Wide-temperature-range cascade heat supply water source heat pump energy station and using method

Abstract

The invention relates to the technical field of water source heat pump energy stations, in particular to a wide-temperature-range cascade heat supply water source heat pump energy station and a using method. The second circulation group is in heat exchange connection with the first circulation group through a first plate heat exchanger; by means of the screw type high-temperature water source heat pump unit, natural low-temperature heat sources such as a lake water source and a river water source are ingeniously utilized for waste heat recovery, energy consumption is greatly reduced, the operation cost is effectively reduced, and a new economical and efficient heat supply way is provided for industrial heat consumption scenes. And an enterprise is assisted to achieve the dual goals of energy conservation, emission reduction, cost reduction and efficiency improvement.

Description

Technical Field

[0001] This invention relates to the field of water source heat pump energy station technology, specifically a water source heat pump energy station with wide temperature range cascade heating and its usage method. Background Technology

[0002] In the context of current industrial development and energy utilization, heating systems in industrial sites have a crucial impact on energy consumption and operating costs. Currently, industrial heating methods remain predominantly traditional, with gas-fired boilers and electric boilers being the most common heat sources. However, these traditional heating methods have several significant drawbacks: From an energy consumption perspective, both gas-fired boilers and electric boilers consume large amounts of fossil fuels or electricity during operation. Gas-fired boilers use natural gas and other fuels, which not only consume a large amount of non-renewable resources during combustion, but also lose some energy as waste heat due to limited combustion efficiency, resulting in low energy utilization. In terms of operating costs, the high energy consumption of both gas-fired and electric boilers directly leads to high operating costs. In terms of meeting high-temperature heating demands, when some equipment in industrial sites, such as coating machines and rotary dehumidifiers, require high-temperature heat sources above 80°C, traditional heat pump units are inadequate in handling such demands. When a single heat pump unit generates high-temperature heat sources, it is limited by its working principle and technology. As the heat generation temperature increases, the compression ratio of the compressor increases, and the loss of refrigerant during the circulation process increases, resulting in a significant reduction in the energy efficiency of the heat pump. This not only increases the cost of generating high-temperature heat sources, but also makes it difficult to stably provide sufficient high-temperature heat, failing to meet the continuous and stable demand for high-temperature heat sources in industrial production.

[0003] Furthermore, different heating areas and equipment within industrial sites have varying requirements for heat source quality. Different equipment requires heat sources of different temperatures based on its process characteristics and operational needs, and the temperature range of these required heat sources can be quite wide. For example, some production processes may only require a low-temperature heat source of 40-50℃ for material preheating, while other processes require a high-temperature heat source of 80-100℃ for operations such as drying. However, most existing heating systems operate on a single temperature output mode, making it difficult to achieve flexible adjustment and supply across a wide temperature range.

[0004] Therefore, the present invention provides a water source heat pump energy station with wide temperature range cascade heating to solve the above problems. Summary of the Invention

[0005] (a) Technical problems to be solved This invention provides a water source heat pump energy station with wide temperature range cascade heating, aiming to solve the problems mentioned in the background art.

[0006] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: a wide-temperature-range cascade heating water source heat pump energy station, comprising: a first circulation group for circulating lake water; a second circulation group connected to the first circulation group via a first plate heat exchanger; a third circulation group connected to the second circulation group to form a closed loop; a fourth circulation group connected to the third circulation group, and the fourth circulation group and the third circulation group are connected via multiple sets of second plate heat exchangers; and a fifth circulation group connected to the fourth circulation group. Multiple sets of second plate heat exchangers form a heat exchange connection for producing high-temperature hot water at different temperatures; the fifth circulation group includes: multiple sets of high-temperature heat pump units, each of which is connected to an external circulation pipe and a connecting circulation pipe. The connecting circulation pipe is interconnected with the multiple sets of second plate heat exchangers, and the external circulation pipe is connected to external equipment. The multiple sets of high-temperature heat pump units are respectively equipped with R134a refrigerant, R515B / R1234ze refrigerant, R245fa refrigerant, and R1233zd refrigerant.

[0007] Preferably, the first circulation group includes: a first circulation pipe, one end of which is provided with an inlet and the other end with an outlet, and multiple sets of water intake pumps and multiple sets of cyclone sand separators are provided on the conveying path of the first circulation pipe, and the first plate heat exchanger is provided on the conveying path of the first circulation pipe.

[0008] Preferably, a grille is provided on the water inlet.

