Control system for medium-deep geothermal energy heat supply temperature

Abstract

A medium-deep geothermal energy heat supply temperature control system comprises a geothermal circulating water pump, a heat pump, a heat supply network circulating water pump, a heat exchanger, an electric heating device and a temperature measuring module which are respectively controlled by a central control system. The temperature of input geothermal water is set to be Ta, the temperature of heat supply network circulating water return passing through a heat supply network water outlet of a heat pump is set to be Tc, the temperature of heat supply network water return passing through a heat supply network water outlet of an electric heating device is set to be Td, the temperatures of the three parts are measured through a temperature measuring module, temperature data are sent to a central control system, and the preset heat supply network circulating water supply temperature is set to be Tb; when Ta is larger than Tb, the geothermal water and the heat supply network circulating water return water are directly subjected to heat exchange through the heat exchanger; and when Ta is smaller than Tb, heat exchange is conducted between the heat supply network circulating water return water and geothermal water through the heat pump, if the temperature of the heat supply network circulating water return water coming out of the heat pump does not reach Tb, the heat supply network circulating water return water continues to be heated through the electric heating device, and if the temperature reaches Tb, the heat supply network circulating water return water is conveyed to a user. The problems that the geothermal circulating water temperature is greatly influenced by geothermal energy, and the water supply temperature of heat supply network circulating water fluctuates greatly are solved.

Description

Technical Field

[0001] The present invention relates to the field of geothermal energy utilization, and in particular to a control system for heating temperature of mid-deep geothermal energy. Background Art

[0002] The current scheme for using mid-deep geothermal energy for heating systems is mainly to absorb the heat energy of the geothermal circulating water system through a heat pump to provide heating to users. The geothermal circulating water enters the geothermal water inlet of the heat pump through the geothermal circulating water, exchanges heat with the heat network circulating water through the heat pump, and flows out from the geothermal water outlet.

[0003] like Figure 1 As shown in the figure, since the temperature of geothermal circulating water is greatly affected by geothermal energy, the temperature of geothermal circulating water will vary greatly during different heating periods. For example, the temperature of geothermal circulating water may reach above 60°C at the beginning of heating, and gradually decrease to below 20°C as heat is absorbed. Heat pump operation generally has an optimal temperature range, such as 20-30°C. This will cause the water supply temperature of the heat network circulating water to fluctuate greatly, resulting in unstable heating. This will have a greater impact on heat users, such as heating for residents in the north.

[0004] Therefore, there is a need for a control system for the heating temperature of mid-deep geothermal energy that reduces the impact of geothermal circulating water on the circulating water of the heat network. Summary of the invention

[0005] The object of the present invention is to provide a control system for the heating temperature of mid-deep geothermal energy, which reduces the influence of geothermal circulating water on the circulating water of the heat network.

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

[0007] A control system for medium-deep geothermal energy heating temperature, comprising a geothermal circulating water pump, a heat pump, a heat network circulating water pump, a heat exchanger, an electric heating device, a valve A, a valve B, a valve C, a valve D, a valve E, a valve F, a valve G, a valve H, a valve I, a valve J, a valve K, and a temperature measurement module, which are respectively controlled by a central control system;

[0008] It also includes a geothermal water input main pipeline whose input end is connected to the output port of the medium-deep heat exchange well, and the output end of the geothermal water input main pipeline is respectively connected to the input end of the first geothermal water input branch pipe and the input end of the second geothermal water input branch pipe; a geothermal circulation water pump is arranged on the geothermal water input main pipeline;

[0009] The output end of the first geothermal water input branch pipe is connected to the geothermal water inlet of the heat pump, and the ground pump is used to absorb the heat energy of the geothermal water provided by the medium-deep heat exchange well and transfer the heat energy to the circulating water return water of the heat network. A valve A is provided on the first geothermal water input branch pipe;

[0010] The heat exchanger is used for exchanging heat between geothermal water and return water of heat network circulation water, the output end of the second geothermal water input branch pipe is connected to the geothermal water inlet of the heat exchanger, and the valve D is arranged on the second geothermal water input branch pipe;

[0011] It also includes a first geothermal water output branch pipe whose input end is connected to the geothermal water outlet of the heat pump, and a second geothermal water output branch pipe whose input end is connected to the geothermal water outlet of the heat exchanger, wherein the output end of the first geothermal water output branch pipe and the output end of the second geothermal water output branch pipe are respectively connected to the input end of the geothermal water output main pipeline, and the output end of the geothermal water output main pipeline is connected to the input port of the mid-deep heat exchange well;

