Heat supply system capable of efficiently utilizing middle-deep layer terrestrial heat

Abstract

The utility model belongs to the technical field of renewable energy utilization, and particularly provides a medium-deep layer geothermal efficient utilization heat supply system which adopts switching of three modes of directly feeding geothermal water into a heat exchanger for heat supply, heat exchange of the heat exchanger and heat supply of a heat pump unit, and heat exchange and heat supply of the heat pump unit. The geothermal well heat supply system solves the problem that hot water directly enters the heat pump unit at the initial stage of geothermal well heat supply and the water temperature is too high, prolongs the service life of the heat pump unit, realizes efficient utilization of the geothermal heat supply system, and greatly reduces the operation cost of the system.

Description

Technical Field

[0001] The utility model belongs to the technical field of renewable energy utilization, and specifically relates to a heating system for high-efficiency utilization of mid-deep geothermal energy. Background Art

[0002] Medium-deep geothermal non-interference clean heating is achieved by drilling holes into the ground 2000~3000m deep underground with a drilling rig, installing a coaxial shell-and-tube heat exchanger in the borehole, absorbing soil heat through the outer wall of the outer tube and transferring it to the circulating medium, then the heat is extracted through the inner tube and supplied to the building through equipment such as heat pump units.

[0003] At present, coaxial shell and tube heat exchangers often use PE pipes as inner pipes. The outlet water temperature of the inner pipe can reach 35~45℃ in the initial stage of heating operation and about 25℃ in the stable period of heating operation. Geothermal resources are often used by directly feeding into the heat pump or mixing water with a mixing pump before feeding into the heat pump. After the heat pump heats up, the water supply temperature is 45 / 35℃ for floor heating or 50 / 40℃ for air conditioning heating.

[0004] With the continuous development of geothermal resource utilization technology, the thermal insulation performance of the inner pipe is gradually enhanced, and the outlet temperature of geothermal water is gradually increasing. The method of using a mixing pump to mix water and cool it down before entering the heat pump cannot achieve efficient cascade utilization of thermal energy, and the system operating costs are relatively high. If the water temperature is higher than 50°C and directly enters the heat pump, it will affect the service life of the heat pump unit.

[0005] The Chinese patent document with the publication number CN220229607U discloses a novel medium-deep geothermal energy heating device, wherein a submersible pump is fixedly connected to the bottom of the heat extraction well, a water outlet pipe is fixedly connected to the top of the submersible pump, a water inlet pipe is fixedly connected to one end of the water treatment warehouse, a decompression valve is fixedly connected to the top of the heat extraction well, a filter valve is fixedly connected to one end of the water inlet pipe, a heating core is fixedly installed inside the heating warehouse, an exhaust valve is fixedly connected to the top of the heating warehouse, a switch valve is fixedly connected to both ends of the heating warehouse, and a heat exchange plate is fixedly connected inside the cooling warehouse. The document uses the setting of the heating warehouse, and when in use, hot water is drawn from the ground and passes through the heating warehouse, and there is a heating core inside the heating warehouse, so that the hot water reaches a certain temperature, avoiding the situation where the temperature of the hot water is not enough when it is transported to the user's home. However, the document does not solve the problem that the water temperature of hot water directly entering the heat pump is too high, which affects the service life of the heat pump unit. Utility Model Content

[0006] The utility model provides a medium-deep geothermal efficient heating system to overcome the problem in the prior art that the water temperature of hot water directly entering the heat pump in the initial stage of geothermal well heating is too high, which affects the service life of the heat pump unit.

[0007] To this end, the utility model provides a medium-deep geothermal efficient utilization heating system, including a medium-deep geothermal well, a coaxial sleeve heat exchanger outer tube and a coaxial sleeve heat exchanger central tube, the medium-deep geothermal well has a coaxial sleeve heat exchanger outer tube and a coaxial sleeve heat exchanger central tube that are sequentially sleeved from outside to inside, the heating system also includes a heat exchanger, a heat pump unit, a water distributor, a water collector, a temperature collection unit and a terminal heat dissipation device, the water outlet of the coaxial sleeve heat exchanger central tube is connected to the first water inlet of the heat exchanger, the first water outlet of the heat exchanger is connected to the second water inlet of the heat exchanger through the water distributor, the terminal heat dissipation device and the water collector in sequence, and the second water outlet of the heat exchanger is connected to the inlet of the coaxial sleeve heat exchanger outer tube;

