A combined heating system for multi-load buildings and multi-span greenhouses

Abstract

The present invention discloses a combined heating system for multiple load buildings and multi-span greenhouses, comprising a geothermal unit, a heating system, and a heating terminal connected in sequence. The geothermal unit includes a water collection well and a recharge well. The heating system comprises a multi-stage heat exchange system and a heat exchange station for sequentially absorbing geothermal water of different temperatures. The evaporation-side water inlet of the multi-stage heat exchange system is connected to the water collection well via a first pipe, and the evaporation-side water outlet is connected to the recharge well via a second pipe. The condensation side of the multi-stage heat exchange system is connected to the evaporation side of the heat exchange station. The heating terminal comprises an internal heating system and at least two sets of heat exchange devices. The input end of the first set of heat exchange devices is connected to the output end of the heat exchange station, the input end of the second set of heat exchange devices is connected to the output end of the first set of heat exchange devices, and so on. The output end of the last set of heat exchange devices is connected to the internal heating system. By connecting the load buildings and the multi-span greenhouses in series, the utilization rate of geothermal energy is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of geothermal heating, and in particular relates to a combined heating system for multi-load buildings and multi-span greenhouses. Background Art

[0002] With the rapid development of industrialization and urbanization, energy consumption for heating residential buildings continues to increase. Furthermore, the energy cost of heating greenhouses in agricultural facilities accounts for over 40% of total costs. To address energy shortages and global warming, my country is vigorously promoting the use of clean energy for heating. Geothermal energy, characterized by its cleanliness, stability, large reserves, and renewable nature, offers promising economic and environmental benefits when applied to heating systems in northern China. While shallow geothermal heating technology is relatively mature, medium- and deep-layer geothermal heating still faces challenges such as a limited heating terminal form, high initial investment costs, and high geothermal water recharge temperatures.

[0003] As a type of facility agriculture, multi-span greenhouses have the advantages of high land utilization rate, high degree of indoor mechanization, uniform indoor temperature and lighting environment, etc. They are more suitable for the development requirements of modern facility agriculture and are widely used in flower planting, aquaculture, etc.

[0004] When in use, such as in a multi-span greenhouse for growing flowers, the temperature requirement range is relatively strict and the load fluctuation is small. When geothermal energy is used, it often causes the front end to be hotter and the temperature at the back end cannot meet the demand, which is inconvenient to use in a multi-span greenhouse. When used for a long time, the accumulation of scale often leads to reduced heating efficiency, which is not convenient for long-term use. In addition, the utilization efficiency of geothermal energy is low when in use, and when in use, when different areas in the multi-span greenhouse require different temperatures, it is not easy to adjust. Summary of the Invention

[0005] The present invention provides a combined heating system for multiple load buildings and multi-span greenhouses. By connecting the load buildings and the multi-span greenhouses in series, the heat in the low-temperature heating circulating water from the civil buildings is extracted and utilized again, thereby increasing the temperature difference of the heating circulating water and improving the utilization rate of geothermal energy.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A combined heating system for a multi-load building and a multi-span greenhouse comprises a geothermal unit, a heating system, and a heating terminal connected in sequence, wherein the geothermal unit comprises a water collection well and a recharge well; the heating system comprises a multi-stage heat exchange system for sequentially absorbing geothermal water of different temperatures, wherein a ground source-side water inlet of the multi-stage heat exchange system is connected to the water collection well via a first pipe, and a ground source-side water outlet of the multi-stage heat exchange system is connected to the recharge well via a second pipe; the heating terminal comprises a heat exchange station, at least two groups of heat exchange devices, and an internal heating system; the load-side water supply pipe of the heat exchange station is connected to the primary-side inlet of the first group of heat exchange devices, the primary-side outlet of the first group of heat exchange devices is connected to the primary-side inlet of the second group of heat exchange devices, and so on, wherein the secondary side of the last group of heat exchange devices is connected to the internal heating system, and the primary-side outlet of the last group of heat exchange devices is connected to the load-side return pipe of the heat exchange station;

[0008] Furthermore, the multi-stage heat exchange system includes a primary heat exchange system, a secondary heat exchange system and a tertiary heat exchange system; the primary heat exchange system includes a primary plate heat exchanger, the primary side inlet of the primary plate heat exchanger is connected to the water well through a first pipe; the secondary heat exchange system includes a secondary plate heat exchanger, a high-temperature heat pump unit and a low-temperature heat pump unit, the secondary side inlet of the secondary plate heat exchanger is connected to the secondary side outlet of the primary plate heat exchanger, the secondary side water outlet of the secondary plate heat exchanger is connected to the steam of the high-temperature heat pump unit The power generation side water inlet is connected by a pipe, the evaporation side water outlet of the high-temperature heat pump unit is connected to the evaporation side water inlet of the low-temperature heat pump unit by a pipe, and the evaporation side water outlet of the low-temperature heat pump unit is connected to the secondary side water inlet of the secondary plate heat exchanger by a pipe; the three-stage heat exchange system includes a three-stage plate heat exchanger and a heat pump unit, the secondary side water outlet of the three-stage plate heat exchanger is connected to the evaporation side water inlet of the heat pump unit by a pipe, and the secondary side water inlet of the three-stage plate heat exchanger is connected to the evaporation side water outlet of the heat pump unit by a pipe.