[0012] The valve B is provided on the first geothermal water output branch pipe, and the valve C is provided on the second geothermal water output branch pipe;

[0013] It also includes a heat network water input main pipeline for inputting heat network circulating water return water, the output end of which is respectively connected to the input end of the first heat network water input branch pipe and the input end of the second heat network water input branch pipe; a heat network circulating water pump is arranged on the heat network water input main pipeline;

[0014] The output end of the first heating network water input branch pipe is connected to the heating network water inlet of the heat pump; the output end of the second heating network water input branch pipe is connected to the heating network water inlet of the heat exchanger, the valve E is provided on the first heating network water input branch pipe, and the valve H is provided on the second heating network water input branch pipe;

[0015] It also includes a first hot water network output branch pipe whose input end is connected to the hot water network outlet of the heat pump, and a second hot water network output branch pipe whose input end is connected to the hot water network outlet of the heat exchanger, the output end of the first hot water network output branch pipe and the output end of the second hot water network output branch pipe are respectively connected to the input end of the hot water network output main pipeline, and the output end of the hot water network output main pipeline is for circulating water supply for the hot water network;

[0016] The valve F is provided on the first heating network water output branch pipe, and the valve G is provided on the second heating network water output branch pipe;

[0017] It further includes an electric heating pipeline connected in parallel with the middle section of the main pipeline for outputting heat network water. A valve I is provided on the middle section of the main pipeline for outputting heat network water. A valve J, an electric heating device, and a valve K are sequentially arranged on the electric heating pipeline in the return water flow direction of the heat network circulating water. The valve J and the valve K are respectively connected to the heat network water inlet and the heat network water outlet of the electric heating device;

[0018] The temperature of the geothermal water at the output end of the main pipeline for inputting geothermal water is set as Ta. The temperature of the heat network water at the heat network water outlet of the heat pump after the return water of the heat network circulating water passes through is set as Tc, the temperature of the heat network water at the heat network water outlet after passing through the electric heating device is set as Td, and the temperature of the heat network water at the heat network water outlet after passing through the heat exchanger is set as Te. The temperatures of Ta, Tc, Td, and Te are respectively measured by the temperature measurement module and the temperature data is sent to the central control system. The preset supply water temperature of the heat network circulating water is Tb;

[0019] When the central control system determines that Ta > Tb, the geothermal water and the return water of the heat network circulating water directly exchange heat using the heat exchanger. Then the central control system controls the heat pump, valve A, valve B, valve E, valve F, and the electric heating pipeline to close; the geothermal water taken out from the medium-deep heat exchange well sequentially passes through the geothermal circulation water pump and valve D and enters the heat exchanger to exchange heat with the return water of the heat network circulating water, and the temperature decreases. The geothermal water after heat exchange sequentially passes through valve C and the main pipeline for outputting geothermal water and returns to the medium-deep heat exchange well; the return water of the heat network circulating water sequentially passes through the heat network circulating water pump and valve H and enters the heat exchanger. The return water of the heat network circulating water exchanges heat with the geothermal water until Te is increased to Tb, and then the return water of the heat network circulating water after heat exchange sequentially passes through valve G and valve I and is transported to the heat user;

[0020] When the central control system determines that Ta < Tb, the central control system controls the heat exchanger, valve C, valve D, valve G, valve H, valve I, and the electric heating pipeline to close; the geothermal water taken out from the medium-deep heat exchange well sequentially passes through the geothermal circulation water pump and valve A and enters the heat pump. The heat of the geothermal water is absorbed by the return water of the heat network circulating water, and the temperature of the geothermal water decreases and then passes through valve B and the main pipeline for outputting geothermal water and returns to the medium-deep heat exchange well; the return water of the heat network circulating water sequentially passes through the heat network circulating water pump and valve E and enters the heat pump to absorb the heat of the geothermal water. The central control system compares Tc and Tb:

[0021] If Tc reaches Tb, then valve I is opened and the electric heating pipeline is closed, and the return water of the heat network circulating water after heat absorption is increased to Tb and is transported to the heat user through valve F and valve I;

[0022] If Tc does not reach Tb, then valve I is closed and the electric heating pipeline is opened. The return water of the heat network circulating water absorbs the heat of the geothermal water and then passes through valve F, the valve J, the electric heating device until Td reaches Tb and then is transported to the heat user through valve K.

