Geothermal heat supply system and method

Abstract

The invention discloses a geothermal heat supply system and method, and the system comprises a ground source side which comprises a geothermal source, a heat exchanger and a three-way valve; the geothermal source is connected with the heat exchanger through a ground source side pipeline; moreover, a three-way valve is arranged in the ground source side pipeline, an inlet of the three-way valve is connected with the water outlet end of the geothermal source, a first outlet of the three-way valve is connected with the primary side water supply and return end of the heat exchanger, and a second outlet of the three-way valve is connected with the primary side water supply end of the heat exchanger. The heat exchange amount of the heat exchanger is controlled; the ground heat exchange side comprises a heat pump unit; the heat pump unit is connected with a ground source side pipeline; and the tail end supply side is connected with the heat pump unit and receives the circulating medium flowing out of the heat pump unit. According to the scheme provided by the invention, load decoupling, flow decoupling, pressure slow change and system stability among the ground source side, the ground heat exchange and extraction side and the end user side can be realized.

Description

Technical Field

[0001] This application relates to the field of heating, ventilation and air conditioning technology, and more particularly to a geothermal heating system and method. Background Art

[0002] A geothermal heating system, also known as an underground heat exchange heating system, is a system that uses geothermal energy for heating. It mainly consists of a geothermal source side, a ground heat exchange and heat extraction side, and a terminal heating side. Its core principle is to extract heat energy from the ground through an underground heat exchanger on the geothermal source side and transfer it to the ground heating system.

[0003] Affected by the underground heat exchange mechanism and characteristics of its geothermal source side, in the current geothermal heating system, the temperature of the geothermal well water outlet is relatively high at the beginning of a heating season, then drops rapidly, and stabilizes at a medium temperature; however, when the geothermal well operates under variable conditions or intermittently, the geothermal well with a low utilization rate can quickly recover a certain temperature. Therefore, the change in the outlet temperature causes a large range of changes in the performance of the heat pump unit, and it is very difficult to match the change in the terminal load with a simple variable flow regulation method. In addition, affected by the deep burial depth, when the geothermal source side water pump installed on the ground starts initially, when the static pressure borne by the buried pipe, especially the inner casing, is converted into dynamic pressure, the pressure change is large. When the water pump starts and stops frequently, it is very easy to damage the pipeline and affect its service life.

[0004] Therefore, how to design a geothermal heating solution to ensure the safe, efficient and economic operation of the system has become a problem to be solved in this field. Summary of the Invention

[0005] In view of this, in the first aspect, this application proposes a geothermal heating system, which includes:

[0006] The geothermal source side includes: a geothermal heat source, a heat exchanger and a three-way valve; the geothermal heat source is connected to the heat exchanger through a geothermal source side pipeline;

[0007] Moreover, a three-way valve is provided in the geothermal source side pipeline. The inlet of the three-way valve is connected to the water outlet end of the geothermal heat source, the first outlet of the three-way valve is connected to the primary side supply and return water ends of the heat exchanger, and the second outlet of the three-way valve is connected to the primary side water supply end of the heat exchanger. By adjusting the opening degrees of the first outlet and the second outlet of the three-way valve, the heat exchange amount of the heat exchanger can be controlled;

[0008] The ground heat exchange side includes: a heat pump unit; the heat pump unit is connected to the geothermal source side pipeline;

[0009] The terminal supply side is connected to the heat pump unit and receives the circulating medium flowing out of the heat pump unit.

[0010] Preferably, the system further includes: a control side.

[0011] Further preferably, the above-ground heat exchange side further includes: a condenser inlet and outlet water temperature sensor of the heat pump unit;

[0012] Both the condenser side inlet and outlet water temperature sensor and the three-way valve are electrically connected to the control side, and the control side adjusts the opening degrees of the first outlet and the second outlet of the three-way valve according to the values in the condenser inlet and outlet water temperature sensor.

[0013] Further preferably, the ground source side further includes: a ground heat source outlet water temperature sensor; a heat exchange pipeline control valve is further arranged in the ground source side pipeline;

[0014] Both the ground heat source outlet water temperature sensor and the heat exchange pipeline control valve are electrically connected to the control side, and the control side controls the opening and closing of the heat exchange pipeline control valve according to the values in the ground heat source outlet water temperature sensor, so as to control the circulating medium flowing out of the ground heat source to enter the heat pump unit after heat exchange through the heat exchanger, or the circulating medium flowing out of the ground heat source does not pass through the heat exchanger for heat exchange and directly enters the heat pump unit.

[0015] Further preferably, the system further includes: a heat pump monitoring side;

[0016] The control side is also electrically connected to the heat pump monitoring side, and the control side controls the operating frequencies of the primary side circulating water pump of the heat exchanger and the evaporator side circulating water pump of the heat pump unit according to the values in the heat pump monitoring side.

