An industrial steam production system coupled with low-medium temperature geothermal and high-temperature heat pump

Abstract

The present application relates to the technical field of industrial steam preparation, in particular to an industrial steam preparation system coupled with medium-low temperature geothermal and high temperature heat pump, comprising an ultrahigh temperature and high efficiency centrifugal heat pump unit, an evaporation side circulating pump, a two-stage water vapor compression system, a cyclone sand remover, a water treatment system, a cooling system and a sealing system, the cyclone sand remover is arranged on the inlet pipeline of medium-low temperature geothermal water, used for sand removal treatment of the medium-low temperature geothermal water, and the medium-low temperature geothermal water treated by the cyclone sand remover is divided into a first geothermal heat exchange branch and a second geothermal heat exchange branch. The industrial steam preparation system coupled with medium-low temperature geothermal and high temperature heat pump realizes cascade utilization and low-carbon heating of geothermal resources, and the coupling of medium-low temperature geothermal preheating and steam production by the ultrahigh temperature and high efficiency centrifugal heat pump unit can construct a clean and efficient industrial steam preparation system, realizes deep utilization of geothermal energy and replacement of fossil fuels, has no direct combustion emission, and only consumes electric power.

Description

Technical Field

[0001] This invention relates to the field of industrial steam preparation technology, specifically to an industrial steam preparation system that couples a medium-low temperature geothermal system with a high-temperature heat pump. Background Technology

[0002] Industrial steam is the core heat source for many industries such as chemical, food, textile, and pharmaceutical. Currently, most industrial steam preparation systems on the market use gas-fired boilers, electric boilers, or other fuel boilers to produce steam. Although these industrial steam preparation systems can meet the industrial steam supply demand, they generally have problems such as high primary energy consumption, high operating costs, high carbon emissions, and strong dependence on fuel supply. Medium and low temperature geothermal resources have advantages such as strong continuity, good stability and less impact from external climate. They can be used as low-grade heat sources for industrial heating systems. However, the temperature of medium and low temperature geothermal water is usually difficult to directly reach the temperature and pressure conditions required for industrial steam production. If only medium and low temperature geothermal water is used for direct heat exchange, only hot water or heat medium at a lower temperature can usually be obtained, and it is difficult to directly output high-temperature steam to the industrial steam pipeline network. High-temperature heat pumps can upgrade low-grade heat energy to higher-grade heat energy for the production of hot water or low-pressure steam. However, if the temperature of the steam makeup water is low, the heat pump needs to bear a large heating load, which leads to an increase in the heat pump input power and a decrease in system operating efficiency. At the same time, the steam pressure and temperature generated by the high-temperature heat pump alone are usually still difficult to directly meet the usage requirements of industrial steam pipeline networks, and further heating and pressurization are required.

[0003] Therefore, we propose an industrial steam preparation system that couples medium- and low-temperature geothermal energy with a high-temperature heat pump to address the problems mentioned above. Summary of the Invention

[0004] The purpose of this invention is to provide an industrial steam preparation system that couples medium- and low-temperature geothermal energy with a high-temperature heat pump, in order to solve the problems mentioned in the background art, such as high operating costs, high carbon emissions, and high steam production load of existing industrial steam preparation systems.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an industrial steam preparation system for medium and low temperature geothermal coupling high temperature heat pump, comprising an ultra-high temperature high efficiency centrifugal heat pump unit, an evaporator-side circulation pump, a two-stage water vapor compression system, a cyclone separator, a water treatment system, a cooling system, and a sealing system; The cyclone separator is installed on the inlet pipe of the medium-low temperature geothermal water and is used to remove sand from the medium-low temperature geothermal water. The medium-low temperature geothermal water after being treated by the cyclone separator is divided into a first geothermal heat exchange branch and a second geothermal heat exchange branch. The first geothermal heat exchange branch is connected to the primary side of the first plate heat exchanger. A buffer water tank is connected between the secondary side of the first plate heat exchanger and the inlet of the evaporation side circulation pump. The outlet end of the evaporation side circulation pump is connected to the evaporator in the ultra-high temperature high efficiency centrifugal heat pump unit. The second geothermal heat exchange branch is connected to the primary side of the second plate heat exchanger, so that the medium and low temperature geothermal water can be used simultaneously for heat extraction on the evaporation side of the ultra-high temperature high efficiency centrifugal heat pump unit and for steam water preheating. The secondary side of the second plate heat exchanger is located between the system water supply pump and the steam water inlet of the ultra-high temperature high efficiency centrifugal heat pump unit. The low-pressure steam outlet of the ultra-high temperature high-efficiency centrifugal heat pump unit is connected to the inlet of the two-stage water vapor compression system.

[0006] Preferably, the medium-low temperature geothermal water supplies heat to the evaporator-side circulating water of the ultra-high temperature high-efficiency centrifugal heat pump unit through a first plate heat exchanger. This heat exchange is used between the medium-low temperature geothermal water and the evaporator-side circulating water of the ultra-high temperature high-efficiency centrifugal heat pump unit, ensuring a stable low-grade heat source for the evaporator side within the ultra-high temperature high-efficiency centrifugal heat pump unit. Three first plate heat exchangers are provided, two of which are in operation and one is in standby. Each exchanger has a heat exchange capacity of 1.4 MW, a primary side temperature of 62 / 54℃, a secondary side temperature of 52 / 60℃, and a heat exchange area of ​​291 m². 2 It adopts a dual-use, one-standby configuration, which can ensure that it maintains a speed of 300m during year-round operation or full-load operation. 3 Heat exchange flow rate per hour; The medium-low temperature geothermal return water after heat exchange on the primary side of the first plate heat exchanger and the medium-low temperature geothermal return water after heat exchange on the primary side of the second plate heat exchanger are merged into the geothermal side return water pipeline and reinjected into the reinjection well. The evaporation side circulating water of the secondary side of the first plate heat exchanger returns to the secondary side of the first plate heat exchanger for heat exchange through the evaporator side return water pipeline of the ultra-high temperature high efficiency centrifugal heat pump unit. The medium-low temperature geothermal water and the evaporation side circulating water are not directly mixed.

[0007] Preferably, butterfly valves are installed on the first geothermal heat exchange branch and the second geothermal heat exchange branch respectively, and thermometers are installed on the evaporator side water inlet pipe and the steam water inlet pipe of the ultra-high temperature high efficiency centrifugal heat pump unit respectively. The second plate heat exchanger is used to preheat the steam makeup water to a preset makeup water temperature before sending it into the condenser of the ultra-high temperature high efficiency centrifugal heat pump unit. This reduces the temperature rise load required for the ultra-high temperature high efficiency centrifugal heat pump unit to heat the steam makeup water into steam. The preheated steam makeup water enters the ultra-high temperature high efficiency centrifugal heat pump unit to form low-pressure steam. The heat exchanger has a heat exchange capacity of 0.52MW, a primary side temperature of 62 / 48℃, a secondary side temperature of 5 / 50℃, and a heat exchange area of ​​14m². 2 .

