Geothermal energy-solar energy double-heat-source dynamic matching power generation system

Abstract

The utility model relates to a geothermal energy-solar energy double-heat-source dynamic matching power generation system. A solar heat collection unit comprises a solar heat collector and a first check valve; the geothermal well heat extraction unit comprises a geothermal well, an inner-layer sleeve, an outer-layer sleeve, a geothermal water pump and a stratum; the heat storage regulation and control unit comprises a heat storage water tank, a water return tank, a heat source water pump, an evaporator, a water supplementing three-way valve, a water supplementing pump and a water supplementing and returning three-way valve. According to the utility model, stable output and grid connection of electric power can be realized, and frequent peak regulation of an electric power network is avoided; the service life of the geothermal well is effectively prolonged, and heat exhaustion is avoided; the system is simple in structure, high in reliability and wide in application range.

Description

TECHNICAL FIELD

[0001] The utility model belongs to geothermal and solar energy resource exploitation and utilization technical field, concretely relates to a geothermal energy-solar energy double heat source dynamic matching power generation system. BACKGROUND

[0002] Among numerous renewable energy technologies, geothermal energy and solar energy become the focus of energy collaborative development and utilization because of large reserves, wide distribution, high reliability and small environmental impact. Geothermal energy can provide stable base load power, but solar energy resources have intermittency due to weather and day-night changes. For a long time, geothermal-solar coupled power generation system has always had problems such as large power output fluctuation and grid connection difficulty.

[0003] In view of the above problems, the industry proposes to use complementary power generation technology of solar energy, geothermal energy and energy storage, but in the existing research on the development of the new technology, a larger area solar collector is used to absorb solar heat and store it in a molten salt tank for stable output of system power in insufficient light, but the larger scale collector field and molten salt energy storage device have large area, high cost and complex operation and regulation of the power generation system. As a base load power source, long-term full-load operation of geothermal energy will cause depletion of geothermal resources, reduce heat output, further cause unstable power output and environmental damage and other problems. CONTENT OF THE UTILITY MODEL

[0004] The utility model aims at overcoming the deficiencies of the prior art, providing a geothermal energy-solar energy double heat source dynamic matching power generation system, which can realize efficient collaborative development and utilization of geothermal energy and solar energy, solve the problems of unstable power output and difficult grid connection of the existing geothermal-solar coupled power generation system, realize stable power output and grid connection, avoid frequent peak shaving of the power network, effectively prolong the service life of the geothermal well, avoid heat depletion, and have simple structure, high reliability and wide application range.

[0005] The utility model solves its technical problem by the following technical scheme:

[0006] A geothermal energy-solar energy double heat source dynamic matching power generation system, comprising a solar heat collecting unit, a geothermal well heat extraction unit and a heat storage regulation unit.

[0007] The solar heat collecting unit comprises a solar collector and a first check valve, low-temperature return water after heat exchange of the heat storage regulation unit flows into an inlet pipeline of the solar collector, and an outlet pipeline of the solar collector is connected to the heat storage regulation unit through the first check valve.

[0008] The geothermal well heat extraction unit comprises a geothermal well, an inner casing, an outer casing, a geothermal water pump and a stratum, the outer casing and the inner casing are installed in the geothermal well, the wall of the geothermal well is in close contact with the outer wall of the outer casing, and the geothermal well is a dry well; the inner casing penetrates the shallow low-temperature geothermal layer, the middle high-temperature geothermal layer and the deep high-temperature geothermal layer of the stratum and is connected with the well mouth and the well bottom, the inner casing forms a heat extraction outlet water channel, and the annular space between the inner casing and the outer casing forms a geothermal well inlet water channel; the heat extraction outlet water channel is connected to the heat storage regulation unit through the geothermal water pump and a water supply three-way valve, and the geothermal water pump is arranged above the ground.