[0023] Furthermore, the electric heating device is an electrode-type hot water boiler or an electromagnetic heater.

[0024] In the above technical solution, the present invention has the following beneficial effects:

[0025] The present invention uses the information such as the geothermal circulating water pump outlet temperature Ta, the heat network circulating water supply temperature Tb, the heat network circulating water supply temperature Tc at the heat network water outlet of the heat pump, and the heat network circulating water return temperature Td at the heat network water outlet of the electric heating device, and the central control system determines the start and stop of each device and valve to achieve the control logic of ensuring the best heating temperature. When Ta>Tb, the geothermal water and the heat network circulating water return water are directly exchanged with the heat exchanger; when Ta<Tb, the heat network circulating water return water and the geothermal water are exchanged with each other through the heat pump. If the temperature of the heat network circulating water return water from the heat pump does not reach Tb, the heat network circulating water return water is continuously heated by the electric heating device, and if the temperature reaches Tb, it is delivered to the user. The problem that the geothermal circulating water temperature is greatly affected by geothermal energy and the water supply temperature of the heat network circulating water fluctuates greatly is solved. Since the requirements of the heat users for the heating temperature may not be single and constant, through the combination of various devices such as the heat pump, the heat exchanger and the electric heating device, the control system is used to timely adjust the heating plan, so that the final target water supply temperature of the heat network water can meet the user's requirements. By judging the temperature of geothermal energy, various devices are coupled and operated to achieve effective utilization of energy ladders and improve heating efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is a structural schematic diagram of a control system of the prior art;

[0028] Figure 2 A schematic diagram of the structure of the control system for the mid-deep geothermal heating temperature provided by the present invention;

[0029] Figure 3 A schematic diagram of the structure of the working condition 1 of the control system provided by the present invention;

[0030] Figure 4 A schematic diagram of the structure of the second working condition of the control system provided by the present invention;

[0031] Figure 5 A schematic diagram of the structure of working condition 3 of the control system provided by the present invention;

[0032] Figure 6A schematic diagram of the structure of the electric heating pipeline provided by the present invention;

[0033] Figure 7 This is a schematic structural diagram of the heat exchanger provided by the present invention.

[0034] Reference numerals:

[0035] Geothermal circulating water pump 1, heat pump 2, heating network circulating water pump 3, heat exchanger 4, electric heating device 5, central control system 6, valve A7, valve B8, valve C9, valve D10, valve E11, valve F12, valve G13, valve H14, valve I15, valve J16, valve K17, hot water input main pipeline 18, first geothermal water input branch pipe 19, second geothermal water input branch pipe 20, first geothermal water output branch pipe 21, second geothermal water output branch pipe 22, geothermal water output main pipeline 23, heating network water input main pipeline 30, first heating network water input branch pipe 31, second heating network water input branch pipe 32, heating network water output main pipeline 40, first heating network water output branch pipe 41, second heating network water output branch pipe 42, electric heating pipeline 50. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0037] It should be noted that the terms "above", "one end", "upper", etc. used in this article to indicate the orientation or position relationship is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description. Similar expressions are only for the purpose of explanation, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention; in addition, the terms "one part", "two parts", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0038] like Figure 2-7 A control system for medium-deep geothermal heating temperature shown in the figure includes a geothermal circulating water pump 1, a heat pump 2, a heat network circulating water pump 3, a heat exchanger 4, an electric heating device 5, a valve A7, a valve B8, a valve C9, a valve D10, a valve E11, a valve F12, a valve G13, a valve H14, a valve I15, a valve J16, a valve K17, and a temperature measurement module, which are respectively controlled by a central control system 6.

[0039] It also includes a geothermal water input main pipeline 18 whose input end is connected to the output port of the medium-deep heat exchange well, and whose output end is respectively connected to the input end of the first geothermal water input branch pipe 19 and the input end of the second geothermal water input branch pipe 20; a geothermal circulation water pump 1 is arranged on the geothermal water input main pipeline 18. The geothermal water input main pipeline 18 coming out of the medium-deep heat exchange well is divided into two branches, the first geothermal water input branch pipe 19 and the second geothermal water input branch pipe 20.