[0017] Preferably, the system further includes: a water replenishment side;

[0018] The water replenishment side is connected to the water inlet end of the primary side and / or the water inlet end of the secondary side of the heat exchanger.

[0019] In a second aspect, the present application further provides a geothermal heating method, characterized in that the method includes:

[0020] Sequentially turn on the heat exchanger arranged on the ground source side and the heat pump unit arranged on the above-ground heat exchange side;

[0021] Monitor the ground heat source outlet water temperature of the ground source side, and according to the ground heat source outlet water temperature, control the circulating medium to supply heat to the end supply side after flowing through the heat exchanger and the heat pump unit, or control the circulating medium not to flow through the heat exchanger and directly flow into the heat pump unit and then supply heat to the end supply side;

[0022] When the circulating medium flows through the heat exchanger and the heat pump unit, monitor the condenser inlet water temperature and the outlet water temperature of the heat pump unit, and adjust the heat extraction amount of the heat exchanger from the ground heat source according to the condenser inlet water temperature and the outlet water temperature of the heat pump unit.

[0023] Preferably, monitor the water outlet temperature of the ground heat source on the ground source side, and according to the water outlet temperature of the ground heat source, control the circulating medium to supply heat to the end supply side after flowing through the heat exchanger and the heat pump unit, or control the circulating medium not to flow through the heat exchanger and directly flow into the heat pump unit and then supply heat to the end supply side, including:

[0024] Monitor the water outlet temperature of the ground heat source on the ground source side;

[0025] If the water outlet temperature of the ground heat source is greater than the first preset value, control the circulating medium to supply heat to the end supply side after flowing through the heat exchanger and the heat pump unit;

[0026] If the water outlet temperature of the ground heat source is not greater than the first preset value, control the circulating medium not to flow through the heat exchanger, directly flow into the heat pump unit, and then supply heat to the end supply side.

[0027] Preferably, monitor the inlet water temperature and outlet water temperature of the condenser of the heat pump unit, and adjust the heat extraction amount of the heat exchanger from the ground heat source according to the inlet water temperature and outlet water temperature of the condenser of the heat pump unit, including:

[0028] Monitor the inlet water temperature and outlet water temperature of the condenser of the heat pump unit;

[0029] If the inlet water temperature of the condenser of the heat pump unit is less than the second preset value, or the outlet water temperature of the condenser of the heat pump unit is less than the third preset value, increase the heat extraction amount of the heat exchanger from the ground heat source;

[0030] If the inlet water temperature of the condenser of the heat pump unit is not less than the second preset value, or the outlet water temperature of the condenser of the heat pump unit is not less than the third preset value, reduce the heat extraction amount of the heat exchanger from the ground heat source.

[0031] Preferably, the method further includes:

[0032] By adjusting the water flow rate at the primary side supply and return ends and the primary side water supply end of the heat exchanger, thereby adjusting the water flow rate at the water outlet end of the ground heat source, and further adjusting the heat extraction amount of the heat exchanger from the ground heat source.

[0033] Preferably, if the water outlet temperature of the ground heat source is greater than the first preset value, the method further includes:

[0034] Monitor the load rate of the heat pump unit, and adjust the operating frequencies of the primary side circulating pump of the heat exchanger and the evaporator side circulating pump of the heat pump unit according to the load rate of the heat pump unit.

[0035] Preferably, the method further includes:

[0036] Construct a learning model;

[0037] Using the learning model, determine the operating frequencies of the primary side circulating water pump of the heat exchanger, the evaporator side circulating water pump of the heat pump unit, and the heat pump of the heat pump unit according to the load on the end-user supply side.

[0038] In a geothermal heating system provided in this application, mechanisms such as a geothermal heat source, a heat exchanger, a three-way valve, and a heat pump unit are included. A three-way valve is provided in the source side pipeline. By adjusting the opening degree of the three-way valve, the heat exchange amount of the heat exchanger is controlled. Without frequently adjusting the water pump at the outlet end of the geothermal heat source, the demand on the end-user supply side is matched, achieving load decoupling, flow decoupling, pressure slow change, and system stability among the geothermal source side, the above-ground heat exchange and heat extraction side, and the end-user side. Moreover, this application is applicable to underground heat exchange heating systems in different regions with different geothermal capabilities.

[0039] Other features and advantages of this application will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings that form a part of this application are used to provide a further understanding of this application. The schematic embodiments and descriptions thereof are used to explain this application. In the drawings:

[0041] Figure 1 is a schematic structural diagram of the architecture of the geothermal heating system according to the preferred embodiment of this application;

[0042] Figure 2 is a schematic pipeline structure diagram of the geothermal heating system according to the preferred embodiment of this application;

[0043] Figure 3 is a method flow chart of the geothermal heating method according to the preferred embodiment of this application.

