Middle-deep geothermal source heat exchange experimental device

Abstract

The utility model provides a medium-deep geothermal source heat exchange experiment device, which relates to the technical field of geothermal source heat exchange experiments, and comprises at least two experiment tables, each experiment table comprises a heat insulation shell, and a rock-soil sample and a heating cavity are arranged in the heat insulation shell; at least two geothermal heat exchangers, wherein each geothermal heat exchanger is arranged in one rock-soil sample; each heating structure is connected with one heating cavity and is used for heating the rock-soil sample; the circulating heat exchange structure comprises a circulating water cooling assembly and a circulating pipeline, and the circulating pipeline is sequentially connected with the at least two geothermal heat exchangers and the circulating water cooling assembly; the first measuring unit and the second measuring unit are respectively arranged on a heat exchange water inlet pipe and a heat exchange water outlet pipe of the circulating pipeline; the problem that an existing heat exchange experiment device is difficult to truly restore the heat exchange effect of an underground heat exchange technology at stratum positions with different depths when a single geothermal heat exchanger is experimented is solved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the geothermal source heat exchange experimental technical field, more specifically, it relates to a kind of middle-deep geothermal source heat exchange experimental device. BACKGROUND

[0002] Geothermal energy, as a clean and renewable energy, has been developed and utilized on a large scale in the world in recent years due to its abundant reserves, wide distribution and easy access, which has brought significant economic and environmental benefits. With the advancement of technology, the exploitation methods of geothermal energy are constantly innovating, and the downhole heat exchange technology has gradually become an important direction for geothermal energy development due to its environmental protection and high efficiency. This technology realizes closed-cycle extraction of geothermal energy by installing heat exchangers underground, avoiding the direct extraction and discharge of geothermal fluids in traditional exploitation methods, thereby reducing the impact on the environment.

[0003] At the policy level, many countries provide tax incentives, financial subsidies and other incentive measures for projects that use downhole heat exchange technology to encourage the development of renewable energy, further reducing development costs and improving the economic benefits of projects. In addition, this technology also avoids the cumbersome procedures such as water intake permit and mining permit required in traditional geothermal exploitation, simplifying the development process.

[0004] Before geothermal energy exploitation, it is necessary to determine the heat that can be extracted by different operating conditions of downhole heat exchange technology under the target geology and geothermal conditions. Experiments can be carried out by establishing a heat exchange experimental device to optimize the structure of geothermal heat exchanger and determine the corresponding operating parameters in the early stage of the project. Traditional heat exchange experimental devices simulate heat exchange experiments for single geothermal heat exchangers, which are difficult to truly restore the heat exchange effect of downhole heat exchange technology at different depth formation positions. UTILITY MODEL CONTENTS

[0005] The utility model aims at the deficiencies in the prior art, provides a kind of middle-deep geothermal source heat exchange experimental device, solves the problem that the heat exchange experimental device in prior art simulates heat exchange experiment for single geothermal heat exchanger, which is difficult to truly restore the heat exchange effect of downhole heat exchange technology at different depth formation positions.

[0006] To achieve the above purpose, the utility model provides a kind of middle-deep geothermal source heat exchange experimental device, comprising:

[0007] At least two experimental tables, each experimental table includes a heat preservation shell, a rock-soil sample and a heating cavity are arranged in the heat preservation shell;

[0008] At least two geothermal heat exchangers, each geothermal heat exchanger is arranged in one rock-soil sample;

[0009] At least two heating structures, each of the heating structures being connected with one of the heating cavities and used for heating the rock-soil sample;

[0010] A circulating heat exchange structure, the circulating heat exchange structure comprising a circulating water cooling assembly and a circulating pipeline, the circulating pipeline being connected with the at least two geothermal heat exchangers and the circulating water cooling assembly in sequence;

[0011] A first measuring unit and a second measuring unit, the first measuring unit and the second measuring unit being arranged on a heat exchange water inlet pipe and a heat exchange water outlet pipe of the circulating pipeline respectively.

[0012] Optionally, an annular partition plate is arranged in the interior of the heat preservation shell, an accommodating cavity is formed in the interior of the partition plate, and the rock-soil sample is arranged in the accommodating cavity, and the annular heating cavity is formed between the partition plate and the heat preservation shell.

[0013] Optionally, a water inlet is arranged at one side bottom of the heating cavity, and a water outlet is arranged at the other side top of the heating cavity.

