heat and raise the temperature to the evaporation temperature, and then flows into the evaporator 6 to absorb the heat released by the saturated liquid and evaporate to saturated gas; saturated gas of the organic working medium enters the expansion machine 11 to perform expansion work, and the generator 12 is driven to output electric energy; then flows through a condenser 15 to be condensed into saturated liquid, and finally flows into a working medium pump 13.

In the present invention, the temperature of the water supply of the return pipe of the hot user 16 is raised from T14 to T14' in the condenser 15 of the orc, and then the water supply enters the hot user 16 to supply heat.

In the invention, the saturated liquid flowing out of the evaporator 6 and the gas-liquid mixture flowing out of the preheater 10 are converged and then flow into the single dry hot rock recharging well 19(a-b-c-d-e), and the fluid in the single dry hot rock recharging well 19(a-b-c-d) is converged into the single dry hot rock recharging well 19(e) and is recharged into the cracks of the dry hot rock; and continuously radiating heat to low-temperature soil in the hot dry rock recharging well 19, reducing the temperature of the hot dry rock recharging well to saturated liquid, storing heat energy in shallow soil, and absorbing heat in cracks in the underground hot dry rock to flow to the position of the hot dry rock production well 1.

In the present invention, the soil source heat pump performs heating using thermal energy stored in soil.

As shown in the figure, water is subjected to heat exchange in a hot dry rock fracture and is heated to T1, the water is pumped out from a hot dry rock production well 1 and enters a sand removing device 2, and solid impurities are removed from the sand removing device 2 to prevent the solid impurities from damaging subsequent equipment; the hot water enters a flash evaporator 3 in a first-stage flash evaporation system after coming out of the sand removing device 2, the temperature is reduced and the pressure is reduced in the flash evaporator 3 for flash evaporation, the temperature is reduced from T1 to T3, and the hot water is divided into saturated liquid and saturated gas in the flash evaporator 3; saturated gas in the flash evaporator 3 enters an expander 5 to perform expansion work and drive a generator 7 to output electric energy; the saturated liquid in the flash evaporator 3 enters a flash evaporator 4 of a second-stage flash evaporation system, the temperature is reduced from T3 to T4, and the hot water is separated into saturated liquid and saturated gas in the flash evaporator 4; the saturated gas in the flash evaporator 4 and the dead steam which does work from the expansion machine 5 enter the expansion machine 8 together for expansion work, and drive the generator 9 to output electric energy; the exhaust steam from the expansion machine 8 enters a preheater 10 to release heat, and preheats the organic working medium, and the temperature of the exhaust steam is reduced to T10; the saturated liquid in the flash evaporator 4 enters an evaporator 6 to release heat, and the temperature of the liquid is reduced to T6; the water flowing out of the evaporator 6 and the dead steam flowing out of the preheater 10 are combined and then flow into the hot dry rock recharging well 19; the organic working medium compressed by the working medium pump 13 enters the preheater 10 to absorb heat and raise the temperature to the evaporation temperature, then enters the evaporator 6 to absorb heat and evaporate to saturated gas, and the saturated gas of the organic working medium enters the expander 11 to perform expansion work and drive the generator 12 to output electric energy; saturated gas of the organic working medium is changed into dead steam after expansion and work, the dead steam enters the condenser 15 for condensation, and the temperature of condensed water is increased from T14 to T14'; the organic working medium from the condenser 15 enters a working medium pump 13 for compression; the saturated liquid flowing out of the evaporator 6 and the gas-liquid mixture flowing out of the preheater 10 are converged and then flow into the hot dry rock recharging single well 19(a-b-c-d-e), and the fluid in the hot dry rock recharging single well 19(a-b-c-d) is converged into the well 19(e) and is recharged into the hot dry rock fractures; continuously radiating heat to shallow low-temperature soil in the hot dry rock recharging well 19, and cooling the shallow low-temperature soil into saturated liquid; the water is recharged from the hot dry rock recharging well 19 to the hot dry rock cracks to exchange heat with the high-temperature rocks, and flows to the hot dry rock production well 1. At the moment, water completes one cycle in a double-stage flash evaporation-organic Rankine cycle coupled power generation system. The heat dissipated in the shallow soil by the saturated liquid flowing out of the evaporator 6 and the gas-liquid mixture flowing out of the preheater 10 will be stored in the shallow soil; the cold water pipe 17 of the soil source heat pump absorbs the heat in the shallow soil and supplies heat to the heat user 16 through the hot water pipe 18 of the soil source heat pump; the shallow soil is used for storing heat energy, so that a condenser required for cooling hot water is omitted, the heat energy can be well stored, and the variable load working condition of heat pump heating is met.