PV / T coupling middle-deep layer sleeve type buried pipe heat supply system based on phase change energy storage

Abstract

The invention provides a PV / T coupling middle-deep layer sleeve type buried pipe heat supply system based on phase change energy storage, and particularly belongs to the technical field of middle-deep layer ground source heat pump systems. Through the arrangement of the middle-deep layer sleeve type buried pipe coupling phase change heat storage device, the coupling system can solve the problem of soil cold accumulation of the middle-deep layer sleeve type buried pipe, and stable operation performance of the system can be guaranteed in the long-term operation process; meanwhile, the problem that the PV / T heat collector is overheated can be solved, so that the photoelectric conversion efficiency is improved, the energy utilization rate of the system is improved, solar energy in a non-heating season can be recycled and stored in soil, cross-season energy storage is achieved, the energy utilization efficiency is improved, and the investment payback period of the system is shortened. The system comprises a middle-deep layer sleeve type buried pipe, a heat pump unit, a heat collection water tank, a heating water tank, a PV / T heat collector, an energy assembly, a control assembly, a water flow circulation assembly and a temperature sensing assembly.

Description

Technical Field

[0001] The present invention relates to a PV / T coupled medium-deep layer casing-type buried pipe heating system based on phase change energy storage, and specifically belongs to the technical field of medium-deep layer ground source heat pump systems. Background Art

[0002] In order to achieve the goal of carbon neutrality and accelerate the application of renewable energy, the application of geothermal energy has been promoted; as a new type of heating system, the medium-deep casing buried pipe system has received extensive attention and corresponding practical applications in recent years due to its high efficiency in heat extraction and land reduction. However, it is still in the development stage due to the lack of corresponding engineering experience and theoretical guidance in the early stage.

[0003] The medium-deep casing-type buried pipe is mainly responsible for winter heating projects, and its depth is generally 500-3000m; during the heating process, the system extracts heat from underground rock and soil to heat the building, which will cause the loss of rock and soil heat. If the rock and soil only recovers its temperature naturally instead of replenishing heat, its temperature will decay year by year, resulting in cold accumulation, which will lead to the gradual decay of the heating power of the medium-deep ground source heat pump system; during the operation of the PV / T system, the photovoltaic components will generate heat, which will seriously reduce the system's photoelectric conversion efficiency and cause energy waste. Summary of the invention

[0004] The purpose of the present invention is to provide a PV / T coupled medium-deep casing buried pipe heating system based on phase change energy storage, so as to solve the problem that the medium-deep casing buried pipe system will produce cold accumulation phenomenon and thus reduce the system performance after long-term operation, and the PV / T system will cause the temperature of the photovoltaic components to overheat during operation, thereby reducing the system's production efficiency.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: the invention includes a medium-deep casing-type underground pipe, a heat pump unit, a heat collection tank, a heating water tank, a PV / T collector, an energy component, a control component, a water flow circulation component and a temperature sensing component, the vertical part of the medium-deep casing-type underground pipe is arranged underground, and the outer side of the part of the medium-deep casing-type underground pipe located underground is filled with a soil heat storage body, and the control component, the water flow circulation component and the temperature sensing component are arranged between the medium-deep casing-type underground pipe, the heat pump unit, the heat collection tank, the heating water tank and the PV / T collector;

[0006] One side of the medium-deep casing buried pipe is connected to a water collection tank, the other side of the water collection tank is connected to a PV / T collector, one side of the PV / T collector is electrically connected to an energy component, the connection between the medium-deep casing buried pipe and the water collection tank is connected to a heat pump unit, the other side of the heat pump unit is connected to a heating water tank, and the heating water tank can provide heating to users.

[0007] Furthermore, the water flow can be circulated between the medium-deep casing buried pipes, the heat pump unit, the water collection tank, the heating water tank, and the PV / T collector, thereby improving the flexibility and stability of the heating system.