[0014] Optionally, the heating structure comprises a heating heat preservation water tank, a heater and a heating water temperature control module, the heating water temperature control module is capable of controlling the heater to heat water in the heating heat preservation water tank to a set heating temperature, the heating heat preservation water tank is connected with the heating cavity through a heating pipeline, and a heating circulating pump is arranged on the heating pipeline.

[0015] Optionally, the geothermal heat exchanger is a coaxial sleeve heat exchanger, the coaxial sleeve heat exchanger comprises an outer sleeve inserted into the rock-soil sample and a central pipe coaxially arranged in the outer sleeve, an annular space is formed between the outer sleeve and the central pipe, and the lower end of the annular space is communicated with the lower end of the central pipe.

[0016] Optionally, the circulating water cooling assembly comprises a circulating heat preservation water tank, a cooling unit and a circulating water temperature control module, and the circulating water temperature control module is capable of controlling the cooling unit to cool water in the circulating heat preservation water tank to a set circulating temperature.

[0017] Optionally, the circulating pipeline comprises the heat exchange water inlet pipe, a heat exchange connecting pipe and the heat exchange water outlet pipe, one end of the heat exchange water inlet pipe is connected with the outlet of the circulating heat preservation water tank, the other end of the heat exchange water inlet pipe is connected with the input port of one of the geothermal heat exchangers, two ends of the heat exchange connecting pipe are connected with the output port and the input port of two different geothermal heat exchangers respectively, one end of the heat exchange water outlet pipe is connected with the inlet of the circulating heat preservation water tank, and the other end of the heat exchange water outlet pipe is connected with the output port of another geothermal heat exchanger.

[0018] Optionally, the heating pipeline is provided with a heating water temperature sensor and a heating water flow sensor.

[0019] Optionally, the first measuring unit comprises a first temperature sensor and a first flow sensor, and the second measuring unit comprises a second temperature sensor and a second flow sensor.

[0020] Optionally, the heat exchange inlet pipe is provided with a variable frequency circulating pump.

[0021] The middle-deep geothermal source heat exchange experimental device has at least two experimental tables, can set at least two geothermal heat exchangers, can heat rock-soil samples in different experimental tables through at least two heating structures, can simulate different depth formation conditions, and can more truly simulate respective actual geothermal exploitation working conditions through series connection of the circulating heat exchange structure, the circulating water cooling assembly and the at least two geothermal heat exchangers.

[0022] Other features and advantages of the present application will be described in detail in the following specific embodiment part. BRIEF DESCRIPTION OF DRAWINGS

[0023] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout the figures, and in which:

[0024] Figure 1 A structure schematic view of a middle-deep geothermal source heat exchange experimental device according to one embodiment of the present application is shown.

[0025] Figure 2 A structure schematic view of an experimental table of a middle-deep geothermal source heat exchange experimental device according to one embodiment of the present application is shown.

[0026] BRIEF DESCRIPTION OF DRAWINGS

[0027] 1, first heater; 2, first heating water temperature control module; 3, first heating and heat preservation water tank; 4, first heating temperature sensor; 5, first heating flow sensor; 6, first heating circulating pump; 7, first experiment table; 8, second experiment table; 9, outer sleeve; 10, center tube; 11, rock and soil sample; 12, heating cavity; 13, heat preservation shell; 14, first water inlet; 15, first water outlet; 16, second water inlet; 17, second water outlet; 18, circulating water temperature control module; 19, cooling unit; 20, circulating heat preservation water tank; 21, second temperature sensor; 22, second flow sensor; 23, first temperature sensor; 24, first flow sensor; 25, variable frequency circulating pump; 26, second heater; 27, second heating water temperature control module; 28, second heating and heat preservation water tank; 29, second heating temperature sensor; 30, second heating flow sensor; 31, second heating circulating water pump. DETAILED DESCRIPTION

[0028] The preferred embodiments of the present application will be described in more detail below. Although the preferred embodiments of the present application are described below, it is understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present application is more complete and complete, and the scope of the present application is fully conveyed to those skilled in the art.

[0029] As shown in Figure 1 The present application provides a kind of middle deep geothermal source heat exchange experimental device, comprising:

[0030] At least two experiment tables, each experiment table includes heat preservation shell 13, and rock and soil sample and heating cavity 12 are arranged in heat preservation shell 13;

[0031] At least two geothermal heat exchangers, each geothermal heat exchanger is arranged in a rock and soil sample;

[0032] At least two heating structures, each heating structure is connected with a heating cavity 12, and is used to heat rock and soil sample;

[0033] Circulating heat exchange structure, circulating heat exchange structure includes circulating water cooling assembly and circulating pipeline, and circulating pipeline is sequentially connected at least two geothermal heat exchangers and circulating water cooling assembly;

[0034] First measurement unit and second measurement unit, first measurement unit and second measurement unit are arranged on heat exchange inlet pipe and heat exchange outlet pipe of circulating pipeline respectively.