[0044] REFERENCE NUMERALS

[0045] Geothermal source side 100; Geothermal heat source 11; Geothermal source side supply and return water interfaces 111; Heat exchanger 12; Heat exchanger primary side circulating water pump 121; Three-way valve 13; Geothermal heat source outlet temperature sensor 14; Heat exchange pipeline control valve 15; Water pump at the outlet end of the geothermal heat source 16; Bypass valve 17; Heat exchanger control valve 18; Pipeline conversion and stability module base 19; Above-ground heat exchange side 200; Heat pump unit 21; Evaporator side circulating water pump 211; Condenser side inlet and outlet water temperature sensor 22; Heat exchange and heat extraction module base 23; End-user supply side 300; End-user supply and return water pipe interfaces 31; End-user circulating water temperature sensor 32; End-user circulating water pump 33; Make-up water side 400; Softening water tank 41, Constant pressure make-up water unit 42, Make-up water pipe 43, Constant pressure make-up module base 44; Make-up water system electric valve 45; Control side 500. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] The technical solution of the present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0047] First, the present application provides a geothermal heating system, as Figure 1-2 shown, the geothermal heating system includes: a ground source side 100, an above-ground heat exchange side 200, and a terminal supply side 300.

[0048] Among them, the ground source side 100 includes: a ground heat source 11 and a heat exchanger 12. The ground heat source 11 is used to provide the most primitive underground heat energy in the system, specifically, it can be a geothermal well. The ground heat source 11 is connected to the heat exchanger 12 through a ground source side pipeline. The heat exchanger 12 can exchange heat with the circulating medium flowing out of the ground heat source 11 and absorb the underground heat energy. The circulating medium is usually water.

[0049] In a specific embodiment, the heat exchanger 12 is a plate heat exchanger. Its core function is to separate two fluids through metal plates to achieve the transfer of heat from the high-temperature primary side to the low-temperature secondary side. In the present application, the primary side of the heat exchanger 12 is connected to the ground heat source 11, and the secondary side is connected to the above-ground heat exchange side 200.

[0050] The above-ground heat exchange side 200 includes: a heat pump unit 21 connected to the ground source side pipeline. The heat pump unit 21 can adjust the circulating medium flowing out of the heat exchanger 12 to a suitable temperature, or directly use the heat pump unit 21 to heat up the circulating medium flowing out of the ground heat source 11.

[0051] Finally, the terminal supply side 300 is connected to the heat pump unit 21, receives the circulating medium flowing out of the heat pump unit 21 and supplies heat.

[0052] In the prior art, if it is necessary to adjust the heat exchange amount of the heat exchanger 12, it is necessary to adjust the water pump at the water outlet end of the ground heat source 11 to adjust the water inflow received by the heat exchanger 12 from the water outlet end of the ground heat source 11. However, frequent operation of the water pump is likely to cause a decrease in the water pump efficiency or equipment wear. To solve this problem, a three-way valve 13 is provided in the ground source side pipeline in the present application. Its three branches include an inlet, a first outlet, and a second outlet, which are respectively connected to the water outlet end of the ground heat source 11, the supply and return water ends of the primary side of the heat exchanger 12, and the water supply end of the primary side of the heat exchanger 12. Among them, the water supply end of the primary side of the heat exchanger 12 is connected to the water outlet end of the ground heat source 11, and is used to introduce the circulating medium into the heat exchanger 12 to provide heat for the circulating medium on the secondary side. The supply and return water ends of the primary side of the heat exchanger 12 are connected to the water return port of the ground heat source 11, and are used to send the low-temperature water after heat exchange back to the ground heat source 11 for reheating and recycling.

[0053] The relationship between the load demand of the terminal supply side 300, the medium flow rate, and the supply and return water temperature difference is as shown in expression (1):

[0054] Q = G·C·Δt (1);

[0055] Wherein, Q represents heat, G represents the medium flow rate, C is the specific heat of the medium, which can be regarded as a fixed value, and Δt represents the temperature difference between the supply and return water of 100 on the ground source side. According to this formula, it can be known that the value of Q can be achieved by increasing or decreasing the value of G.

[0056] In this application, by adjusting the opening degrees of the first outlet and the second outlet of the three-way valve 13, the water output of the primary side supply and return water end of the heat exchanger 12 and the water output of the primary side water supply end of the heat exchanger 12 can be adjusted, thereby indirectly adjusting the water inflow at the inlet of the three-way valve 13, that is, the water inflow of the heat exchanger 12 from the ground heat source 11, and further realizing the adjustment of the supply and return water temperatures. Without frequently adjusting the water pump at the water outlet end of the ground heat source 11, the heat exchange amount of the heat exchanger 12 is adjusted to match the demand of the terminal supply side 300, thereby avoiding the damage to the pipeline caused by frequently adjusting the water pump.