[0008] The energy component includes an inverter and an energy storage battery; one side of the PV / T collector is electrically connected to the inverter, the other side of the inverter is electrically connected to the energy storage battery, and the output end of the energy storage battery is electrically connected to the heat pump unit;

[0009] Furthermore, thermal energy is collected by PV / T collectors, converted into electrical energy by inverters, and stored in energy storage batteries, thereby improving the energy utilization rate of the system.

[0010] It also includes a phase change energy storage device; the phase change energy storage device is connected to the connection between the medium-deep casing buried pipe and the heat pump unit;

[0011] Furthermore, the system can store and use thermal energy through the phase change heat storage device, thereby improving the flexibility and stability of the system.

[0012] The water circulation assembly includes a first circulating water pump, a second circulating water pump, a third circulating water pump, a fourth circulating water pump and a fifth circulating water pump; the first circulating water pump is provided at the connection between the heat collecting tank and the PV / T collector, the second circulating water pump is provided at the connection between the medium-deep casing buried pipe and the heat collecting tank, the third circulating water pump is provided at the connection between the heat pump unit and the heating water tank, the fourth circulating water pump is provided at the connection between the heating water tank and the heating equipment in the user's building, and the fifth circulating water pump is provided at the connection between the medium-deep casing buried pipe and the phase change energy storage device;

[0013] Furthermore, the efficiency of water flow in the system is improved by using five sets of circulating water pumps.

[0014] The temperature sensing component includes a first temperature sensor, a second temperature sensor, a third temperature sensor, a fourth temperature sensor, a fifth temperature sensor and a sixth temperature sensor; a first temperature sensor is arranged at the connection between the water collecting tank and the PV / T collector, a second temperature sensor is fixedly arranged on one side of the water collecting tank, a third temperature sensor is fixedly arranged on one side of the heating water tank, a fourth temperature sensor is fixedly arranged on one side of the medium-deep casing buried pipe, a fifth temperature sensor is arranged at the connection between the phase change energy storage device and the heat pump unit, and a sixth temperature sensor is arranged at the connection between the medium-deep casing buried pipe and the phase change energy storage device;

[0015] Furthermore, six sets of temperature sensors are used to detect the temperature of the water flow and devices in the system, thereby improving the accuracy of system use.

[0016] The control component includes a first electromagnetic valve, a second electromagnetic valve, a third electromagnetic valve, a fourth electromagnetic valve, a fifth electromagnetic valve, a sixth electromagnetic valve, a seventh electromagnetic valve and an eighth electromagnetic valve; the first electromagnetic valve is provided at the input end of the heat collecting tank connected to the medium-deep casing-type buried pipe, the second electromagnetic valve is provided at the input end of the heat pump unit connected to the medium-deep casing-type buried pipe, the third electromagnetic valve is provided at the output end of the heat pump unit connected to the medium-deep casing-type buried pipe, the fourth electromagnetic valve is provided at the output end of the heat collecting tank connected to the medium-deep casing-type buried pipe, the fifth electromagnetic valve is provided at the input end of the phase change energy storage device connected to the medium-deep casing-type buried pipe and the heat pump unit, the sixth electromagnetic valve is provided at the output end of the phase change energy storage device connected to the medium-deep casing-type buried pipe and the heat pump unit, the seventh electromagnetic valve is provided at the output end of the heat pump unit connected to the medium-deep casing-type buried pipe and the phase change energy storage device, and the eighth electromagnetic valve is provided at the input end of the heat pump unit connected to the medium-deep casing-type buried pipe and the phase change energy storage device;

[0017] Furthermore, eight groups of electromagnetic valves are used to control the switching of water flow and devices in the system, thereby achieving convenient control of the system.

[0018] The soil heat storage body includes backfill material, an outer pipe wall, an annular space, an inner pipe wall and an internal space; the outer pipe wall and the inner pipe wall are both arranged on the inner side of the backfill material, the inner pipe wall is arranged on the inner side of the outer pipe wall, an internal space is formed on the inner side of the inner pipe wall, and an annular space is formed between the inner pipe wall and the outer pipe wall;

[0019] Furthermore, the utilization efficiency of geothermal energy can be improved through soil heat storage, maintaining the flexibility and stability of the system in providing heating to users during the heating season.