[0008] Preferably, the two-stage steam compression system includes a centrifugal steam compressor unit and a screw steam compressor unit. The screw steam compressor unit 6.2 is provided with a start-up preheating branch. The start-up preheating branch is used to introduce external high-temperature steam or heat source into the screw steam compressor unit 6.2 during the start-up stage of the industrial steam preparation system, so that the screw steam compressor unit 6.2 starts up after reaching the preset start-up temperature. The low-pressure steam outlet of the ultra-high temperature high-efficiency centrifugal heat pump unit is connected to the inlet of the centrifugal steam compressor unit, and the outlet of the centrifugal steam compressor unit is connected to the inlet of the screw steam compressor unit. The outlet of the screw steam compressor unit is used to connect to the industrial steam network. The low-pressure steam is compressed, heated and pressurized by the centrifugal steam compressor unit and the screw steam compressor unit in sequence and then output to the industrial steam network to supply high-temperature industrial steam to the industrial steam network. The low-pressure steam outlet, centrifugal steam compressor unit, and screw steam compressor unit of the ultra-high temperature high-efficiency centrifugal heat pump unit are connected in series along the steam flow direction. The centrifugal steam compressor unit is used to compress the low-pressure steam output by the ultra-high temperature high-efficiency centrifugal heat pump unit to an intermediate steam parameter suitable for entering the screw steam compressor unit. The screw steam compressor unit is used to further compress the steam at the intermediate steam parameter to the steam parameter required by the industrial steam pipeline network. This allows the low-pressure steam generated by the ultra-high temperature high-efficiency centrifugal heat pump unit to undergo a first-stage compression by the centrifugal steam compressor unit and then a second-stage compression by the screw steam compressor unit, forming a two-stage steam compression path. The centrifugal steam compressor unit has an inlet steam temperature of 103.6℃ and a pressure of 0.115MPa(a), an outlet steam temperature of 124.7℃ and a pressure of 0.23MPa(a), an inlet steam flow rate of 5.0t / h, and an outlet steam flow rate of 5.213t / h. Both the centrifugal steam compressor unit and the screw steam compressor unit can be equipped with a frequency converter cabinet and a PLC to achieve speed regulation and operation monitoring. The screw-type steam compressor unit has an inlet steam temperature of 124.4℃ and a pressure of 0.225MPa(a), an outlet steam temperature of 173℃ and a pressure of 0.85MPa(a), an inlet steam flow rate of 5.213t / h, and an outlet steam flow rate of 6.0t / h. The screw-type steam compressor unit is equipped with a buffer tank.

[0009] Preferably, the evaporator-side circulation pump drives the evaporator-side circulating water of the ultra-high temperature high-efficiency centrifugal heat pump unit to circulate between the first plate heat exchanger and the ultra-high temperature high-efficiency centrifugal heat pump unit. The evaporator-side circulation pump ensures that heat from the medium-low temperature geothermal water can be stably transferred to the evaporator side of the ultra-high temperature high-efficiency centrifugal heat pump unit. The evaporator-side circulation pump can employ two variable frequency pumps, one in operation and one in standby, with a design flow rate of 320 m³ / h. 3 With a pump head of 25m and a power of 30kW, the variable frequency control helps to adjust the circulation flow rate according to the load of the evaporator-side circulating pump, avoiding low-load or over-flow operation.

[0010] Preferably, the cooling system includes a closed-loop cooling tower, and the outlet of the closed-loop cooling tower is connected to the cooling water inlet of an ultra-high temperature high-efficiency centrifugal heat pump unit, a centrifugal steam compressor unit, and a screw steam compressor unit respectively via a cooling system circulation pump. The cooling water outlet of the ultra-high temperature high-efficiency centrifugal heat pump unit, the centrifugal steam compressor unit, and the screw steam compressor unit is connected to the return water end of the closed-loop cooling tower. The circulation temperature of the closed-loop cooling tower is 35 / 30℃, and the cooling water flow rate is 80m³ / h. 3 / h; The cooling system circulation pump drives cooling water to circulate between the closed cooling tower, the ultra-high temperature high efficiency centrifugal heat pump unit, the centrifugal steam compressor unit, and the screw steam compressor unit, forming a closed cooling cycle to remove the waste heat from the operation of the ultra-high temperature high efficiency centrifugal heat pump unit, the centrifugal steam compressor unit, and the screw steam compressor unit, ensuring that the operating temperature of the ultra-high temperature high efficiency centrifugal heat pump unit, the centrifugal steam compressor unit, and the screw steam compressor unit is within the allowable range.

[0011] Preferably, the sealing system includes an air compressor system, and the air compressor system is connected to the sealing parts of the centrifugal steam compressor unit and the screw steam compressor unit, for providing a sealing or make-up air source for the centrifugal steam compressor unit and the screw steam compressor unit, preventing steam leakage, and improving the operational stability of the centrifugal steam compressor unit and the screw steam compressor unit. The air compressor system consists of two air compressors, one of which is in operation and the other is on standby to ensure the supply of sealing gas to the centrifugal steam compressor unit and the screw steam compressor unit. The exhaust pressure of the air compressor system is 4-6 bar, and the flow rate is 220 Nm³. 3 / h, with a power of 30kW, the air compressor system is used to establish sealing gas pressure before the centrifugal steam compressor unit and screw steam compressor unit are started, and to allow the corresponding centrifugal steam compressor unit and screw steam compressor unit to start after the sealing gas pressure reaches the preset pressure.

[0012] Preferably, the buffer water tank is connected to the water supply pipeline on the system water supply pump and is used to supply water to the steam preparation system. The buffer water tank is used to supply water to the steam preparation system when the steam preparation system is initially filled with water, water is drained from the pipeline, or the pressure of the evaporation side circulating water circuit is lower than the preset pressure, and to stop supplying water when the pressure of the evaporation side circulating water circuit or the liquid level of the buffer water tank reaches the preset value.

[0013] Preferably, a bypass pipeline is installed on the steam makeup water inlet pipe of the ultra-high temperature high efficiency centrifugal heat pump unit. This bypass pipeline allows the system makeup water pump to bypass the second plate heat exchanger and directly deliver steam makeup water to the ultra-high temperature high efficiency centrifugal heat pump unit during maintenance or malfunction of the second plate heat exchanger. The system makeup water pump can employ two variable frequency pumps, one in operation and one on standby, with a design flow rate of 10 m³ / h. 3 / h, head is 40m, power is 4kW.

[0014] Preferably, the water treatment system includes a water treatment unit and a soft water tank, and the tap water pipe at the inlet of the water treatment unit is connected to the external water supply pipe, and the drain pipe of the water treatment unit is connected to the inlet pipe of the soft water tank. The soft water tank has two outlet pipes, one of which is connected to the inlet of the system water supply pump, and the other of which is connected to the inlet of the cooling system water supply pump. A sampling port is connected to the drain pipe of the water treatment unit. The soft water tank is also equipped with a bypass pipeline on its outlet pipe. The bypass pipeline is used to connect with an external temporary water source or high-level water tank when the system water supply pump is under maintenance or malfunctioning, so that the steam water supply bypasses the system water supply pump and enters the second plate heat exchanger and the ultra-high temperature high efficiency centrifugal heat pump unit. The other end of the bypass pipe installed on the outlet end of the system's water supply pump and the outlet pipe of the soft water tank is connected to the steam water supply inlet pipe of the ultra-high temperature high efficiency centrifugal heat pump unit. The closed-loop cooling tower, cooling system circulation pump, and cooling system makeup water pump constitute a cooling loop, used to remove waste heat generated during the operation of the ultra-high temperature high-efficiency centrifugal heat pump unit, centrifugal steam compressor unit, and screw steam compressor unit, facilitating cooling operations. The drain end of the cooling system makeup water pump is connected to the outlet end of the closed-loop cooling tower. The cooling system makeup water pump is used to replenish the lost water volume in the cooling loop, ensuring stable operation of the cooling operation. At the same time, the pipeline between the system makeup water pump and the steam makeup water inlet of the ultra-high temperature high-efficiency centrifugal heat pump unit can be used by a hydraulic press to deliver part of the steam makeup water to the centrifugal steam compressor unit and the screw steam compressor unit. This ensures that the portion of the steam output of the centrifugal steam compressor unit that is greater than the steam input is formed by the evaporation of the steam makeup water entering the centrifugal steam compressor unit; similarly, the portion of the steam output of the screw steam compressor unit that is greater than the steam input is formed by the evaporation of the steam makeup water entering the screw steam compressor unit.