[0057] In a specific embodiment, as Figure 2 shown, the right branch of the three-way valve 13 is the inlet end of the three-way valve 13, which is connected to the water outlet end of the ground heat source 11. The left branch of the three-way valve 13 is the first outlet end of the three-way valve 13, which is connected to the primary side supply and return water end of the heat exchanger 12. The upper branch of the three-way valve 13 is the second outlet end of the three-way valve 13, which is connected to the primary side water supply end of the heat exchanger 12.

[0058] Regarding the control method of the three-way valve 13, the system further includes a control side 500. The three-way valve 13 is an electric three-way valve and can be controlled by the control side 500.

[0059] It can be understood that the heat pump unit 21 includes an evaporator side and a condenser side. The evaporator side is used to absorb the heat provided by the ground source side 100, and the condenser side is used to release the absorbed heat to the terminal supply side 300. The inlet and outlet water temperatures of the condenser side directly affect the supply temperature of the terminal supply side 300, and the inlet and outlet water temperatures of the condenser side are also related to the heat extraction amount from the ground heat source 11. Therefore, in this application, a condenser side inlet and outlet water temperature sensor 22 of the heat pump unit 21 is also provided on the ground heat exchange side 200. The condenser side inlet and outlet water temperature sensor 22 and the three-way valve 13 are both electrically connected to the control side 500. The control side 500 adjusts the opening degrees of the first outlet and the second outlet of the three-way valve 13 according to the value in the condenser inlet and outlet water temperature sensor 22, thereby indirectly adjusting the water inflow of the heat exchanger 12 from the ground heat source 11, that is, the heat extraction amount from the ground heat source 11, and further adapting to the demand of the terminal supply side 300.

[0060] In a specific embodiment, as Figure 1As shown, when the condenser inlet and outlet water temperature sensor 22 of the heat pump unit monitors that the inlet water temperature T3 of the condenser of the heat pump unit is less than 42°C or the outlet water temperature T4 of the condenser of the heat pump unit is less than 47°C, the control side 500 reduces the opening degrees of the first outlet and the second outlet of the ground source side three-way valve 13 to increase the heat extraction from the ground heat source 11, so as to make the heating keep up with the end demand; while when the inlet water temperature T3 of the condenser of the heat pump unit is not less than 42°C or the outlet water temperature T4 of the condenser of the heat pump unit is not less than 47°C, the control side 500 increases the opening degrees of the first outlet and the second outlet of the three-way valve 13 to reduce the heat extraction from the ground heat source 11, so as to reduce the energy consumption.

[0061] In addition, during the heating process of a quarter, the heat source temperature that the ground source side 100 can provide will change with time. At the beginning of heating, the heat source temperature that the ground heat source 11 can provide is relatively high. As time goes by, in the middle and late stages of heating, the heat source temperature that the ground heat source 11 can provide will become lower. In this regard, a ground heat source outlet water temperature sensor 14 is also provided on the ground source side 100 in this application, and a heat exchange pipeline control valve 15 is also provided in the ground source side pipeline. The ground heat source outlet water temperature sensor 14 and the heat exchange pipeline control valve 15 are both electrically connected to the control side 500. The control side 500 controls the opening and closing of the heat exchange pipeline control valve 15 according to the value in the ground heat source outlet water temperature sensor 14, so as to control the circulating medium flowing out of the ground heat source 11 to enter the heat pump unit 21 after heat exchange through the heat exchanger 12, or the circulating medium flowing out of the ground heat source 11 does not enter the heat pump unit 21 through heat exchange of the heat exchanger 12. In the initial stage of system operation, the heat quality of the middle and deep layers underground is high. By means of the heat exchanger 12, the water temperature provided to the heat pump unit 21 can be controlled within a certain range, avoiding large fluctuations in water temperature in the initial stage and the middle and late stages, which may cause the heat pump unit 21 to not always operate efficiently. In the middle and late stages of system operation, the water temperature in the middle and deep buried pipes is relatively low compared with the initial stage. Directly supplying water to the heat pump unit 21 can enable the condenser side of the heat pump unit 21 to obtain a heat source of higher quality, thereby providing higher heating efficiency.