[0008] The second water outlet of the heat exchanger is connected to the first water inlet of the heat pump unit in another way, the first water outlet of the heat pump unit is connected to the second water inlet of the heat pump unit through the water distributor, the terminal heat dissipation device and the water collector in sequence, and the second water outlet of the heat pump unit is connected to the inlet of the outer tube of the coaxial sleeve heat exchanger;

[0009] Another water outlet of the central tube of the coaxial shell-and-tube heat exchanger is connected to the first water inlet of the heat pump unit;

[0010] The temperature collection unit is connected to the water outlet pipeline of the central tube of the coaxial shell and tube heat exchanger.

[0011] Preferably, the heat exchanger is a plate heat exchanger.

[0012] Preferably, the heating system includes a first pipeline, a second pipeline, a third pipeline, a fourth pipeline and a fifth pipeline, the water outlet of the central tube of the coaxial shell and tube heat exchanger is connected to the first water inlet of the heat exchanger through the first pipeline, the second water outlet of the heat exchanger is connected to the first water inlet of the heat pump unit through the second pipeline, the third pipeline is connected between the first pipeline and the second pipeline, the second water outlet of the heat pump unit is connected to the inlet of the outer tube of the coaxial shell and tube heat exchanger through the fourth pipeline, and the fifth pipeline is connected between the second pipeline and the fourth pipeline.

[0013] Preferably, the heat pump unit includes a compressor, an evaporator, an expansion valve and a condenser, the outlet of the second pipeline is connected to the first inlet of the evaporator, the first outlet of the evaporator is connected to the first inlet of the condenser through the expansion valve, the first outlet of the condenser is connected to the inlet of the water separator, the outlet of the water collector is connected to the second inlet of the condenser, the second outlet of the condenser is connected to the second inlet of the evaporator through the compressor, and the second outlet of the evaporator is connected to the inlet of the fourth pipeline.

[0014] Preferably, the heating system also includes a geothermal circulation pump, a secondary plate exchanger circulation pump, a secondary heat pump circulation pump and a secondary total circulation pump, the geothermal circulation pump is connected to the fourth pipeline, the secondary plate exchanger circulation pump is connected to the pipeline between the water outlet of the water collector and the second water inlet of the heat exchanger, the secondary heat pump circulation pump is connected to the pipeline between the water outlet of the water collector and the second inlet of the condenser, and the secondary total circulation pump is connected to the pipeline between the water distributor and the terminal heat dissipation device.

[0015] Preferably, the temperature collection unit includes a geothermal side temperature sensor, and the geothermal side temperature sensor is connected to the first pipeline.

[0016] Preferably, the temperature collection unit also includes a climate compensator and an outdoor temperature collector, and the climate compensator is electrically connected to the outdoor temperature collector, the geothermal circulation pump, the secondary plate exchange circulation pump, the secondary heat pump circulation pump and the secondary total circulation pump.

[0017] Preferably, the third pipeline is provided with a first control valve, the first pipeline between the first control valve and the heat exchanger is provided with a second control valve, the second pipeline between the first control valve and the heat exchanger is provided with a third control valve, the fifth pipeline is provided with a fourth control valve, the second pipeline between the fifth pipeline and the heat exchanger is provided with a fifth control valve, and the fourth pipeline between the fifth pipeline and the heat exchanger is provided with a sixth control valve.

[0018] Preferably, the first control valve, the second control valve, the third control valve, the fourth control valve, the fifth control valve and the sixth control valve are all electric control valves.

[0019] A method for efficiently utilizing mid-deep geothermal heat for heating comprises the following steps:

[0020] Geothermal water with a water temperature of t2 enters the medium-deep geothermal well, and the outer tube of the coaxial shell and tube heat exchanger absorbs geothermal energy and then transfers it to the circulating medium. After the heat exchange, the circulating medium enters the central tube of the coaxial shell and tube heat exchanger from the bottom of the medium-deep geothermal well and then flows out as the circulating medium with a water temperature of t1.