[0009] Moreover, the heat storage regulation unit comprises a heat storage water tank, a return water tank, a heat source water pump, an evaporator, a water supplementing three-way valve, a water supplementing pump and a water supplementing and returning three-way valve, the high end of the heat storage water tank is connected to the outlet pipeline of the solar heat collecting unit through the water supply three-way valve, the low end of the heat storage water tank is connected to the hot water inlet of the evaporator through the heat source water pump, the hot water outlet of the evaporator is connected to the inlet pipeline of the solar heat collector through the first outlet of the return water three-way valve and the outlet of the water supplementing and returning three-way valve, the working medium outlet of the evaporator and the working medium inlet of the evaporator are jointly connected to a generator set, the second outlet of the return water three-way valve is connected to the high end of the return water tank, the low end of the return water tank is connected to the inlet of the water supplementing and returning three-way valve through the water supplementing three-way valve and the water supplementing pump, and the outlet of the water supplementing three-way valve is connected to the geothermal well inlet water channel.

[0010] Moreover, a second check valve is arranged on the outlet pipeline of the geothermal water pump.

[0011] Moreover, the solar heat collector is a light-concentrating parabolic trough type heat collector, a temperature control valve is arranged on the outlet pipeline of the solar heat collector in front of the first check valve, and the temperature control valve controls the constant temperature of the heat transfer working medium at the outlet of the solar heat collector with the change of the irradiation intensity.

[0012] Moreover, the generator set is an organic Rankine cycle generator set, and the working medium of the generator set is Rfa or Ra.

[0013] Moreover, the inner casing and the outer casing are concentric casings, the flow direction of the circulating water in the concentric casings is "outer injection and inner outlet", the circulating water is not in direct contact with the stratum, the circulating water in the geothermal well heat extraction unit directly reaches the bottom of the geothermal well through the geothermal well inlet water channel, flows out of the ground after heat exchange with the stratum and is pumped into the heat storage water tank by the geothermal water pump.

[0014] Moreover, the return water tank is arranged close to the well mouth of the geothermal well.

[0015] Moreover, the volume of the heat storage water tank is greater than that of the return water tank.

[0016] The positive effect that the utility model can produce is:

[0017] 1. The geothermal energy-solar dual heat source dynamic matching power generation system provided by the utility model breaks the limitation of unstable power output of the existing geothermal-solar coupled power generation system, can realize all-weather stable output and high-quality grid connection, and avoids frequent peak regulation of the power grid.

[0018] 2. The geothermal energy-solar dynamic matching power generation system provided by the utility model can realize intermittent operation of geothermal wells while realizing stable power output, avoids heat depletion of hot dry rock geothermal resources, and effectively prolongs the service life of the geothermal well.

[0019] 3. The geothermal energy-solar dynamic matching power generation system provided by the utility model is provided with a heat storage water tank and a return water tank, compared with the existing geothermal-solar-molten salt energy storage coupled power generation system, the system structure is simple, the heat storage working medium is water, the investment construction and operation cost of the heat storage system can be greatly reduced, and the system economy is improved.

[0020] 4. The geothermal energy-solar dynamic matching power generation system provided by the utility model, the area of the solar heat collector is determined by the maximum output of the geothermal well, compared with the existing geothermal-solar-molten salt energy storage coupled power generation system, the area of the heat collector, the land occupation area and the volume of the heat storage tank can be greatly reduced, and the overall economy is improved. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a structural schematic view of the utility model;

[0022] Figure 2 It is a low irradiation power generation working condition heat source circuit water flow direction schematic view in the utility model;

[0023] Figure 3 It is a high irradiation power generation working condition heat source circuit water flow direction schematic view in the utility model;

[0024] Figure 4 It is a no-irradiation geothermal energy power generation working condition heat source circuit water flow direction schematic view in the utility model;

[0025] Figure 5 It is a no-irradiation heat storage water tank power generation working condition heat source circuit water flow direction schematic view in the utility model.