[0062] In a specific embodiment, such as Figure 1-2As shown in the figure, the heat exchange pipeline control valve 15 includes a bypass valve 17 and a heat exchanger control valve 18. When the bypass valve 17 is open and the heat exchanger control valve 18 is closed, the circulating medium flowing out of the ground heat source 11 does not pass through the heat exchanger 12 for heat exchange and directly enters the heat pump unit 21. When the bypass valve 17 is closed and the heat exchanger control valve 18 is open, the circulating medium flowing out of the ground heat source 11 enters the heat pump unit 21 after passing through the heat exchanger 12 for heat exchange. Further, when the ground heat source water temperature sensor 14 monitors that the water temperature T1 at the outlet of the ground heat source is greater than 25 °C, the heat exchanger control valve 18 is opened and the bypass valve 17 is closed. The hot water above 25 °C coming out of the ground heat source passes through the primary side circulating pump 121 of the ground source side heat exchanger 12, flows through the plate heat exchanger 12, and exchanges heat with the water at about 7 - 10 °C in the secondary side supply and return water pipe of the plate heat exchanger into hot water at 15 - 20 °C. Then, the hot water is sent into the evaporator of the heat pump unit 21 through the evaporator side circulating pump 211 of the heat pump unit 21, and the temperature is raised by the heat pump, so that the temperature of the water in the condenser side inlet pipe of the heat pump unit 21 is raised from 45 °C to 50 °C, thereby providing water with a supply and return water temperature of 50 °C / 45 °C for users. When the ground heat source water temperature sensor 14 monitors that the water temperature T1 at the outlet of the ground heat source is not greater than 25 °C, the heat exchanger control valve 18 is closed and the bypass valve 17 is opened. The hot water not greater than 25 °C coming out of the ground heat source 11 directly enters the evaporator of the heat pump unit 21, and the temperature is raised by the heat pump unit 21, so that the temperature of the water in the condenser side inlet pipe of the heat pump unit 21 is raised from 45 °C to 50 °C, thereby providing water with a supply and return water temperature of 50 °C / 45 °C for users.

[0063] In addition, the present application can also adjust the operating frequencies of the heat pump and the primary side circulating pump 121 of the heat exchanger 12 by monitoring the operating load rate of the heat pump in the heat pump unit 21 to balance the energy consumption of each component. The system in the present application further includes a heat pump monitoring side (not shown in the figure) for detecting the operating load rate of the heat pump in the heat pump unit 21. The control side 500 is also electrically connected to the heat pump monitoring side and is used to control the operating frequencies of the primary side circulating pump 121 of the heat exchanger 12 and the evaporator side circulating pump 211 of the heat pump unit 21 according to the value in the heat pump monitoring side.

[0064] In a specific embodiment, when the operating load rate of the heat pump in the heat pump unit 21 is less than 30%, the primary side circulating pump 121 and the evaporator side circulating pump 211 are controlled to operate at a low frequency to reduce the conveying energy consumption. When the load rate is between 30% and 60%, the primary side circulating pump 121 is controlled to operate at the power frequency, and the frequency of the evaporator side circulating pump 211 is controlled to operate at a variable frequency and low frequency. When the load rate is greater than 60%, the primary side circulating pump 121 and the evaporator side circulating pump 211 are both controlled to operate at the power frequency.

[0065] In another specific embodiment, the control side 500 also has a learning function. The historical data of the operating frequencies of the primary-side circulating water pump 121 and the evaporator-side circulating water pump 211 and the overall operating energy consumption of the system (such as water consumption and power consumption) are used as samples for learning. By continuous learning, the optimal operating frequencies of the primary-side circulating water pump 121 and the evaporator-side circulating water pump 211 are determined under the lowest energy consumption that meets the load requirements.

[0066] By setting the control side 500, it is possible to make judgments based on the feedback parameters of each sensor, realize the automatic control of the internal equipment of the system, intelligently solve the control problems, and establish a geothermal heating system integrating measurement, control, and management.

[0067] In view of the possible situation of insufficient water pressure during the operation of the system, the system of the present application further includes: a make-up water side 400, which is connected to the water inlet end of the primary side and / or the water inlet end of the secondary side of the heat exchanger 12. Preferably, affected by the high head of the buried pipe side water pump and the low head of the secondary side water pump of the heat exchanger 12, the primary side and the secondary side of the heat exchanger 12 need to be replenished with water separately to avoid water leakage due to different pressures.

[0068] In a specific embodiment, the make-up water side 400 includes mechanisms such as a softened water tank 41, a constant pressure make-up water unit 42, a make-up water pipe 43, a constant pressure make-up water module base 44, and a make-up water system electric valve 45. The softened water system enters the softened water tank 41 through the make-up water pipe interface. According to the system pressure feedback, the primary side and the secondary side circulating water systems of the plate heat exchanger are replenished with water through the constant pressure make-up water unit 42 and the make-up water system electric valve 45. When the water in the system causes the pressure to drop due to heat dissipation or other reasons, the make-up water device will automatically start the water pump to supplement water from the atmospheric tank or other water sources into the system to maintain the system pressure constant. At the same time, the constant pressure make-up water unit 42 also has the functions of constant pressure and exhaust. In the air conditioning water system, temperature changes will cause the expansion and contraction of the water volume, thereby affecting the system pressure. The constant pressure make-up water device detects the system pressure in real time through a pressure sensor and automatically adjusts when the pressure is too high or too low to ensure that the system pressure is maintained within the set range, thus ensuring the stable operation of the system. During the exhaust process, the high-pressure circulating water enters the atmospheric tank for pressure reduction. After gas-water separation, the gas is discharged into the atmosphere through the exhaust valve. This can discharge the gas in the system, prevent air blockage, and ensure the smooth circulation of the system.

