CN207647704U - The S-CO2 electricity generation systems of hot dry rock geothermal energy are developed based on fin casing - Google Patents

Abstract

The utility model discloses the S CO that hot dry rock geothermal energy is developed based on fin casing₂Electricity generation system, fin casing are coaxial sleeve, decline pipeline section, outer layer enhanced heat exchange pipeline section, interior return duct, S CO by outer layer₂The compositions such as gas-turbine, generator, compressor.The innovative point of the utility model is to utilize S CO₂Geothermal energy is transferred to gas-turbine by the closed cycle in fin casing from hot dry rock；Fin casing and gas-turbine are all made of S CO₂As cycle fluid, it is poor to eliminate heat exchanger end；The additional fin of hot dry rock section increases heat transfer area, improves individual well and contributes.S‑CO₂Being flow to from heat removal clutch outer layer takes hot well bottom to be pooled to internal layer, and the geothermal energy in decline process absorbs hot dry rock constantly heats up, then is back to ground from internal layer, passes through S CO₂Gas-turbine and generator convert geothermal energy to high-grade electric energy.S‑CO₂Start new cycle after the detection of working medium detection unit and compressor pressurization, realizes the suitable development of hot dry rock geothermal energy.

Description

The S-CO of hot dry rock geothermal energy is developed based on fin casing2Electricity generation system

Technical field

The utility model is related to hot dry rock underground heat to exploit field, and in particular to develop hot dry rock geothermal energy based on fin casing S-CO₂(supercritical CO₂) electricity generation system.

Background technology

Geothermal energy is a kind of green low-carbon, recyclable regenerative resource, has that large storage capacity, distribution be wide, wiper ring The features such as protecting, is reliable and stable, is a kind of practicable and competitive clean energy resource.Geothermal energy is divided into geothermal money Source, geothermal resource of hydrothermal type and hot dry rock resource, shallow-layer and geothermal resource of hydrothermal type have obtained extensive utilization at present, and account for The hot dry rock resource of 95% or more China's underground heat energy storage does not obtain exploitation also and utilizes.There is water level decreasings for geothermal resource of hydrothermal type Or the problem of resource exhaustion, the small grade of geothermal total resources is low, and hot dry rock resource is with high existing for solid forms Warm rock, temperature reach 200 DEG C or more, and resource is uniform and stable, can adopt total amount and convert into 17,000,000,000,000 tons of standard coals, can meet China Energy demand in 4400 has huge Exploitative potential.

8 countries such as the U.S., Japan, Germany, France are opened since the last century 70's using enhanced geothermal system Hair utilizes hot dry rock.The exploitation of enhanced geothermal system is broadly divided into four-stage, and resource exploration and addressing, artificial reservoir are built Make, the foundation of geothermal field, the exploitation of geothermal field and detection.The construction of wherein artificial reservoir is needed first with hydraulic fracturing high temperature rock System produces the Fracture Systems with high osmosis, then injects high pressure water to subterranean fracture system, from producing well from injection well It extracts the geothermal vapour generated or GEOTHERMAL WATER is produced.The foundation of artificial reservoir is faced with flowing short circuit, rock dissolution, rock stratum The problems such as leakage, huge challenge is brought to the exploitation of hot dry rock.Since technical reason and economic benefit are bad, at present The only enhanced geothermal system of France and Germany is also being run, remaining equal termination test.Traditional enhanced geothermal system It is that medium takes energy from underground by water, system complex, pipeline is various, and reliability is low, and there is an urgent need for a kind of simple and reliable hot dry rocks to open Extraction system realizes the extensive utilization of hot dry rock.

CO₂It can be changed into above-critical state, supercritical CO under conditions of 31.1 DEG C and 7.38MPa₂As cycle fluid With good fluidity, heat transfer efficiency is high, the good density of viscosity is big, kinetic energy is big, the good characteristics such as without phase-change, both logical as cycle fluid Crossing casing takes hot well to extract heat from hot dry rock, and is directly entered gas-turbine acting as acting working medium.Supercritical CO₂Power generation system System is also with efficient, small, noise is low, using good characteristics such as low temperature heat energies.Current CO₂Gas-turbine single-machine capacity The individual well output rank of hot well is taken to match in MW ranks and hot dry rock；Hot dry rock temperature is at 200 DEG C or more, it is ensured that super Critical CO₂The two is organically combined, is createed with supercritical CO by the Effec-tive Function of electricity generation system₂For the hot dry rock of working medium Electricity generation system.