[0020] The beneficial effects of the present invention are:

[0021] 1. Through the setting of medium-deep casing-type buried pipe coupled phase change heat storage device, the coupling system can solve the problem of soil cold accumulation of medium-deep casing-type buried pipes, and can ensure the stable operation performance of the system during long-term operation; the solar energy in the non-heating season can be recovered and stored in the soil, realizing cross-season energy storage, improving energy utilization efficiency, and reducing the investment payback period of the system.

[0022] 2. By injecting cooling water, the problem of overheating of PV / T collector can be solved, the photoelectric conversion efficiency can be improved, and the energy utilization rate of the system can be improved.

[0023] 3. By installing a phase change heat storage device, the utilization efficiency of geothermal energy can be improved, maintaining the flexibility and stability of the system in providing heating to users during the heating season. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1This is the operating principle diagram of the PV / T coupled medium-deep casing underground pipe heating system based on phase change energy storage. DETAILED DESCRIPTION

[0025] The following will be combined with the attached Figure 1 , clearly and completely describe the technical solutions in the embodiments. Figure 1 As shown, the heating system is mainly composed of a medium-deep casing buried pipe 1, a heat pump unit 11, a water collection tank 9, a heating water tank 12, a phase change energy storage device 10 and a PV / T collector 14. The heating system can be used to guide the design of the coupling system and promote the utilization and development of renewable energy through five sets of operation modes of the system under different time periods and operating conditions; the five operation modes are:

[0026] Mode 1: Medium-deep casing buried pipe 1 soil heating mode;

[0027] The soil heating supplement mode of the medium-deep casing buried pipe 1 includes the medium-deep casing buried pipe 1, the PV / T collector 14 and the heat collecting water tank 9;

[0028] In the non-heating season, as the PV / T collector 14 operates, the temperature of the PV / T collector 14 continues to rise. By using cooling water to cool the PV / T collector 14, the water temperature flowing through the PV / T collector 14 will rise and enter the heat collection tank 9. When the outlet water temperature of the PV / T collector 14 is 7°C higher than the temperature of the soil heat storage body, the soil heat supplement condition is met and this mode is operated; at the end of the heating season, when the outdoor temperature is low and the cooling demand of the PV / T collector 14 can be met by natural cooling, this mode stops operating;

[0029] The specific operation is: turn on the first circulating water pump B1, the second circulating water pump B2, the first electromagnetic valve V1, the fourth electromagnetic valve V4, and keep the other circulating water pumps and electromagnetic valves closed. Under the action of the first circulating water pump B1, the hot water heated by the PV / T collector 14 flows through the heat collecting tank 9 to transfer the heat to the water flow on the side of the medium-deep casing buried pipe 1. Under the action of the second circulating water pump B2, the water flow on the side of the medium-deep casing buried pipe 1 transfers the heat to the soil heat storage body around the medium-deep casing buried pipe 1, and supplements the heat to the soil heat storage body;

[0030] This alleviates the cold accumulation problem of the soil and dissipates heat from the PV / T collector 14, which can ensure stable system performance during long-term operation;

[0031] Mode 2: heat storage mode of the phase change energy storage device 10;

[0032] The heat storage mode of the phase change heat storage device 10 includes a medium-deep casing buried pipe 1, a heat pump unit 11, a PV / T collector 14, an inverter 7, an energy storage battery 8 and a phase change energy storage device 10;

[0033] During the heating season, when the outdoor temperature is high at noon, the heating load of the building is low, so the heating of the building is suspended and the heat storage mode of the phase change energy storage device 10 is turned on; hot water flows from the medium-deep casing buried pipe 1 into the heat pump unit 11, and the heat pump unit heats the hot water under the power generated by the PV / T collector 14, the inverter 7 and the energy storage battery 8, and then the heat of the hot water is sent to the phase change energy storage device 10 for storage. When the temperature difference between the inlet and outlet of the phase change energy storage device 10 is less than 0.5°C, this mode stops running;