[0009] Preferably, the second circulation group includes: a first screw heat pump host and a second screw heat pump host, the evaporation side ports of the first screw heat pump host and the second screw heat pump host are connected to a second circulation pipe, and the condensation side ports of the first screw heat pump host and the second screw heat pump host are both connected to a third circulation pipe; a first plate heat exchanger is provided on the conveying path of the second circulation pipe so that the second circulation pipe and the first circulation pipe can exchange heat, and multiple sets of cold water pumps are also provided on the conveying path of the second circulation pipe.

[0010] Preferably, the third circulation group includes: a water distributor and a water collector, the water distributor and the water collector are connected to a third circulation pipe, the transport path of the third circulation pipe is connected to a bypass pipe, and the bypass pipe is equipped with a sealed pressure tank, multiple sets of water replenishment pumps and a water replenishment tank. An electric boiler and multiple sets of hot water pumps are also installed along the transport path of the third circulation pipe.

[0011] Preferably, the fourth circulation group includes: a water distributor and a water collector shared with the third circulation group. The water distributor is connected to a domestic hot water discharge pipe and also to multiple sets of water outlet pipes. The water collector is connected to multiple sets of water return pipes. A second plate heat exchanger is connected to each of the multiple sets of water outlet pipes and the multiple sets of water return pipes.

[0012] Preferably, the third circulation pipe is provided with a buffer unit, which includes a spiral coil, a buffer tank and a bubble separator, all arranged on the conveying path of the third circulation pipe, and the buffer tank is provided with a dosing port.

[0013] Preferably, it also includes a water quality sensor, which is installed on the delivery path of the third circulation pipe for detecting water quality.

[0014] A method for using a wide-temperature-range cascade hot water source heat pump energy station: S1. After the lake water enters the first circulation pipe, multiple sets of water intake pumps are started to draw and transport the lake water. During the transportation process, multiple sets of cyclone desanders remove sand from the lake water to remove fine particles such as mud and sand, ensuring the cleanliness of the lake water entering the first plate heat exchanger. S2. The treated lake water is transported to the first plate heat exchanger through the first circulation pipe to exchange heat with the fluid in the second circulation group. At this time, multiple cold water pumps in the second circulation group are started to transport the fluid in the second circulation pipe to the first plate heat exchanger to absorb the heat in the lake water and raise the fluid temperature. The heated fluid enters the evaporation side of the first screw heat pump host and the second screw heat pump host. Inside the heat pump host, the fluid releases heat, causing the refrigerant inside the heat pump host to evaporate and absorb heat. The evaporated refrigerant enters the condensation side and exchanges heat with the fluid in the third circulation pipe, transferring heat to the fluid in the third circulation pipe and raising its temperature. S3, the water distributor and water collector in the third circulation group form a closed circulation through the third circulation pipe. By starting multiple sets of hot water pumps on the third circulation pipe, the heated fluid is transported into the water distributor and then distributed to different branches according to demand. S4 and the fourth circulation group share the water distributor and water collector with the third circulation group. A portion of the hot water in the water distributor is directly supplied to domestic hot water through the domestic hot water discharge pipe to meet the daily needs of washing and bathing. Multiple sets of water outlet pipes on the water distributor transport the hot water to multiple sets of second plate heat exchangers to exchange heat with the return water in the fourth circulation group. Through the multi-stage heat exchange of multiple sets of second plate heat exchangers, heating for different temperature requirements is achieved. S5. Multiple high-temperature heat pump units in the fifth circulation group are started, connected to multiple second-plate heat exchangers via circulation pipes, absorbing heat from the fluid in the second-plate heat exchangers. Different high-temperature heat pump units are equipped with R134a refrigerant, R515B / R1234ze refrigerant, R245fa refrigerant, and R1233zd refrigerant, respectively. These refrigerants have different physical properties and operating temperature ranges. The appropriate high-temperature heat pump unit can be selected for operation according to the actual temperature requirements of producing high-temperature hot water. The high-temperature hot water heated by the high-temperature heat pump unit is connected to external equipment through external circulation pipes to provide high-temperature hot water for industrial production, district heating, etc.

[0015] (III) Beneficial Effects 1. By using screw-type high-temperature water source heat pump units, waste heat is recovered from natural low-temperature heat sources such as lake water and river water, which greatly reduces energy consumption and effectively reduces operating costs. This provides an economical and efficient new heating method for industrial heating scenarios, helping enterprises achieve the dual goals of energy conservation, emission reduction and cost reduction.