[0009] Furthermore, the internal heating system includes a heating unit, a heating component and an auxiliary component; the heating unit includes a water supply pipe and a return pipe, and a heating component is arranged between the water supply pipe and the return pipe, the heating component includes a heating end and a heat exchanger, and the heating end is located inside the multi-span greenhouse, the water inlet and outlet of the heating end are both connected to the heat exchanger, a heating main pipe is connected between the heat source end and the return end of the heat exchanger, and the heating components are connected through the heating main pipe; the water supply pipe and the return pipe are respectively connected to the heating main pipes in the head-end heating component and the end-end heating component, and the water inlet and outlet of the auxiliary component are connected to the heating end in the heating component.

[0010] Furthermore, the heat source water inlet end of the heat exchanger is connected to a hot water pipe, and the return water end of the heat exchanger is connected to a warm water pipe. The heat exchanger is connected to the heating main pipe through the hot water pipe and the warm water pipe. The hot water pipe is connected to the thermostatic pipe, and the thermostatic pipes of all heating components are connected. The thermostatic pipe on the terminal heating component is connected to the return water pipe, and a thermostatic pump is installed on the thermostatic pipe of the terminal heating component.

[0011] Furthermore, a first flow valve is installed on the thermostatic pipe, a second flow valve is installed on the hot water pipe between the thermostatic pipe and the heating main pipe, a one-way valve is installed on the heating main pipe, and a temperature detector is installed on the hot water pipe.

[0012] Furthermore, a water inlet pipe is installed at the heat exchange water outlet end of the heat exchanger, and a circulation pump is installed at the end of the water inlet pipe close to the heating end. A circulation pipe is installed at the heat exchange water inlet end of the heat exchanger, and the water inlet pipe and the circulation pipe are both connected to the heating end. A circulation is formed between the water inlet pipe, the circulation pipe, the heat exchanger and the heating end through the circulation pump.

[0013] Furthermore, a first solenoid valve is installed on the water inlet pipe and the circulation pipe, a first branch pipe is installed on the water inlet pipe near the heating end, a second branch pipe is installed on the circulation pipe near the heating end, a second solenoid valve is installed on the first branch pipe and the second branch pipe, and the first branch pipe and the second branch pipe are both connected to the auxiliary component.

[0014] Furthermore, a wastewater pipe is installed on the water supply pipe, and a wastewater valve is installed on the wastewater pipe, a closing valve is installed on the return pipe, and both sides of the closing valve are connected to the two ends of the connecting pipe, a backwash pump is installed on the connecting pipe, and a pulse air pump is installed on the connecting pipe.

[0015] Furthermore, the auxiliary component includes an auxiliary heat exchanger and a heating source, and the heating source is connected to the auxiliary heat exchanger, and the auxiliary heat exchanger is connected to the first branch pipe and the second branch pipe.

[0016] Furthermore, an auxiliary hot water pipe is installed at the hot water inlet end of the auxiliary heat exchanger, and an auxiliary return pipe is installed at the cold water outlet end of the auxiliary heat exchanger. The auxiliary hot water pipe and the auxiliary return pipe are respectively connected to the hot end and the cold end of the heating source. The auxiliary heat exchange outlet hot end of the auxiliary heat exchanger is installed with an auxiliary heat supply main pipe, and the auxiliary heat exchange inlet cold end of the auxiliary heat exchanger is installed with an auxiliary return main pipe. The first branch pipe is respectively connected to the auxiliary heat supply main pipe, and the second branch pipe is respectively connected to the auxiliary return main pipe.

[0017] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0018] The present invention will connect greenhouses and other buildings in series. Since multi-span greenhouses have poor thermal insulation performance and large heat demand, but require low water supply temperature, the multi-span greenhouses will be connected in series to the end of the civil building, so that the heat from the entire heating circulation water return water can be reused, thereby improving the utilization rate of geothermal energy and reducing the reinjection temperature of geothermal water. In addition, the plants planted in the greenhouse have a certain carbon fixation ability, which can reduce the carbon footprint of the entire heating process. Taking the use of a medium-deep geothermal heating system for regional heating of 320,000 square meters of civil buildings + 80,000 square meters of multi-span greenhouses as an example, the medium-deep geothermal heating system is a "civil building + greenhouse" mode heating system with an energy efficiency of 2.3 higher than that of a single 320,000 square meter civil building heating system, and the carbon emissions per unit time per unit area are reduced from 110.4g / (m 2 ·d) is reduced to 96.6g / (m 2 ·d).

