A compression type temperature difference heat exchange unit for heat exchange station
By using a compressed temperature differential heat exchange unit in the heat exchange station and using the heat energy of primary return water for cascade utilization, the problem of insufficient waste heat recovery in traditional heat exchange systems is solved, and the heat network transportation capacity and heating energy efficiency are improved.
Patent Information
- Application Number
- CN202421480037.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-26
- Publication Date
- 2025-04-11
- Estimated Expiration
- 2034-06-26
AI Technical Summary
During the heat exchange process, the traditional water-water plate heat exchange system has problems such as limited capacity of large temperature difference heat exchange unit and incomplete cooling of the primary network return water, resulting in insufficient waste heat recovery of heat sources, reduced heat supply, and low heating energy efficiency.
A compressed temperature difference heat exchange unit for heat exchange stations is adopted, including a primary pipeline network, a secondary pipeline network, a plate heat exchanger, a compressed heat pump unit and a control device. The compressed heat pump unit uses the thermal energy of the primary return water for cascade utilization, increase the secondary water supply temperature and reduce the primary return water temperature.
Without changing the primary water supply temperature and secondary return water temperature, the heat network conveying capacity is improved, the operating cost of the heat network is reduced, the heating capacity of the existing pipeline network is enhanced, the heating demand of the user side is met, and the later maintenance costs are reduced.
Smart Images
Figure CN222747337U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of centralized heating, and in particular relates to a compression type temperature difference heat exchange unit for a heat exchange station. Background Art
[0002] With the development of society and the improvement of people's living standards, the use of centralized heating systems for winter heating of buildings or building communities in cities is becoming more and more widespread. In the traditional centralized heating system using waste heat from power plants as the heat source, the high-temperature water produced by the heat source is transported to the heat exchange station through the primary network and heats the return water of the secondary pipe network through the primary heat exchanger. The heated hot water in the secondary pipe network is supplied to users. At present, the heat exchange station adopts the traditional water-water plate heat exchange system, which has problems such as limited capacity of large temperature difference heat exchange units and incomplete cooling of return water from the primary network, resulting in excessively high return water temperature of the primary heat network returning to the heat exchange station. After the return water is transported back to the heat source, the waste heat cannot be effectively recovered, resulting in reduced heat supply and low heating efficiency. It is also not conducive to fully utilizing the heating capacity of the existing pipe network, affecting the economic efficiency of project operation. Moreover, with the rapid development of urbanization, the gradual expansion of urban scale, and the improvement of people's living standards, the demand for urban centralized heating has increased significantly, the centralized heating area and heat load have also increased significantly, and the centralized heating network is also facing the problem of insufficient heating capacity; new pipelines are needed to meet the heating requirements, but the investment in new pipelines is large and the cost is high. Therefore, the effective use of the waste heat of the primary network return water is of great significance to improving the transmission capacity of the heating network and reducing the operating cost of the heating network. Summary of the invention
[0003] To solve the above problems, the purpose of the utility model is to provide a compression type temperature difference heat exchange unit for a heat exchange station with reasonable structural design and good use effect, which can effectively improve the heat network transmission capacity and reduce the operation cost of the heat network.
[0004] In order to achieve the above-mentioned invention object, the utility model adopts the following technical solutions:
[0005] A compression type temperature difference heat exchange unit for a heat exchange station, comprising a primary pipe network, a secondary pipe network, a plate heat exchanger, a compression type heat pump unit and a control device, wherein the primary water supply pipeline and the primary return water pipeline of the primary pipe network are respectively connected to the primary side inlet and the primary side outlet of the plate heat exchanger, and the secondary water supply pipeline and the secondary return water pipeline of the secondary pipe network are respectively connected to the secondary side outlet and the secondary side inlet of the plate heat exchanger; the compression type heat pump unit comprises an evaporator, at least two parallel compressors, a condenser and an expansion valve connected in sequence through pipelines, the primary side inlet of the evaporator is connected to the primary return water pipeline of the primary pipe network and the primary side outlet of the plate heat exchanger through a first pipeline, and the primary side outlet The condenser is connected to the primary return water pipeline of the primary pipeline network through the second pipeline, the secondary side inlet of the condenser is connected to the secondary water supply pipeline of the secondary pipeline network and the secondary side outlet of the plate heat exchanger through the third pipeline, and the secondary side outlet is connected to the secondary water supply pipeline of the secondary pipeline network through the fourth pipeline; the primary water supply pipeline of the primary pipeline network, the primary return water pipeline, the secondary water supply pipeline of the secondary pipeline network, the secondary return water pipeline, the first pipeline, the second pipeline, the third pipeline, and the fourth pipeline are all provided with temperature transmitters, solenoid valves, pressure transmitters, and flow transmitters, and each of the temperature transmitters, solenoid valves, pressure transmitters, flow transmitters, and the compression heat pump unit are all connected to the control device.