[0021] When the geothermal water direct heat exchange heating method is adopted: when the outdoor temperature collected and fed back by the climate compensator and the outdoor temperature collector is higher than the target temperature, the circulating medium with a temperature of t1 enters the heat exchanger for heat exchange. After the heat exchange, the circulating medium with a temperature of t4 passes through the water distributor, the terminal heat dissipation equipment and the water collector in turn. The circulating medium with a temperature reduced to t3 finally passes through the heat exchanger for heat exchange. After the heat exchange, the circulating medium with a temperature of t2 finally enters the outer tube of the coaxial shell and tube heat exchanger to complete a heating cycle.

[0022] When direct heat exchange cannot meet the terminal heating demand: when the temperature sensor on the geothermal side measures that the water temperature t1 is above the target value 2, the circulating medium with a water temperature of t1 enters the heat exchanger for heat exchange. After heat exchange, the circulating medium with a temperature of t4 passes through the water distributor, the terminal heat dissipation equipment and the water collector in turn. The circulating medium with a temperature of t3 enters the heat pump unit for heat exchange. After heat exchange, the circulating medium with a temperature of t2 finally enters the outer tube of the coaxial shell and tube heat exchanger to complete a heating cycle.

[0023] When direct heat exchange cannot meet the terminal heating demand: when the temperature sensor on the geothermal side measures that the water temperature t1 is less than the target value 2, the circulating medium with a temperature of t1 exchanges heat through the heat pump unit. After heat exchange, the circulating medium with a temperature of t4 passes through the water distributor, the terminal heat dissipation equipment and the water collector in turn. The circulating medium with a temperature reduced to t3 finally exchanges heat through the heat pump unit. After heat exchange, the circulating medium with a temperature of t2 finally enters the outer tube of the coaxial shell and tube heat exchanger to complete a heating cycle.

[0024] Beneficial effects of the utility model:

[0025] 1. The medium-deep geothermal efficient heating system provided by the utility model can switch between three modes of direct geothermal water feeding into a heat exchanger for heating, heat exchange by a heat exchanger + heat pump unit for heating, and heat exchange by a heat pump unit for heating, according to the geothermal water intake temperature and outdoor climate changes. The cascade utilization of geothermal water solves the problem of excessively high water temperature when hot water directly feeds into a heat pump unit, greatly reduces the system operating costs, realizes maximum utilization of the heat pump, and extends the service life of the heat pump unit.

[0026] 2. The medium-deep geothermal efficient heating system provided by the utility model, in the initial stage of heating, when the outdoor temperature collector measures a high outdoor temperature (higher than the target temperature), the heating demand of the terminal can be met by directly entering the heat exchanger with geothermal water for heat exchange, which is the most energy-saving operation mode.

[0027] 3. In the medium-deep geothermal efficient heating system provided by the utility model, the first control valve, the second control valve, the third control valve, the fourth control valve, the fifth control valve and the sixth control valve are all electric control valves; the electric control valves have an adjustment function, which is convenient for adjusting the supply ratio of each energy source. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be described in further detail below in conjunction with the accompanying drawings.

[0029] Figure 1 It is a working principle diagram of the heating system for efficient utilization of mid-deep geothermal energy.

[0030] Description of the reference numerals: 1. Medium-deep geothermal well; 2. Heat exchanger; 3. Heat pump unit; 4. Geothermal circulation pump; 5. Secondary plate exchange circulation pump; 6. Secondary heat pump circulation pump; 7. Water collector; 8. Water distributor; 9. Secondary total circulation pump; 10. Terminal heat dissipation equipment; 11. Geothermal side temperature sensor; 12. Climate compensator; 13. Outdoor temperature collector;

[0031] 101. outer tube of coaxial tube heat exchanger; 102. center tube of coaxial tube heat exchanger;

[0032] 201, first control valve; 202, second control valve; 203, third control valve; 204, fourth control valve; 205, fifth control valve; 206, sixth control valve;

[0033] 301. Compressor; 302. Evaporator; 303. Expansion valve; 304. Condenser. DETAILED DESCRIPTION

[0034] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples are only used to explain the present invention and are not used to limit the scope of the present invention. If no specific conditions are specified in the embodiments, the conventional conditions or the conditions recommended by the manufacturer are followed. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0035] Embodiment 1:

[0036] like Figure 1 As shown, a medium-deep geothermal efficient utilization heating system comprises a medium-deep geothermal well 1, a coaxial sleeve heat exchanger outer tube 101 and a coaxial sleeve heat exchanger central tube 102, wherein the medium-deep geothermal well 1 has a coaxial sleeve heat exchanger outer tube 101 and a coaxial sleeve heat exchanger central tube 102 which are sequentially sleeved from outside to inside, and the heating system further comprises a heat exchanger 2, a heat pump unit 3, a water distributor 8, a water collector 7, a temperature acquisition unit and a terminal heat dissipation device 10, wherein the water outlet of the coaxial sleeve heat exchanger central tube 102 is connected to the first water inlet of the heat exchanger 2, the first water outlet of the heat exchanger 2 is connected to the second water inlet of the heat exchanger 2 through the water distributor 8, the terminal heat dissipation device 10 and the water collector 7 in sequence, and the second water outlet of the heat exchanger 2 is connected to the inlet of the coaxial sleeve heat exchanger outer tube 101;

[0037] The second water outlet of the heat exchanger 2 is connected to the first water inlet of the heat pump unit 3 in another way. The first water outlet of the heat pump unit 3 is connected to the second water inlet of the heat pump unit 3 through the water distributor 8, the terminal heat dissipation device 10 and the water collector 7 in sequence. The second water outlet of the heat pump unit 3 is connected to the inlet of the coaxial sleeve heat exchanger outer tube 101;

[0038] Another water outlet of the central tube 102 of the coaxial shell and tube heat exchanger is connected to the first water inlet of the heat pump unit 3;

[0039] The temperature collection unit is connected to the water outlet pipeline of the central tube 102 of the coaxial shell and tube heat exchanger.

[0040] The medium-deep geothermal efficient heating system provided by the utility model has a temperature collection unit that collects the geothermal water intake temperature and outdoor climate changes. According to the geothermal water intake temperature and outdoor climate changes, three modes of heating can be switched: geothermal water directly entering the heat pump unit 3 for heating, heat exchanger 2 for heat exchange + heat pump unit 3 for heating, and heat exchanger 2 for heat exchange. The geothermal water cascade utilization method is adopted to solve the problem of too high water temperature when hot water directly enters the heat pump unit 3, the system operation cost is greatly reduced, the maximum utilization of the heat pump is achieved, and the service life of the heat pump unit 3 is extended.

[0041] Preferably, the heat exchanger 2 is a plate heat exchanger, which has high heat transfer coefficient, compact structure, small footprint, low cost, and is easy to disassemble and clean.

[0042] Preferably, the heating system includes a first pipeline, a second pipeline, a third pipeline, a fourth pipeline and a fifth pipeline, the water outlet of the coaxial tube heat exchanger central tube 102 is connected to the first water inlet of the heat exchanger 2 through the first pipeline, the second water outlet of the heat exchanger 2 is connected to the first water inlet of the heat pump unit 3 through the second pipeline, the third pipeline is connected between the first pipeline and the second pipeline, the second water outlet of the heat pump unit 3 is connected to the inlet of the coaxial tube heat exchanger outer tube 101 through the fourth pipeline, and the fifth pipeline is connected between the second pipeline and the fourth pipeline. The structure and distribution are simple, and the thermal energy utilization rate is high.

[0043] Preferably, the heat pump unit 3 includes a compressor 301, an evaporator 302, an expansion valve 303 and a condenser 304, the outlet of the second pipeline is connected to the first inlet of the evaporator 302, the first outlet of the evaporator 302 is connected to the first inlet of the condenser 304 through the expansion valve 303, the first outlet of the condenser 304 is connected to the inlet of the water separator 8, the outlet of the water collector 7 is connected to the second inlet of the condenser 304, the second outlet of the condenser 304 is connected to the second inlet of the evaporator 302 through the compressor 301, and the second outlet of the evaporator 302 is connected to the inlet of the fourth pipeline. The evaporator 302 is convenient for absorbing heat, and the condenser 304 is convenient for dissipating heat.

[0044] Preferably, the heating system also includes a geothermal circulation pump 4, a secondary plate exchanger circulation pump 5, a secondary heat pump circulation pump 6 and a secondary total circulation pump 9, the geothermal circulation pump 4 is connected to the fourth pipeline, the secondary plate exchanger circulation pump 5 is connected to the pipeline between the water outlet of the water collector 7 and the second water inlet of the heat exchanger 2, the secondary heat pump circulation pump 6 is connected to the pipeline between the water outlet of the water collector 7 and the second inlet of the condenser 304, and the secondary total circulation pump 9 is connected to the pipeline between the water distributor 8 and the terminal heat dissipation device 10.