[0019] Furthermore, the temperature inside the greenhouse can be adjusted according to the needs of the plants. When in use, the heating components installed in the array at the heating end of the multi-span greenhouse improve the uniformity of the heating; and the temperature regulating pipe allows the warm water to flow back and mix with the hot water, improving the stability of the heating.

[0020] Furthermore, it is convenient to adjust the flow valve opening according to usage needs to accurately control the temperature of different areas of the greenhouse and meet the temperature requirements of different plants at different growth stages.

[0021] Furthermore, auxiliary components are used to facilitate backwashing of the heat exchanger without stopping the heating, so as to prevent problems such as low heat exchange efficiency and failure to meet plant growth temperatures caused by scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the present invention under the overall operating conditions;

[0023] Figure 2 This is a schematic diagram of the present invention in a heating operation state;

[0024] Figure 3 is a schematic diagram of the heating component of the present invention;

[0025] Figure 4 is a schematic diagram of the auxiliary components of the present invention;

[0026] Figure 5 It is a schematic diagram of the present invention in a recoil state;

[0027] In the figure: 1. Heating unit; 101. Water supply pipe; 102. Return pipe; 103. Wastewater pipe; 104. Wastewater valve; 105. Closing valve; 106. Connecting pipe; 107. Backflush pump; 108. Pulse aeration pump; 2. Heating component; 201. Heating end; 202. Heat exchanger; 203. Heating main pipe; 204. Hot water pipe; 205. Warm water pipe; 206. Thermostatic pipe; 207. Thermostatic pump; 208. First flow valve; 209. Second flow valve; 2010. One-way valve; 2011. Temperature detector; 2012. Water inlet pipe; 2013. Circulation pump; 2014. Circulation pipe; 2015. First solenoid valve; 2016. First branch pipe; 2017. Second branch pipe; 2018. Second solenoid valve ; 3. Auxiliary components; 301. Auxiliary heat exchanger; 302. Heating source; 303. Auxiliary hot water pipe; 304. Auxiliary return pipe; 305. Auxiliary heating main pipe; 306. Auxiliary return main pipe; 4. First-stage plate heat exchanger; 5. Heat exchange station; 6. Second-stage plate heat exchanger; 7. Third-stage plate heat exchanger; 8. High-temperature heat pump unit; 9. Low-temperature heat pump unit; 10. Heat pump unit; 11. Third-stage circulation pump; 12. Recharge pump; 13. First terminal heat exchanger; 14. First radiator; 15. Second radiator; 16. Ground radiation radiator; 17. Valve one; 18. Valve two; 19. Valve three; 20. Geothermal unit; 21. Heat exchange system; 22. Heating terminal; 23. Submersible pump; 24. Third-stage circulation pump; 25. Secondary circulation pump; 26. Main circulation pump; 27. Water production well; 28. Recharge well; 29. ​​Second terminal heat exchanger; 30. Third terminal heat exchanger; 31. Fourth terminal heat exchanger.

[0028] Indicates that the valve is open; Indicates that the valve is closed, and the arrow on the pipe indicates the flow direction of the medium in the pipe. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] See also Figure 1-5 As shown, a combined heating system for multi-load buildings and multi-span greenhouses using mid- and deep-layer geothermal energy includes a geothermal unit 20 , a heating system 21 and a heating terminal 22 .

[0031] The geothermal unit 20 includes a water production well 27 and a recharge well 28. The water production well 27 is connected to the primary side inlet of the first-stage plate heat exchanger 4 in the heating system 21 through a first pipe, and a submersible pump 23 is installed on the first pipe. The recharge well 28 is connected to the primary side outlet of the third-stage plate heat exchanger 7 in the heating system 21 through a second pipe, and a recharge pump 12 is installed on the second pipe.

[0032] Heating system 21 includes a primary heat exchange system consisting of a primary plate heat exchanger 4; a secondary heat exchange system consisting of a secondary plate heat exchanger 6, a high-temperature heat pump unit 8, and a low-temperature heat pump unit 9; and a tertiary heat exchange system consisting of a tertiary plate heat exchanger 7 and a heat pump unit 10. These primary, secondary, and tertiary heat exchange systems sequentially absorb geothermal water at different temperatures, improving geothermal energy utilization.

[0033] The heat supply terminal 22 includes a heat exchange station 5 and heat dissipation equipment in the building terminal.