Invention content

In order to solve the deficiency of existing enhanced system for geothermal production of electricity, the purpose of this utility model is to provide based on fin Casing develops the S-CO of hot dry rock geothermal energy₂Electricity generation system, fin casing are divided into two layers inside and outside, S-CO₂Shaft bottom is flow to from outer layer to inhale Hot dry rock thermal energy is received, being back to ground by interior return duct enters gas-turbine acting, later again from taking hot well outer tube layer to flow to Shaft bottom absorbs hot dry rock thermal energy；S‐CO₂Closed cycle inside hot well pipe is being taken, heat is absorbed by the outer surface that fin reinforcing exchanges heat The thermal energy of dry rock stratum, it is only necessary to which a bite geothermal well can ensure the sustainable progress of hot dry rock heat power generation.

In order to achieve the above object, the utility model adopts the following technical solution：

The S-CO of hot dry rock geothermal energy is developed based on fin casing₂Electricity generation system, including：Fin casing is coaxial sleeve, It is divided into inside and outside i.e. two layers outer tube and interior return duct, outer tube provides S-CO₂It flow to the channel that shaft bottom absorbs geothermal energy, outer layer Pipe is divided into outer layer and declines pipeline section and outer layer enhanced heat exchange pipeline section；Outer layer declines pipeline section, provides cycle fluid from well head to hot dry rock The flow channel of layer；Outer layer enhanced heat exchange pipeline section is located at hot dry rock, and outer surface has circumferentially equally distributed with vertical direction Enhanced heat exchange fin can be obviously improved the heat exchange area of fin casing, and working medium, which is mainly absorbed heat in outer layer thermoexcell section, to heat up； Interior return duct provides flow channel of the cycle fluid from shaft bottom to well head；Gas-turbine is located at well head, is exported with interior return duct It is connected, by S-CO₂Thermal energy be converted into mechanical energy, drive electrical power generators；Working medium detection unit is located at gas-turbine and exports, Detect CO₂In impurity content, put into antisludging agent or preservative in due course and removable parts go bad CO₂；Regenerator is located at working medium and examines It surveys after unit, preheats the S-CO of compressor outlet₂Fluid；Condenser is located at after regenerator, by CO₂Fully cooling, to subtract Few work done during compression；Compressor is located at after condenser, by CO₂It is compressed to above-critical state, and circulation power is provided, controls CO₂Stream Amount and pressure.

The fin casing uses S-CO₂As taking thermal cycle working medium, CO₂There is good fluidity, heat transfer as cycle fluid It is efficient, property is stable, corrosion and scaling is inclined to the advantage that low, heat transfer coefficient is big, specific heat capacity is big；CO₂In 31.1 DEG C and 7.38MPa Under conditions of can be changed into above-critical state, by circulating pump to CO₂Pressurize 8MPa or more, that is, can guarantee CO₂In cyclic process Whole process keeps above-critical state, and flow regime is more stable, and exchange heat heat transfer efficiency higher.

The outer layer declines pipeline section from well head until hot dry rock, and oil casing steel or stainless is selected according to geological conditions Steel；Outer layer declines length of pipe section and accounts for 70% or more of outer tube total length, and temperature change is slow, just can guarantee without additional fin Fully heat exchange；Outer layer thermoexcell section is located among hot dry rock, and alusil alloy or copper alloys are selected according to geological conditions Metal material corrosion-resistant, intensity is big, heat conduction is excellent is exchanged heat by heat exchange pattern and hot dry rock；Outer layer enhanced heat exchange pipeline section Length disclosure satisfy that design discharge at a temperature of heat exchange demand.