[0045] Specifically, when geothermal water is directly introduced into the heat exchanger 2 for heating, power is provided by the geothermal circulation pump 4, the secondary plate exchange circulation pump 5 and the secondary total circulation pump 9 to meet the heating demand; when the heat exchanger 2 is used for heat exchange + the heat pump unit 3 is used for heating, power is provided by the geothermal circulation pump 4, the secondary plate exchange circulation pump 5, the secondary heat pump circulation pump 6 and the secondary total circulation pump 9 to meet the heating demand; when the heat pump unit 3 is used for heat exchange and heating, power is provided by the geothermal circulation pump 4, the secondary heat pump circulation pump 6, the secondary total circulation pump 9 and the terminal heat dissipation device 10 to meet the heating demand.

[0046] Preferably, the temperature acquisition unit includes a geothermal side temperature sensor 11, which is connected to the first pipeline. The geothermal side temperature sensor 11 facilitates real-time acquisition of the outlet water temperature after heat exchange of the central tube 102 of the coaxial shell and tube heat exchanger.

[0047] Preferably, the temperature collection unit also includes a climate compensator 12 and an outdoor temperature collector 13, and the climate compensator 12 is electrically connected to the outdoor temperature collector 13, the geothermal circulation pump 4, the secondary side plate exchange circulation pump 5, the secondary side heat pump circulation pump 6 and the secondary side total circulation pump 9 respectively.

[0048] Specifically, the outdoor temperature collector 13 is convenient for collecting the outdoor temperature in real time, and sends the collected outdoor temperature to the climate compensator 12, and the climate compensator 12 performs temperature feedback, thereby switching the control mode.

[0049] Preferably, the third pipeline is provided with a first control valve 201, the first pipeline between the first control valve 201 and the heat exchanger 2 is provided with a second control valve 202, the second pipeline between the first control valve 201 and the heat exchanger 2 is provided with a third control valve 203, the fifth pipeline is provided with a fourth control valve 204, the second pipeline between the fifth pipeline and the heat exchanger 2 is provided with a fifth control valve 205, and the fourth pipeline between the fifth pipeline and the heat exchanger 2 is provided with a sixth control valve 206.

[0050] By controlling the opening or closing of the first control valve 201, the second control valve 202, the third control valve 203, the fourth control valve 204, the fifth control valve 205 and the sixth control valve 206, the switching of the heating mode is completed, which is simple and convenient.

[0051] Preferably, the first control valve 201, the second control valve 202, the third control valve 203, the fourth control valve 204, the fifth control valve 205 and the sixth control valve 206 are all electric control valves. The electric control valves have a regulating function, which is convenient for adjusting the supply ratio of each energy source.

[0052] Embodiment 2:

[0053] Based on Example 1, a method for efficiently utilizing mid-deep geothermal heat for heating comprises the following steps:

[0054] The geothermal water with a water temperature of t2 enters the medium-deep geothermal well 1, and is transferred to the circulating medium after absorbing the geothermal energy by the outer tube 101 of the coaxial shell and tube heat exchanger. The circulating medium after heat exchange enters the central tube 102 of the coaxial shell and tube heat exchanger from the bottom of the medium-deep geothermal well 1 and flows out as the circulating medium with a water temperature of t1.

[0055] When the geothermal water direct heat exchange heating method is adopted: when the outdoor temperature collected and fed back by the climate compensator 12 and the outdoor temperature collector 13 is higher than the target temperature, the circulating medium with a temperature of t1 enters the heat exchanger 2 for heat exchange, and the circulating medium with a temperature of t4 after heat exchange passes through the water distributor 8, the terminal heat dissipation device 10 and the water collector 7 in sequence, and the circulating medium with a temperature reduced to t3 finally passes through the heat exchanger 2 for heat exchange, and the circulating medium with a temperature of t2 after heat exchange finally enters the outer tube 101 of the coaxial tube heat exchanger, completing a heating cycle;

[0056] Specifically, at the initial stage of heating, when the outdoor temperature collector 13 measures a high outdoor temperature (higher than the target temperature), the heating demand of the terminal can be met by directly feeding geothermal water into the heat exchanger 2 for heat exchange, which is the most energy-saving operation mode.