[0034] The primary side water outlet of the first-stage plate heat exchanger 4 is connected to the primary side water inlet of the second-stage plate heat exchanger 6 through a pipe, and the primary side water outlet of the second-stage plate heat exchanger 6 is connected to the primary side water inlet of the third-stage plate heat exchanger 7 through a pipe. The secondary side water inlet of the first-stage plate heat exchanger 4 is connected to the return water pipe on the ground source side of the heat exchange station 5, and the secondary side water outlet of the first-stage plate heat exchanger 4 is connected to the water supply pipe on the ground source side of the heat exchange station 5; the secondary side inlet of the second-stage plate heat exchanger 6 is connected to the evaporation side water outlet of the low-temperature heat pump unit 9 through a pipe, and the secondary side water outlet of the second-stage plate heat exchanger 6 is connected to the evaporation side water inlet of the high-temperature heat pump unit 8 through a pipe, and the evaporation side water outlet of the high-temperature heat pump unit 8 is connected to the evaporation side water inlet of the low-temperature heat pump unit 9 through a pipe, and the condensation side water inlet of the high-temperature heat pump unit 8 is connected to the condensation side water inlet of the low-temperature heat pump unit 9 The side outlets are connected by pipes, the condensing side water outlet of the high-temperature heat pump unit 8 is connected to the ground source side water supply pipe of the heat exchange station 5, and the condensing side water inlet of the low-temperature heat pump unit 9 is connected to the ground source side return pipe of the heat exchange station 5; the secondary side water inlet of the three-stage plate heat exchanger 7 is connected to the evaporation side water outlet of the heat pump unit 10 through a pipe, the secondary side water outlet of the three-stage plate heat exchanger 7 is connected to the evaporation side water inlet of the heat pump unit 10 through a pipe, the condensing side water inlet of the heat pump unit 10 is connected to the ground source side return pipe of the heat exchange station 5, and the condensing side water outlet of the heat pump unit 10 is connected to the ground source side water supply pipe of the heat exchange station 5. The heating system 21 can be provided by installing a temperature sensor at the heat exchange station 5. When the ambient temperature is higher than T1, the submersible pump 23 is not turned on and heating is stopped; when the ambient temperature is lower than T1 and higher than T2, the submersible pump 23, the primary circulation pump 24, the main circulation pump 26 and the recharging pump 12 are turned on, and only the primary heat exchange system is used for heating; when the ambient temperature is lower than T2 and higher than T3, the submersible pump 23, the primary circulation pump 24, the secondary circulation pump 25, the main circulation pump 26 and the recharging pump 12 are turned on, and the primary heat exchange system and the secondary heat exchange system are used for heating at the same time. In the secondary heat exchange system, the valve 18 can be controlled to be closed and the valve three 19 to be opened, so that only one low-temperature heat pump unit can be used for heating 9, or the valve three 19 can be controlled to be closed and the valve two 18 to be opened, so that both heat pump units work, and the flow entering the high-temperature heat pump 8 can be controlled by adjusting the opening of the valve one 17; when the ambient temperature is lower than T3, all the circulation pumps are turned on, and the primary heat exchange system, the secondary heat exchange system and the tertiary heat exchange system are used for heating at the same time.

[0035] The heating terminal 22 is composed of the heat exchange station 5, the terminal heat exchanger 13, the heat dissipation equipment in the terminals of four types of buildings, and the internal heating system. By connecting multi-load civil buildings in series with the multi-span greenhouse, the total supply and return water temperature difference on the load side of the heat exchange station 5 is increased, and the flow rate of the circulating water is reduced. The principle of "small flow, large temperature difference" is adopted to more effectively utilize the heat in the circulating water, and the crops in the multi-span greenhouse can absorb part of the carbon dioxide, reducing the carbon emissions of the entire heating system.

[0036] In this embodiment, the heating terminal 22 includes a heat exchange station 5, a terminal heat exchanger 13, a first radiator 14, a second radiator 15, a ground radiation radiator 16, a multi-span greenhouse, and an internal heating system. The internal heating system is used to heat the residential building and the multi-span greenhouse. The first radiator 14 is installed in the residential building, the second radiator 15 is installed in the school, and the ground radiation radiator 16 is installed in the residential building, where the terminal uses ground radiation to dissipate heat.

[0037] The load-side water supply pipe of the heat exchange station 5 is connected to the primary-side inlets of the first terminal heat exchanger 13 and the second terminal heat exchanger 29. The primary-side outlets of the first terminal heat exchanger 13 and the second terminal heat exchanger 29 are both connected to the primary-side inlet of the third terminal heat exchanger 30. The primary-side outlet of the third terminal heat exchanger 30 is connected to the primary-side inlet of the fourth terminal heat exchanger 31. The primary-side outlet of the fourth terminal heat exchanger 31 is connected to the load-side return pipe of the heat exchange station 5.