[0016] 2. The 50-60℃ hot water produced by the screw heat pump host serves as the evaporator-side heat source for the terminal distributed high-temperature heat pump unit. After compression by the terminal high-temperature heat pump unit, it can produce high-temperature pressurized hot water with a maximum temperature of 145℃, breaking through the limitations of a single heat pump host in high-temperature heating, meeting the normal operation of equipment in the factory that requires high-temperature heat sources, and ensuring the smooth operation of the production process.

[0017] 3. The water distributor stores and distributes 50-60℃ hot water produced by the screw-type heat pump unit. It can serve as a buffer tank to balance the temperature fluctuations of the system and store energy during peak and off-peak electricity prices. At the terminal, small distributed high-temperature heat pump units are arranged nearby to heat-using equipment. The water in the distributor is heated a second time before being supplied. In addition, various refrigerants are used to match the corresponding circulation system for different temperature requirements. The hot water from the large distributor is used as the heat source on the evaporation side. After secondary compression, hot water of 80-145℃ can be produced, flexibly meeting the heating needs of the factory in a wide temperature range.

[0018] 4. Through the water distributor, the heat circulation on the condenser side of the screw-type water source heat pump unit takes place between the "water distributor - water collector - main unit". The water quality is clean and meets drinking water standards. The water distributor is equipped with a domestic hot water interface, which can directly supply domestic hot water. At the same time, the closed circulation pipeline of "water distributor - water collector - main unit" is equipped with a constant pressure water replenishment device, which can replenish the water lost in the water distributor in real time. One system realizes the dual functions of domestic hot water and industrial production heat, simplifying the system structure and reducing construction and maintenance costs.

[0019] 5. By starting the electric boiler, heat is added to the system to ensure stable water temperature in the distributor, ensuring that the domestic hot water temperature meets the standard, and that the heating temperature of the terminal heating equipment meets the design requirements, thus providing a reliable guarantee for the stable operation of the system under severe weather conditions. Attached Figure Description

[0020] Figure 1 Here are schematic diagrams of the circulation pipelines of this invention: Figure 2 Here is a schematic diagram of the overall structure of the present invention: Figure 3 This is a schematic diagram of the first loop group structure in this invention: Figure 4 This is a schematic diagram of the second loop group structure in this invention: Figure 5 This is a schematic diagram of the third loop group structure in this invention: Figure 6 This is a schematic diagram of the fourth cycle group structure in this invention: Figure 7 This is a schematic diagram of the fifth cycle group structure in this invention.

[0021] In the diagram: 1. First circulation group; 11. First circulation pipe; 12. Inlet; 13. Outlet; 14. Cyclone sand separator; 15. Grille; 16. Water intake pump; 2. Second circulation group; 21. First screw heat pump unit; 22. Second screw heat pump unit; 23. Second circulation pipe; 24. Cold water pump; 3. Third circulation group; 31. Water distributor; 32. Water collector; 33. Third circulation pipe; 34. Hot water pump; 35. Closed-loop pressure tank; 36. 37. Makeup water pump; 38. Makeup water tank; 39. Electric boiler; 40. Bypass pipe; 51. Fourth circulation group; 62. Outlet pipe; 73. Return pipe; 84. Domestic hot water discharge pipe; 95. Fifth circulation group; 10. High-temperature heat pump unit; 11. External circulation pipe; 12. Connecting circulation pipe; 13. First plate heat exchanger; 14. Second plate heat exchanger; 15. Buffer tank; 16. Spiral coil; 17. Bubble separator; 18. Chemical dosing port; 19. Water quality sensor. Detailed Implementation

[0022] 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.