[0040] The output end of the first geothermal water input branch pipe 19 is connected to the geothermal water inlet of the heat pump 2. The ground pump 2 is used to absorb the thermal energy of the geothermal water provided by the medium-deep heat exchange well and transfer the thermal energy to the circulating water return water of the heat network. A valve A7 is provided on the first geothermal water input branch pipe 19. Valve A7 starts and stops the geothermal water from entering the heat pump 2.

[0041] The heat exchanger 4 is used for exchanging heat between geothermal water and return water of circulating water in the heat network. The output end of the second geothermal water input branch pipe 20 is connected to the geothermal water inlet of the heat exchanger 4. A valve D10 is provided on the second geothermal water input branch pipe 20. Valve D starts and stops geothermal water from entering the heat exchanger 4.

[0042] It also includes a first geothermal water output branch pipe 21 whose input end is connected to the geothermal water outlet of the heat pump 2, and a second geothermal water output branch pipe 22 whose input end is connected to the geothermal water outlet of the heat exchanger 4. The output ends of the first geothermal water output branch pipe 21 and the second geothermal water output branch pipe 22 are respectively connected to the input ends of the geothermal water output main pipeline 23, and the output end of the geothermal water output main pipeline 23 is connected to the input port of the medium-deep heat exchange well; the output ends of the first geothermal water output branch pipe 21 and the second geothermal water output branch pipe 22 are connected in parallel to the geothermal water output main pipeline 23.

[0043] A valve B8 is provided on the first geothermal water output branch pipe 21, and a valve C9 is provided on the second geothermal water output branch pipe 22; the valve B8 can open or prevent the geothermal water from flowing from the heat pump 2 into the geothermal water output main pipe 23, and start and stop the first geothermal water output branch pipe 21, and the valve C9 can open or prevent the geothermal water from flowing from the heat exchanger 4 into the geothermal water output main pipe 23, and start and stop the second geothermal water output branch pipe 22.

[0044] It also includes a heat network water input main pipeline 30 for inputting heat network circulating water return water, the output end of the heat network water input main pipeline 30 is respectively connected to the input end of the first heat network water input branch pipe 31 and the input end of the second heat network water input branch pipe 32, and the heat network water input main pipeline 30 is divided into two branches, the first heat network water input branch pipe 31 and the second heat network water input branch pipe 32; a heat network circulating water pump 3 is arranged on the heat network water input main pipeline 30.

[0045] The output end of the first heating network water input branch pipe 31 is connected to the heating network water inlet of the heat pump 2; the output end of the second heating network water input branch pipe 32 is connected to the heating network water inlet of the heat exchanger 4, and a valve E11 is arranged on the first heating network water input branch pipe 31, and the valve E11 starts and stops the first heating network water input branch pipe 31, and a valve H14 is arranged on the second heating network water input branch pipe 32, and the valve H14 starts and stops the second heating network water input branch pipe 32.

[0046] It also includes a first hot water network output branch pipe 41 whose input end is connected to the hot water network outlet of the heat pump 2, and a second hot water network output branch pipe 42 whose input end is connected to the hot water network outlet of the heat exchanger 4. The output ends of the first hot water network output branch pipe 41 and the second hot water network output branch pipe 42 are respectively connected to the input end of the hot water network output main pipeline 40, and the output ends of the first hot water network output branch pipe 41 and the second hot water network output branch pipe 42 are both merged into the hot water network output main pipeline 40. The output end of the hot water network output main pipeline 40 is for circulating water supply for the hot water network.

[0047] A valve F12 is provided on the first heating network water output branch pipe 41 , and a valve G13 is provided on the second heating network water output branch pipe 42 ; the valve F12 starts and stops the first heating network water output branch pipe 41 , and the valve G13 starts and stops the second heating network water output branch pipe 42 .

[0048] It also includes an electric heating pipeline 50 connected in parallel with the middle section of the main water output pipeline 40 of the heating network. A valve I15 is arranged on the middle section of the main water output pipeline 40 of the heating network. A valve J16, an electric heating device 5 and a valve K17 are arranged on the electric heating pipeline 50 in sequence according to the flow direction of the circulating water return of the heating network. The valve J16 and the valve K17 are respectively connected to the heating network water inlet and the heating network water outlet of the electric heating device 5. The two ends of the valve I15 are connected to the valves J16 and K17.