[0057] When direct heat exchange cannot meet the terminal heating demand: when the geothermal temperature sensor 11 measures that the water temperature t1 is above the target value 2, the circulating medium with a water temperature of t1 enters the heat exchanger 2 for heat exchange, and the circulating medium with a temperature of t4 after heat exchange passes through the water distributor 8, the terminal heat dissipation device 10 and the water collector 7 in sequence, and the circulating medium with a temperature reduced to t3 enters the heat pump unit 3 for heat exchange, and the circulating medium with a temperature of t2 after heat exchange finally enters the outer tube 101 of the coaxial shell and tube heat exchanger, completing a heating cycle;

[0058] Specifically, the heat exchanger 2 first exchanges heat to extract a portion of heat, and the geothermal water after heat exchange then enters the evaporator 302 in the heat pump unit 3 to absorb heat and provide heat. After the geothermal water finally reaches the water temperature t2, it enters the geothermal well for heat exchange.

[0059] When direct heat exchange cannot meet the terminal heating demand: when the geothermal side temperature sensor 11 measures that the water temperature t1 is less than the target value 2, the circulating medium with a temperature of t1 exchanges heat through the heat pump unit 3, and the circulating medium with a temperature of t4 after heat exchange passes through the water distributor 8, the terminal heat dissipation device 10 and the water collector 7 in turn, and the circulating medium with a temperature reduced to t3 finally exchanges heat through the heat pump unit 3, and the circulating medium with a temperature of t2 after heat exchange finally enters the outer tube 101 of the coaxial shell and tube heat exchanger, completing a heating cycle.

[0060] The high-efficiency heating method using medium-deep geothermal energy provided by the utility model collects geothermal water intake temperature and outdoor climate change, and can switch between three methods of directly feeding geothermal water into the heat pump unit 3 for heating, heat exchanger 2 for heat exchange + heat pump unit 3 for heating, and heat exchanger 2 for heat exchange according to the geothermal water intake temperature and outdoor climate change, so that the temperature entering the heat pump unit 3 and the temperature finally returning to the outer tube 101 of the coaxial sleeve heat exchanger are both within the target range; the geothermal water cascade utilization method is adopted to solve the problem of too high water temperature when hot water directly enters the heat pump unit 3, the system operation cost is greatly reduced, the maximum utilization of the heat pump is achieved, and the service life of the heat pump unit 3 is extended.

[0061] Embodiment 3:

[0062] Based on Example 2, a method for efficiently utilizing mid-deep geothermal heat for heating comprises the following steps:

[0063] The geothermal water with a water temperature of t2 enters the medium-deep geothermal well 1, and is transferred to the circulating medium after absorbing the geothermal energy by the outer tube 101 of the coaxial shell and tube heat exchanger. The circulating medium after heat exchange enters the central tube 102 of the coaxial shell and tube heat exchanger from the bottom of the medium-deep geothermal well 1 and flows out as the circulating medium with a water temperature of t1.

[0064] When the outdoor temperature collected and fed back by the climate compensator 12 and the outdoor temperature collector 13 is high, direct heat exchange can meet the terminal heat load, the first control valve 201 is closed, the second control valve 202 is opened, the third control valve 203 is opened, the fourth control valve 204 is opened, the fifth control valve 205 is closed, and the sixth control valve 206 is closed. The system is powered by the geothermal circulation pump 4, the secondary plate heat exchanger circulation pump 5 and the secondary total circulation pump 9 to bear the heat load of the heat-using equipment of the terminal heat dissipation device 10. Specifically, the circulating medium with a temperature of t1 enters the plate heat exchanger for heat exchange, and the circulating medium with a temperature of t4 after heat exchange passes through the water distributor 8, the terminal heat dissipation device 10 and the water collector 7 in turn. The circulating medium with a temperature reduced to t3 finally passes through the heat exchanger 2 for heat exchange, and the circulating medium with a temperature of t2 after heat exchange finally enters the outer tube 101 of the coaxial sleeve heat exchanger to complete a heating cycle;

[0065] The COP of the heating system using direct heat exchanger 2 for heating is greater than that of the heating system using heat pump (COP is 3-4).