[0034] The specific operation is: turn on the second circulating water pump B2, the fifth circulating water pump B5, the second electromagnetic valve V2, the third electromagnetic valve V3, the fifth electromagnetic valve V5, and the sixth electromagnetic valve V6, and keep the other circulating water pumps and electromagnetic valves closed. Under the action of the second circulating water pump B2 and the fifth circulating water pump B5, the hot water flow that takes heat through the medium-deep casing buried pipe 1 transfers the heat to the phase change energy storage device 10 to store the heat, and then the water flows back to the medium-deep casing buried pipe 1, and the cycle repeats;

[0035] By storing heat through the phase change energy storage device 10, solar energy in the non-heating season can be recovered and stored in the soil, realizing cross-season energy storage, improving energy utilization efficiency, and reducing the investment payback period of the system;

[0036] Mode 3: heating mode of the phase change energy storage device 10;

[0037] The heating mode of the phase change thermal storage device 10 includes the phase change thermal storage device 10, the heat pump unit 11, the PV / T collector 14, the inverter 7, the energy storage battery 8, the heating water tank 12 and the user 13;

[0038] At the beginning of the heating season or when the heating load of the building is low, only the heat provided by the phase change heat storage device 10 can meet the heating load demand of the building, and this mode can be operated. The heat of the phase change energy storage device 10 is obtained by hot water and then flows through the heat pump unit 11. The heat pump unit 11 heats the hot water under the power generated by the PV / T collector 14, the inverter 7 and the energy storage battery 8, and then sends the heat to the building through the heating water tank 12 and the user 13 loop for heating. When the heating load further increases and the heat provided by the phase change energy storage device 10 cannot meet the heating demand, this mode stops running;

[0039] The specific operation is: turn on the third circulating water pump B3, the fourth circulating water pump B4, the fifth circulating water pump B5, the seventh electromagnetic valve V7, and the eighth electromagnetic valve V8, and keep the other circulating water pumps and electromagnetic valves closed. Under the action of the fifth circulating water pump B5, the hot water in the phase change heat storage device 10 flows into the heat pump unit 11 for heating, and then under the action of the third circulating water pump B3 and the fourth circulating water pump B4, the hot water flows into the heating water tank 12 for heat exchange, and then the heat is delivered to the user 13;

[0040] The phase change energy storage device 10 improves the utilization efficiency of geothermal energy, maintaining the flexibility and stability of the system in providing heating to users during the heating season;

[0041] Mode 4: Medium-deep casing buried pipe 1 heating mode;

[0042] The heating mode of the medium-deep casing underground pipe 1 includes the medium-deep casing underground pipe 1, the heat pump unit 11, the PV / T collector 14, the inverter 7, the energy storage battery 8, the heating water tank 12 and the user 13;

[0043] This mode is operated when the heating load is large, the heat provided by the phase change heat storage device 10 cannot meet the heating demand of the building, and the outlet water temperature of the medium-deep casing buried pipe 1 can meet the heating standard; the hot water obtains the heat stored underground through the medium-deep casing buried pipe 1 and flows through the heat pump unit 11. The heat pump unit 11 heats the hot water under the power generated by the PV / T collector 14, the inverter 7 and the energy storage battery 8, and then sends the heat to the building through the heating water tank 12 and the user 13 loop for heating. When the heating load further increases and the heat provided by the medium-deep casing buried pipe 1 alone cannot meet the heating demand, this mode stops running;

[0044] The specific operation is: turn on the second circulating water pump B2, the third circulating water pump B3, the fourth circulating water pump B4, the second electromagnetic valve V2, the third electromagnetic valve V3, and keep the other circulating water pumps and electromagnetic valves closed. Under the action of the second circulating water pump B2, the water flow obtains heat from the medium-deep casing buried pipe 1 and flows to the heat pump unit 11. After being heated by the heat pump unit 11, under the action of the third circulating water pump B3 and the fourth circulating water pump B4, the hot water flows into the heating water tank 12 for heat exchange, and then the heat is delivered to the home of the user 13;