[0023] This invention provides a water source heat pump energy station with wide temperature range cascade heating, such as... Figures 1-7As shown, the system includes: a first circulation group 1, used for lake water circulation, which prevents lake water from directly entering the subsequent heat exchange system, effectively isolating impurities, microorganisms and other pollutants in the lake water, and reducing the risk of corrosion and scaling of core equipment such as the first screw heat pump host 21, the second screw heat pump host 22 and the first plate heat exchanger 6 in the second circulation group 2; the second circulation group 2, which forms a heat exchange connection with the first circulation group 1 through the first plate heat exchanger 6, avoiding direct contact between the media of the two circulation groups, preventing cross-contamination, and further improving the operational reliability of the first screw heat pump host 21 and the second screw heat pump host 22; a third circulation group 3, which connects to the second circulation group 2 to form a closed loop; and a fourth circulation group 4, which connects to the third circulation group 3, and the fourth circulation group 4 and the third circulation group 3 form a heat exchange connection through multiple sets of second plate heat exchangers 61. The setting of multiple sets of second plate heat exchangers 61 realizes the distributed transfer of heat, which can be adjusted according to the high temperature of the terminal heat pump. The heat distribution of unit 51 is flexible to meet the heat demand, thereby improving heat utilization efficiency. The fifth circulation group 5, which is connected to the fourth circulation group 4 through multiple sets of second plate heat exchangers 61, is used to produce high-temperature hot water at different temperatures. The fifth circulation group 5 includes multiple high-temperature heat pump units 51, each of which is connected to an external circulation pipe 52 and a connecting circulation pipe 53. The connecting circulation pipe 53 is connected to multiple sets of second plate heat exchangers 61 to ensure that the heat from the fourth circulation group 4 is efficiently transferred to the high-temperature heat pump units 51. The external circulation pipe 52 is connected to external equipment to improve system adaptability. The multiple high-temperature heat pump units 51 are equipped with R134a refrigerant, R515B / R1234ze refrigerant, R245fa refrigerant, and R1233zd refrigerant, respectively. The thermal characteristics of different refrigerants are adapted to the heating demand in different temperature ranges, and can accurately output various high-temperature hot water required for industrial production to meet diverse heating scenarios.

[0024] The first circulation group 1 includes: a first circulation pipe 11, with an inlet 12 at one end and an outlet 13 at the other end. Multiple sets of water intake pumps 16 are installed along the conveying path of the first circulation pipe 11, which can flexibly adjust the water intake flow according to the changes in lake water level and temperature to ensure sufficient supply of low-temperature heat source and avoid system shutdown due to failure of a single water intake pump 16. Multiple sets of cyclone sand separators 14 can efficiently remove fine particles such as silt from the lake water, preventing impurities from entering the first plate heat exchanger 6 and causing blockage, ensuring stable heat exchange efficiency. The first plate heat exchanger 6 is installed along the conveying path of the first circulation pipe 11, which shortens the heat exchange path, reduces pipeline resistance, and improves system operating efficiency.

[0025] A grid 15 is installed on the inlet 12. The grid 15 can pre-intercept large particles of impurities such as branches, stones, and aquatic organisms in the lake water, preventing them from entering the first circulation pipe 11 and clogging the water intake pump 16, the cyclone sand separator 14, or the first plate heat exchanger 6, thereby reducing the probability of equipment failure, reducing maintenance costs, and ensuring the smooth operation of the first circulation group 1.

[0026] The second circulation group 2 includes: a first screw heat pump host 21 and a second screw heat pump host 22. The evaporation side ports of the first screw heat pump host 21 and the second screw heat pump host 22 are connected to a second circulation pipe 23. The condensation side ports of the first screw heat pump host 21 and the second screw heat pump host 22 are both connected to a third circulation pipe 33. A first plate heat exchanger 6 is installed on the conveying path of the second circulation pipe 23, so that the second circulation pipe 23 and the first circulation pipe 11 can exchange heat, which can fully recover the low-grade heat energy of the lake water source in the first circulation pipe 11. In addition, multiple sets of cold water pumps 24 are also installed on the conveying path of the second circulation pipe 23, which can flexibly adjust the flow rate of the medium in the second circulation pipe 23 according to the heat exchange requirements, ensure the energy supply matching of the evaporation side of the heat pump host, and improve the energy efficiency of the system.

[0027] The third circulation group 3 includes: a water distributor 31 and a water collector 32 to achieve uniform distribution and collection of the circulating medium, ensuring balanced heat exchange in each branch and avoiding local overheating or insufficient heat. A third circulation pipe 33 is connected to the water distributor 31 and the water collector 32. A bypass pipe 39 is connected to the conveying path of the third circulation pipe 33. A closed pressure tank 35 is installed on the bypass pipe 39 to automatically balance the system pressure. Multiple sets of water replenishment pumps 36 work in conjunction with the water replenishment tank 37 to quickly replenish the medium that has been leaked or lost in the system, ensuring the continuity of circulation. An electric boiler 38 on the third circulation pipe 33 serves as an emergency heating device, which can replenish heat in extreme low temperatures, avoid system heating interruption, and improve heating reliability. Multiple sets of hot water pumps 34 on the third circulation pipe 33 provide power for the heat medium in the third circulation pipe 33, driving the medium to circulate between the water distributor 31, the water collector 32, and the condenser side of the heat pump host.