[0015] Compared with existing technologies, the beneficial effects of this invention are as follows: This industrial steam preparation system, which couples medium- and low-temperature geothermal energy with a high-temperature heat pump, realizes the cascade utilization of geothermal resources and low-carbon heating. The coupling of medium- and low-temperature geothermal preheating and ultra-high-temperature high-efficiency centrifugal heat pump unit steam generation can construct a clean and efficient industrial steam preparation system, realizing the deep utilization of geothermal energy and the substitution of fossil fuels. There are no direct combustion emissions; it only consumes electricity and has no direct combustion emissions, thus contributing to industrial decarbonization. The specific details are as follows: (1) Using medium and low temperature geothermal water for evaporation side heating and steam makeup water preheating of ultra-high temperature high efficiency centrifugal heat pump unit respectively improves the utilization rate of medium and low temperature geothermal resources. By preheating medium and low temperature geothermal water, the temperature rise load before steam makeup water enters ultra-high temperature high efficiency centrifugal heat pump unit can be reduced, the steam production efficiency of ultra-high temperature high efficiency centrifugal heat pump unit can be improved, and the operating energy efficiency of industrial steam preparation system can be improved. Low pressure steam is generated by ultra-high temperature high efficiency centrifugal heat pump unit, and then staged compression is carried out by centrifugal steam compressor unit and screw steam compressor unit to finally produce high temperature industrial steam that meets the needs of industrial pipeline network, reducing operating costs and reducing dependence on fuel supply. (2) Geothermal resources have advantages such as good stability, strong continuity and little impact from climate. In particular, medium and low temperature geothermal water can provide a stable heat source for industrial heating systems. By utilizing medium and low temperature geothermal resources, the heat energy quality can be improved through ultra-high temperature high efficiency centrifugal heat pump units, thereby enabling the industrial steam preparation system to achieve high efficiency and energy saving. This system mainly solves the problem that medium and low temperature geothermal heat is difficult to directly generate high temperature industrial steam, realizing the cascade utilization of geothermal resources and low-carbon heating. The coupling of medium and low temperature geothermal preheating and ultra-high temperature high efficiency centrifugal heat pump unit steam generation can construct a clean and efficient industrial steam preparation system. There is no direct emission from on-site combustion during operation. It mainly consumes electricity. When renewable electricity is used, near-zero carbon heating can be achieved, which helps industrial decarbonization. (3) Instead of simply using medium-low temperature geothermal water as a single heat source, the medium-low temperature geothermal water is distributed to the first plate heat exchanger and the second plate heat exchanger. The first plate heat exchanger supplies heat to the evaporation side circulating water of the ultra-high temperature high efficiency centrifugal heat pump unit, and the second plate heat exchanger preheats the steam makeup water. This achieves the graded utilization of geothermal energy. On the one hand, it ensures the stability of the evaporation side heat source of the ultra-high temperature high efficiency centrifugal heat pump unit, and on the other hand, it increases the initial temperature of the steam makeup water before it enters the ultra-high temperature high efficiency centrifugal heat pump unit. The medium-low temperature geothermal water provides dual-path heating to the evaporation side and steam makeup water of the ultra-high temperature high efficiency centrifugal heat pump unit, so that geothermal heat can be utilized at multiple temperature levels. (4) By coordinating the configuration of closed cooling tower, cooling system circulating pump, air compressor system, buffer water tank, system water supply pump and cooling system water supply pump, the stability of the industrial steam preparation system for continuous operation throughout the year is improved, and part of the steam load of traditional gas boilers is reduced or replaced, so as to achieve energy saving and consumption reduction in the industrial steam preparation process. (5) The ultra-high temperature high efficiency centrifugal heat pump unit is coupled in series with the centrifugal steam compressor unit and the screw steam compressor unit. The low-pressure steam of 105℃ generated by the ultra-high temperature high efficiency centrifugal heat pump unit is sequentially sent to the centrifugal steam compressor unit and the screw steam compressor unit. The centrifugal steam compressor unit is suitable for the primary pressure boosting of low-pressure steam, and the screw steam compressor unit is suitable for further pressure boosting to the industrial pipeline parameters. The two-stage compression enables the steam output by the ultra-high temperature high efficiency centrifugal heat pump unit to be gradually increased to 173℃ and 0.85MPa(a), thereby improving the adaptability of the industrial steam preparation system to industrial steam application scenarios. (6) The first plate heat exchanger is configured with three units, with two first plate heat exchangers in operation and one first plate heat exchanger in standby. After adopting the parallel structure of two in operation and one in standby, when the industrial steam preparation system is running at full load, the two first plate heat exchangers in operation can jointly bear the heat exchange load on the evaporation side of the ultra-high temperature high efficiency centrifugal heat pump unit. When running at full load or throughout the year, the evaporation side circulation flow and heat exchange of the ultra-high temperature high efficiency centrifugal heat pump unit can be kept stable. When one of the first plate heat exchangers is under maintenance or its performance deteriorates, the standby first plate heat exchanger can be put into operation to ensure the continuity of heat supply on the evaporation side of the ultra-high temperature high efficiency centrifugal heat pump unit. The evaporation side circulation pump, system water supply pump, air compressor system, cooling system circulation pump and cooling system water supply pump are all configured with one in operation and one in standby, which can improve the maintenance and fault switching capabilities of the industrial steam preparation system. (7) By using a closed cooling tower, a cooling system circulation pump, an air compressor system and a cooling system water supply pump, the problems of heat dissipation and sealing during the compression process of centrifugal steam compressor units and screw steam compressor units are solved, ensuring the reliable operation of centrifugal steam compressor units and screw steam compressor units, and enabling the industrial steam preparation system to have continuous industrial operation conditions. (8) By installing a cyclone sand remover in the inlet pipe of medium and low temperature geothermal water, sand particles and solid impurities can be removed before the geothermal water enters the first plate heat exchanger and the second plate heat exchanger, thereby reducing the risk of wear and blockage of the first plate heat exchanger and the second plate heat exchanger and improving the reliability of continuous system operation. Attached Figure Description

[0016] Figure 1 This is a process flow diagram of the overall industrial steam preparation system of the present invention; Figure 2 This is a process flow diagram showing the connection between the cyclone sand separator and the first plate heat exchanger of the present invention. Figure 3 This is a process flow diagram showing the connection between the ultra-high temperature high efficiency centrifugal heat pump unit and the centrifugal steam compressor unit of the present invention. Figure 4 This is a process flow diagram of the two-stage water vapor compression system of the present invention; Figure 5 This is a process flow diagram of the screw steam compressor unit of the present invention; Figure 6 This is a process flow diagram of the water treatment system of the present invention; Figure 7 For the present invention Figure 1 The symbol illustration table is shown in the table.

[0017] In the diagram: 1. Ultra-high temperature high-efficiency centrifugal heat pump unit; 2. Evaporator-side circulation pump; 3. System makeup water pump; 4. Closed-loop cooling tower; 5. Air compressor system; 6. Two-stage steam compression system; 6.1. Centrifugal steam compressor unit; 6.2. Screw steam compressor unit; 7. First plate heat exchanger; 8. Second plate heat exchanger; 9. Buffer water tank; 10. Cooling system circulation pump; 11. Cooling system makeup water pump; 12. Cyclone sand separator. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figures 1-7 The present invention provides the following technical solution: Example 1: The industrial steam production system of medium-low temperature geothermal coupled with a high-temperature heat pump in this example realizes the cascade utilization of geothermal resources and low-carbon heating. The coupling of medium-low temperature geothermal preheating and ultra-high temperature high-efficiency centrifugal heat pump unit 1 can construct a clean and efficient industrial steam production system, realizing the deep utilization of geothermal energy and the substitution of fossil fuels. There are no direct combustion emissions, only electricity consumption, and no direct combustion emissions, which helps industrial decarbonization. For the specific structure, please refer to the appendix. Figures 1-4 and appendix Figures 5-7 As shown, the system includes an ultra-high temperature high-efficiency centrifugal heat pump unit 1, an evaporator-side circulation pump 2, a two-stage water vapor compression system 6, a cyclone separator 12, a water treatment system, a cooling system, and a sealing system. The cyclone separator 12 is installed on the inlet pipe of the medium-low temperature geothermal water and is used to remove sand from the medium-low temperature geothermal water. The medium-low temperature geothermal water treated by the cyclone separator 12 is divided into a first geothermal heat exchange branch and a second geothermal heat exchange branch. The first geothermal heat exchange branch is connected to the primary side of the first plate heat exchanger 7. A buffer water tank 9 is connected between the secondary side of the first plate heat exchanger 7 and the inlet of the evaporator-side circulation pump 2. The outlet end of the evaporator-side circulation pump 2 is connected to the evaporator inside the ultra-high temperature high-efficiency centrifugal heat pump unit 1.

