CN203655374U - Dry and hot rock heat energy recovery and power generation device based on organic Rankine cycle - Google Patents

Abstract

A hot dry rock heat recovery power generation device based on organic Rankine cycle, including evaporator, power machine, generator, condenser, circulating working medium storage tank, working medium circulating pump, geothermal recovery well and geothermal recharge well, from geothermal The geothermal water produced by the mining well is boosted and pumped into the evaporator by the geothermal working medium pump to transfer heat. The water after heat transfer enters the heat supply user and then enters the geothermal recharge well; the geothermal water transfers heat to The low-boiling point organic medium pumped through the working fluid circulation pump is heat-exchanged. The low-boiling point organic medium is heated and vaporized in the evaporator, and comes out of the evaporator into the power machine, which drives the power machine and drives the generator to generate electricity; the gas from the power machine enters The condenser condenses into a low-boiling-point organic medium and enters the circulating working medium storage tank, and then pumps the working medium into the evaporator to be heated and vaporized through the working medium circulation pump, so that the power machine drives the generator to continuously generate electricity. Fully exerting the potential heat energy benefits of dry hot rock heat energy adds a new channel for solving the electric energy and heat energy needed in national construction.

Description

Dry hot rock heat recovery power generation device based on organic Rankine cycle

technical field

The invention relates to the field of hot dry rock system power generation, in particular to a hot dry rock heat recovery power generation device based on an organic Rankine cycle. the

Background technique

Geothermal is a type of energy that comes from within the earth. It is estimated that the heat stored in the interior of the earth is about 170 million times that of global coal reserves, and the heat lost from the interior of the earth through the surface every year is equivalent to the heat of 100 billion barrels of oil. Geothermal energy has outstanding advantages such as large reserves, renewable, clean and environmentally friendly, and can better supplement and replace the dwindling fossil energy. the

Hot dry rock refers to a high-temperature rock mass with a general temperature greater than 200°C, a buried depth of several kilometers, and no fluid or only a small amount of underground fluid inside. There are two main aspects of hot dry rock geothermal energy utilization: direct utilization and power generation. Power generation methods include direct steam method, expansion method and organic Rankine cycle power generation. Organic rankine cycle (Organic Rankine Cycle, referred to as ORC) is a thermodynamic cycle using environmentally friendly organic matter as the working medium and low-temperature heat as the driving energy. High efficiency and other characteristics are considered to be one of the effective technical ways to recover low-grade heat energy. the

The potential for hot dry rock to generate electricity is huge. Rational development and utilization of geothermal resources is of great significance for alleviating the tension of the energy situation, improving the energy structure and realizing low-carbon economic development. the

Contents of the invention

The object of the present invention is to provide a dry hot rock heat energy recovery power generation device based on organic Rankine cycle. The device is used to solve the problem of using dry hot rock thermal energy to generate electricity. the

Technical scheme of the present invention is realized in the following manner:

The invention includes an evaporator, a power machine, a generator, a condenser, a circulating working medium storage tank, a working medium circulating pump, a geothermal recovery well and a geothermal recharge well, and is characterized in that the geothermal hot water produced from the geothermal recovery well is The mass pump is boosted and pumped into the evaporator to transfer heat, the remaining water after heat transfer enters the heat supply user, and the water after heat supply enters the geothermal recharge well; the geothermal water transfers heat in the evaporator to the working fluid circulation pump The low-boiling point organic medium is heated and vaporized in the evaporator, and enters the power machine from the evaporator, which drives the power machine and drives the generator to generate electricity; the gas coming out of the power machine enters the condenser, and in the condenser The medium condenses into a low boiling point organic medium and enters the circulating working medium storage tank. The low boiling point organic medium in the circulating working medium storage tank is pumped into the evaporator by the working medium circulating pump to be heated and vaporized, and then enters the power machine, which drives the generator to continuously generate electricity. the

The evaporator 3 is provided with a liquid level gauge, and the working medium flow control valve 12 is linked with the liquid level gauge to control the working medium flow. the

A cooling water control valve is provided between the cooling water inlet of the condenser and the organic Rankine cycle low boiling point working medium outlet of the condenser, and the cooling water flow control valve 9 is linked with the outlet temperature of the organic Rankine cycle low boiling point working medium to control condensation The flow rate of cooling water in device 8. the

Organic Rankine cycle low boiling point working fluid is R134a or R236fa or R114 or R236ea or R245fa or R11 or R245ca. the

The hot dry rock thermal energy development working medium can be water or carbon dioxide. Carbon dioxide CO2 has a large expansion and low viscosity. As a solvent, it has low effectiveness in dissolving rock minerals. It can accelerate energy extraction and effectively eliminate scaling, and is in line with greenhouse gas geology store. the

The present invention has the following advantages:

1. The thermal energy of dry hot rock can be fully utilized to turn it into electric energy for national construction, which is a huge profit. the

2. It can use the thermal energy of dry hot rocks brought out by the oilfield sewage to generate electricity by raising the temperature, and then reinject the oil layer to drive oil, killing two birds with one stone, which not only reduces the cost of oil production, but also prevents environmental pollution.