[0049] The temperature of the geothermal water at the output end of the geothermal water input main pipeline 18 is set to Ta, which represents the temperature of the geothermal water. The temperature of the heat network circulating water return water passing through the heat pump 2 is set to Tc, the temperature of the heat network water outlet passing through the electric heating device 5 is set to Td, and the temperature of the heat network water outlet passing through the heat exchanger 4 is set to Te. The temperatures of Ta, Tc, Td, and Te are measured by the temperature measurement module respectively and the temperature data are sent to the central control system 6. The pre-set heat network circulating water supply temperature is Tb, which is the target temperature of the heat network water delivered to the heat user. The temperature measurement module can set a temperature instrument at the node of the pipeline that needs to be measured.

[0050] When the central control system 6 determines that Ta > Tb, the geothermal water directly exchanges heat with the return water of the heat network circulating water using the heat exchanger 4. Then, the central control system 6 controls the heat pump 2, valve A7, valve B8, valve E11, valve F12, and the electric heating pipeline 50 to close. The geothermal water taken out from the medium-deep heat exchange well passes through the geothermal circulating water pump 1 and valve D10 in sequence and enters the heat exchanger 4 to exchange heat with the return water of the heat network circulating water, and then the temperature decreases. The geothermal water passes through the geothermal water that has completed heat exchange and returns to the medium-deep heat exchange well through valve C9 and the main geothermal water output pipeline 23 in sequence. The path of the geothermal water is: the main hot water input pipeline 18, the second geothermal water input branch pipe 20, the heat exchanger 4, the second geothermal water output branch pipe 22, and the main geothermal water output pipeline 23. The return water of the heat network circulating water passes through the heat network circulating water pump 3 and valve H14 in sequence and enters the heat exchanger 4. The return water of the heat network circulating water exchanges heat with the geothermal water until the temperature Te rises to Tb, and then the heat-exchanged return water of the heat network circulating water is transported to the heat user through valve G13 and valve I15 in sequence. The path of the return water of the heat network circulating water is: the main heat network water input pipeline 30, the second heat network water input branch pipe 32, the heat exchanger 4, the second heat network water output branch pipe 42, and the main heat network water output pipeline 40.

[0051] When the central control system 6 determines that Ta < Tb, the central control system 6 initially closes the heat exchanger 4, valve C9, valve D10, valve G13, valve H14, valve I15, and the electric heating pipeline 50. The geothermal water taken out from the medium-deep heat exchange well passes through the geothermal circulating water pump 1 and valve A7 in sequence and enters the heat pump 2. Then, the heat of the geothermal water is absorbed by the return water of the heat network circulating water. After the temperature of the geothermal water decreases, it returns to the medium-deep heat exchange well through valve B8 and the main geothermal water output pipeline 23. The path of the geothermal water is: the main geothermal water input pipeline 18, the first geothermal water input branch pipe 19, the heat pump 2, the first geothermal water output branch pipe 21, and the main geothermal water output pipeline 23.

[0052] The return water of the heat network circulating water passes through the heat network circulating water pump 3 and valve E11 in sequence and enters the heat pump 2 to absorb the heat of the geothermal water. The central control system 6 compares Tc and Tb:

[0053] If Tc reaches and equals Tb, then valve I15 is opened and the electric heating pipeline 50 is closed. After the temperature of the heat-absorbed return water of the heat network circulating water rises to Tb, it is transported to the heat user through valve F12 and valve I15. The path of the return water of the heat network circulating water is: the main heat network water input pipeline 30, the first heat network water input branch pipe 31, the heat pump 2, the first heat network water output branch pipe 41, and the main heat network water output pipeline 40.

[0054] If Tc does not reach Tb, then close valve I15 and open electric heating pipe 50, the heat network circulating water return water absorbs the heat of geothermal water and then passes through valve F12, valve J16, electric heating device 5, the electric heating device 5 continues to heat the heat network circulating water return water until Td reaches Tb and then passes through valve K17 to heat users. The path of the heat network circulating water return water is: the heat network water input main pipe 30, the first heat network water input branch pipe 31, the heat pump 2, the first heat network water output branch pipe 41, the upstream section of the heat network water output main pipe 40, the electric heating pipe 50 and the downstream section of the heat network water output main pipe 40.

[0055] Preferably, the electric heating device 5 is an electrode-type hot water boiler or an electromagnetic heater.

[0056] Specifically, the control system is divided into three working conditions:

[0057] Working condition 1: The outlet water temperature of the geothermal well is greater than the target water supply temperature of the heating network, that is, Ta>Tb.