[0020] The second geothermal heat exchange branch is connected to the primary side of the second plate heat exchanger 8, so that the medium and low temperature geothermal water can be used simultaneously for heat extraction on the evaporation side of the ultra-high temperature high efficiency centrifugal heat pump unit 1 and for steam makeup water preheating. The secondary side of the second plate heat exchanger 8 is set between the system makeup water pump 3 and the steam makeup water inlet of the ultra-high temperature high efficiency centrifugal heat pump unit 1. The low-pressure steam outlet of the ultra-high temperature high efficiency centrifugal heat pump unit 1 is connected to the inlet of the two-stage water vapor compression system 6.

[0021] Medium- and low-temperature geothermal water supplies heat to the evaporator-side circulating water of the ultra-high temperature and high-efficiency centrifugal heat pump unit 1 through the first plate heat exchanger 7. This heat exchange is used between the medium- and low-temperature geothermal water and the evaporator-side circulating water of the ultra-high temperature and high-efficiency centrifugal heat pump unit 1, ensuring a stable low-grade heat source for the evaporator side within the unit. Three first plate heat exchangers 7 are installed, two of which are in operation and one is on standby. Each exchanger has a heat exchange capacity of 1.4 MW, a primary side temperature of 62 / 54℃, a secondary side temperature of 52 / 60℃, and a heat exchange area of ​​291 m². 2 It adopts a dual-use, one-standby configuration, which can ensure that it maintains a speed of 300m during year-round operation or full-load operation. 3 / h heat exchange flow rate.

[0022] The ultra-high temperature high-efficiency centrifugal heat pump unit 1 has a heating capacity of 3400kW, a coefficient of performance (COP) of 4.55, and circulating water side design parameters of 60 / 52℃ and a flow rate of 300m³ / h. 3The outlet steam flow rate is 5t / h, the steam temperature is 105℃, and the steam pressure is 0.12MPa(a). The ultra-high temperature and high efficiency centrifugal heat pump unit 1 contains a heat pump control cabinet. The medium and low temperature geothermal return water after heat exchange on the primary side of the first plate heat exchanger 7 and the medium and low temperature geothermal return water after heat exchange on the primary side of the second plate heat exchanger 8 are merged into the geothermal side return water pipeline and reinjected to the reinjection well. The evaporation side circulating water on the secondary side of the first plate heat exchanger 7 returns to the secondary side of the first plate heat exchanger 7 for heat exchange through the evaporator side return water pipeline of the ultra-high temperature and high efficiency centrifugal heat pump unit 1. The medium and low temperature geothermal water and the evaporation side circulating water are not directly mixed.

[0023] The formula for the coefficient of performance (COP) of the ultra-high temperature high-efficiency centrifugal heat pump unit 1 is as follows: ,in Heat output is measured in kW. This refers to the compressor input power, measured in kW. The specific power output can be determined based on the operating conditions. Calculated values, taking rated operating conditions as an example, when For 3400kW, When the value is 4.55, the compressor input power W is approximately 747kW, which matches the evaporator-side heat extraction capacity of approximately 2.8MW when the two first plate heat exchangers 7 are running.

[0024] The second plate heat exchanger 8 is used to preheat the steam makeup water to a preset makeup water temperature before sending it into the condenser inside the ultra-high temperature high efficiency centrifugal heat pump unit 1. This reduces the temperature rise load required for the ultra-high temperature high efficiency centrifugal heat pump unit 1 to heat the steam makeup water into steam. The preheated steam makeup water enters the ultra-high temperature high efficiency centrifugal heat pump unit 1 to form low-pressure steam. The second plate heat exchanger 8 has a heat exchange capacity of 0.52MW, a primary side temperature of 62 / 48℃, a secondary side temperature of 5 / 50℃, and a heat exchange area of ​​14m². 2 .

[0025] Evaporation-side circulation pump 2 drives the evaporation-side circulating water of the ultra-high temperature high-efficiency centrifugal heat pump unit 1 to circulate between the first plate heat exchanger 7 and the ultra-high temperature high-efficiency centrifugal heat pump unit 1. Evaporation-side circulation pump 2 ensures that heat from the medium-low temperature geothermal water can be stably transferred to the evaporation side of the ultra-high temperature high-efficiency centrifugal heat pump unit 1. Evaporation-side circulation pump 2 can employ two variable frequency pumps, one in operation and one in standby, with a design flow rate of 320 m³ / h. 3 / h, with a head of 25m and a power of 30kW, the variable frequency control is beneficial to adjust the circulation flow according to the load of the evaporator side circulation pump 2, and avoid low load or overflow operation.

[0026] A bypass pipeline is installed on the steam makeup water inlet pipe of the ultra-high temperature high efficiency centrifugal heat pump unit 1. This bypass pipeline allows the system makeup water pump 3 to bypass the second plate heat exchanger 8 and directly deliver steam makeup water to the ultra-high temperature high efficiency centrifugal heat pump unit 1 during maintenance or malfunction of the second plate heat exchanger 8. The system makeup water pump 3 can be composed of two variable frequency pumps, one in operation and one on standby, with a design flow rate of 10 m³ / h. 3 / h, head is 40m, power is 4kW.

[0027] The two-stage steam compression system 6 includes a centrifugal steam compressor unit 6.1 and a screw steam compressor unit 6.2. The screw steam compressor unit 6.2 is equipped with a start-up preheating branch, which is used to introduce external high-temperature steam or heat source into the screw steam compressor unit 6.2 during the start-up phase of the industrial steam preparation system, so that the screw steam compressor unit 6.2 reaches the preset start-up temperature and starts up.

[0028] During the startup phase of the industrial steam preparation system, the screw-type steam compressor unit 6.2 is preheated with high-temperature steam from the outside environment until it reaches a temperature above 100°C. Only then can the screw-type steam compressor unit 6.2 start normally; otherwise, it cannot start. Once the temperature reaches above 100°C, further heating of the screw-type steam compressor unit 6.2 is unnecessary. At this point, medium-low temperature geothermal water from the pumping well is drawn through an external submersible pump or deep well pump into the hydrocyclone desander 12 via the geothermal water inlet pipe. The hydrocyclone desander 12 separates sand, mud particles, or other solid impurities from the medium-low temperature geothermal water, preventing these impurities from affecting the later operation of the system. The components in the first plate heat exchanger 7 and the second plate heat exchanger 8 are worn. The medium-low temperature geothermal water after sand removal is divided into the first geothermal heat exchange branch and the second geothermal heat exchange branch. Some of the medium-low temperature geothermal water enters the first plate heat exchanger 7 through the first geothermal heat exchange branch. During operation, the evaporation side circulating water absorbs the heat released by the medium-low temperature geothermal water in the first plate heat exchanger 7. The evaporation side circulating water after heat absorption enters the evaporation side of the ultra-high temperature high efficiency centrifugal heat pump unit 1 through the evaporation side circulating pump 2. The ultra-high temperature high efficiency centrifugal heat pump unit 1 absorbs the heat in the evaporation side circulating water through the internal circulating working fluid, provides a heat source for the ultra-high temperature high efficiency centrifugal heat pump unit 1, and releases this part of the heat to a higher temperature to the makeup water side or the steam generation side.