3. It can make full use of the carbon dioxide captured by the flue gas of thermal coal power plants as the working medium for thermal energy development of dry hot rocks. After the temperature is raised to generate electricity, and then reinjected into the oil layer to drive oil, a virtuous cycle will be formed, which will generate huge productivity, and the expansion of carbon dioxide is large. The viscosity is low, and the effectiveness of dissolving rock minerals as a solvent is very low; choosing carbon dioxide as a thermally conductive working fluid can not only accelerate energy extraction and effectively eliminate scaling, but also fits the assumption of geological storage of greenhouse gases. the

Description of drawings

Accompanying drawing 1 is the schematic flow chart of the present invention. the

Description of attached drawings 1: 1-hot dry rock thermal energy exploitation well, 2-geothermal working medium pump, 3-evaporator, 4-heat supply user, 5-geothermal recharge well, 6-generator, 7-power machine, 8 - condenser, 9 - cooling water flow control valve, 10 - circulating working medium storage tank, 11 - working medium circulation pump, 12 - working medium flow control valve. the

Detailed ways

In order to further disclose the technical solution of the present invention, the present invention will be described in detail in conjunction with the accompanying drawings:

The present invention includes an evaporator 3, a power machine 7, a generator 6, a condenser 8, a circulating working medium storage tank 10, a working medium circulating pump 11, a dry hot rock thermal energy exploitation well 1 and a geothermal recharge well 5, and is characterized in that The geothermal hot water produced by the hot rock thermal energy exploitation well 1 is boosted by the geothermal working medium pump 2 and pumped into the evaporator 3 to transfer heat, the remaining water after heat transfer enters the heating user, and the heated water enters the geothermal recharge well; The geothermal water transfers heat in the evaporator to the low-boiling point organic medium pumped by the working fluid circulation pump for heat exchange. The low-boiling point organic medium is heated and vaporized in the evaporator, and enters the power machine from the evaporator to drive the power machine and drive power generation. The gas from the power machine enters the condenser, where it condenses into a low-boiling point organic medium and enters the circulating working medium storage tank 10, and the low-boiling point organic medium in the circulating working medium storage tank is pumped in by the working medium circulating pump The evaporator is heated and vaporized, so that the power machine drives the generator 6 to generate electricity continuously. the

The heat conduction flow of water or carbon dioxide from the hot dry rock thermal energy exploitation well 1 enters the evaporator 3 through the geothermal working medium pump 2, and exchanges heat with the low boiling point medium R245ca in the evaporator 3 . The heat conduction flow after heat exchange can be sent to heat supply users, etc., for continuous utilization of low-grade heat, and then introduced into the recharge well. the

The low-boiling point organic medium is heated and vaporized in the evaporator 3, drives the power machine 7 and drives the generator 6 to generate electricity. The gas discharged from the power machine 7 is condensed into a liquid state in the condenser 8 and stored in the circulating working fluid storage tank 10 . Use the working fluid circulation pump 11 to send the low-temperature and low-boiling-point working fluid in the storage tank to the evaporator 3, and continue to absorb heat and evaporate into a gaseous state. In this way, the heat of the geothermal conduction flow is continuously transferred to the low-boiling point medium for continuous power generation. the

The evaporator 3 is provided with a liquid level gauge, and the working medium flow control valve 12 is linked with the liquid level gauge to control the working medium flow. A cooling water flow control valve 9 is used to control the flow of cooling water in the condenser 8 in conjunction with the outlet temperature of the organic working medium. the

Case number one:

System design conditions: heat source is saturated water at 120°C, power generation capacity is 50KW, organic working medium is R245fa, and cooling water temperature is 20°C. The evaporation temperature of the organic working medium in the evaporator is 105°C, the condensation temperature of the organic working medium in the condenser is 35°C, the internal efficiency of the power machine is 0.6, and the efficiency of the generator is 0.96. the

(1) Power machine design plan

power machine temperature (°C) Pressure (MPa) to import 105 1.41 exit 62.30 0.21 Flow (kg/s) Effective enthalpy drop KJ/kg efficiency 2.48 20.13 0.6

(2) Design scheme of evaporator for hot water type heat source ORC system

Evaporator Geothermal conduction flow side Organic side Inlet temperature (°C) 120 40 Outlet temperature (°C) 95 105 Flow (kg/s) 5.38 2.48

(3) Condenser design scheme

condenser Organic side cooling water side Inlet temperature (°C) 62 20 Outlet temperature (°C) 35 28 Flow (kg/s) 2.48 15.7

The scheme assumes that the cooling water temperature is 20°C, which is close to the situation in spring and autumn considering seasonal changes. Assuming that the cooling water temperature is 30°C in summer and 10°C in winter, the key parameters of the system in different seasons are calculated, as shown in the table below. the

Comparison of key parameters of the system in different seasons

Case 2:

System design conditions: heat source is 120°C saturated steam, power generation is 50KW, organic working medium is R245fa, cooling water temperature is 20°C. The evaporation temperature of the organic working medium in the evaporator is 105°C, the condensation temperature of the organic working medium in the condenser is 35°C, the internal efficiency of the power machine is 0.6, and the efficiency of the generator is 0.96. the