[0038] The secondary side of first terminal heat exchanger 13 is connected to first radiator 14, the secondary side of second terminal heat exchanger 29 is connected to second radiator 15, the secondary side of third terminal heat exchanger 30 is connected to ground radiation radiator 16, and the secondary side of fourth terminal heat exchanger 31 is connected to water supply pipe 101 in heating unit 1. The internal heating system of the multi-span greenhouse includes heating unit 1, heating component 2, and auxiliary component 3.

[0039] The heating unit 1 includes a water supply pipe 101 and a return pipe 102, and the water supply pipe 101 and the return pipe 102 are connected through the heating component 2. The heating components 2 are arranged in an array. The heating component 2 includes a heating end 201 and a heat exchanger 202, and the heating end 201 is located inside the multi-span greenhouse. The water inlet pipe 2012 and the circulation pipe 2014 of the heating end 201 are both connected to the heat exchanger 202, and a heating main pipe 203 is connected between the heat source end and the return water end of the heat exchanger 202. The heating components 2 are connected through the heating main pipe 203, and the water supply pipe 101 and the return pipe 102 in the heating unit 1 are respectively connected to the heating main pipe 203 in the head-end heating component 2 and the end-end heating component 2, and the water inlet end and the water outlet end of the auxiliary component 3 are both connected to the heating end 201.

[0040] When in use, the heating ends 201 of the heating components 2 are evenly fixed in an array inside the multi-span greenhouse, and the heating unit 1 is connected to the heat exchanger 202. A heat exchange medium is injected into the pipe of the heating end 201 of the heating component 2. The heat exchange medium is pure water or thermal oil, and a sealed circulation environment is formed in the heating component 2 to avoid external impurity pollution, thereby reducing the frequency of internal cleaning and maintenance of the heating component 2 and increasing its service life. The heating unit 1 supplies the heating circulating water to the interior of the heat exchanger 202 through the water supply pipe 101, and heats the flowing medium inside the heating component 2. Heat is generated, thereby achieving the effect of heating the multi-span greenhouse, improving the uniformity of heating, avoiding uneven heating inside the multi-span greenhouse during heating, affecting the use of the multi-span greenhouse, and after long-term use, the heating unit 1 is turned off, and the heating end 201 is connected to the auxiliary component 3, so that the auxiliary component 3 heats the heating end 201 in the heating component 2, and the fluid in the heating unit 1 flows in the reverse direction to flush the heat exchanger 202, avoiding clogging with scale or impurities, affecting the heat exchange efficiency, and facilitating cleaning and maintenance without stopping heating, and facilitating use and operation.

[0041] As a technical optimization solution of the present invention, a hot water pipe 204 is fixedly installed at the heat source water inlet end of the heat exchanger 202, a warm water pipe 205 is fixedly installed at the return water end of the heat exchanger 202, and the heat exchanger 202 is connected to the heating main pipe 203 through the hot water pipe 204 and the warm water pipe 205. A thermostatic pipe 206 is connected to the middle position of the hot water pipe 204, and the thermostatic pipes 206 in all the heating components 2 are connected to each other, the thermostatic pipe 206 on the terminal heating component 2 is connected to the return water pipe 102, and a thermostatic pump 207 is fixedly installed on the side of the thermostatic pipe 206 in the terminal heating component 2 close to the return water pipe 102. A first flow valve 208 is fixedly installed on the side of the thermostat pipe 206 close to the hot water pipe 204, a second flow valve 209 is fixedly installed on the hot water pipe 204 between the thermostat pipe 206 and the heating main pipe 203, and a one-way valve 2010 is fixedly installed in the middle of the heating main pipe 203. A temperature detector 2011 is fixed on the hot water pipe 204 between the thermostat pipe 206 and the heat exchanger 202. A water inlet pipe 2012 is fixedly installed at the water outlet end, a circulation pump 2013 is fixedly installed on the end of the water inlet pipe 2012 close to the heating end 201, and a circulation pipe 2014 is fixedly installed at the heat exchange water inlet end of the heat exchanger 202. The water inlet pipe 2012 and the circulation pipe 2014 are both connected to the heating end 201, and a circulation is formed between the water inlet pipe 2012, the circulation pipe 2014, the heat exchanger 202 and the heating end 201 through the circulation pump 2013. A first solenoid valve 2015 is fixedly installed on the water inlet pipe 2012 and the circulation pipe 2014, and a first branch pipe 2016 is fixedly installed on the water inlet pipe 2012 near the heating end 201, and a second branch pipe 2017 is fixedly installed on the circulation pipe 2014 near the heating end 201. A second solenoid valve 2018 is fixedly installed on the first branch pipe 2016 and the second branch pipe 2017, and the first branch pipe 2016 and the second branch pipe 2017 are both connected to the auxiliary component 3.