[0066] When direct heat exchange cannot meet the terminal heating demand: when the geothermal side temperature sensor 11 measures that the water temperature t1 is above 45°C, the first control valve 201 is closed, the second control valve 202 is opened, and the third control valve 203 is opened. The geothermal circulation pump 4, the secondary side plate exchange circulation pump 5, the secondary side heat pump circulation pump 6 and the secondary side total circulation pump 9 provide power. The circulating medium with a water temperature of t1 enters the heat exchanger 2 for heat exchange, extracts 5~10°C of heat through heat exchange, and the circulating medium with a temperature of t4 after heat exchange passes through the water distributor 8, the terminal heat dissipation device 10 and the water collector 7 in turn. The fourth control valve 204 is closed, the fifth control valve 205 is opened, and the sixth control valve 206 is opened. The circulating medium with a temperature reduced to t3 enters the heat pump unit 3 for heat exchange. The circulating medium with a temperature reduced to t2 (generally 10-15°C) after heat exchange finally enters the outer tube 101 of the coaxial shell and tube heat exchanger, completing a heating cycle.

[0067] When direct heat exchange cannot meet the terminal heating demand: when the geothermal side temperature sensor 11 measures the water temperature t1 to be less than 45°C, the first control valve 201 is opened, the second control valve 202 is closed, the third control valve 203 is closed, the fourth control valve 204 is closed, the fifth control valve 205 is opened, and the sixth control valve 206 is opened, and power is provided by the geothermal circulation pump 4, the secondary side heat pump circulation pump 6, the secondary side total circulation pump 9 and the terminal heat dissipation device 10 to meet the heating demand; the circulating medium with a temperature of t1 exchanges heat through the heat pump unit 3, and the circulating medium with a temperature of t4 after heat exchange passes through the water distributor 8, the terminal heat dissipation device 10 and the water collector 7 in turn, and the circulating medium with a temperature reduced to t3 finally exchanges heat through the heat pump unit 3, and the circulating medium with a temperature of t2 (generally 10-15°C) after heat exchange finally enters the outer tube 101 of the coaxial shell and tube heat exchanger to complete a heating cycle.

[0068] According to the geothermal water intake temperature and outdoor climate changes, the geothermal water is directly fed into the heat exchanger 2 for heating, the heat exchanger 2 for heat exchange + the heat pump unit 3 for heating, and the heat pump unit 3 for heat exchange and heating is switched. The geothermal water cascade utilization method is adopted to solve the problem of too high water temperature when the hot water directly enters the heat pump unit 3. The system operation cost is greatly reduced, the heat pump is maximized, and the service life of the heat pump unit 3 is extended.

[0069] In the description of the present invention, it should be understood that if there are terms indicating an orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on the present invention.

[0070] The above examples are merely illustrative of the present invention and do not constitute a limitation on the protection scope of the present invention. All designs that are identical or similar to the present invention fall within the protection scope of the present invention.

Claims

1. A medium-deep geothermal efficient utilization heating system, comprising a medium-deep geothermal well (1), a coaxial shell and tube heat exchanger outer tube (101) and a coaxial shell and tube heat exchanger center tube (102), wherein the medium-deep geothermal well (1) has a coaxial shell and tube heat exchanger outer tube (101) and a coaxial shell and tube heat exchanger center tube (102) which are sequentially sleeved from outside to inside, characterized in that: The heating system further comprises a heat exchanger (2), a heat pump unit (3), a water distributor (8), a water collector (7), a temperature collection unit and a terminal heat dissipation device (10); the water outlet of the central tube (102) of the coaxial tube heat exchanger is connected to a first water inlet of the heat exchanger (2); the first water outlet of the heat exchanger (2) is connected to a second water inlet of the heat exchanger (2) via the water distributor (8), the terminal heat dissipation device (10) and the water collector (7); the second water outlet of the heat exchanger (2) is connected to an inlet of an outer tube (101) of the coaxial tube heat exchanger; The second water outlet of the heat exchanger (2) is connected to the first water inlet of the heat pump unit (3) through another path; the first water outlet of the heat pump unit (3) is connected to the second water inlet of the heat pump unit (3) through the water distributor (8), the terminal heat dissipation device (10) and the water collector (7) in sequence; the second water outlet of the heat pump unit (3) is connected to the inlet of the outer tube (101) of the coaxial shell and tube heat exchanger; Another water outlet of the central tube (102) of the coaxial shell-and-tube heat exchanger is connected to the first water inlet of the heat pump unit (3); The temperature collection unit is connected to the water outlet pipeline of the central tube (102) of the coaxial shell and tube heat exchanger.