[0028] The fourth circulation group 4 includes a water distributor 31 and a water collector 32 shared with the third circulation group 3. The water distributor 31 is connected to a domestic hot water discharge pipe 43, which is used to directly extract heat from the water distributor 31 and supply domestic hot water directly, realizing the cascade utilization of heat and improving the comprehensive energy utilization rate. The water distributor 31 is also connected to multiple sets of water outlet pipes 41, and the water collector 32 is connected to multiple sets of water return pipes 42. The multiple sets of water outlet pipes 41 and multiple sets of water return pipes 42 are all connected to a second plate heat exchanger 61. The setting of multiple sets of second plate heat exchangers 61 realizes the distributed transfer of heat, and can flexibly allocate heat according to the heat demand of the terminal high-temperature heat pump unit 51, thereby improving the heat utilization efficiency.

[0029] A buffer unit is provided on the third circulation pipe 33. The buffer unit includes a spiral coil 71, a buffer tank 7, and a bubble separator 72, all of which are arranged on the conveying path of the third circulation pipe 33. The spiral coil 71 is used to extend the residence time of the medium in the buffer unit, promote the precipitation and floating of non-condensable gases and micro bubbles in the circulating medium, and at the same time slow down the medium flow rate, stabilize the pipeline pressure fluctuation, and avoid system noise and component wear caused by water flow impact. The buffer tank 7 is used to contain the expansion medium and balance the pressure changes in the third circulation pipe 33 to ensure the pressure stability of the closed circulation system. The bubble separator 72 can effectively separate the air and bubbles entrained in the circulation medium, reduce the adverse effects of cavitation on the third circulation pipe 33, the first screw heat pump host 21 and the second screw heat pump host 22, improve the heat exchange stability and system operation safety. The buffer tank 7 is provided with a chemical dosing port 73, through which corrosion inhibitors, scale inhibitors and bactericides and algaecides can be periodically added to the third circulation pipe 33 to inhibit scaling, corrosion and microbial growth in the circulation medium and extend the service life of the pipeline and core heat exchange equipment.

[0030] It also includes a water quality sensor 74, which is installed on the transport path of the third circulation pipe 33 to detect water quality. It is used to monitor key water quality parameters such as conductivity, pH value and turbidity of the circulating medium in real time, and to reflect the trend of medium pollution, corrosion and scaling in a timely manner. The water quality sensor 74 can upload the detection signal to the control system. When the water quality index exceeds the preset range, the system can issue an early warning in time, prompting the operator to replenish the agent or adjust the water quality through the chemical addition port 73 of the buffer tank 7, thereby realizing online monitoring and active maintenance of circulating water quality, and ensuring the long-term stable and efficient operation of the third circulation group 3 and subsequent cascade heating circuits.