[0035] Specifically, in order to solve the problem that the heat exchange experiment device in the prior art can only simulate heat exchange experiment for a single geothermal heat exchanger and is difficult to truly restore the heat exchange effect of the downhole heat exchange technology in different depth stratum positions, the deep geothermal source heat exchange experiment device has at least two experimental tables, can set at least two geothermal heat exchangers, and can heat the rock-soil samples in different experimental tables through at least two heating structures to simulate different depth stratum conditions, and the circulating heat exchange structure is connected in series with the circulating water cooling assembly and the at least two geothermal heat exchangers, so that the actual geothermal exploitation conditions of each can be more truly simulated, and the experimental data can be obtained through the measurement of the first measurement unit and the second measurement unit, so as to evaluate the heat extraction capacity under different conditions, which has important significance for improving the development efficiency of geothermal energy.

[0036] Optionally, the inside of the heat preservation shell 13 is provided with an annular partition plate, the inside of the partition plate forms a containing cavity, the rock-soil sample is arranged in the containing cavity, and the annular heating cavity 12 is formed between the partition plate and the heat preservation shell 13.

[0037] Specifically, as shown in Figure 2 the heat preservation shell 13 can adopt a rectangular shell, the annular partition plate is arranged in the inside of the heat preservation shell 13, and the heating cavity 12 is formed between the outer periphery of the partition plate and the inner periphery of the heat preservation shell 13. After the heating medium enters the heat preservation cavity, the rock-soil sample in the partition plate can be heated, so that the stratum temperature of the target stratum can be simulated.

[0038] Further, the partition plate is made of a material with high thermal conductivity, and the inside of the heat preservation shell 13 is filled with a heat preservation material with low thermal conductivity, so as to prevent heat loss in the stage of heating the rock-soil sample 11 and the experimental stage.

[0039] Optionally, one side bottom of the heating cavity 12 is provided with a water inlet, and the other side top of the heating cavity 12 is provided with a water outlet.

[0040] Specifically, hot water can be introduced into the heating cavity 12, the hot water enters from the water inlet and flows upwards until it flows out from the water outlet, forming a circulating flow.

[0041] Optionally, the heating structure includes a heating heat preservation water tank, a heater and a heating water temperature control module, the heating water temperature control module can control the heater to heat the water in the heating heat preservation water tank to a set heating temperature, the heating heat preservation water tank is connected with the heating cavity 12 through a heating pipeline, and a heating circulating pump is arranged on the heating pipeline.

[0042] Specifically, under the action of the heating circulating pump, the heated hot water in the heating heat preservation water tank circulates in the heating cavity 12 until the rock-soil sample is heated to the set heating temperature, at which time the hot water in the heating cavity 12 can be discharged for heat exchange experiment.

[0043] In this embodiment, the heater is an electric water heater.

[0044] Optionally, the geothermal heat exchanger is a coaxial tube heat exchanger, which includes an outer tube 9 inserted into the soil sample and a central tube 10 coaxially disposed inside the outer tube 9. An annular space is formed between the outer tube 9 and the central tube 10, and the lower end of the annular space is connected to the lower end of the central tube 10.

[0045] Specifically, a coaxial casing heat exchanger is used to simulate downhole heat exchange technology for heat extraction.

[0046] Optionally, the circulating water cooling assembly includes a circulating insulated water tank 20, a cooling unit 19, and a circulating water temperature control module 18. The circulating water temperature control module 18 can control the cooling unit 19 to cool the water in the circulating insulated water tank 20 to a set circulating temperature.

[0047] Specifically, under the cooling effect of the cooling unit 19, the water temperature of the circulating water in the circulating insulated water tank 20 is kept constant, the same as the water inlet temperature of the coaxial tube heat exchanger simulated in the experiment.

[0048] In this embodiment, the cooling unit 19 is a small air-cooled unit.

[0049] Optionally, the circulation pipeline includes a heat exchange inlet pipe, a heat exchange connecting pipe, and a heat exchange outlet pipe. One end of the heat exchange inlet pipe is connected to the outlet of the circulating insulated water tank 20, and the other end of the heat exchange inlet pipe is connected to the inlet of a geothermal heat exchanger. The two ends of the heat exchange connecting pipe are respectively connected to the outlet and inlet of two different geothermal heat exchangers. One end of the heat exchange outlet pipe is connected to the inlet of the circulating insulated water tank 20, and the other end of the heat exchange outlet pipe is connected to the outlet of another geothermal heat exchanger.