[0042] During use, the heating circulating water enters the interior of the heating main pipe 203 from the water supply pipe 101, and by adjusting the second flow valve 209 in different heating components 2, it is convenient to control the flow of high-temperature hot water into the heat exchanger 202, and through the thermostatic pipe 206 and the thermostatic pump 207, the cold water generated after the heat exchange is refluxed, and according to the heat exchange requirements and the temperature detected by the temperature detector 2011, the opening of the first flow valve 208 and the second flow valve 209 is controlled to control the flow so that the hot water and the cold water are mixed, thereby avoiding the temperature being too high, which leads to the temperature of the heating end 201 being too high, and facilitating the control of the heat exchange temperature, thereby achieving the effect of controlling the heating temperature inside the multi-span greenhouse, and without the need for an external water source, the cold water generated after the heat exchange is used to neutralize the temperature, which is convenient for use, so that the temperature of the heating end 201 in each heating component 2 is the same, thereby facilitating stable heating of various positions in the multi-span greenhouse, and avoiding the problem of the front end temperature being too high and the back end temperature not being able to meet the use requirements. And when in use, by controlling the first flow valve 208 and the second flow valve 209, it is convenient to adjust the temperature in different heating components 2, so that the temperature in different areas of the multi-span greenhouse can be flexibly adjusted, and the applicability is strong. In normal use, the second solenoid valve 2018 on the first branch pipe 2016 and the second branch pipe 2017 is closed, so that the auxiliary component 3 is in standby state. When the heat exchanger 202 needs to be backflushed, the first solenoid valve 2015 is closed and the second solenoid valve 2018 is opened, so that the auxiliary component 3 heats the medium inside the heating end 201, and the first flow valve 208 on the temperature regulating tube 206 is closed, and the second flow valve 209 is opened. Since a one-way valve 2010 is installed on the heating main pipe 203, when backflushing is performed, the backflushing water enters the interior of the heat exchanger 202 through the warm water pipe 205 and flows out through the hot water pipe 204, thereby achieving the backflushing effect on the heat exchanger 202, facilitating operation, and avoiding affecting the heating end 201 during backflushing.

[0043] As a technical optimization solution of the present invention, a wastewater pipe 103 is fixedly installed on the water supply pipe 101, and a wastewater valve 104 is fixedly installed on the wastewater pipe 103, a closing valve 105 is fixedly installed on the return pipe 102, and connecting pipes 106 are fixedly installed on both sides of the closing valve 105, a backwash pump 107 is installed in the middle position of the connecting pipe 106, and a pulse aerator 108 is fixedly installed on the connecting pipe 106 on one side of the backwash pump 107. When backwashing is performed, the backwash pump 107 and the pulse aerator 108 are turned on by closing the closing valve 105 and opening the wastewater valve 104, and a cleaning agent is added to the inside of the backwash pump 107 to dissolve the dirt, so that the water inside the return pipe 102 is aerated and becomes a pulse state to backwash the heat exchanger 202 for backwashing, and the wastewater generated during flushing is discharged through the wastewater pipe 103, which is convenient for operation.

[0044] As a technical optimization solution of the present invention, refer to Figure 4 The auxiliary component 3 includes an auxiliary heat exchanger 301 and a heating source 302, and the heating source 302 is connected to the auxiliary heat exchanger 301. One end of the first branch pipe 2016 and the second branch pipe 2017 is connected to the auxiliary heat exchanger 301, and the other end is connected to the circulation pipe 2014 and the second branch pipe 2017. The hot water inlet end of the auxiliary heat exchanger 301 is fixedly installed with an auxiliary hot water pipe 303, and the cold water outlet end of the auxiliary heat exchanger 301 is fixedly installed with an auxiliary return pipe 304. The auxiliary hot water pipe 303 and the auxiliary return pipe 304 are respectively connected to the hot end and the cold end of the heating source 302, and the heat exchange outlet hot end of the auxiliary heat exchanger 301 is connected to the auxiliary heating main pipe 305. The heat exchange inlet of the auxiliary heat exchanger 301 is fixedly installed with an auxiliary hot water pipe 303. The water-cooling end is connected to the auxiliary return water main 306, the first branch pipe 2016 is connected to the auxiliary heating main 305, and the second branch pipe 2017 is connected to the auxiliary return water main 306. When backwashing is performed, the interior of the auxiliary heat exchanger 301 is heated by the heating source 302, and the heating source 302 includes but is not limited to boiler heating and solar heating. Heat is exchanged through the auxiliary heat exchanger 301, so that the heat transfer medium in the heating component 2 is circulated between the auxiliary heating main 305, the auxiliary return water main 306, the first branch pipe 2016, the second branch pipe 2017 and the heating end 201 through the circulation pump 2013, thereby facilitating the auxiliary heating of the multi-span greenhouse and achieving the effect of backwashing without stopping heating.