[0031] A method for using a wide-temperature-range cascade hot water source heat pump energy station: S1. Start multiple sets of water intake pumps 16. Lake water enters the system from the inlet 12 of the first circulation pipe 11. The lake water first passes through the screen 15 at the end of the inlet 12. The screen 15 effectively intercepts large particles such as branches and stones, preventing them from entering subsequent equipment and causing damage or blockage. After preliminary filtration by the screen 15, the lake water flows into the cyclone separator 14. Under the action of cyclone separation, fine particles such as silt in the water are separated and settled, completing the pretreatment of the water source and ensuring the cleanliness of the lake water entering subsequent stages. The pretreated lake water continues to flow along the first circulation pipe 11. When it passes through the first plate heat exchanger 6, it undergoes indirect heat exchange with the medium of the second circulation group 2. The heat in the lake water is absorbed by the medium, and the lake water that has released the heat finally flows back into the lake from the outlet 13, realizing the circulation and isolation function on the lake water source side, and avoiding excessive extraction and pollution of the lake water. S2. The treated lake water is transported to the first plate heat exchanger 6 through the first circulation pipe 11 to exchange heat with the fluid in the second circulation group 2. At this time, multiple cold water pumps 24 in the second circulation group 2 are started to transport the fluid in the second circulation pipe 23 to the first plate heat exchanger 6 to absorb the heat in the lake water and raise the fluid temperature. The heated fluid enters the evaporation side of the first screw heat pump host 21 and the second screw heat pump host 22. Inside the first screw heat pump host 21 and the second screw heat pump host 22, the fluid releases heat, causing the refrigerant inside the first screw heat pump host 21 and the second screw heat pump host 22 to evaporate and absorb heat. The evaporated refrigerant enters the condensation side and exchanges heat with the fluid in the third circulation pipe 33, transferring heat to the fluid in the third circulation pipe 33 and raising its temperature. When the first screw heat pump host 21 and the second screw heat pump host 22 are running, their condenser side releases heat to heat the circulating water in the third circulation pipe 33. By starting multiple sets of hot water pumps 34 on the third circulation pipe 33, the heated fluid is transported into the water distributor 31. The temperature gauge and pressure gauge on the water distributor 31 monitor the internal water temperature and pressure in real time to ensure the stability and safety of the domestic hot water supply. When maintenance is required or the system is over-pressurized, the drain valve can discharge excess water to ensure system safety. The return water after heat exchange is collected in the water collector 32 along multiple sets of return water pipes 42, and then flows back to the condenser side of the first screw heat pump host 21 and the second screw heat pump host 22 through the third circulation pipe 33, forming a closed loop on the condenser side to continuously provide heat to the system. S4, the fourth circulation group 4 and the third circulation group 3 share the water distributor 31 and the water collector 32. A portion of the hot water in the water distributor 31 is directly supplied to domestic hot water through the domestic hot water discharge pipe 43 to meet the daily needs of washing, bathing and other activities. Multiple sets of water outlet pipes 41 on the water distributor 31 transport the hot water to multiple sets of second plate heat exchangers 61 to exchange heat with the return water in the fourth circulation group 4. Through the multi-stage heat exchange of multiple sets of second plate heat exchangers 61, heating for different temperature requirements is achieved. S5, the multiple high-temperature heat pump units 51 in the fifth circulation group 5 are started, and the circulation pipe 53 is connected to multiple second plate heat exchangers 61 to absorb the heat of the fluid in the second plate heat exchangers 61. The different high-temperature heat pump units 51 are respectively equipped with R134a refrigerant, R515B / R1234ze refrigerant, R245fa refrigerant and R1233zd refrigerant. These refrigerants have different physical properties and operating temperature ranges, which can realize step-by-step heating. For example, R134a refrigerant can raise the temperature to 85℃, R515B / R1234ze refrigerant can raise it to 100℃, R245fa refrigerant can raise it to 125℃, and R1233zd refrigerant can raise it to 145℃. After being heated in stages by different high-temperature heat pump units 51, the high-temperature hot water is finally output to external equipment in different industrial scenarios through external circulation pipes 52, meeting diverse heating needs, such as heating and drying processes in industrial production, as well as district heating.

[0032] Working principle: Lake water source side water intake and pretreatment circulation First circulation group 1: Start multiple water intake pumps 16, the lake water source enters from the inlet 12 of the first circulation pipe 11, after passing through the grid 15 at the end of the inlet 12 to intercept large particles of impurities such as branches and stones, it flows into the cyclone sand separator 14, and removes fine particles such as silt and sand in the water through cyclone separation, completing the water source pretreatment; the pretreated lake water continues to flow along the first circulation pipe 11, and when passing through the first plate heat exchanger 6, it undergoes indirect heat exchange with the medium of the second circulation group 2. After releasing heat, the lake water finally flows back to the lake from the outlet 13, realizing the circulation and isolation function of the lake water source side.

[0033] Second circulation group 2 of closed-loop heat exchange cycle on the evaporator side of the heat pump host: The cold water pump 24 is started to drive the circulation medium in the second circulation pipe 23 to flow. When the medium flows through the first plate heat exchanger 6, it absorbs the heat of the lake water in the first circulation pipe 11 and rises in temperature. Then it flows into the evaporator side of the first screw heat pump host 21 and the second screw heat pump host 22. Inside the first screw heat pump host 21 and the second screw heat pump host 22, the heat in the medium is absorbed by the refrigerant. After cooling down, it flows back to the first plate heat exchanger 6 along the second circulation pipe 23, forming a closed loop cycle, and continuously providing a low-temperature heat source for the first screw heat pump host 21 and the second screw heat pump host 22.

[0034] The third circulation group 3 of the closed-loop heating cycle on the condenser side of the heat pump host: When the first screw heat pump host 21 and the second screw heat pump host 22 are running, the heat released from their condenser side heats the circulating water in the third circulation pipe 33. The heated hot water flows into the water distributor 31 and is divided into two paths after being distributed by the water distributor 31: one path directly supplies domestic hot water through the domestic hot water discharge pipe 43; the other path is transported to the terminal heat exchange unit through multiple sets of water outlet pipes 41. The temperature gauge and pressure gauge installed on the water distributor 31 monitor the internal water temperature and water pressure in real time. The drain valve can discharge excess water during maintenance or overpressure. The return water after heat exchange is collected along multiple sets of return water pipes 42 to the water collector 32, and then flows back to the condenser side of the first screw heat pump host 21 and the second screw heat pump host 22 through the third circulation pipe 33, forming a closed-loop cycle on the condenser side.