[0029] The water treatment system includes a water treatment unit and a soft water tank. The tap water pipe at the inlet of the water treatment unit is connected to the external water supply pipe, and the drain pipe of the water treatment unit is connected to the inlet pipe of the soft water tank. The soft water tank has two outlet pipes: one outlet pipe is connected to the inlet of the system makeup water pump 3, and the other outlet pipe is connected to the inlet of the cooling system makeup water pump 11. A sampling port is connected to the drain pipe of the water treatment unit. A bypass pipe is also provided on the outlet pipe of the soft water tank. The bypass pipe is used to connect to an external temporary water source or a high-level water tank when the system makeup water pump 3 is under maintenance or malfunctioning, so that the steam makeup water bypasses the system makeup water pump 3 and enters the second plate heat exchanger 8 and the ultra-high temperature high efficiency centrifugal heat pump unit 1. The other end of the bypass pipe provided on the outlet of the system makeup water pump 3 and the outlet pipe of the soft water tank is connected to the steam makeup water inlet pipe of the ultra-high temperature high efficiency centrifugal heat pump unit 1.

[0030] The external water supply pipe is connected to the tap water pipe of the water treatment unit. The water purifier and reverse osmosis membrane inside the water treatment unit purify and soften the external water. The steam makeup water after purification, softening, and reverse osmosis treatment is delivered to the soft water tank. Then, the system makeup water pump 3 delivers the steam makeup water in the soft water tank to the second plate heat exchanger 8. At the same time, another part of the medium-low temperature geothermal water enters the second plate heat exchanger 8 through the second geothermal heat exchange branch to preheat the steam makeup water after it has been treated by the water treatment unit. The steam makeup water absorbs medium-low temperature water in the second plate heat exchanger 8. After the geothermal water temperature rises from a lower temperature to 50℃, and the temperature of the circulating water on the evaporation side and the temperature of the steam makeup water in the ultra-high temperature high efficiency centrifugal heat pump unit 1 both meet the operating requirements, the ultra-high temperature high efficiency centrifugal heat pump unit 1 is started. The preheated steam makeup water enters the condenser in the ultra-high temperature high efficiency centrifugal heat pump unit 1. The ultra-high temperature high efficiency centrifugal heat pump unit 1 releases the geothermal heat absorbed on the evaporation side to the steam makeup water side, so that the steam makeup water is heated and vaporized to form low-pressure steam with a temperature of 105℃ and a pressure of 0.12MPa(a).

[0031] The formula for the heat transfer area (A) of the first plate heat exchanger 7 and the second plate heat exchanger 8 is: ,in The heat transfer area is expressed in square meters (m²). 2 , Heat load, in kW. The overall heat transfer coefficient is expressed in kW / (m²). 2 ·K), The temperature difference is logarithmic and the unit is °C. When selecting the first plate heat exchanger 7 and the second plate heat exchanger 8, the heat exchange area can be determined by combining the design flow rate, inlet and outlet temperatures and heat transfer coefficient.

[0032] Compared with the direct entry of steam makeup water into the ultra-high temperature and high efficiency centrifugal heat pump unit 1, in this embodiment, the steam makeup water can be preheated by medium and low temperature geothermal water before entering the ultra-high temperature and high efficiency centrifugal heat pump unit 1, thereby reducing the makeup water heating load that the ultra-high temperature and high efficiency centrifugal heat pump unit 1 needs to bear. The higher the makeup water temperature, the smaller the temperature rise required for the ultra-high temperature and high efficiency centrifugal heat pump unit 1 to heat the makeup water into steam, which is conducive to reducing the energy consumption per unit of steam production.

[0033] By using medium- and low-temperature geothermal water to directly increase the initial temperature of the steam makeup water, the higher the temperature of the steam makeup water before entering the ultra-high temperature and high-efficiency centrifugal heat pump unit 1, the smaller the temperature rise required for the ultra-high temperature and high-efficiency centrifugal heat pump unit 1 to heat the steam makeup water into steam, resulting in higher energy efficiency and greater power saving for the entire industrial steam preparation system.

[0034] The low-pressure steam outlet of the ultra-high temperature high-efficiency centrifugal heat pump unit 1 is connected to the inlet of the centrifugal steam compressor unit 6.1, and the outlet of the centrifugal steam compressor unit 6.1 is connected to the inlet of the screw steam compressor unit 6.2. The outlet of the screw steam compressor unit 6.2 is used to connect to the industrial steam network. The low-pressure steam is compressed, heated and pressurized by the centrifugal steam compressor unit 6.1 and the screw steam compressor unit 6.2 in sequence and then output to the industrial steam network to supply high-temperature industrial steam to the industrial steam network, achieving no direct combustion emissions and only consuming electricity.

[0035] The low-pressure steam outlet of the ultra-high temperature high-efficiency centrifugal heat pump unit 1, the centrifugal steam compressor unit 6.1, and the screw steam compressor unit 6.2 are connected in series along the steam flow direction. The centrifugal steam compressor unit 6.1 is used to compress the low-pressure steam output from the ultra-high temperature high-efficiency centrifugal heat pump unit 1 to intermediate steam parameters suitable for entering the screw steam compressor unit 6.2. The screw steam compressor unit 6.2 is used to further compress the steam with intermediate steam parameters to the steam parameters required by the industrial steam pipeline network. This ensures that the low-pressure steam generated by the ultra-high temperature high-efficiency centrifugal heat pump unit 1 undergoes first-stage compression via the centrifugal steam compressor unit 6.1 and then second-stage compression via the screw steam compressor unit 6.2, forming a two-stage steam compression path. The inlet steam temperature of unit 6.1 is 103.6℃, ​​the pressure is 0.115MPa(a), the outlet steam temperature is 124.7℃, the pressure is 0.23MPa(a), the inlet steam flow rate is 5.0t / h, and the outlet steam flow rate is 5.213t / h. Centrifugal steam compressor unit 6.1 and screw steam compressor unit 6.2 can be equipped with frequency converter cabinets and PLCs to realize speed regulation and operation monitoring. The inlet steam temperature of screw steam compressor unit 6.2 is 124.4℃, the pressure is 0.225MPa(a), the outlet steam temperature is 173℃, the pressure is 0.85MPa(a), the inlet steam flow rate is 5.213t / h, and the outlet steam flow rate is 6.0t / h. Screw steam compressor unit 6.2 is equipped with a buffer tank.

[0036] Once the temperature and pressure of the low-pressure steam output from the ultra-high temperature high-efficiency centrifugal heat pump unit 1 meet the inlet conditions of the centrifugal steam compressor unit 6.1, the centrifugal steam compressor unit 6.1 is started. The low-pressure steam generated by the ultra-high temperature high-efficiency centrifugal heat pump unit 1 then enters the centrifugal steam compressor unit 6.1. The centrifugal steam compressor unit 6.1 performs the first stage of compression on the low-pressure steam, raising the steam temperature from 103.6℃ to 124.7℃ and the pressure from 0.115MPa(a) to 0.23MPa(a). The inlet steam flow rate is 5.0t / h, and the outlet steam flow rate is 5.213t / h. This raises the steam pressure and temperature to intermediate steam parameters suitable for entering the screw steam compressor unit 6.2. Subsequently, the screw steam compressor unit 6.2 is started, and the intermediate steam after the first stage of compression enters... Inside the screw-type steam compressor unit 6.2, the intermediate steam is further compressed in a second stage, raising its temperature from 124.4℃ to 173℃ and its pressure from 0.225MPa(a) to 0.85MPa(a). The inlet steam flow rate is 5.213t / h, and the outlet steam flow rate is 6.0t / h, forming high-temperature industrial steam that meets the transportation requirements of the industrial steam pipeline network. The industrial steam pipeline network can be connected to the external boiler room distribution cylinder to divert the industrial steam. A portion of the industrial steam is diverted to the high-pressure steam pipeline to supply equipment requiring high-pressure steam, while the other portion flows to the medium-pressure steam pipeline to supply equipment requiring medium-pressure steam. This allows the industrial steam to be used in food processing, textile printing and dyeing, pharmaceutical enterprises, and regional centralized steam supply, meeting different usage needs.