The outer layer enhanced heat exchange pipeline section outer surface is circumferentially uniform-distribution with fin with vertical direction, and fin can increase Outer layer enhanced heat exchange pipeline section is fixed in geothermal well by heat exchange area using the excellent high temperature resistant cement of heat conduction；Fin root with Outer layer enhanced heat exchange pipeline section outer surface is connected, and absorbs the heat in hot dry rock by heat exchange pattern；Fin selects plate wing or needle Wing is fixed on outer surface using welding manner, and plate wing is fixed in the vertical direction, in order to avoid influence the flowing of cementing concrete；Fin The excellent metal material of the corrosion-resistant heat conductivility of aluminium silicon alloys.

The outer layer enhanced heat exchange pipeline section bottom is provided with bottom shock resistance thickening layer, and hot dry rock takes hot well bottom to bear Cycle fluid static pressure reaches 30MPa or more, also attached Working fluid flow direction and changes the impact dynamic pressure brought, it is big to bear pressure；It adopts With thick-walled forgings end socket and outer layer enhanced heat exchange pipeline section using together with wide U-shaped or narrow U-shaped groove butt welding, to which heat will be taken Well casing sealed bottom and supercritical pressure is born, forms the closed cycle taken inside hot well pipe.

The interior reflux tube inlet is connected in underground heat bottom, outlet with the gas-turbine on ground, absorbs hot dry rock heat Take hot working fluid from outer layer flow into return duct；Interior return duct have good heat-insulating property, with ensure export working medium have compared with High grade, to promote generating efficiency；Steady flow unit is arranged in the entrance of interior return duct, is pulled back entrance using edge turning mode 12-15 ° of horn mouth makes that hot working fluid is taken in tube bottom to accelerate, avoids flowing back.

The interior return duct uses steel-plastics composite pipe, the plastic outer layer of steel-plastics composite pipe that can resist the high temperature of circulatory mediator Corrosion, while there is low thermal coefficient, effectively improve the outlet temperature that hot dry rock takes hot well pipe；Steel internal layer intensity is big, energy Enough bear the high pressure of cycle fluid.

To ensure good connection and the fixation of fin casing, uses and be threadedly coupled between every section of fin casing；Placement takes heat It is first put into outer tube when well casing, interior return duct is placed into after being fixed using cement；3 or more plates are set in each section of outer tube Shape holder with return duct in fixation, into outer layer enhanced heat exchange pipeline section plate-shaped carrier in addition to fixed function, should also be by plate Holder and interior reflux tube hub line are in be more than 0 ° to be less than 90 ° of slightly eddy flows, form eddy flow, weaken flow boundary layer, enhanced heat exchange With avoid temperature distributing disproportionation；Plate-shaped carrier selects stainless steel.

The working medium detection unit is located at S-CO₂Gas-turbine exports, being capable of periodic detection supercritical CO₂In impurity contain Amount, will contain more polymictic CO₂Discharge, adds new CO₂；Corrosion inhibiter is periodically added, prevents geothermal well-pipe from S-CO occurs₂It is rotten Erosion.

The S-CO that hot dry rock geothermal energy is developed based on fin casing₂The electricity-generating method of electricity generation system, by compressor It works CO₂It is compressed to above-critical state, and powered S-CO is provided₂Enter outer layer after regenerator preheating and declines pipeline section Entrance, valve cooperation adjust S-CO₂Cycle fluid flow and pressure；S‐CO₂Cycle fluid fin casing outer tube to flow down The heat in rock and hot dry rock is moved and absorbed, interior return duct is collected to taking hot well bottom；Cycle fluid after heating is from interior The outlet of return duct enters S-CO₂Gas-turbine passes through S-CO₂Gas-turbine converts heat into mechanical energy, drives generator rotation hair Electricity；S-CO after decrease temperature and pressure₂Into working medium detection unit 4, checked for impurities concentration adds corrosion inhibiter, and removable parts are rotten Working medium；CO after detection₂Waste heat is discharged by regenerator, compressor is entered after condenser further cools and is pressurizeed Start new cycle afterwards.

To ensure to take hot well pipe efficient stable to exchange heat, further preferably：The CO₂All in overcritical in entire cycle State, it is ensured that acute variation does not occur in density, does not occur local gasification, keeps the efficient progress of the stabilization and heat exchange of flowing.

The S-CO₂Gas-turbine, preferred embodiment are as follows：S‐CO₂Gas-turbine is located at interior return duct floor outlet；S‐CO₂Gas Turbine selects resistance to S-CO₂The stainless steel of corrosion, outside package thermal insulation material.Adjust gas-turbine outlet pressure, it is ensured that outlet CO₂Still In above-critical state.