[0026] MARKED WITH A REFERENCE:

[0027] 1. Heat source water pump; 2. Evaporator; 3. Evaporator hot water inlet; 4. Evaporator hot water outlet; 5. Evaporator working fluid inlet; 6. Evaporator working fluid outlet; 7. Return water three-way valve; 8. Return water three-way valve inlet; 9. Return water three-way valve second outlet; 10. Return water three-way valve first outlet; 11. Return water tank; 12. Makeup water three-way valve; 13. Makeup water three-way valve inlet; 14. Makeup water three-way valve first outlet; 15. Makeup water three-way valve second outlet; 16. Makeup water pump; 17. Makeup and return water three-way valve; 18. Makeup and return water... 19. First inlet of water three-way valve; 20. Second inlet of water replenishment three-way valve; 21. Outlet of water replenishment three-way valve; 22. Inner casing; 23. Outer casing; 24. Geothermal well; 25. Formation; 26. Solar collector; 27. Temperature control valve; 28. First check valve; 29. ​​Geothermal water pump; 30. Second check valve; 31. Water supply three-way valve; 32. First inlet of water supply three-way valve; 33. Second inlet of water supply three-way valve; 34. Water storage tank; 35. Generator set. Detailed Implementation

[0028] The present invention will be further described in detail below through specific embodiments. The following embodiments are only descriptive and not limiting, and should not be used to limit the protection scope of the present invention.

[0029] like Figure 1 As shown, a geothermal-solar dual-source dynamic matching power generation system is innovative in that it includes a solar thermal collector unit, a geothermal well heat extraction unit, and a thermal storage and regulation unit.

[0030] The solar thermal collector unit includes a solar collector 25 and a first check valve 27. The low-temperature return water after heat exchange in the thermal storage control unit flows into the inlet pipe of the solar collector 25, and the outlet pipe of the solar collector 25 is connected to the thermal storage control unit through the first check valve 27.

[0031] The geothermal well heat extraction unit includes a geothermal well 23, an inner casing 21, an outer casing 22, a geothermal water pump 28, and a formation 24. The outer casing 22 and the inner casing 21 are installed inside the geothermal well 23, and the wall of the geothermal well 23 is in close contact with the outer wall of the outer casing. The geothermal well 23 is a dry well without water. The inner casing 21 penetrates the shallow low-temperature geothermal layer, the middle high-temperature geothermal layer, and the deep high-temperature geothermal layer of the formation 24 and connects the wellhead and the bottom of the well. A heat extraction water outlet channel is formed inside the inner casing 21, and the annular space between the inner casing 21 and the outer casing 22 forms a geothermal well water inlet channel. The heat extraction water outlet channel is connected to the second inlet 32 ​​of the water supply three-way valve through the geothermal water pump 28, and is connected to the heat storage control unit through the outlet 33 of the water supply three-way valve. The geothermal water pump 28 is located above the ground surface.

[0032] The heat storage regulating unit comprises a heat storage water tank 34, a return water tank 11, a heat source water pump 1, an evaporator 2, a water supplementing three-way valve 14, a water supplementing pump 16, and a water supplementing and returning three-way valve 17. The high end of the heat storage water tank 34 is connected to the outlet pipeline of the solar heat collecting unit through the water feeding three-way valve 30. The low end of the heat storage water tank 34 is connected to the hot water inlet 3 of the evaporator 2 through the heat source water pump 1. The hot water outlet 4 of the evaporator 2 is connected to the water returning three-way valve inlet 8. After being connected to the water supplementing and returning three-way valve first inlet 18 through the water returning three-way valve first outlet 10, the hot water outlet 4 is connected to the inlet pipeline of the solar heat collector 25 through the water supplementing and returning three-way valve outlet 20. The evaporator working medium outlet 6 and the evaporator working medium inlet 5 are jointly connected to the generator set 35. The water returning three-way valve second outlet 9 of the water returning three-way valve 7 is connected to the high end of the return water tank 11. The low end of the return water tank 11 is connected to the water supplementing three-way valve inlet 13 and is connected to the water supplementing and returning three-way valve second inlet 19 through the water supplementing three-way valve second outlet 15 and the water supplementing pump 16. The water supplementing three-way valve first outlet 14 is connected to the water inlet channel of the geothermal well.

[0033] A second check valve 29 is installed on the outlet pipeline of the geothermal water pump 28 to prevent the heat fluid in the solar heat collector 25 circuit from entering the geothermal well heat taking unit circuit through the water feeding three-way valve first inlet 31.

[0034] The solar heat collector 25 is a light-concentrating parabolic trough type heat collector. A temperature control valve 26 is arranged on the outlet pipeline of the solar heat collector 25 before the first check valve 27. The temperature control valve 26 controls the outlet temperature of the heat transfer working medium in the solar heat collector 25 to be constant with the change of the irradiation intensity.