[0058] Since Ta>Tb, the geothermal water and the hot water network can be directly exchanged with each other using the heat exchanger 4, thereby saving the power consumption of the heat pump 2 and achieving the purpose of saving operating costs.

[0059] Geothermal water flow loop: The hot water taken out from the medium-deep heat exchange well is pressurized by the geothermal circulation water pump 1, passes through valve D10, and passes through the heat exchanger 4. At this time, the geothermal water completes the heat exchange with the hot network water, the temperature drops, and then passes through valve C and finally returns to the medium-deep heat exchange well.

[0060] Heating network water flow loop: After the pressure of the heating network circulating water return water is increased by the heating network circulating water pump 3, it passes through the equipment valve H14 and the heat exchanger 4. At this time, the heating network water completes the heat exchange with the geothermal water, and the temperature is increased to the target water supply temperature Tb, and then passes through the valve G13, the valve I15, and finally delivered to the heat user.

[0061] The start and stop of all equipment and valves in the system are automatically controlled by the central control system. In this working condition, the temperature Ta at the outlet of geothermal circulating water pump 1 is measured to determine whether it is higher than the target water supply temperature Tb of the heat network circulating water. Then the equipment to be turned on is controlled: geothermal circulating water pump 1, heat network circulating water pump 3, heat exchanger 4, valve C9, valve D10, valve G13, valve H14, valve I15, and the equipment to be turned off is: heat pump 2, electric heating device 5, valve A7, valve B8, valve E11, valve F12, valve J16, valve K17.

[0062] Working condition 2: The outlet water temperature of the medium-deep heat exchange well is lower than the target water supply temperature of the heating network water, that is, Ta<Tb. After the heating network water is heated by the heat pump, Tc can reach Tb.

[0063] When Ta < Tb, the geothermal water and the heat network water cannot directly exchange heat using the heat exchanger 4 of the equipment. At this time, the heat pump 2 of the equipment needs to be started, which can transfer the heat in the geothermal water to the heat network water.

[0064] Geothermal water flow circuit: The hot water taken out from the medium-deep heat exchange well is pressurized by the geothermal circulation pump 1 of the equipment, passes through the valve A7 of the equipment, passes through the heat pump 2. At this time, the heat of the geothermal water is absorbed by the heat network water and the temperature decreases. Then it passes through the valve B8 of the equipment and finally returns to the medium-deep heat exchange well.

[0065] Heat network water flow circuit: The return water of the heat network circulating water is pressurized by the heat network circulating pump 3 of the equipment, passes through the valve E11 of the equipment, passes through the heat pump 2 of the equipment. At this time, the heat network water absorbs the heat of the geothermal water and the temperature is raised to the target supply water temperature Tb. Then it passes through the valve F12 of the equipment, passes through the valve I15 of the equipment, and finally is transported to the heat user.

[0066] The start and stop of all equipment in the system are automatically controlled by the central control system. In this working condition, by measuring the temperature Ta at the outlet of the geothermal circulation pump 1 of the equipment and judging that it is lower than Tb, the equipment controlled to be turned on at this time: geothermal circulation pump 1, heat pump 2, heat network circulating pump 3, valve A7, valve B8, valve E11, valve F12, valve I15, and the equipment turned off: heat exchanger 4, valve C9, valve D10, valve G13, valve H14, electric heating device 5, valve J16, valve K17. After completing the above operations, by judging the temperature Tc at the outlet of the heat network water of the heat pump 2 of the equipment and that it is greater than or equal to the target supply water temperature Tb of the heat network circulating water, the operation of the temperature control system is completed.

[0067] Working condition 3: The outlet water temperature of the geothermal well is lower than the target supply water temperature of the heat network water, that is, Ta < Tb. After the heat network water is heated by the heat pump and Tc is still lower than Tb, the outlet temperature Td of the heat network water can reach Tb after being heated by the electric heating device.

[0068] When Ta < Tb, the geothermal water and the heat network water cannot directly exchange heat using the heat exchanger 4 of the equipment. At this time, the heat pump 2 of the equipment needs to be started, which can transfer the heat in the geothermal water to the heat network water.

[0069] Geothermal water flow circuit: The hot water taken out from the medium-deep heat exchange well is pressurized by the geothermal circulation pump 1 of the equipment, passes through the valve A7 of the equipment, passes through the heat pump 2 of the equipment. At this time, the heat of the geothermal water is absorbed by the heat network water and the temperature decreases. Then it passes through the valve B8 of the equipment and finally returns to the medium-deep heat exchange well.