The working medium detection unit, preferred embodiment are as follows：Working medium detection unit is located at S-CO₂Gas-turbine exports, Ke Yiding Phase detects supercritical CO₂In impurity content, more polymictic supercritical CO will be contained₂Discharge, adds new CO₂；Periodically it is added Corrosion inhibiter prevents geothermal well-pipe corrosion failure.

The regenerator, preferred embodiment are as follows：Regenerator is located at after working medium detection unit, utilizes S-CO₂Gas-turbine goes out Mouth CO₂Low temperature exhaust heat preheat compressed low temperature CO₂, improve the efficiency of power generation cycle.

The condenser, preferred embodiment are as follows：Condenser is after regenerator, by CO₂It is further cooling, to reduce compression Machine power consumption；It is circulating cooling medium that water, which can be used, in condenser, and the recirculated water after heating can be used for chamber planting, breed in stew etc. The occasion for needing low temperature heat energy realizes the cascade utilization of geothermal energy, improves geothermal energy utilization efficiency.

The compressor, preferred embodiment are as follows：Compressor is located at after regenerator and condenser and S-CO₂Gas-turbine is same Shaft rotation is dynamic, by the CO after the acting expansion in gas-turbine₂It is compressed to specified pressure, and cycle is pushed to carry out；It is compressed through compressor Supercritical CO afterwards₂It flows through and takes hot well into hot dry rock after regenerator preheats；The heat supplement speed tune of hot dry rock under base area Whole cycle fluid flow obtains hot dry rock energy in underground as much as possible within the scope of reasonable pump work.

The utility model innovative point, advantage and good effect are：

1, the S-CO that hot dry rock geothermal energy is developed based on fin casing of the utility model₂Electricity generation system uses S-CO₂As Heat is transmitted to S-CO by heat transfer medium from hot dry rock₂Gas-turbine, cycle fluid recycle stream between outer tube and interior return duct It is dynamic, it is not contacted with hot dry rock, without establishing subsurface reservoir system, the problems such as leakage, fouling, corrosion is avoided, with tradition Enhanced geothermal system compare and greatly reduce the exploitation difficulty and development cost of hot dry rock.Supercritical carbon dioxide conduct Cycle fluid, property are stablized, and corrosion and scaling tendency is low, and heat transfer coefficient is big, and specific heat capacity is big.It is dry that heat is realized in single port geothermal well The suitable development of rock geothermal energy.

2, the S-CO that hot dry rock geothermal energy is developed based on fin casing of the utility model₂Electricity generation system uses S-CO₂Make For generate electricity gas-turbine cycle fluid, have it is efficient, small, noise is low, using good characteristics such as low temperature heat energies.With biography The double-work medium thermal cycle of system is compared, and only just realizes heat acquisition using a kind of working medium and gas-turbine is pushed to do work, structure is more Add simply, circulating generation efficiency is even more to improve 50% or more, greatly improves the economy of hot dry rock power generation.

3, the S-CO that hot dry rock geothermal energy is developed based on fin casing of the utility model₂Electricity generation system, hot dry rock section are adopted Strengthen outer layer heat exchange with needle wing and increase heat exchange area while maintaining caliber constant, improves individual well output, shorten Hot well length is taken, probing and operating cost are reduced, improves economic benefit.

4, the S-CO that hot dry rock geothermal energy is developed based on fin casing of the utility model₂Electricity generation system selects steel plastic compount Pipe can resist the high temperature corrosion of circulatory mediator as interior return duct, the plastic outer layer of steel-plastics composite pipe, while have low lead Hot coefficient can effectively improve the outlet temperature that hot dry rock takes hot well pipe；Steel internal layer intensity is big, can bear the height of cycle fluid Pressure.

5, the S-CO that hot dry rock geothermal energy is developed based on fin casing of the utility model₂Electricity generation system is examined provided with working medium Survey unit, periodic detection S-CO₂Quality, add corrosion inhibiter, avoid that hot well pipe is taken corrosion failure occur.Realize following for working medium Ring utilizes, and is CO₂Utilization open new approach.