[0069] In a specific embodiment, the water replenishing side 400 is integrally installed on the constant pressure water replenishing module base 44, the ground source side 100 is integrally installed on the pipeline conversion and stability adaptation module base 19, and the above-ground heat exchange side 200 is integrally installed on the heat exchange and heat extraction module base 23. After assembling the three bases respectively, connect the constant pressure water replenishing pipe, connect the supply and return water pipes on the evaporator side of the ground source heat pump, and then connect the external interfaces in sequence, such as the water replenishing pipe, the supply and return water pipes on the buried pipe side, the supply and return water pipes on the user side, the power distribution cable interface, etc., to complete the assembly of the entire geothermal heating system. Through system and pipeline integration, the installation process is simple. The overall installation of the system can be prefabricated in the factory, and the three modules of water replenishing, heating, and heat extraction are directly transported to the site for assembly, greatly reducing the on-site construction and installation time. As Figure 2 shown, the water replenishing side 400, the ground source side 100, and the above-ground heat exchange side 200 of the present application can be combined and connected in multiple ways according to the site conditions, with only four supply and return water pipe interfaces and one electrical interface reserved externally, enabling rapid on-site installation, reducing the workload, and decreasing the occupied area of the machine room.

[0070] In a geothermal heating system provided by the present application, it includes mechanisms such as a geothermal heat source, a heat exchanger, a three-way valve, a heat pump unit, etc. A three-way valve is set in the pipeline on the source side. By adjusting the opening degree of the three-way valve, the heat exchange amount of the heat exchanger is controlled. Without frequently adjusting the water pump at the water outlet end of the geothermal heat source, the demand on the terminal supply side is matched, realizing load decoupling, flow decoupling, pressure slow change, and system stability adaptation among the ground source side, the above-ground heat exchange and heat extraction side, and the terminal user side. Moreover, the present application is applicable to underground heat exchange heating systems in different regions with different geothermal capabilities.

[0071] In addition, the present application also provides a geothermal heating method, which can be implemented in the above geothermal heating system. As Figure 3 shown, the method includes the following steps 110 - 130:

[0072] Step 110: Turn on the heat exchanger set on the ground source side and the heat pump unit set on the above-ground heat exchange side in sequence;

[0073] Specifically, to ensure the stable operation of the heating system, first turn on the heat exchanger on the ground source side, and then start the heat pump unit on the above-ground heat exchange side. During this process, the system water pressure can be continuously monitored, and water replenishment is carried out when the water pressure is insufficient.

[0074] In a specific embodiment, first start the primary side circulation water pump of the heat exchanger to operate at the minimum frequency for two hours, then slowly increase the operation frequency of this water pump until it operates at the power frequency. After operating at the power frequency for two hours, start the circulation water pump on the evaporator side of the heat pump unit and the heat pump unit in sequence, so as to achieve lower energy consumption.

[0075] Step 120: Monitor the water outlet temperature of the ground heat source on the ground source side, and based on the water outlet temperature of the ground heat source, control the circulating medium to supply heat to the terminal supply side after flowing through the heat exchanger and the heat pump unit, or control the circulating medium not to flow through the heat exchanger and directly flow into the heat pump unit and then supply heat to the terminal supply side;

[0076] Specifically, if the water outlet temperature of the ground heat source is relatively high, controlling the circulating medium to supply heat to the terminal supply side after flowing through the heat exchanger and the heat pump unit can better control the heating temperature. If the water outlet temperature of the ground heat source is relatively low, controlling the circulating medium to directly extract heat in the heat pump unit and then supply heat to the terminal supply side can achieve higher heating efficiency. The specific principle and detailed process have been described above and will not be elaborated here.

[0077] In a specific embodiment, step 120 may specifically include:

[0078] Monitor the water outlet temperature of the ground heat source on the ground source side. If the water outlet temperature of the ground heat source is greater than the first preset value, control the circulating medium to supply heat to the terminal supply side after flowing through the heat exchanger and the heat pump unit. If the water outlet temperature of the ground heat source is not greater than the first preset value, control the circulating medium not to flow through the heat exchanger and directly flow into the heat pump unit and then supply heat to the terminal supply side. This first preset value can be set as needed, for example, set to 25°C.

[0079] Step 130: When the circulating medium flows through the heat exchanger and the heat pump unit, monitor the inlet water temperature and outlet water temperature of the condenser of the heat pump unit, and adjust the heat extraction amount of the heat exchanger from the ground heat source according to the inlet water temperature and outlet water temperature of the condenser of the heat pump unit;

[0080] Specifically, in the case where the circulating medium flows through the heat exchanger, the heat extraction amount of the heat exchanger from the ground heat source can be adjusted according to the inlet water temperature and outlet water temperature of the condenser of the heat pump unit to meet the supply demand of the terminal. The specific principle and detailed process have also been described above and will not be elaborated here.