[0070] Heating network water flow loop: After the return water of the heating network circulating water is pressurized by the equipment heating network circulating water pump 3, it passes through the equipment valve E and the equipment heat pump 2. At this time, the heating network water absorbs the heat of the geothermal water and the temperature does not reach the target water supply temperature Tb. It then passes through the equipment valve F12, the equipment valve J16, the equipment electric heating device, the equipment valve K17, and is finally delivered to the heat user.

[0071] All equipment in the system are automatically started and stopped by the central control system 6. In this working condition, the temperature Ta at the outlet of the geothermal circulating water pump 1 is measured and judged to be lower than Tb. At this time, the equipment to be opened is: geothermal circulating water pump 1, heat pump 2, heat network circulating water pump 3, valve A7, valve B8, valve E11, valve F12, valve I15, and the equipment to be closed is: heat exchanger 4, electric heating device 5, valve C9, valve D10, valve G13, valve H14, valve J16, valve K16. After completing the above operation, the outlet temperature Tc of the heat network water of the heat pump 2 is judged to be lower than Tb. At this time, the electric heating device 5, valve J16, valve K17 of the equipment are opened, and the valve I15 of the equipment is closed. Finally, the outlet temperature Td of the heat network water of the equipment 5 reaches the target water supply temperature Tb of the heat network circulating water, and the operation of the system is completed. The final state of this operating system is: open equipment: geothermal circulation water pump 1, heat pump 2, heat network circulation water pump 3, electric heating device 5, valve A7, valve B8, valve E11, valve F12, valve J16, valve K17; closed equipment: heat exchanger 4, valve C9, valve D10, valve G13, valve H14, valve I15.

[0072] This control system is suitable for various geothermal heating scenarios, and does not require cogeneration units, heating boilers, etc. as centralized heat sources. The control system is coupled by absorption heat pumps, water-to-water heat exchangers, electric heating devices, central control systems and other equipment, using geothermal energy to achieve effective energy ladder utilization and improve heating efficiency.