[0045] Highly efficient heating is provided through the medium-deep casing buried pipe 1, thereby avoiding the problem of insufficient heating in the home of the user 13, thereby promoting the application of the system in the north and achieving the goal of energy conservation and emission reduction;

[0046] Mode 5: Medium-deep casing buried pipe 1 coupled with phase change energy storage device 10 heating mode;

[0047] The heating mode of the medium-deep casing type underground pipe 1 coupled with the phase change heat storage device 10 includes the medium-deep casing type underground pipe 1, the phase change energy storage device 10, the heating water tank 12 and the user 13;

[0048] In extremely cold regions, when the heating load is very large and the heating demand of the building cannot be met by heating with only the medium-deep casing buried pipe 1, this mode is operated; the building is heated by the medium-deep casing buried pipe 1 and the phase change energy storage device 10 through the heating water tank 12 and the user 13 to meet its demand. When the heating demand gradually decreases to the point where the heating demand can be met by the medium-deep casing buried pipe 1, this mode stops operating;

[0049] The specific operation is: turn on the second circulating water pump B2, the third circulating water pump B3, the fourth circulating water pump B4, the fifth circulating water pump B5, the second electromagnetic valve V2, the third electromagnetic valve V3, the seventh electromagnetic valve V7, the eighth electromagnetic valve V8, and keep the other circulating water pumps and electromagnetic valves closed. At this time, the heat provided to the user 13 has two sources, one is the heat obtained from the medium-deep casing buried pipe 1, and the other is the heat provided by the heating water tank 12;

[0050] The heating provided by the medium-deep casing-type buried pipe 1 coupled with the phase-change heat storage device 10 increases the upper limit of the user 13 building heating system, thereby facilitating the improvement of the stability of the building heating.

[0051] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement made to the above embodiments without departing from the content of the technical solution of the present invention, based on the technical essence of the present invention, within the spirit and principles of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims

1. A PV / T coupled medium-deep casing underground pipe heating system based on phase change energy storage, characterized in that: The invention comprises a medium-deep casing-type underground pipe (1), a heat pump unit (11), a heat collecting tank (9), a heating water tank (12), a PV / T collector (14), an energy component, a control component, a water circulation component and a temperature sensing component. The vertical part of the medium-deep casing-type underground pipe (1) is arranged underground, and the outer side of the part of the medium-deep casing-type underground pipe (1) located underground is filled with a soil heat storage body. The control component, the water circulation component and the temperature sensing component are arranged between the medium-deep casing-type underground pipe (1), the heat pump unit (11), the heat collecting tank (9), the heating water tank (12) and the PV / T collector (14); One side of the medium-deep casing-type buried pipe (1) is connected to a water collecting tank (9), the other side of the water collecting tank (9) is connected to a PV / T collector (14), one side of the PV / T collector (14) is electrically connected to an energy component, the connection between the medium-deep casing-type buried pipe (1) and the water collecting tank (9) is connected to a heat pump unit (11), the other side of the heat pump unit (11) is connected to a heating water tank (12), and heating is provided to a user (13) through the heating water tank (12).

2. According to claim 1, a PV / T coupled medium-deep casing buried pipe heating system based on phase change energy storage is characterized in that: The energy component includes an inverter (7) and an energy storage battery (8); One side of the PV / T collector (14) is electrically connected to an inverter (7), the other side of the inverter (7) is electrically connected to an energy storage battery (8), and the output end of the energy storage battery (8) is electrically connected to a heat pump unit (11).

3. A PV / T coupled medium-deep casing underground pipe heating system based on phase change energy storage according to claim 1, characterized in that: Also included is a phase change energy storage device (10); A phase-change energy storage device (10) is connected to the connection point between the medium-deep casing-type buried pipe (1) and the heat pump unit (11).