Description of the drawings

Fig. 1 is the S-CO that hot dry rock geothermal energy is developed based on fin casing of the utility model₂Electricity generation system figure.

Fig. 2 is the S-CO that hot dry rock geothermal energy is developed based on fin casing of the utility model₂Electricity generation system takes hot wing The floor map of piece casing.

Fig. 3 is the S-CO that hot dry rock geothermal energy is developed based on fin casing of the utility model₂Electricity generation system takes hot wing The stereoscopic schematic diagram of piece casing (needle wing and plate wing), wherein：Fig. 3 a are to take hot needle wing casing to take hot needle wing casing, Fig. 3 b Partial cutaway view, Fig. 3 c are the partial cutaway view for taking hot plate wing casing.

Fig. 4 is the S-CO that hot dry rock geothermal energy is developed based on fin casing of the utility model₂The outer layer of electricity generation system is strong Change heat exchange pipeline section bottom thick-walled forgings end socket figure.

Fig. 5 is the S-CO that hot dry rock geothermal energy is developed based on fin casing of the utility model₂The interior reflux of electricity generation system Artwork is flared at tube inlet.

Fig. 6 is the S-CO that hot dry rock geothermal energy is developed based on fin casing of the utility model₂The reinforcing of electricity generation system is changed The spiral-flow plate-type holder figure for fixed interior return duct of hot pipe section.

Specific implementation mode

Utility model is described in detail with reference to the accompanying drawings and detailed description.

As shown in Figure 1, developing the S-CO of hot dry rock geothermal energy based on fin casing₂Electricity generation system, system is by interior return duct 1、S‐CO₂Gas-turbine 2, generator 3, working medium detection unit 4, regenerator 5, condenser 6, compressor 7, valve 8, outer layer down-comer The compositions such as section entrance 9；System composition form is as follows：It is worked CO by compressor 7₂It is compressed to above-critical state, and power is provided and is pushed away Dynamic CO₂Enter outer layer after the preheating of regenerator 5 and decline pipeline section entrance 9, valve 8 can coordinate adjust cycle fluid flow and Pressure；Heat of the cycle fluid in the outer tube of fin casing flows downward and absorbs rock and hot dry rock is taking hot well bottom Portion is collected to interior return duct 1；Cycle fluid after heating enters S-CO from the outlet of interior return duct 1₂Gas-turbine 2, S-CO₂Turbine Machine 2 drives the rotation power generation of generator 3；S-CO after decrease temperature and pressure₂Into working medium detection unit 4, checked for impurities concentration, addition is slow Lose agent, and the rotten working medium of removable parts；CO after detection₂Waste heat is discharged by regenerator 5, it is further cold by condenser 6 But start new cycle into compressor 7 after cooling down.

As shown in Fig. 2, hot dry rock takes hot fin casing to be declined by well cementation heat conduction cement layer 10, interior return duct 11, outer layer The compositions such as pipeline section 12, outer layer enhanced heat exchange pipeline section 13, outer surface fin 14, bottom shock resistance thickening layer 15,16 be common rocks, 17 be hot dry rock.

Interior return duct 1 uses steel and plastic composite material.The plastic outer layer of steel-plastics composite pipe can resist the high temperature of circulatory mediator Corrosion, while there is low thermal coefficient, it can effectively put forward the outlet temperature of cycle fluid；Steel internal layer intensity is big, can bear The impact of cycle fluid.

S‐CO₂Gas-turbine 2 is arranged in geothermal well exit.S‐CO₂Gas-turbine 2 need to select resistance to S-CO₂The material of corrosion, with Mitigate corrosion of the cycle fluid to gas-turbine；The single-machine capacity of gas-turbine should be in 2MW or more, to ensure the economy of individual well；Hair Motor 3, compressor 7 and S-CO₂Gas-turbine 2 is connected, rotation power generation, compression working medium under the drive of gas-turbine.

Working medium detection unit 4 is located at S-CO₂Gas-turbine 2 exports, can be with periodic detection supercritical CO₂In impurity content, More polymictic cycle fluid will be contained to be discharged, add new CO₂；Antisludging agent or corrosion inhibiter is periodically added, prevents geothermal well-pipe Fouling or corrosion failure.