(1) Power machine design plan

power machine temperature (°C) Pressure (MPa) to import 105 1.41 exit 62.30 0.21 Flow (kg/s) Effective enthalpy drop KJ/kg efficiency 2.48 20.13 0.6

(2) Design scheme of steam type heat source ORC system evaporator

Evaporator Geothermal conduction flow side Organic side Inlet temperature (°C) 120℃ saturated steam 35 Outlet temperature (°C) 120℃ saturated water 105 Flow (kg/s) 0.25 2.48

(3) Condenser design scheme

condenser Organic side cooling water side Inlet temperature (°C) 62 20 Outlet temperature (°C) 35 28 Flow (kg/s) 2.48 15.7

Considering the change of cooling water temperature with seasons, assuming that the cooling water temperature is 30°C in summer and 10°C in winter, the key parameters of the system in different seasons are calculated, as shown in the table below. the

Comparison of main parameters of the system in different seasons

Case three:

System design conditions: the heat source is a 120°C supercritical _CO2 heat source, the cooling water temperature is 20°C, the power generation is 50KW, and the organic working medium is R245fa. The evaporation temperature of the organic working medium is 105°C, the condensation temperature of the organic working medium is 30°C, the internal efficiency of the power machine is 0.6, and the efficiency of the generator is 0.96.

(1) Power machine design plan

power machine temperature (°C) Pressure (MPa) to import 105 1.41 exit 62.30 0.21 Flow (kg/s) Effective enthalpy drop KJ/kg efficiency 2.48 20.13 0.6

(2) Design scheme of evaporator for ORC system with hot water type heat source

Evaporator hot water side Working fluid side Inlet temperature (°C) 120 35 Outlet temperature (°C) 96 105 Flow (kg/s) 17.78 2.48

(3) Condenser design scheme

condenser Working fluid side cooling water side Inlet temperature (°C) 62 20 Outlet temperature (°C) 35 28 Flow (kg/s) 2.48 15.7

Considering the change of cooling water temperature with seasons, assuming that the cooling water temperature is 30°C in summer and 10°C in winter, the key parameters of the system in different seasons are calculated, as shown in the table below. the

Comparison of main parameters of the system in different seasons

Considering the change of cooling water temperature with seasons, assuming that the cooling water temperature is 30°C in summer and 10°C in winter, the key parameters of the system in different seasons are calculated, as shown in the table below. the

Comparison of key parameters in different season systems

The technical parameters of the above three embodiments were compared, and the results are as follows. the

Comparison of various programs

Comparison of the main parameters of the three steamers

parameters Hot water type heat source evaporator Steam type heat source evaporator _CO2 heat source evaporator Overall heat transfer coefficient (W/m ² k) 1004 3116 800 Average heat transfer temperature difference (℃) 11.7 21.1 12.1 Heat exchange area (m^2) 51 9 66 Design margin (%) 7.88 8.22 14.7 Evaporator Shell Outer Diameter (m) 0.5 0.27 0.5 Total length of evaporator (m) 3 2.3 3.5

Claims (5)

1. the hot dry rock heat energy recovery generating set of an organic Rankine circulation, comprise vaporizer, power engine, generator, condenser, cycle fluid storage tank, working medium circulating pump, underground heat production well and geothermal reinjection well, it is characterized in that pumping into vaporizer transferring heat from the underground heat hot water of underground heat production well extraction through the supercharging of underground heat working medium pump, water after heat output enters heat supply user, and the water after heat supply enters geothermal reinjection well; Geothermal water passes to heat the low boiling organic media heat exchange pumping into through working medium circulating pump in vaporizer, and the vaporization of being heated in vaporizer of low boiling organic media out enters power engine in vaporizer, and propulsion power machine also drives generator to generate electricity; Enter condenser from power engine gas out, in condenser, condense into low boiling organic media and enter cycle fluid storage tank, the vaporization of being heated in working medium circulating pump pumps into vaporizer of low boiling organic media in cycle fluid storage tank, then enter power engine, power engine drives generator uninterruptable power generation.

2. the hot dry rock heat energy recovery generating set of organic Rankine circulation according to claim 1, is characterized in that being provided with level meter on vaporizer, working medium flow control valve, working medium flow control valve and level meter interlock controlled medium flow.

3. the hot dry rock heat energy recovery generating set of machine Rankine cycle, it is characterized in that being provided with cooling water control valve between the cooling water intake of condenser and the outlet of condenser organic Rankine circulation low boiling working fluid, adopt the flow of cooling water flow control valve and the outlet temperature interlock control condenser cooling water of organic Rankine circulation low boiling working fluid.

4. the hot dry rock heat energy recovery generating set of organic Rankine circulation according to claim 1, is characterized in that organic Rankine circulation low boiling working fluid is R134a or R236fa or R114 or R236ea or R245fa or R11 or R245ca.

5. the hot dry rock heat energy recovery generating set of organic Rankine circulation according to claim 1, is characterized in that the hot dry rock heat energy exploitation optional water of working medium or carbon dioxide.

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