[0050] Specifically, the circulation pipeline connects at least two geothermal heat exchangers in series. The circulating water first enters the inlet of one geothermal heat exchanger and flows out from its outlet. Then it enters the inlet of the next geothermal heat exchanger and flows out from its outlet until it flows back to the circulating insulated water tank 20 through the heat exchange outlet pipe.

[0051] Optionally, a heating water temperature sensor and a heating water flow sensor are installed on the heating pipeline.

[0052] Specifically, the heating water temperature sensor and heating water flow sensor on the heating pipeline can detect the water temperature and flow rate of the hot water flowing out of the heating and insulation water tank, which facilitates the control of the heating of the rock and soil samples by the hot water in the heating chamber 12.

[0053] Optionally, the first measuring unit includes a first temperature sensor 23 and a first flow sensor 24, and the second measuring unit includes a second temperature sensor 21 and a second flow sensor 22.

[0054] Specifically, the second temperature sensor 21 and the second flow sensor 22 are used to record the temperature and flow of the water out of the central pipe 10 after heat exchange, and the first temperature sensor 23 and the first flow sensor 24 are used to record the temperature and flow of the water into the annular space, through the measurement of the first and second measurement units, the heat exchange efficiency and heat extraction capacity can be evaluated through calculation and analysis.

[0055] Optionally, the heat exchange inlet pipe is provided with a variable frequency circulating pump 25.

[0056] Specifically, the variable frequency circulating pump 25 can drive the circulating water in the circulating heat preservation water tank 20 to circulate between the at least two geothermal heat exchangers and the circulating heat preservation water tank 20, and complete heat exchange.

[0057] In this embodiment, by adjusting the frequency of the variable frequency circulating pump 25 and the opening of the valve, the flow and head of the circulating water can be controlled, and by adjusting the circulating water temperature control module 18, the inlet water temperature can be adjusted to realize geothermal source heat exchange experiment under more working conditions.

[0058] In this embodiment, two experimental tables are provided, which are a first experimental table 7 and a second experimental table 8, the first experimental table 7 has a first water inlet 14 and a first water outlet 15, and the second experimental table 8 has a second water inlet 16 and a second water outlet 17, and the heating structure is provided with two, which are a first heating structure and a second heating structure, the first heating structure includes a first heating heat preservation water tank 3, a first heater 1, and a first heating water temperature control module 2, and the heating pipeline is provided with a first heating circulating pump 6, a first heating temperature sensor 4 and a first heating flow sensor 5, and the second heating structure includes a second heating heat preservation water tank 28, a second heater 26, and a second heating water temperature control module 27, and the heating pipeline is provided with a second heating circulating pump 31, a second heating temperature sensor 29 and a second heating flow sensor 30.

[0059] In summary, the middle-deep geothermal source heat exchange experimental device provided by the utility model uses one experiment as an example: the first heating structure and the second heating structure respectively provide constant-temperature hot water for the first experiment table 7 and the second experiment table 8, and set temperature boundary conditions for the rock-soil samples 11 in the experiment table; the heating structure is used to provide hot water with the required temperature for the heating cavity 12, so as to ensure that the two rock-soil samples 11 are heated to the geothermal temperature required by the actual experiment, and the hot water temperature in the first heating insulation water tank 3 and the second heating insulation water tank 28 is respectively the same as the temperature of the two simulated strata; during the heating process, the heating cavity 12 always maintains the state of being filled with hot water, which is used to heat the rock-soil samples 11, and after the rock-soil samples 11 are heated to the set heating temperature, the hot water in the heating cavity 12 is discharged; the two experiment tables can simulate the temperature and rock-soil conditions of two actual middle-deep strata with different depths, the two experiment tables are arranged in series, and the rock-soil samples 11 are configured according to the actual middle-deep geological conditions; during the heat exchange experiment, heat is taken away by the circulating water in the circulating insulation water tank 20, the circulating water flows into the annular space of the first experiment table 7, exchanges heat with the rock-soil samples 11, and then flows out from the central pipe 10, and then enters the annular space of the second experiment table 8 and flows out from the central pipe 10 of the second experiment table 8 to complete the heat exchange; the second temperature sensor 21 and the second flow sensor 22 are used to record the temperature and flow of the water out of the central pipe 10 after the heat exchange is completed, the first temperature sensor 23 and the first flow sensor 24 are used to record the water temperature and flow of the annular space in real time, and the circulating water is circulated under the driving of the frequency conversion circulating pump 25, in this process, the circulating water temperature control module 18 is electrically connected with the small air cooling unit, so as to control the water temperature in the circulating insulation water tank 20, so that the circulating water temperature is maintained constant, and is the same as the water inlet temperature of the coaxial double-pipe heat exchanger simulated by the experiment; different pipe diameters of the central pipe 10 and the outer sleeve pipe 9 can be used for multiple experiments during the experiment, so as to study the heat exchange of the coaxial double-pipe heat exchanger under different design parameters, and the heat taking capacity under different working conditions can be obtained through analysis and calculation according to the measurement results of the first measurement unit and the second measurement unit.