[0037] The formula for the coefficient of performance (COPsys) of this industrial steam preparation system is as follows: ,in The thermal power (kW) of the output steam. This refers to the input power of the two-stage steam compression system 6 and the heat pump compressor, in kW. The power of each water pump is given in kW. The power of the closed cooling tower 4, air compressor system 5, control cabinet and other auxiliary equipment is expressed in kW. The above formula is used to characterize the overall energy efficiency of the system's electric drive.

[0038] The buffer water tank 9 is connected to the water supply pipeline on the system water supply pump 3 and is used to supply water to the steam preparation system. The buffer water tank 9 is used to supply water to the steam preparation system when the steam preparation system is initially filled with water, water is drained from the pipeline, or the pressure of the evaporation side circulating water circuit is lower than the preset pressure. The water supply stops when the pressure of the evaporation side circulating water circuit or the liquid level of the buffer water tank 9 reaches the preset value.

[0039] When the industrial steam preparation system is put into operation for the first time, water can be supplied to the buffer water tank 9 and related water supply pipelines through the system water supply pump 3. When the liquid level of the buffer water tank 9 or the pressure of the evaporation side circulating water circuit reaches the preset value, the system water supply pump 3 stops running or the corresponding water supply valve is closed. When the steam preparation system is subjected to maintenance and water leakage, pipeline maintenance or a drop in operating pressure, the buffer water tank 9 can cooperate with the system water supply pump 3 to supply water to the steam preparation system, so that the pressure or liquid level of the evaporation side circulating water circuit is restored to the set range.

[0040] Example 2: The industrial steam preparation system of medium-low temperature geothermal coupled with high temperature heat pump in this example, based on Example 1, prioritizes the supply of medium-low temperature geothermal water to the evaporator side of the ultra-high temperature high-efficiency centrifugal heat pump unit 1 for heating, while utilizing the remaining heat exchange capacity to preheat the steam makeup water. The specific structure is shown in the attached diagram. Figure 2 and attached Figure 7 As shown.

[0041] Butterfly valves are installed on the first and second geothermal heat exchange branches respectively. Thermometers are installed on the evaporator-side inlet pipe and the steam makeup water inlet pipe of the ultra-high temperature high efficiency centrifugal heat pump unit 1 respectively. When the evaporator-side inlet water temperature of the ultra-high temperature high efficiency centrifugal heat pump unit 1 is lower than the set range, the flow rate of the medium and low temperature geothermal water in the first plate heat exchanger 7 is increased first. When the evaporator-side inlet water temperature of the ultra-high temperature high efficiency centrifugal heat pump unit 1 meets the operating requirements and the steam makeup water temperature is lower than the set value, the heat exchange capacity of the medium and low temperature geothermal water in the second plate heat exchanger 8 is increased. Therefore, the heat exchange priority of the first and second heat exchange branches can be adjusted according to the evaporator-side inlet water temperature and the steam makeup water temperature of the ultra-high temperature high efficiency centrifugal heat pump unit 1.

[0042] Example 3: The industrial steam production system of the medium-low temperature geothermal coupled high temperature heat pump in this example discloses a cooling system based on Example 1. The specific structure is shown in the appendix. Figure 4 and attached Figure 7 As shown, the cooling system includes a closed-circuit cooling tower 4. The outlet of the closed-circuit cooling tower 4 is connected to the cooling water interface of the ultra-high temperature high-efficiency centrifugal heat pump unit 1, the centrifugal steam compressor unit 6.1, and the screw steam compressor unit 6.2 respectively via the cooling system circulation pump 10. The cooling water outlets of the ultra-high temperature high-efficiency centrifugal heat pump unit 1, the centrifugal steam compressor unit 6.1, and the screw steam compressor unit 6.2 are connected to the return water end of the closed-circuit cooling tower 4. The circulation temperature of the closed-circuit cooling tower 4 is 35 / 30℃, and the cooling water flow rate is 80m³ / h. 3 / h, the flow rate of cooling system circulating pump 10 is 80m³ / h. 3 The pump has a flow rate of 1.6 m³ / h, a head of 20 m, and a power of 7.5 kW. Two pumps are used for both the cooling system circulating pump 10 and the cooling system makeup water pump 11, one in operation and one on standby. The flow rate of the cooling system makeup water pump 11 is 1.6 m³ / h. 3 / h, head is 15m, power is 0.37kW.

[0043] The cooling system circulation pump 10 drives the cooling water to circulate between the closed cooling tower 4, the ultra-high temperature high efficiency centrifugal heat pump unit 1, the centrifugal steam compressor unit 6.1, and the screw steam compressor unit 6.2, forming a closed cooling cycle to remove the waste heat from the operation of the ultra-high temperature high efficiency centrifugal heat pump unit 1, the centrifugal steam compressor unit 6.1, and the screw steam compressor unit 6.2, ensuring that the operating temperature of the ultra-high temperature high efficiency centrifugal heat pump unit 1, the centrifugal steam compressor unit 6.1, and the screw steam compressor unit 6.2 is within the allowable range.

[0044] During the industrial steam production process, the ultra-high temperature high efficiency centrifugal heat pump unit 1, centrifugal steam compressor unit 6.1, and screw steam compressor unit 6.2 generate mechanical and motor heat during operation. At this time, the cooling system circulation pump 10 drives cooling water to circulate between the closed cooling tower 4 and the ultra-high temperature high efficiency centrifugal heat pump unit 1, centrifugal steam compressor unit 6.1, and screw steam compressor unit 6.2, carrying away the heat generated during their operation. This ensures that the operating temperature of the ultra-high temperature high efficiency centrifugal heat pump unit 1, centrifugal steam compressor unit 6.1, and screw steam compressor unit 6.2 remains within the allowable range.

[0045] The closed-loop cooling tower 4, the cooling system circulation pump 10, and the cooling system makeup water pump 11 constitute a cooling loop to remove waste heat generated during the operation of the ultra-high temperature high-efficiency centrifugal heat pump unit 1, the centrifugal steam compressor unit 6.1, and the screw steam compressor unit 6.2, facilitating cooling operations. The drain end of the cooling system makeup water pump 11 is connected to the outlet end of the closed-loop cooling tower 4. The cooling system makeup water pump 11 is used to replenish the lost water volume in the cooling loop, ensuring stable operation of the cooling operation. Simultaneously, the system makeup water pump 3 connects to the ultra-high temperature high-efficiency centrifugal heat pump unit 1. The steam makeup water inlet pipe of the centrifugal heat pump unit 1 can be used to deliver part of the steam makeup water to the centrifugal steam compressor unit 6.1 and the screw steam compressor unit 6.2 through a hydraulic press. This results in the portion of the steam output of the centrifugal steam compressor unit 6.1 exceeding the steam input being formed by the evaporation of the steam makeup water entering the centrifugal steam compressor unit 6.1. Similarly, the portion of the steam output of the screw steam compressor unit 6.2 exceeding the steam input being formed by the evaporation of the steam makeup water entering the screw steam compressor unit 6.2.

[0046] The cooling system circulating pump 10 and the closed cooling tower 4 are interlocked with the centrifugal steam compressor unit 6.1 and the screw steam compressor unit 6.2. When the centrifugal steam compressor unit 6.1 starts, the cooling system circulating pump 10 starts synchronously. When both the centrifugal steam compressor unit 6.1 and the screw steam compressor unit 6.2 stop running, the cooling system circulating pump 10 stops after a delay to ensure that the residual heat of the centrifugal steam compressor unit 6.1 and the screw steam compressor unit 6.2 is carried away in time.