[0035] Terminal high-temperature heat pump heat source side circulation and cascade heating: In the fourth circulation group 4, the hot water output from the distributor 31 enters the heat source side of the second plate heat exchanger 61 through the outlet pipe 41, transfers heat to the circulating medium of the fifth circulation group 5, and then flows back to the collector 32 along the return pipe 42; the connecting circulation pipe 53 in the fifth circulation group 5 forms a closed loop with the cold source side of the second plate heat exchanger 61. After absorbing heat, the medium flows into multiple high-temperature heat pump units 51. Each high-temperature heat pump unit 51 uses R134a, R515B / R1234ze, R245fa, and R1233zd refrigerants respectively. The refrigerant temperature can be raised to 85℃, 100℃, 125℃ and 145℃ respectively. The temperature is raised in stages by using the thermodynamic characteristics of different refrigerants. Finally, high-temperature hot water of the corresponding temperature is output to external equipment in different industrial scenarios through the external circulation pipe 52 to meet diverse heating needs.

[0036] System Regulation and Emergency Support: During the circulation process, the system automatically adjusts the operating status of the first screw heat pump host 21 and the second screw heat pump host 22 according to the return water temperature of the water collector 32: when the return water temperature is lower than the set value, the host increases the operating frequency to increase the heat generation on the condensing side; when the return water temperature is higher than the set value, the host decreases the operating frequency to reduce heat generation and maintain system temperature stability. When the pressure or water volume in the third circulation pipe 33 is insufficient, the water supply pump 36 is started to draw water from the water supply tank 37 and supplement it to the circulation system through the bypass pipe 39, while the closed pressure tank 35 synchronously maintains the system pressure stability. When encountering prolonged extreme low temperature weather that causes the lake water temperature to drop and the heat source to be insufficient, the heat generation on the condensing side of the first screw heat pump host 21 and the second screw heat pump host 22 cannot meet the demand. At this time, the electric boiler 38 is started to supplement the heating of the water in the third circulation pipe 33 to ensure that the output water temperature of the water distributor 31 is stable at 50-55℃, ensuring the reliability of heating.

[0037] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A water source heat pump energy station with wide temperature range cascade heating, characterized in that, include: The first circulation group (1) is used for lake water circulation; The second circulation group (2) is connected to the first circulation group (1) through the first plate heat exchanger (6) for heat exchange. The third loop group (3) is connected to the second loop group (2) to form a closed loop; The fourth circulation group (4) is connected to the third circulation group (3), and the fourth circulation group (4) and the third circulation group (3) are connected by multiple sets of second plate heat exchangers (61). The fifth circulation group (5) is connected to the fourth circulation group (4) by multiple sets of second plate heat exchangers (61) to produce high-temperature hot water at different temperatures. The fifth circulation group (5) includes: multiple high-temperature heat pump units (51), each of the multiple high-temperature heat pump units (51) is connected to an external circulation pipe (52) and a connecting circulation pipe (53), the connecting circulation pipe (53) is connected to multiple second plate heat exchangers (61), the external circulation pipe (52) is connected to external equipment, and the multiple high-temperature heat pump units (51) are respectively equipped with R134a refrigerant, R515B / R1234ze refrigerant, R245fa refrigerant and R1233zd refrigerant.

2. The water source heat pump energy station with wide temperature range cascade heating according to claim 1, characterized in that: The first loop group (1) includes: The first circulation pipe (11) has an inlet (12) at one end and an outlet (13) at the other end. Multiple sets of water pumps (16) and multiple sets of cyclone sand removers (14) are installed on the conveying path of the first circulation pipe (11), and the first plate heat exchanger (6) is installed on the conveying path of the first circulation pipe (11).

3. A water source heat pump energy station with wide temperature range cascade heating according to claim 2, characterized in that: A grille (15) is provided on the water inlet (12).

4. A water source heat pump energy station with wide temperature range cascade heating according to claim 1, characterized in that: The second loop group (2) includes: The first screw heat pump host (21) and the second screw heat pump host (22) are connected to the evaporation side port of the first screw heat pump host (21) and the second screw heat pump host (22) via a second circulation pipe (23), and the condensation side port of the first screw heat pump host (21) and the second screw heat pump host (22) are connected to a third circulation pipe (33). A first plate heat exchanger (6) is provided on the conveying path of the second circulation pipe (23) so that the second circulation pipe (23) and the first circulation pipe (11) can exchange heat. Multiple sets of cold water pumps (24) are also provided on the conveying path of the second circulation pipe (23).