[0081] In a specific embodiment, step 130 may specifically include:

[0082] Monitor the inlet water temperature and outlet water temperature of the condenser of the heat pump unit. If the inlet water temperature of the condenser of the heat pump unit is less than the second preset value, or the outlet water temperature of the condenser of the heat pump unit is less than the third preset value, then increase the heat extraction amount of the heat exchanger from the ground heat source. If the inlet water temperature of the condenser of the heat pump unit is not less than the second preset value, or the outlet water temperature of the condenser of the heat pump unit is not less than the third preset value, then decrease the heat extraction amount of the heat exchanger from the ground heat source. Among them, when adjusting the heat extraction amount of the heat exchanger from the ground heat source, the heat extraction amount of the heat exchanger from the ground heat source can be adjusted by adjusting the water flow rate at the primary side supply and return ends and the primary side water supply end of the heat exchanger, so as to adjust the water flow rate at the outlet end of the ground heat source. The second preset value and the third preset value can also be set as needed. For example, the second preset value is set to 42 °C and the third preset value is set to 47 °C.

[0083] In some preferred embodiments, if the outlet water temperature of the ground heat source is greater than the first preset value, that is, when the circulating medium flows through the heat exchanger, the method further includes: monitoring the load rate of the heat pump unit, and adjusting the operating frequencies of the primary side circulating pump of the heat exchanger and the evaporator side circulating pump of the heat pump unit according to the load rate of the heat pump unit to balance the energy consumption of each workpiece. The specific control logic in this embodiment is as described above for adjusting the operating frequency of the primary side circulating pump 121 of the heat pump and the heat exchanger 12 according to the operating load rate of the heat pump in the heat pump unit 21, and will not be elaborated here.

[0084] In some more preferred embodiments, the method further includes: constructing a learning model, inputting the historical data of the operating frequencies of the primary side circulating pump and the evaporator side circulating pump and the overall operating energy consumption of the system (such as water consumption, power consumption) as samples into the learning model for learning, and using the learning model to determine the optimal operating frequencies of the primary side circulating pump of the heat exchanger, the evaporator side circulating pump of the heat pump unit, and the heat pump of the heat pump unit according to the load on the current user end supply side.

[0085] The geothermal heating method provided by the present application controls the circulating medium to supply heat to the end supply side after flowing through the heat exchanger and the heat pump unit according to the outlet water temperature of the ground heat source, or controls the circulating medium not to flow through the heat exchanger and directly flow into the heat pump unit to supply heat to the end supply side. At the same time, according to the inlet water temperature and outlet water temperature of the condenser of the heat pump unit, the heat extraction amount of the heat exchanger from the ground heat source is adjusted. In this way, load decoupling, flow decoupling, pressure slow change and system stability can be achieved among the ground source side, the above-ground heat exchange and heat extraction side, and the end user side, and the geothermal heating control problem is intelligently solved.

[0086] Other preferred embodiments of the geothermal heating method provided by the present application are the same as the above-mentioned geothermal heating system and will not be elaborated here.

[0087] The preferred embodiments of the present application have been described in detail above. However, the present application is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, and these simple modifications all fall within the protection scope of the present application.

[0088] In addition, it should be noted that, in the various specific technical features described in the above specific embodiments, they can be combined in any appropriate manner without conflict. To avoid unnecessary repetition, the present application will not separately describe various possible combination methods.

[0089] Furthermore, any combination can be made between the various different embodiments of the present application, as long as it does not violate the idea of the present application, and it should also be regarded as the content disclosed by the present invention.

Claims

1. A geothermal heating system, characterized in that, The system includes: The ground source side (100) includes: a ground heat source (11), a heat exchanger (12) and a three-way valve (13); the ground heat source (11) is connected to the heat exchanger (12) through a ground source side pipeline; And, a three-way valve (13) is provided in the ground source side pipeline, the inlet of the three-way valve (13) is connected to the water outlet end of the ground heat source (11), the first outlet of the three-way valve (13) is connected to the primary side supply and return water ends of the heat exchanger (12), and the second outlet of the three-way valve (13) is connected to the primary side water supply end of the heat exchanger (12). By adjusting the opening degrees of the first outlet and the second outlet of the three-way valve (13), the heat exchange amount of the heat exchanger (12) is controlled; The above-ground heat exchange side (200) includes: a heat pump unit (21); the heat pump unit (21) is connected to the ground source side pipeline; The terminal supply side (300) is connected to the heat pump unit (21) and receives the circulating medium flowing out of the heat pump unit (21).

2. The system according to claim 1, wherein The system further includes: a control side (500).

3. The system according to claim 2, characterized in that, The above-ground heat exchange side (200) further includes: a condenser inlet and outlet water temperature sensor (21) of the heat pump unit (21); Both the condenser side inlet and outlet water temperature sensor (21) and the three-way valve (13) are electrically connected to the control side (500). The control side (500) adjusts the opening degrees of the first outlet and the second outlet of the three-way valve (13) according to the value in the condenser inlet and outlet water temperature sensor (21).