[0047] Example 4: The industrial steam preparation system of the medium-low temperature geothermal coupled high-temperature heat pump in this example discloses a sealing system based on Example 1. The specific structure is shown in the appendix. Figure 4 and attached Figure 7 As shown, the sealing system includes an air compressor system 5, which is connected to the sealing parts of the centrifugal steam compressor unit 6.1 and the screw steam compressor unit 6.2. It is used to provide a sealing or make-up air source for the centrifugal steam compressor unit 6.1 and the screw steam compressor unit 6.2 to prevent steam leakage and improve the operational stability of the centrifugal steam compressor unit 6.1 and the screw steam compressor unit 6.2.

[0048] Air compressor system 5 includes two air compressors, one of which is in operation and the other is in standby mode to ensure the supply of sealing gas for centrifugal steam compressor unit 6.1 and screw steam compressor unit 6.2. The discharge gauge pressure of air compressor system 5 is 4-6 bar, and the flow rate is 220 Nm³. 3 / h, with a power of 30kW, the air compressor system 5 is used to establish the sealing gas pressure before the centrifugal steam compressor unit 6.1 and the screw steam compressor unit 6.2 are started, and allows the corresponding centrifugal steam compressor unit 6.1 and screw steam compressor unit 6.2 to start after the sealing gas pressure reaches the preset pressure.

[0049] Since the processing medium in the centrifugal steam compressor unit 6.1 and the screw steam compressor unit 6.2 is steam, if the seal is not tight, steam leakage can easily occur, leading to a decrease in compression efficiency and potential operational safety hazards. Therefore, before starting the centrifugal steam compressor unit 6.1 or the screw steam compressor unit 6.2, the air compressor system 5 establishes a sealing gas pressure. The air compressor system 5 then supplies sealing gas with a preset pressure to the sealing parts of the centrifugal steam compressor unit 6.1 and the screw steam compressor unit 6.2. When the sealing gas pressure reaches the preset pressure, the corresponding centrifugal steam compressor unit 6.1 and the screw steam compressor unit 6.2 are allowed to start. When the sealing gas pressure is lower than the preset pressure, the start-up of the centrifugal steam compressor unit 6.1 and the screw steam compressor unit 6.2 is restricted or they are put into a protection state to prevent steam leakage.

[0050] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An industrial steam preparation system for medium- and low-temperature geothermal coupling with a high-temperature heat pump, characterized in that: It includes an ultra-high temperature high efficiency centrifugal heat pump unit (1), an evaporator-side circulation pump (2), a two-stage water vapor compression system (6), a cyclone separator (12), a water treatment system, a cooling system, and a sealing system; The cyclone separator (12) is installed on the inlet pipe of the medium-low temperature geothermal water and is used to remove sand from the medium-low temperature geothermal water. The medium-low temperature geothermal water after being treated by the cyclone separator (12) is divided into a first geothermal heat exchange branch and a second geothermal heat exchange branch. The first geothermal heat exchange branch is connected to the primary side of the first plate heat exchanger (7). A buffer water tank (9) is connected between the secondary side of the first plate heat exchanger (7) and the inlet of the evaporation side circulation pump (2). The outlet end of the evaporation side circulation pump (2) is connected to the evaporator in the ultra-high temperature high efficiency centrifugal heat pump unit (1). The second geothermal heat exchange branch is connected to the primary side of the second plate heat exchanger (8), so that the medium and low temperature geothermal water can be used simultaneously for heat extraction on the evaporation side of the ultra-high temperature high efficiency centrifugal heat pump unit (1) and steam water preheating. The secondary side of the second plate heat exchanger (8) is set between the system water pump (3) and the steam water inlet of the ultra-high temperature high efficiency centrifugal heat pump unit (1). The low-pressure steam outlet of the ultra-high temperature high-efficiency centrifugal heat pump unit (1) is connected to the inlet of the two-stage water vapor compression system (6).

2. The industrial steam preparation system of a medium-low temperature geothermal coupled high temperature heat pump according to claim 1, characterized in that: Butterfly valves are respectively installed on the first geothermal heat exchange branch and the second geothermal heat exchange branch. Thermometers are respectively installed on the evaporation side water inlet pipe and the steam water inlet pipe of the ultra-high temperature high efficiency centrifugal heat pump unit (1). Medium- and low-temperature geothermal water supplies heat to the evaporator-side circulating water of the ultra-high temperature and high-efficiency centrifugal heat pump unit (1) through the first plate heat exchanger (7). This heat exchange is used between the medium- and low-temperature geothermal water and the evaporator-side circulating water of the ultra-high temperature and high-efficiency centrifugal heat pump unit (1), so that the evaporator side of the ultra-high temperature and high-efficiency centrifugal heat pump unit (1) obtains a stable low-grade heat source. There are three first plate heat exchangers (7), two of which are in operation and one is in standby. The heat exchange capacity of a single unit is 1.4MW, the primary side temperature is 62 / 54℃, the secondary side temperature is 52 / 60℃, and the heat exchange area is 291m². 2 It adopts a dual-use, one-standby configuration, which can ensure that it maintains a speed of 300m during year-round operation or full-load operation. 3 Heat exchange flow rate per hour; The medium-low temperature geothermal return water after heat exchange on the primary side of the first plate heat exchanger (7) and the medium-low temperature geothermal return water after heat exchange on the primary side of the second plate heat exchanger (8) are merged into the geothermal side return water pipeline and reinjected into the reinjection well. The evaporation side circulating water of the secondary side of the first plate heat exchanger (7) is returned to the secondary side of the first plate heat exchanger (7) for heat exchange through the evaporator side return water pipeline of the ultra-high temperature high efficiency centrifugal heat pump unit (1). The medium-low temperature geothermal water and the evaporation side circulating water are not directly mixed.

3. The industrial steam preparation system of a medium-low temperature geothermal coupled high temperature heat pump according to claim 1, characterized in that: The second plate heat exchanger (8) is used to preheat the steam makeup water to a preset steam makeup water temperature before sending it into the condenser inside the ultra-high temperature high efficiency centrifugal heat pump unit (1) to reduce the temperature rise load required by the ultra-high temperature high efficiency centrifugal heat pump unit (1) to heat the steam makeup water into steam. The preheated steam makeup water enters the ultra-high temperature high efficiency centrifugal heat pump unit (1) to form low-pressure steam. The heat exchange capacity of the second plate heat exchanger (8) is 0.52MW, the primary side temperature is 62 / 48℃, the secondary side temperature is 5 / 50℃, and the heat exchange area is 14m². 2 .

4. The industrial steam preparation system of a medium-low temperature geothermal coupled high temperature heat pump according to claim 1, characterized in that: The two-stage steam compression system (6) includes a centrifugal steam compressor unit (6.1) and a screw steam compressor unit (6.2). The screw steam compressor unit (6.2) is equipped with a start-up preheating branch. The start-up preheating branch is used to introduce external high-temperature steam or heat source into the screw steam compressor unit (6.2) during the start-up stage of the industrial steam preparation system, so that the screw steam compressor unit (6.2) can start after reaching the preset start-up temperature. The low-pressure steam outlet of the ultra-high temperature high-efficiency centrifugal heat pump unit (1) is connected to the inlet of the centrifugal steam compressor unit (6.1), and the outlet of the centrifugal steam compressor unit (6.1) is connected to the inlet of the screw steam compressor unit (6.2). The outlet of the screw steam compressor unit (6.2) is used to connect to the industrial steam network. The low-pressure steam is compressed, heated and pressurized by the centrifugal steam compressor unit (6.1) and the screw steam compressor unit (6.2) in sequence and then output to the industrial steam network to supply high-temperature industrial steam to the industrial steam network. The low-pressure steam outlet of the ultra-high temperature high-efficiency centrifugal heat pump unit (1), the centrifugal steam compressor unit (6.1), and the screw steam compressor unit (6.2) are connected in series along the steam flow direction. The centrifugal steam compressor unit (6.1) is used to compress the low-pressure steam output by the ultra-high temperature high-efficiency centrifugal heat pump unit (1) to an intermediate steam parameter suitable for entering the screw steam compressor unit (6.2). The screw steam compressor unit (6.2) is used to further compress the steam with the intermediate steam parameter to the steam parameter required by the industrial steam pipeline network. This allows the low-pressure steam generated by the ultra-high temperature high-efficiency centrifugal heat pump unit (1) to undergo a first-stage compression by the centrifugal steam compressor unit (6.1) and then a second-stage compression by the screw steam compressor unit (6.2), forming a two-stage steam compression path.