Compressor 7 is located at after regenerator 5 and condenser 6 and S-CO₂Gas-turbine 2 rotates coaxially, will be in S-CO₂Gas-turbine CO in 2 after acting expansion₂It is compressed to specified pressure, and cycle is pushed to carry out；Through 7 compressed S-CO of compressor₂Flow through backheat After device preheating hot well is taken into hot dry rock.

According to the difference of rock temperature, hot fin set outer tube layer is taken to be divided into two sections hot dry rock, outer layer declines pipeline section 12 and outer layer enhanced heat exchange pipeline section 13.It is light pipe that outer layer, which declines pipeline section 12, accounts for 70% of total length or more, temperature is promoted slow Slowly, rock pressure and cycle fluid pressure are smaller, select oil casing steel.It is dry that outer layer enhanced heat exchange pipeline section 13 is located at heat In rock stratum, the big temperature of rock pressure is high, and the big corrosivity of cycle fluid static pressure is strong, and the corrosion-resistant, intensity such as alusil alloy steel can be selected Greatly, the excellent metal material of heat conduction；13 outer surface of outer layer enhanced heat exchange pipeline section circumferentially fin with vertical direction uniform welding 14, heat transfer surface area is increased, individual well output is improved.Hot dry rock takes hot well bottom of the tube to use closure designs, setting bottom anti- Thickening layer 15 is impacted, the static pressure and impact for bearing cycle fluid are denuded.

As shown in Fig. 3 a, Fig. 3 b in Fig. 3 and Fig. 3 c, hot dry rock takes hot fin casing to use coaxial sleeve structure, is divided into interior Outer two layers；Outer layer declines the not additional fin of pipeline section 12；13 outer surfaces of outer layer enhanced heat exchange pipeline section are circumferentially uniform with vertical direction It is dispersed with fin 14, fin 14 can increase heat exchange area, improve individual well and contribute；Plate wing (Fig. 3 a, Fig. 3 b) can be selected in fin 14 Or needle wing (Fig. 3 c).

As shown in figure 4, outer layer enhanced heat exchange pipeline section bottom is provided with bottom shock resistance thickening layer 15, using thick-walled forgings End socket and outer layer enhanced heat exchange pipeline section 13 are using together with wide U-shaped or narrow U-shaped groove butt welding.

As shown in figure 5, steady flow unit is arranged in the entrance of interior return duct 11, entrance is pulled back by 12- using edge turning mode 15 ° of horn mouth makes that hot working fluid is taken in tube bottom to accelerate, avoids flowing back.

As shown in fig. 6, the plate-shaped carrier of setting 3 or more is with return duct in fixation in each section of outer tube, into outer layer Plate-shaped carrier 19 and 11 center line of interior return duct are in also to be more than 0 ° in addition to fixed function by the plate-shaped carrier of enhanced heat exchange pipeline section 13 The slightly eddy flow less than 90 °.

The operation principle of the utility model：Hot dry rock takes hot fin casing to use coaxial sleeve structure, is divided into two layers inside and outside. Cycle fluid is flow to from outer layer take hot well bottom after be pooled to internal layer, in the process of decline absorbs soil, rock and hot dry rock Geothermal energy constantly heats up, then is back to ground from good internal layer is kept the temperature, and passes through S-CO₂Gas-turbine converts heat into machinery Can, then drive electrical power generators.Enter compressor after regenerator and condenser cooling to pressurize, is again introduced into outer layer and absorbs ground Thermal energy starts new cycle.S‐CO₂It only flows, is not contacted with hot dry rock, without establishing open type in hot dry rock heat removing tube system Subsurface reservoir system it is many to avoid leakage, corrosion and scaling etc. without drilling complicated injection well, fractured well, producing well Problem.In order to enhance the exchange capability of heat of hot dry rock section, it is additionally arranged fin in heat removal clutch outer surface, to increase heat transfer area, is carried High individual well is contributed, while being shortened and being taken hot well length, and probing and operating cost are reduced.