4. A PV / T coupled medium-deep casing underground pipe heating system based on phase change energy storage according to claim 1, characterized in that: The water circulation assembly comprises a first circulating water pump (B1), a second circulating water pump (B2), a third circulating water pump (B3), a fourth circulating water pump (B4) and a fifth circulating water pump (B5); A first circulating water pump (B1) is provided at the connection point between the heat collecting tank (9) and the PV / T collector (14); a second circulating water pump (B2) is provided at the connection point between the medium-deep casing-type buried pipe (1) and the heat collecting tank (9); a third circulating water pump (B3) is provided at the connection point between the heat pump unit (11) and the heating water tank (12); a fourth circulating water pump (B4) is provided at the connection point between the heating water tank (12) and the heating equipment in the user's (13) building; and a fifth circulating water pump (B5) is provided at the connection point between the medium-deep casing-type buried pipe (1) and the phase change energy storage device (10).

5. A PV / T coupled medium-deep casing underground pipe heating system based on phase change energy storage according to claim 1, characterized in that: The temperature sensing component includes a first temperature sensor (T1), a second temperature sensor (T2), a third temperature sensor (T3), a fourth temperature sensor (T4), a fifth temperature sensor (T5) and a sixth temperature sensor (T6); A first temperature sensor (T1) is arranged at the connection point between the heat collecting tank (9) and the PV / T collector (14), a second temperature sensor (T2) is fixedly arranged on one side of the heat collecting tank (9), a third temperature sensor (T3) is fixedly arranged on one side of the heating water tank (12), a fourth temperature sensor (T4) is fixedly arranged on one side of the medium-deep casing-type buried pipe (1), a fifth temperature sensor (T5) is arranged at the connection point between the phase change energy storage device (10) and the heat pump unit (11), and a sixth temperature sensor (T6) is arranged at the connection point between the medium-deep casing-type buried pipe (1) and the phase change energy storage device (10).

6. A PV / T coupled medium-deep casing underground pipe heating system based on phase change energy storage according to claim 1, characterized in that: The control component includes a first electromagnetic valve (V1), a second electromagnetic valve (V2), a third electromagnetic valve (V3), a fourth electromagnetic valve (V4), a fifth electromagnetic valve (V5), a sixth electromagnetic valve (V6), a seventh electromagnetic valve (V7) and an eighth electromagnetic valve (V8); The input end of the heat collecting tank (9) connected to the medium-deep casing-type underground pipe (1) is provided with a first electromagnetic valve (V1), the input end of the heat pump unit (11) connected to the medium-deep casing-type underground pipe (1) is provided with a second electromagnetic valve (V2), the output end of the heat pump unit (11) connected to the medium-deep casing-type underground pipe (1) is provided with a third electromagnetic valve (V3), the output end of the heat collecting tank (9) connected to the medium-deep casing-type underground pipe (1) is provided with a fourth electromagnetic valve (V4), and the phase change energy storage device (10) connected to the medium-deep casing-type underground pipe (1) is provided with a fourth electromagnetic valve (V4). A fifth electromagnetic valve (V5) is provided at an input end connected to the heat pump unit (11); a sixth electromagnetic valve (V6) is provided at an output end connected to the phase change energy storage device (10), the medium-deep casing-type underground pipe (1) and the heat pump unit (11); a seventh electromagnetic valve (V7) is provided at an output end connected to the heat pump unit (11), the medium-deep casing-type underground pipe (1) and the phase change energy storage device (10); and an eighth electromagnetic valve (V8) is provided at an input end connected to the heat pump unit (11), the medium-deep casing-type underground pipe (1) and the phase change energy storage device (10).

7. A PV / T coupled medium-deep casing underground pipe heating system based on phase change energy storage according to claim 1, characterized in that: The soil heat storage body comprises backfill material (2), an outer pipe wall (3), an annular space (4), an inner pipe wall (5) and an inner space (6); The outer tube wall (3) and the inner tube wall (5) are both arranged inside the backfill material (2), the inner tube wall (5) is arranged inside the outer tube wall (3), an internal space (6) is formed inside the inner tube wall (5), and an annular space (4) is formed between the inner tube wall (5) and the outer tube wall (3).

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