[0045] Combine Figure 1 As shown, after the hot water in the geothermal well passes through the first-stage plate heat exchanger 4 for a first gradient heat supply, the hot water after heat exchange enters the heat exchange station 5. The geothermal water after heat exchange in the first-stage plate heat exchanger 4 then enters the second-stage plate heat exchanger 6 and the third-stage plate heat exchanger 7 for cascade utilization and reflow through the recharge well. The second-stage plate heat exchanger 6 performs a heat exchange cycle through heat pump unit 1 8 and heat pump unit 2 9. The water returning from the heat exchange station 5 is heated to the supply water temperature by the high-temperature heat pump unit 8 and the low-temperature heat pump unit 9, and then supplied to the heat exchange station 5. The third-stage plate heat exchanger 7 can further extract heat from the low-temperature geothermal water, and heat the heat by the heat pump unit 10 to heat the heating circulating water returning from the heating station 5 to the heating temperature. The water then merges with the load-side outlet fluids of the first-stage plate heat exchanger 4 and the high-temperature heat pump unit 8, and is then input into the heat exchange station 5 through the main circulation pump 26 to provide heating for the terminal.

[0046] The hot water in the heat exchange station 5 is heat exchanged through the first terminal heat exchanger 13 and the second terminal heat exchanger 13, and the 50-degree hot water is supplied to the first radiator and the second radiator to heat the residential buildings and school buildings. The water discharged from the evaporation side of the first terminal heat exchanger 13 and the second terminal heat exchanger 29 is combined and enters the third terminal heat exchanger 30. The 40-degree hot water obtained after heat exchange is supplied to the ground radiation radiator 16 to heat the residential buildings that use ground radiation to dissipate heat at the end. The water discharged from the primary side of the terminal heat exchanger 30 is heat exchanged again through the fourth terminal heat exchanger 31, and the 35-degree Celsius hot water is supplied to the water supply pipe 101, so that the 35-degree Celsius hot water is supplied to the multi-span greenhouse to heat the plants planted in the greenhouse. The return water after heating the multi-span greenhouse is heat exchanged again with the fourth terminal heat exchanger 31 through the return pipe 102, forming a cycle. The water flowing out of the primary side of the fourth terminal heat exchanger 31 returns to the load side inlet of the heat exchange station 5 again and is heated to 50 degrees Celsius.

[0047] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0048] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A combined heating system for multi-load buildings and multi-span greenhouses, characterized in that: The invention relates to a geothermal unit (20), a heating system (21) and a heating terminal (22) which are connected in sequence. The geothermal unit (20) includes a water collection well (27) and a recharging well (28). The heating system (21) includes a multi-stage heat exchange system for sequentially absorbing geothermal water of different temperatures. The water inlet on the ground source side of the multi-stage heat exchange system is connected to the water collection well (27) through a first pipe, and the water outlet on the ground source side of the multi-stage heat exchange system is connected to the recharging well (28) through a second pipe. The heating terminal (22) includes a heat exchange station (5), at least two groups of heat exchange devices and an internal heating system. The load-side water supply pipe of the heat exchange station (5) is connected to the primary-side inlet of the first group of heat exchange devices, and the primary-side outlet of the first group of heat exchange devices is connected to the secondary-side outlet of the second group of heat exchange devices. The primary side inlet of the heating device is connected, and so on, the secondary side of the last group of heat exchange devices is connected to the internal heating system, and the primary side outlet of the last group of heat exchange devices is connected to the load side return pipe of the heat exchange station (5); the internal heating system includes a heating unit (1), a heating component (2) and an auxiliary component (3); the heating unit (1) includes a water supply pipe (101) and a return pipe (102), and a heating component (2) is provided between the water supply pipe (101) and the return pipe (102), the heating component (2) includes a heating end (201) and a heat exchanger (202), and the heating end (201) is located inside the multi-span greenhouse, and the water inlet and outlet of the heating end (201) are both connected to the heat exchanger (202). A heating main pipe (203) is connected between the heat source water inlet and the return water end of the heat exchanger (202), and the heating components (2) are connected through the heating main pipe (203); the water supply pipe (101) and the return water pipe (102) are respectively connected to the heating main pipe (203) in the head end heating component (2) and the terminal heating component (2); the water inlet and the water outlet of the auxiliary component (3) are connected to the heating end (201) in the heating component (2); the heat source water inlet of the heat exchanger (202) is connected to a hot water pipe (204), the return water end of the heat exchanger (202) is connected to a warm water pipe (205), and the heat exchanger (202) is connected to the heating main pipe (203) through the hot water pipe (204) and the warm water pipe (205). ) are connected, a temperature regulating pipe (206) is connected to the middle position of the hot water pipe (204), and the temperature regulating pipes (206) of all heating components (2) are connected, the temperature regulating pipe (206) on the terminal heating component (2) is connected to the return pipe (102), and a temperature regulating pump (207) is installed on the temperature regulating pipe (206) of the terminal heating component (2); a first flow valve (208) is installed on the temperature regulating pipe (206), a second flow valve (209) is installed on the hot water pipe (204) between the temperature regulating pipe (206) and the heating main pipe (203), a one-way valve (2010) is installed on the heating main pipe (203), and a temperature detector (2011) is installed on the hot water pipe (204);The heat exchange outlet end of the heat exchanger (202) is provided with a water inlet pipe (2012), and a circulation pump (213) is provided on the end of the water inlet pipe (2012) close to the heating end (201). The heat exchange water inlet end of the heat exchanger (202) is provided with a circulation pipe (214), and the water inlet pipe (212) and the circulation pipe (214) are both connected to the heating end (201). A circulation is formed between the water inlet pipe (2012), the circulation pipe (2014), the heat exchanger (202) and the heating end (201) through the circulation pump (2013); a waste water pipe is provided on the water supply pipe (101). (103), and a waste water valve (104) is installed on the waste water pipe (103), a closed valve (105) is installed on the return water pipe (102), and both sides of the closed valve (105) are connected to the two ends of the connecting pipe (106), and a backwash pump (107) and a pulse air pump (108) are installed on the connecting pipe (106); when the heat exchanger (202) is backwashed, the medium inside the heating end (201) is heated by the auxiliary component (3), and the backwash water enters the interior of the heat exchanger 202 through the warm water pipe (205) and then flows out through the hot water pipe (204).