[0035] The generator set 35 is an organic Rankine cycle generator set. The working medium of the generator set 35 is R245fa or R134a.

[0036] The inner sleeve 21 and the outer sleeve 22 are concentric sleeves. The flow direction of the circulating water in the concentric sleeves is "outer injection and inner outlet". The circulating water has no direct contact with the stratum. The circulating water in the geothermal well heat taking unit directly reaches the bottom of the geothermal well through the water inlet channel of the geothermal well. After heat exchange with the stratum, the circulating water flows out of the ground through the heat taking water outlet channel and is sent into the heat storage water tank 34 by the geothermal water pump 28.

[0037] The return water tank 11 is installed near the geothermal well mouth and is used for storing the return water required by the geothermal well heat taking and the water supplementing of the solar heat collector.

[0038] The heat storage water tank 34 has a larger volume than the return water tank 11 and is used for storing the heat source water of the same temperature from the geothermal well and the solar heat collector.

[0039] In the strong irradiation power generation condition, the return water tee valve 7, the return water tank 11, the makeup water tee valve 12, the makeup water pump 16, the makeup return water tee valve 17, the solar collector 25, the temperature control valve 26, the first check valve 27, the feed water tee valve 30, the thermal storage water tank 34, the heat source water pump 1 and the evaporator 2 constitute a strong irradiation power generation condition heat source water circuit, and a specific water flow direction schematic diagram is shown in Figure 3 ;

[0040] In the low irradiation power generation condition, the return water tee valve 7, the return water tank 11, the makeup water tee valve 12, the inner layer sleeve pipe 21, the outer layer sleeve pipe 22, the geothermal water pump 28, the second check valve 29, the makeup return water tee valve 17, the solar collector 25, the temperature control valve 26, the check valve 27, the feed water tee valve 30, the thermal storage water tank 34, the heat source water pump 1 and the evaporator 2 constitute a low irradiation power generation condition heat source circuit, and a specific water flow direction schematic diagram is shown in Figure 2 ;

[0041] In the non-irradiation geothermal energy power generation condition, the return water tee valve 7, the return water tank 11, the makeup water tee valve 12, the inner layer sleeve pipe 21, the outer layer sleeve pipe 22, the geothermal water pump 28, the second check valve 29, the feed water tee valve 30, the thermal storage water tank 34, the heat source water pump 1 and the evaporator 2 constitute a non-irradiation power generation condition heat source water circuit, and a specific water flow direction schematic diagram is shown in Figure 4 ;

[0042] Specifically, in the optimal output condition of the geothermal well heat source water flow rate 20 m 3 / h and temperature 110℃, the strong irradiation intensity DNI = 800 W / m 2 The lower limit preset value is taken as an example, and the heat source matching and utilization process of the geothermal energy-solar dual heat source dynamic matching power generation system is introduced in detail in the low irradiation power generation condition and the strong irradiation power generation condition:

[0043] In the low irradiation power generation condition, the vertical irradiation intensity 0 W / m 2 ≤DNI≤800 W / m 2When the low-temperature return water is discharged from the evaporator hot water outlet 4, it enters the return water three-way valve 7. Part of the low-temperature return water enters the return water three-way valve first outlet 10, and the return water three-way valve second inlet 19 is closed. The low-temperature return water enters the solar collector 25 through the return water three-way valve outlet 20, is heated and then flows out of the collector into the temperature control valve 26. The temperature control valve 26 automatically adjusts the valve opening according to the outlet fluid temperature of the solar collector 25 to control the flow of low-temperature return water until the outlet temperature reaches the preset temperature of 110°C. Then, it enters the second inlet 32 of the feed water three-way valve through the check valve 27, and is mixed with the geothermal water from the first inlet 31 of the feed water three-way valve. The check valve 27 prevents geothermal water from entering the solar collector unit. The remaining low-temperature return water flows out of the three-way valve second outlet 9, enters the return water tank 11 through the pipeline, and the second outlet 15 of the feed water three-way valve is closed. The low-temperature return water enters the annular channel formed by the inner layer sleeve 21 and the outer layer sleeve 22 of the return water tank 11 under the suction of the geothermal water pump 23. The outer layer sleeve 22 is in close contact with the well wall of the geothermal well 23. The low-temperature return water continuously absorbs heat from the formation 24 from top to bottom and reaches the bottom of the geothermal well 23. Then it flows to the ground through the internal channel of the inner layer sleeve 21. The 110°C geothermal water after heating enters the check valve 29 through the geothermal water pump 28 arranged on the ground. The geothermal water pump 28 always maintains a flow rate of 20m 3 / h to maintain a stable geothermal water outlet temperature. The check valve prevents hot water from the solar collector unit from entering the geothermal well heat extraction unit. After the high-temperature geothermal water exits the check valve 29, it is mixed with high-temperature hot water from the second inlet 32 of the feed water three-way valve through the first inlet 31 of the feed water three-way valve, and then flows out of the outlet 33 of the feed water three-way valve. It enters the heat storage tank 34 through the pipeline. The 110°C hot water enters the evaporator 2 from the low position of the tank through the heat source water pump 1. The heat source water pump always maintains a flow rate of 20m 3 / h. The tank stores high-temperature hot water from the geothermal well heat extraction unit and the solar collector unit. After the heat source hot water releases heat in the evaporator, it flows out of the evaporator hot water outlet 4. The organic working medium absorbs heat in the evaporator 2 and enters the generator set 35 to realize power output, and the next cycle begins.

[0044] Strong irradiation power generation condition, i.e. vertical irradiance intensity DNI > 800W / m 2When the low-temperature return water after heat release flows out from the evaporator hot water outlet 4, it enters the return water three-way valve 7, the second outlet 9 of the return water three-way valve is fully closed, the return water flows out from the first outlet 10 of the return water three-way valve, enters the supplementary return water three-way valve first inlet 18 through the pipeline, and the first outlet 14 of the supplementary water three-way valve is fully closed. The low-temperature return water stored in the return water tank 11 is sucked into the supplementary water pump 16 through the supplementary water three-way valve 12 under the suction of the supplementary water pump 16, then enters the supplementary water pump 16 through the pipeline, enters the second inlet 19 of the supplementary return water three-way valve 17 from the first inlet 18 of the supplementary return water three-way valve, and is mixed with the low-temperature return water. After mixing, the low-temperature return water enters the solar collector 25 through the pipeline, the solar hot water after heat absorption enters the temperature control valve 26, the temperature control valve 26 automatically adjusts the valve opening degree according to the outlet fluid temperature of the solar collector 25 to control the supplementary return water flow, until the outlet temperature reaches the preset temperature 110℃, wherein the low-temperature return water flow after heat exchange of the evaporator 2 is constant at 20m 3 / h, and the temperature control valve 26 only controls the flow of the supplementary water pump. Then, the first inlet 31 of the water supply three-way valve is closed, the high-temperature solar hot water enters the second inlet 32 of the water supply three-way valve through the check valve 27, flows out from the outlet 33 of the water supply three-way valve, and enters the heat storage water tank 34. Under the suction of the heat source water pump 1, the 110℃ heat source water enters the evaporator 2 at a flow rate of 20m 3 / h, and the temperature control valve 26 only controls the flow of the supplementary water pump. Then, the first inlet 31 of the water supply three-way valve is closed, the high-temperature solar hot water enters the second inlet 32 of the water supply three-way valve through the check valve 27, flows out from the outlet 33 of the water supply three-way valve, and enters the heat storage water tank 34. Under the suction of the heat source water pump 1, the 110℃ heat source water enters the evaporator 2 at a flow rate of 20m

[0045] Although the embodiments and drawings of the utility model are disclosed for the purpose of illustration, those skilled in the art can understand that various substitutions, changes and modifications are possible without departing from the spirit and scope of the utility model and the appended claims, therefore, the scope of the utility model is not limited to the content disclosed in the embodiments and drawings.