5. The industrial steam preparation system of a medium-low temperature geothermal coupled high temperature heat pump according to claim 1, characterized in that: The evaporation-side circulation pump (2) is used to drive the evaporation-side circulating water of the ultra-high temperature high efficiency centrifugal heat pump unit (1) to circulate between the first plate heat exchanger (7) and the ultra-high temperature high efficiency centrifugal heat pump unit (1). The evaporation-side circulation pump (2) ensures that the heat in the medium and low temperature geothermal water can be stably transferred to the evaporation side of the ultra-high temperature high efficiency centrifugal heat pump unit (1). The evaporation-side circulation pump (2) can be equipped with two variable frequency pumps, one in operation and one in standby. Variable frequency control is beneficial to adjust the circulation flow according to the load of the evaporation-side circulation pump (2) to avoid low load or overflow operation.

6. The industrial steam preparation system of a medium-low temperature geothermal coupled high temperature heat pump according to claim 4, characterized in that: The cooling system includes a closed-circuit cooling tower (4), and the outlet of the closed-circuit cooling tower (4) is connected to the cooling water interface of the ultra-high temperature high efficiency centrifugal heat pump unit (1), the centrifugal steam compressor unit (6.1), and the screw steam compressor unit (6.2) respectively through the cooling system circulation pump (10). The cooling water outlet of the ultra-high temperature high efficiency centrifugal heat pump unit (1), the centrifugal steam compressor unit (6.1), and the screw steam compressor unit (6.2) is connected to the return water end of the closed-circuit cooling tower (4). The circulation temperature of the closed-circuit cooling tower (4) is 35 / 30℃, and the cooling water flow rate is 80m³ / h. 3 / h; The cooling system circulation pump (10) is used to drive cooling water to circulate between the closed cooling tower (4), the ultra-high temperature high efficiency centrifugal heat pump unit (1), the centrifugal steam compressor unit (6.1), and the screw steam compressor unit (6.2) to form a closed cooling cycle for removing the waste heat from the operation of the ultra-high temperature high efficiency centrifugal heat pump unit (1), the centrifugal steam compressor unit (6.1), and the screw steam compressor unit (6.2), ensuring that the operating temperature of the ultra-high temperature high efficiency centrifugal heat pump unit (1), the centrifugal steam compressor unit (6.1), and the screw steam compressor unit (6.2) is within the allowable range.

7. The industrial steam preparation system of a medium-low temperature geothermal coupled high temperature heat pump according to claim 4, characterized in that: The sealing system includes an air compressor system (5), and the air compressor system (5) is connected to the sealing parts of the centrifugal steam compressor unit (6.1) and the screw steam compressor unit (6.2), which is used to provide a sealing or replenishing air source for the centrifugal steam compressor unit (6.1) and the screw steam compressor unit (6.2), prevent steam leakage, and improve the stability of the operation of the centrifugal steam compressor unit (6.1) and the screw steam compressor unit (6.2); The air compressor system (5) includes two air compressors, one of which is in operation and the other is in standby mode, to ensure the supply of sealing gas to the centrifugal steam compressor unit (6.1) and the screw steam compressor unit (6.2). The air compressor system (5) is used to establish the sealing gas pressure before the centrifugal steam compressor unit (6.1) and the screw steam compressor unit (6.2) are started, and to allow the corresponding centrifugal steam compressor unit (6.1) and screw steam compressor unit (6.2) to start after the sealing gas pressure reaches the preset pressure.

8. The industrial steam preparation system of a medium-low temperature geothermal coupled high temperature heat pump according to claim 1, characterized in that: The buffer tank (9) is connected to the water supply pipeline on the system water supply pump (3) and is used to supply water to the steam preparation system. The buffer tank (9) is used to supply water to the steam preparation system after the initial water injection, water discharge from the pipeline, or when the pressure of the evaporation side circulating water circuit is lower than the preset pressure. The water supply is stopped after the pressure of the evaporation side circulating water circuit or the liquid level of the buffer tank (9) reaches the preset value.

9. The industrial steam preparation system of a medium-low temperature geothermal coupled high temperature heat pump according to claim 1, characterized in that: The ultra-high temperature high efficiency centrifugal heat pump unit (1) is equipped with a bypass pipeline on the steam water inlet pipe. The bypass pipeline is used to allow the system water pump (3) to bypass the second plate heat exchanger (8) and directly deliver the steam water to the ultra-high temperature high efficiency centrifugal heat pump unit (1) when the second plate heat exchanger (8) is under maintenance or abnormal. The system water pump (3) can be two variable frequency pumps, one for use and one for standby.

10. An industrial steam preparation system for a medium-low temperature geothermal coupled high-temperature heat pump according to claim 6, characterized in that: The water treatment system includes a water treatment unit and a soft water tank. The tap water pipe at the inlet of the water treatment unit is connected to the external water supply pipe, and the drain pipe of the water treatment unit is connected to the inlet pipe of the soft water tank. The soft water tank has two outlet pipes. One outlet pipe is connected to the inlet of the system water supply pump (3), and the other outlet pipe is connected to the inlet of the cooling system water supply pump (11). A sampling port is connected to the drain pipe of the water treatment unit. A bypass pipeline is also provided on the outlet pipeline of the soft water tank. The bypass pipeline is used to connect with the external temporary water source or high-level water tank when the system water supply pump (3) is under maintenance or abnormal, so that the steam water supply bypasses the system water supply pump (3) and enters the second plate heat exchanger (8) and the ultra-high temperature high efficiency centrifugal heat pump unit (1). The other end of the bypass pipe installed on the outlet end of the system water pump (3) and the outlet pipe of the soft water tank is connected to the steam water inlet pipe of the ultra-high temperature high efficiency centrifugal heat pump unit (1). The closed-loop cooling tower (4), the cooling system circulation pump (10), and the cooling system makeup water pump (11) constitute a cooling loop, which is used to remove the waste heat generated during the operation of the ultra-high temperature high-efficiency centrifugal heat pump unit (1), the centrifugal steam compressor unit (6.1), and the screw steam compressor unit (6.2), facilitating cooling operations. The drain end of the cooling system makeup water pump (11) is connected to the outlet end of the closed-loop cooling tower (4). The cooling system makeup water pump (11) is used to replenish the lost water volume of the cooling loop, ensuring stable operation of the cooling operation. At the same time, the system makeup water pump (3) is connected to the ultra-high temperature high-efficiency centrifugal heat pump unit (1), the centrifugal steam compressor unit (6.1), and the screw steam compressor unit (6.2). The steam makeup water inlet pipe of the high-efficiency centrifugal heat pump unit (1) can be used to transport part of the steam makeup water to the centrifugal steam compressor unit (6.1) and the screw steam compressor unit (6.2) through a water press. This results in the steam output of the centrifugal steam compressor unit (6.1) being greater than the steam inlet, which is formed by the evaporation of the steam makeup water entering the centrifugal steam compressor unit (6.1). The steam output of the screw steam compressor unit (6.2) being greater than the steam inlet, is formed by the evaporation of the steam makeup water entering the screw steam compressor unit (6.2).

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