5. A water source heat pump energy station with wide temperature range cascade heating according to claim 1, characterized in that: The third cyclic group (3) includes: The water distributor (31) and the water collector (32) are connected to a third circulation pipe (33), and a bypass pipe (39) is connected to the conveying path of the third circulation pipe (33). A closed pressure tank (35), multiple sets of water replenishment pumps (36) and a water replenishment tank (37) are installed on the bypass pipe (39). An electric boiler (38) and multiple sets of hot water pumps (34) are also installed along the conveying path of the third circulation pipe (33).

6. A water source heat pump energy station with wide temperature range cascade heating according to claim 1, characterized in that: The fourth cycle group (4) includes: The water distributor (31) and water collector (32) are shared with the third circulation group (3). The water distributor (31) is connected to a domestic hot water discharge pipe (43), and the water distributor (31) is also connected to multiple sets of water outlet pipes (41). The water collector (32) is connected to multiple sets of water return pipes (42). The multiple sets of water outlet pipes (41) and multiple sets of water return pipes (42) are all connected to a second plate heat exchanger (61).

7. A water source heat pump energy station with wide temperature range cascade heating according to claim 5, characterized in that: The third circulation pipe (33) is provided with a buffer unit, which includes a spiral coil (71), a buffer tank (7) and a bubble separator (72), all of which are arranged on the conveying path of the third circulation pipe (33). The buffer tank (7) is provided with a dosing port (73).

8. A water source heat pump energy station with wide temperature range cascade heating according to claim 7, characterized in that: Also includes: A water quality sensor (74) is installed on the transport path of the third circulation pipe (33) to detect water quality.

9. A method for using a wide-temperature-range cascade hot water source heat pump energy station, characterized in that: S1. After the lake water enters the first circulation pipe (11), multiple sets of water pumps (16) are started to draw and transport the lake water. During the transportation process, multiple sets of cyclone sand removers (14) remove sand from the lake water to remove fine particles such as mud and sand, ensuring the cleanliness of the lake water entering the first plate heat exchanger (6). S2. The treated lake water is transported to the first plate heat exchanger (6) through the first circulation pipe (11) to exchange heat with the fluid in the second circulation group (2). At this time, multiple cold water pumps (24) in the second circulation group (2) are started to transport the fluid in the second circulation pipe (23) to the first plate heat exchanger (6) to absorb the heat in the lake water and raise the fluid temperature. The heated fluid enters the evaporation side of the first screw heat pump host (21) and the second screw heat pump host (22). Inside the heat pump host, the fluid releases heat, causing the refrigerant inside the heat pump host to evaporate and absorb heat. The evaporated refrigerant enters the condensation side and exchanges heat with the fluid in the third circulation pipe (33), transferring heat to the fluid in the third circulation pipe (33) and raising its temperature. S3, the water distributor (31) and water collector (32) in the third circulation group (3) form a closed circulation through the third circulation pipe (33). By starting multiple sets of hot water pumps (34) on the third circulation pipe (33), the heated fluid is transported into the water distributor (31) and then distributed to different branches according to demand. S4, the fourth circulation group (4) and the third circulation group (3) share a water distributor (31) and a water collector (32). A portion of the hot water in the water distributor (31) is directly supplied to domestic hot water through the domestic hot water discharge pipe (43) to meet the daily needs of washing, bathing and other activities. Multiple sets of water outlet pipes (41) on the water distributor (31) transport the hot water to multiple sets of second plate heat exchangers (61) to exchange heat with the return water in the fourth circulation group (4). Through the multi-stage heat exchange of multiple sets of second plate heat exchangers (61), the heating for different temperature requirements is realized. S5. The high-temperature heat pump units (51) in the fifth circulation group (5) are started and connected to the circulation pipe (53) and the second plate heat exchanger (61) to absorb the heat of the fluid in the second plate heat exchanger (61). The different high-temperature heat pump units (51) are equipped with R134a refrigerant, R515B / R1234ze refrigerant, R245fa refrigerant and R1233zd refrigerant respectively. These refrigerants have different physical properties and operating temperature ranges. The appropriate high-temperature heat pump unit (51) can be selected to operate according to the actual temperature requirements of high-temperature hot water production. The high-temperature hot water heated by the high-temperature heat pump unit (51) is connected to external equipment through the external circulation pipe (52) to provide high-temperature hot water for industrial production, district heating and other purposes.

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