2. A multi-load building and multi-span greenhouse combined heating system according to claim 1, characterized in that: The multi-stage heat exchange system includes a primary heat exchange system, a secondary heat exchange system and a tertiary heat exchange system; the primary heat exchange system includes a primary plate heat exchanger (4), the primary side inlet of the primary plate heat exchanger (4) is connected to the water well (27) through a first pipeline; the secondary heat exchange system includes a secondary plate heat exchanger (6), a high-temperature heat pump unit (8) and a low-temperature heat pump unit (9), the primary side inlet of the secondary plate heat exchanger (6) is connected to the primary side outlet of the primary plate heat exchanger (4), the secondary side water outlet of the secondary plate heat exchanger (6) is connected to the evaporation side outlet of the high-temperature heat pump unit (8), and the secondary side water outlet of the secondary plate heat exchanger (6) is connected to the evaporation side outlet of the high-temperature heat pump unit (8). The water inlet is connected through a pipeline, the evaporation side water outlet of the high-temperature heat pump unit (8) is connected to the evaporation side water inlet of the low-temperature heat pump unit (9) through a pipeline, and the evaporation side water outlet of the low-temperature heat pump unit (9) is connected to the secondary side water inlet of the secondary plate heat exchanger (6) through a pipeline; the three-stage heat exchange system includes a three-stage plate heat exchanger (7) and a heat pump unit (10), the secondary side water outlet of the three-stage plate heat exchanger (7) is connected to the evaporation side water inlet of the heat pump unit (10) through a pipeline, and the secondary side water inlet of the three-stage plate heat exchanger (7) is connected to the evaporation side water outlet of the heat pump unit (10) through a pipeline.

3. The multi-load building and multi-span greenhouse combined heating system according to claim 1, characterized in that: A first solenoid valve (2015) is installed on both the water inlet pipe (2012) and the circulation pipe (2014); a first branch pipe (2016) is installed on the water inlet pipe (2012) near the heating end (201); a second branch pipe (2017) is installed on the circulation pipe (2014) near the heating end (201); a second solenoid valve (2018) is installed on both the first branch pipe (2016) and the second branch pipe (2017); and both the first branch pipe (2016) and the second branch pipe (2017) are connected to the auxiliary component (3).

4. The multi-load building and multi-span greenhouse combined heating system according to claim 3, characterized in that: The auxiliary component (3) includes an auxiliary heat exchanger (301) and a heating source (302), and the heating source (302) is connected to the auxiliary heat exchanger (301), and the auxiliary heat exchanger (301) is connected to the first branch pipe (2016) and the second branch pipe (2017).

5. The multi-load building and multi-span greenhouse combined heating system according to claim 4, characterized in that: The hot water inlet end of the auxiliary heat exchanger (301) is installed with an auxiliary hot water pipe (303), and the cold water outlet end of the auxiliary heat exchanger (301) is installed with an auxiliary return water pipe (304). The auxiliary hot water pipe (303) and the auxiliary return water pipe (304) are respectively connected to the hot end and the cold end of the heating source (302). The heat exchange outlet hot end of the auxiliary heat exchanger (301) is installed with an auxiliary heat supply main pipe (305), and the heat exchange inlet cold end of the auxiliary heat exchanger (301) is installed with an auxiliary return water main pipe (306). The first branch pipe (2016) is connected to the auxiliary heat supply main pipe (305), and the second branch pipe (2017) is connected to the auxiliary return water main pipe (306).

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