[0060] The above has described the embodiments of the utility model, and the above description is exemplary, is not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A heat exchange experimental device for a middle-deep geothermal source, characterized in that, The utility model relates to a geothermal energy test device, which comprises: at least two experimental tables, each of which comprises a heat preservation shell, a geotechnical sample and a heating cavity arranged in the heat preservation shell; at least two geothermal heat exchangers, each of which is arranged in one of the geotechnical samples; at least two heating structures, each of which is connected with one of the heating cavities and used for heating the geotechnical sample; a circulating heat exchange structure, which comprises a circulating water cooling assembly and a circulating pipeline connected with the at least two geothermal heat exchangers and the circulating water cooling assembly in sequence; a first measuring unit and a second measuring unit arranged on a heat exchange water inlet pipe and a heat exchange water outlet pipe of the circulating pipeline, respectively.

2. The experimental device for heat exchange of middle-deep geothermal heat source according to claim 1, characterized in that, The heat preservation shell is internally provided with an annular partition plate, the inside of the partition plate forms a containing cavity, the geotechnical sample is arranged in the containing cavity, and the annular heating cavity is formed between the partition plate and the heat preservation shell.

3. The experimental device for heat exchange of middle-deep geothermal heat source according to claim 1, characterized in that, One side bottom of the heating cavity is provided with a water inlet, and the other side top of the heating cavity is provided with a water outlet.

4. The experimental device for heat exchange of middle-deep geothermal heat source according to claim 1, characterized in that, The heating structure comprises a heating heat preservation water tank, a heater and a heating water temperature control module, the heating water temperature control module can control the heater to heat the water in the heating heat preservation water tank to a set heating temperature, the heating heat preservation water tank is connected with the heating cavity through a heating pipeline, and a heating circulating pump is arranged on the heating pipeline.

5. The experimental device for heat exchange of middle-deep geothermal heat source according to claim 1, characterized in that, The geothermal heat exchanger is a coaxial double-pipe heat exchanger, which comprises an outer sleeve pipe inserted into the geotechnical sample and a central pipe coaxially arranged in the outer sleeve pipe, an annular space is formed between the outer sleeve pipe and the central pipe, and the lower end of the annular space is communicated with the lower end of the central pipe.

6. The experimental device for heat exchange of middle-deep geothermal source according to claim 1, characterized in that, The circulating water cooling assembly comprises a circulating heat preservation water tank, a cooling unit and a circulating water temperature control module, and the circulating water temperature control module can control the cooling unit to cool the water in the circulating heat preservation water tank to a set circulating temperature.

7. The experimental device for heat exchange of middle-deep geothermal heat source according to claim 6, characterized in that, The circulating pipeline comprises the heat exchange water inlet pipe, a heat exchange connecting pipe and the heat exchange water outlet pipe, one end of the heat exchange water inlet pipe is connected with the outlet of the circulating heat preservation water tank, the other end of the heat exchange water inlet pipe is connected with the input port of one of the geothermal heat exchangers, the two ends of the heat exchange connecting pipe are connected with the output port and the input port of two different geothermal heat exchangers, respectively, one end of the heat exchange water outlet pipe is connected with the inlet of the circulating heat preservation water tank, and the other end of the heat exchange water outlet pipe is connected with the output port of the other geothermal heat exchanger.

8. The experimental device for heat exchange of middle-deep geothermal heat source according to claim 4, characterized in that, The heating pipeline is provided with a heating water temperature sensor and a heating water flow sensor.

9. The experimental device for heat exchange of middle-deep geothermal heat source according to claim 1, characterized in that, The first measuring unit comprises a first temperature sensor and a first flow sensor, and the second measuring unit comprises a second temperature sensor and a second flow sensor.

10. The experimental device for heat exchange of middle-deep geothermal heat source according to claim 7, characterized in that, The heat exchange water inlet pipe is provided with a variable-frequency circulating pump.

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