2. The high-efficiency heating system for mid-deep geothermal energy utilization according to claim 1, characterized in that: The heat exchanger (2) is a plate heat exchanger.

3. The high-efficiency heating system for utilizing mid-deep geothermal energy as claimed in claim 1, characterized in that: The heating system comprises a first pipeline, a second pipeline, a third pipeline, a fourth pipeline and a fifth pipeline, wherein the water outlet of the central tube (102) of the coaxial tube heat exchanger is connected to the first water inlet of the heat exchanger (2) via the first pipeline, the second water outlet of the heat exchanger (2) is connected to the first water inlet of the heat pump unit (3) via the second pipeline, the third pipeline is connected between the first pipeline and the second pipeline, the second water outlet of the heat pump unit (3) is connected to the inlet of the outer tube (101) of the coaxial tube heat exchanger via the fourth pipeline, and the fifth pipeline is connected between the second pipeline and the fourth pipeline.

4. The high-efficiency heating system for utilizing mid-deep geothermal energy as claimed in claim 3 is characterized by: The heat pump unit (3) comprises a compressor (301), an evaporator (302), an expansion valve (303) and a condenser (304); the outlet of the second pipeline is connected to the first inlet of the evaporator (302); the first outlet of the evaporator (302) is connected to the first inlet of the condenser (304) through the expansion valve (303); the first outlet of the condenser (304) is connected to the inlet of the water separator (8); the outlet of the water collector (7) is connected to the second inlet of the condenser (304); the second outlet of the condenser (304) is connected to the second inlet of the evaporator (302) through the compressor (301); and the second outlet of the evaporator (302) is connected to the inlet of the fourth pipeline.

5. The high-efficiency heating system for utilizing mid-deep geothermal energy as claimed in claim 4, characterized in that: The heating system further comprises a geothermal circulation pump (4), a secondary plate exchange circulation pump (5), a secondary heat pump circulation pump (6) and a secondary total circulation pump (9); the geothermal circulation pump (4) is connected to a fourth pipeline; the secondary plate exchange circulation pump (5) is connected to a pipeline between a water outlet of the water collector (7) and a second water inlet of the heat exchanger (2); the secondary heat pump circulation pump (6) is connected to a pipeline between a water outlet of the water collector (7) and a second inlet of the condenser (304); and the secondary total circulation pump (9) is connected to a pipeline between the water distributor (8) and a terminal heat dissipation device (10).

6. The medium-deep geothermal efficient heating system according to claim 5, characterized in that: The temperature collection unit comprises a geothermal side temperature sensor (11), and the geothermal side temperature sensor (11) is connected to the first pipeline.

7. The high-efficiency heating system for utilizing mid-deep geothermal energy as claimed in claim 6, characterized in that: The temperature collection unit further comprises a climate compensator (12) and an outdoor temperature collector (13), wherein the climate compensator (12) is respectively electrically connected to the outdoor temperature collector (13), the geothermal circulation pump (4), the secondary side plate exchange circulation pump (5), the secondary side heat pump circulation pump (6) and the secondary side total circulation pump (9).

8. The high-efficiency heating system for utilizing mid-deep geothermal energy as claimed in claim 7, characterized in that: The third pipeline is provided with a first control valve (201), the first pipeline between the first control valve (201) and the heat exchanger (2) is provided with a second control valve (202), the second pipeline between the first control valve (201) and the heat exchanger (2) is provided with a third control valve (203), the fifth pipeline is provided with a fourth control valve (204), the second pipeline between the fifth pipeline and the heat exchanger (2) is provided with a fifth control valve (205), and the fourth pipeline between the fifth pipeline and the heat exchanger (2) is provided with a sixth control valve (206).

9. The medium-deep geothermal efficient heating system according to claim 8, characterized in that: The first control valve (201), the second control valve (202), the third control valve (203), the fourth control valve (204), the fifth control valve (205) and the sixth control valve (206) are all electric control valves.

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