4. The system according to claim 2, characterized in that, The ground source side (100) further includes: a ground heat source outlet water temperature sensor (14); a heat exchange pipeline control valve (15) is also provided in the ground source side pipeline; Both the ground heat source outlet water temperature sensor (14) and the heat exchange pipeline control valve (15) are electrically connected to the control side (500). The control side (500) controls the opening and closing of the heat exchange pipeline control valve (15) according to the value in the ground heat source outlet water temperature sensor (14), so as to control the circulating medium flowing out of the ground heat source (11) to enter the heat pump unit (21) after heat exchange through the heat exchanger (12), or the circulating medium flowing out of the ground heat source (11) directly enters the heat pump unit (21) without passing through the heat exchanger (12) for heat exchange.

5. The system according to claim 2, wherein The system further includes: a heat pump monitoring side; The control side (500) is also electrically connected to the heat pump monitoring side. The control side (500) controls the operating frequencies of the primary side circulating water pump (121) of the heat exchanger (12) and the evaporator side circulating water pump (211) of the heat pump unit (21) according to the value in the heat pump monitoring side.

6. The system according to claim 1, wherein The system further includes: a make-up water side (400); The make-up water side (400) is connected to the inlet end of the primary side and / or the inlet end of the secondary side of the heat exchanger (12).

7. A geothermal heating method, characterized in that, The method includes: Sequentially starting the heat exchanger provided on the ground source side and the heat pump unit provided on the above-ground heat exchange side; Monitor the water outlet temperature of the ground heat source on the ground source side, and control the heating of the end supply side by the circulating medium after flowing through the heat exchanger and the heat pump unit according to the water outlet temperature of the ground heat source, or control the circulating medium not to flow through the heat exchanger and directly flow into the heat pump unit and then supply heat to the end supply side; When the circulating medium flows through the heat exchanger and the heat pump unit, monitor the inlet water temperature and the outlet water temperature of the condenser of the heat pump unit, and adjust the heat extraction amount of the heat exchanger from the ground heat source according to the inlet water temperature and the outlet water temperature of the condenser of the heat pump unit.

8. The method according to claim 7, characterized in that Monitoring the water outlet temperature of the ground heat source on the ground source side, and controlling the heating of the end supply side by the circulating medium after flowing through the heat exchanger and the heat pump unit according to the water outlet temperature of the ground heat source, or controlling the circulating medium not to flow through the heat exchanger and directly flowing into the heat pump unit and then supplying heat to the end supply side, includes: Monitor the water outlet temperature of the ground heat source on the ground source side; If the water outlet temperature of the ground heat source is greater than the first preset value, control the circulating medium to flow through the heat exchanger and the heat pump unit and then supply heat to the end supply side; If the water outlet temperature of the ground heat source is not greater than the first preset value, control the circulating medium not to flow through the heat exchanger and directly flow into the heat pump unit and then supply heat to the end supply side.

9. The method according to claim 7, wherein Monitoring the inlet water temperature and the outlet water temperature of the condenser of the heat pump unit, and adjusting the heat extraction amount of the heat exchanger from the ground heat source according to the inlet water temperature and the outlet water temperature of the condenser of the heat pump unit, includes: Monitor the inlet water temperature and the outlet water temperature of the condenser of the heat pump unit; If the inlet water temperature of the condenser of the heat pump unit is less than the second preset value, or the outlet water temperature of the condenser of the heat pump unit is less than the third preset value, increase the heat extraction amount of the heat exchanger from the ground heat source; If the inlet water temperature of the condenser of the heat pump unit is not less than the second preset value, or the outlet water temperature of the condenser of the heat pump unit is not less than the third preset value, reduce the heat extraction amount of the heat exchanger from the ground heat source.

10. The method according to claim 7 or 9, characterized in that, The method further includes: Adjust the water flow rate at the primary side supply and return ends and the primary side water supply end of the heat exchanger, thereby adjusting the water flow rate at the water outlet end of the ground heat source, and further adjusting the heat extraction amount of the heat exchanger from the ground heat source.

11. The method according to claim 7, wherein If the water outlet temperature of the ground heat source is greater than the first preset value, the method further includes: Monitor the load rate of the heat pump unit, and adjust the operating frequencies of the primary side circulating pump of the heat exchanger and the evaporator side circulating pump of the heat pump unit according to the load rate of the heat pump unit.

12. The method according to claim 7, characterized in that The method further includes: Construct a learning model; Use the learning model to determine the operating frequencies of the primary side circulating pump of the heat exchanger, the evaporator side circulating pump of the heat pump unit, and the heat pump of the heat pump unit according to the load on the current user end supply side.

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