[0073] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A control system for medium-deep geothermal heating temperature, characterized in that: It comprises a geothermal circulating water pump (1), a heat pump (2), a heat network circulating water pump (3), a heat exchanger (4), an electric heating device (5), a valve A (7), a valve B (8), a valve C (9), a valve D (10), a valve E (11), a valve F (12), a valve G (13), a valve H (14), a valve I (15), a valve J (16), a valve K (17), and a temperature measurement module, which are respectively controlled by a central control system (6); It also comprises a geothermal water input main pipeline (18) whose input end is connected to the output port of the medium-deep heat exchange well, and whose output end is respectively connected to the input end of the first geothermal water input branch pipe (19) and the input end of the second geothermal water input branch pipe (20); a geothermal circulation water pump (1) is arranged on the geothermal water input main pipeline (18); The output end of the first geothermal water input branch pipe (19) is connected to the geothermal water inlet of the heat pump (2). The ground pump (2) is used to absorb the heat energy of the geothermal water provided by the medium-deep heat exchange well and transfer the heat energy to the circulating water return water of the heat network. A valve A (7) is provided on the first geothermal water input branch pipe (19); The heat exchanger (4) is used for exchanging heat between geothermal water and return water of the heat network circulation water, the output end of the second geothermal water input branch pipe (20) is connected to the geothermal water inlet of the heat exchanger (4), and the valve D (10) is provided on the second geothermal water input branch pipe (20); It also comprises a first geothermal water output branch pipe (21) whose input end is connected to the geothermal water outlet of the heat pump (2), and a second geothermal water output branch pipe (22) whose input end is connected to the geothermal water outlet of the heat exchanger (4), the output end of the first geothermal water output branch pipe (21) and the output end of the second geothermal water output branch pipe (22) are respectively connected to the input end of the geothermal water output main pipe (23), and the output end of the geothermal water output main pipe (23) is connected to the input port of the medium-deep heat exchange well; The valve B (8) is provided on the first geothermal water output branch pipe (21), and the valve C (9) is provided on the second geothermal water output branch pipe (22); It also includes a heating network water input main pipeline (30) for inputting circulating water return from the heating network, wherein the output end of the heating network water input main pipeline (30) is respectively connected to the input end of the first heating network water input branch pipe (31) and the input end of the second heating network water input branch pipe (32); a heating network circulating water pump (3) is arranged on the heating network water input main pipeline (30); The output end of the first heating network water input branch pipe (31) is connected to the heating network water inlet of the heat pump (2); the output end of the second heating network water input branch pipe (32) is connected to the heating network water inlet of the heat exchanger (4), the valve E (11) is provided on the first heating network water input branch pipe (31), and the valve H (14) is provided on the second heating network water input branch pipe (32); It also comprises a first hot water network output branch pipe (41) whose input end is connected to the hot water network outlet of the heat pump (2), and a second hot water network output branch pipe (42) whose input end is connected to the hot water network outlet of the heat exchanger (4), the output end of the first hot water network output branch pipe (41) and the output end of the second hot water network output branch pipe (42) are respectively connected to the input end of the hot water network output main pipe (40), and the output end of the hot water network output main pipe (40) is used for circulating water supply for the hot water network; The valve F (12) is provided on the first heating network water output branch pipe (41), and the valve G (13) is provided on the second heating network water output branch pipe (42); It also includes an electric heating pipeline (50) connected in parallel with the middle section of the heating network water output main pipeline (40), the valve I (15) is arranged on the middle section of the heating network water output main pipeline (40), and the valve J (16), the electric heating device (5) and the valve K (17) are arranged on the electric heating pipeline (50) in sequence according to the return flow direction of the heating network circulating water, and the valve J (16) and the valve K (17) are respectively connected to the heating network water inlet and the heating network water outlet of the electric heating device (5); The temperature of the geothermal water at the output end of the geothermal water input main pipeline (18) is set to Ta, the temperature of the heat network water outlet of the heat pump (2) is set to Tc, the temperature of the heat network water outlet of the electric heating device (5) is set to Td, and the temperature of the heat network water outlet of the heat exchanger (4) is set to Te. The temperatures of Ta, Tc, Td, and Te are measured by the temperature measurement module respectively and the temperature data are sent to the central control system (6). The pre-set heat network circulating water supply temperature is Tb; When the central control system (6) determines that Ta>Tb, the geothermal water and the heat network circulating water return water are directly exchanged with each other using the heat exchanger (4), and the central control system (6) controls the heat pump (2), valve A (7), valve B (8), valve E (11), valve F (12) and electric heating pipe (50) to be closed; the geothermal water taken out of the medium-deep heat exchange well passes through the geothermal circulating water pump (1) and valve D (10) in sequence to enter the heat exchanger (4) and exchange heat with the heat network circulating water return water, and the temperature is reduced. The geothermal water that has completed the heat exchange is returned to the medium-deep heat exchange well in sequence through valve C (9) and the geothermal water output main pipe (23); the heat network circulating water return water passes through the heat network circulating water pump (3) and valve H (14) in sequence to enter the heat exchanger (4), and the heat network circulating water return water exchanges heat with the geothermal water until Te is increased to Tb. The heat network circulating water return water that has completed the heat exchange is transported to the heat user through valve G (13) and valve I (15) in sequence; When the central control system (6) determines that Ta < Tb, the central control system (6) controls the initial closing of the heat exchanger (4), valve C (9), valve D (10), valve G (13), valve H (14), valve I (15), and the electric heating pipeline (50); after the geothermal water taken out from the medium-deep heat exchange well passes through the geothermal circulation water pump (1) and valve A (7) and enters the heat pump (2) in sequence, the heat of the geothermal water is absorbed by the return water of the heat network circulation water, and after the temperature of the geothermal water decreases, it returns to the medium-deep heat exchange well through valve B (8) and the main geothermal water output pipeline (23); the return water of the heat network circulation water passes through the heat network circulation water pump (3) and valve E (11) and enters the heat pump (2) in sequence, and then absorbs the heat of the geothermal water. The central control system (6) compares Tc and Tb: If Tc reaches Tb, open valve I (15) and close the electric heating pipeline (50), and the temperature of the heat network circulation water return after heat absorption is raised to Tb and is transported to the heat user through valve F (12) and valve I (15); If Tc does not reach Tb, close valve I (15) and open the electric heating pipeline (50). After the heat network circulation water return absorbs the heat of the geothermal water, it passes through valve F (12), valve J (16), and the electric heating device (5) until Td reaches Tb and then is transported to the heat user through valve K (17).

2. A control system for medium-deep geothermal heating temperature according to claim 1, characterized in that: The electric heating device (5) is an electrode type hot water boiler or an electromagnetic heater.

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