Claims (8)

1. developing the S-CO of hot dry rock geothermal energy based on fin casing₂Electricity generation system, it is characterised in that：Including：Fin casing is Coaxial sleeve, is divided into inside and outside i.e. two layers outer tube and interior return duct, and outer tube provides S-CO₂It flow to shaft bottom and absorbs the logical of geothermal energy Road, outer tube are divided into outer layer and decline pipeline section and outer layer enhanced heat exchange pipeline section；Outer layer decline pipeline section, provide cycle fluid from well head to The flow channel of hot dry rock；Outer layer enhanced heat exchange pipeline section is located at hot dry rock, and outer surface has circumferentially uniform with vertical direction The enhanced heat exchange fin of distribution, can be obviously improved the heat exchange area of fin casing, and working medium is mainly inhaled in outer layer thermoexcell section Heat heating；Interior return duct provides flow channel of the cycle fluid from shaft bottom to well head；Gas-turbine is located at well head, with interior reflux Pipe outlet is connected, by S-CO₂Thermal energy be converted into mechanical energy, drive electrical power generators；Working medium detection unit is located at gas-turbine Outlet detects CO₂In impurity content, put into antisludging agent or preservative in due course and removable parts go bad CO₂；Regenerator is located at work After quality detection unit, the S-CO of compressor outlet is preheated₂Fluid；Condenser is located at after regenerator, by CO₂Fully cooling, To reduce work done during compression；Compressor is located at after condenser, by CO₂It is compressed to above-critical state, and circulation power is provided, controls CO₂ Flow and pressure.

2. the S-CO according to claim 1 for developing hot dry rock geothermal energy based on fin casing₂Electricity generation system, feature exist In：The fin casing uses S-CO₂As taking thermal cycle working medium.

3. the S-CO according to claim 1 for developing hot dry rock geothermal energy based on fin casing₂Electricity generation system, feature exist In：The outer layer declines pipeline section from well head until hot dry rock, petroleum casing pipe steel or stainless steel is selected according to geological conditions；Outside Layer declines length of pipe section and accounts for 70% or more of outer tube total length.

4. the S-CO according to claim 1 for developing hot dry rock geothermal energy based on fin casing₂Electricity generation system, feature exist In：The outer layer enhanced heat exchange pipeline section outer surface is circumferentially uniform-distribution with fin with vertical direction, and fin can increase heat exchange Outer layer enhanced heat exchange pipeline section is fixed in geothermal well by area using the excellent high temperature resistant cement of heat conduction；Fin root and outer layer Enhanced heat exchange pipeline section outer surface is connected, and absorbs the heat in hot dry rock by heat exchange pattern；Fin selects plate wing or needle wing, adopts It is fixed on outer surface with welding manner, plate wing is fixed in the vertical direction, in order to avoid influence the flowing of cementing concrete；Fin aluminium The excellent metal material of the corrosion-resistant heat conductivility of silicon alloys.

5. the S-CO according to claim 1 for developing hot dry rock geothermal energy based on fin casing₂Electricity generation system, feature exist In：The outer layer enhanced heat exchange pipeline section bottom is provided with bottom shock resistance thickening layer, and hot dry rock takes the cycle that hot well bottom is born Working medium static pressure reaches 30MPa or more；Using thick-walled forgings end socket and outer layer enhanced heat exchange pipeline section using wide U-shaped or narrow U-shaped groove pair It connects and welds together, to which hot well bottom of the tube will be taken to seal and bear supercritical pressure, form take inside hot well pipe closed circuit and follow Ring.

6. the S-CO according to claim 1 for developing hot dry rock geothermal energy based on fin casing₂Electricity generation system, feature exist In：The interior reflux tube inlet is in underground heat bottom, the S-CO of outlet and ground₂Gas-turbine is connected；The entrance of interior return duct is set Steady flow unit is set, entrance is pulled back to 12-15 ° of horn mouth using edge turning mode.

7. the S-CO according to claim 1 for developing hot dry rock geothermal energy based on fin casing₂Electricity generation system, feature exist In：The interior return duct uses steel-plastics composite pipe.

8. the S-CO according to claim 1 for developing hot dry rock geothermal energy based on fin casing₂Electricity generation system, feature exist In：To ensure good connection and the fixation of fin casing, uses and be threadedly coupled between every section of fin casing；In each section of outer tube 3 or more plate-shaped carriers are set with return duct in fixation.