Claims

1. A geothermal-solar dual-source dynamic matching power generation system, characterized in that: The application relates to a heat storage system, which comprises a solar heat collecting unit, a geothermal well heat collecting unit and a heat storage regulating unit. The solar heat collecting unit comprises a solar heat collector (25) and a first check valve (27), low-temperature return water after heat exchange of the heat storage regulating unit flows into an inlet pipeline of the solar heat collector (25), and an outlet pipeline of the solar heat collector (25) is connected to the heat storage regulating unit through the first check valve (27). The geothermal well heat collecting unit comprises a geothermal well (23), an inner layer sleeve (21), an outer layer sleeve (22), a geothermal water pump (28) and a stratum (24), the outer layer sleeve (22) and the inner layer sleeve (21) are installed in the geothermal well (23), the wall of the geothermal well (23) is in close contact with the outer wall of the outer layer sleeve, and the geothermal well (23) is a dry well without water. The inner layer sleeve (21) penetrates through shallow low-temperature geothermal layers, middle high-temperature geothermal layers and deep high-temperature geothermal layers of the stratum (24) and is communicated with a well mouth and a well bottom, a heat collecting and discharging water channel is formed in the inner layer sleeve (21), an annular space between the inner layer sleeve (21) and the outer layer sleeve (22) forms a geothermal well water inlet channel, the heat collecting and discharging water channel is connected to the heat storage regulating unit through the geothermal water pump (28) and a water feeding three-way valve (30), and the geothermal water pump (28) is arranged above the ground.

2. The geothermal-solar dual heat source dynamic matching power generation system according to claim 1, characterized in that: The heat storage regulating unit comprises a heat storage water tank (34), a return water tank (11), a heat source water pump (1), an evaporator (2), a water supplementing three-way valve (12), a water supplementing pump (16) and a water supplementing and return three-way valve (17), a high-position end of the heat storage water tank (34) is connected to an outlet pipeline of the solar heat collecting unit through the water feeding three-way valve (30), a low-position end of the heat storage water tank (34) is connected to a hot water inlet (3) of the evaporator (2) through the heat source water pump (1), a hot water outlet (4) of the evaporator (2) is connected to an inlet pipeline of the solar heat collector (25) through a first outlet of the return water three-way valve (7) and an outlet of the water supplementing and return three-way valve (17), an evaporator working medium outlet (6) and an evaporator working medium inlet (5) are jointly connected to a generator set (35), a second outlet of the return water three-way valve (7) is connected to a high-position end of the return water tank (11), a low-position end of the return water tank (11) is connected to an inlet of the water supplementing and return three-way valve (17) through the water supplementing three-way valve (12) and the water supplementing pump (16), and an outlet of the water supplementing three-way valve (12) is connected to the geothermal well water inlet channel.

3. The geothermal-solar dual heat source dynamic matching power generation system according to claim 1, characterized in that: A second check valve (29) is arranged on an outlet pipeline of the geothermal water pump (28).

4. The geothermal-solar dual heat source dynamic matching power generation system of claim 1, wherein: The solar heat collector (25) is a light-concentrating parabolic trough type heat collector, a temperature control valve (26) is arranged on the outlet pipeline of the solar heat collector (25) and located in front of the first check valve (27), and the temperature control valve (26) controls the outlet temperature of heat transfer working medium of the solar heat collector (25) to be constant with the change of irradiation intensity.

5. The geothermal-solar dual heat source dynamic matching power generation system of claim 2, wherein: The generator set (35) is an organic Rankine cycle generator set, and the working medium of the generator set (35) is R245fa or R134a.

6. The geothermal-solar dual heat source dynamic matching power generation system of claim 1, wherein: The inner sleeve (21) and the outer sleeve (22) are concentric sleeves, the flow direction of the circulating water in the concentric sleeves is "injection from outside and out from inside", the circulating water has no direct contact with the stratum, the circulating water in the heat extraction unit of the geothermal well directly reaches the bottom of the geothermal well through the water inlet channel of the geothermal well, flows out of the ground after heat exchange with the stratum through the water outlet channel, and is sent into the heat storage tank (34) by the geothermal water pump (28).

7. The geothermal-solar dual heat source dynamic matching power generation system of claim 2, wherein: The backwater tank (11) is installed close to the geothermal well mouth.

8. The geothermal-solar dual heat source dynamic matching power generation system of claim 2, wherein: The volume of the heat storage tank (34) is greater than that of the backwater tank (11).

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