[0006] Furthermore, the above-mentioned control device includes a PLC controller, and an analog input module, an analog output module, an RS485 communication module, a DTU wireless transmission module, a touch screen, and a DC power supply connected to the PLC controller. The analog input module is connected to the various temperature transmitters, pressure transmitters, and flow transmitters, and is connected to the feedback signal ends of the various solenoid valves via a relay assembly. The analog output module is connected to the given signal ends of the various solenoid valves via a relay assembly; the DTU wireless transmission module is connected to a cloud server or a monitoring center computer via a wireless network; and the compression heat pump unit is connected to the PLC controller via an RS485 communication module.
[0007] Furthermore, the DC power supply includes an AC-DC converter, the 220V AC mains is connected to the input end of the AC-DC converter via an isolation transformer, and the output end of the AC-DC converter is connected to the power end of the PLC controller.
[0008] Furthermore, a circulation pump and a solenoid valve are provided on the secondary water return pipeline in the secondary pipe network, the circulation pump is connected to the first frequency converter, and the first frequency converter is connected to the PLC controller via an RS485 communication module.
[0009] Furthermore, the above-mentioned compression temperature difference heat exchanger unit for the heat exchange station also includes a water tank, and the water outlet provided on the water tank is connected to the secondary return water pipeline in the secondary pipe network through a water supply pipe. The water supply pipe is provided with a water supply pump and a solenoid valve. The water supply pump is connected to the second frequency converter, and the second frequency converter is connected to the PLC controller through an RS485 communication module. The feedback signal end and the given signal end of the solenoid valve are respectively connected to the analog input module and the analog output module.
[0010] Furthermore, the water return port of the water tank is connected to the secondary water return pipeline in the secondary pipe network through a water return pipe, and a pressure relief solenoid valve is provided on the water return pipe, and the pressure relief solenoid valve is connected to the PLC controller.
[0011] Furthermore, the water inlet of the water tank is connected to an external water source through a water inlet pipe, and a float-type liquid level sensor, a temperature sensor, and a heater are arranged in the water tank; a water pump and a solenoid valve are arranged on the water inlet pipe, and the float-type liquid level sensor, temperature sensor, heater, water pump, and solenoid valve are all connected to the PLC controller.
[0012] Due to the adoption of the above-mentioned technical solution, the utility model has the following advantages:
[0013] The heat exchange station uses a compression temperature difference heat exchange unit with a compact structure, small footprint and easy installation. It is improved on the basis of the existing water-water plate heat exchange system and adds a heat pump unit. It can use the heat energy of the primary return water as a heat source to increase the secondary water supply temperature and significantly reduce the primary return water temperature without changing the primary water supply temperature and the secondary return water temperature in the heat exchange station. Under the condition that the primary water supply temperature is constant and the secondary return water temperature and flow rate remain unchanged, the primary water supply flow rate is reduced, the heating capacity of the existing primary pipe network is improved, and the heating demand of the user end is met; the construction is convenient, the transformation cost is low, the system is highly intelligent, the operation is simple, the working efficiency is high, the practicality is strong, the system can flexibly meet various heating needs, the later maintenance cost is low, and the system has good promotion and application value. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is a structural schematic diagram of a compression type temperature difference heat exchange unit for a heat exchange station of the utility model;
[0015] Figure 2 It is a structural schematic diagram of a control device for a compression-type temperature difference heat exchange unit for a heat exchange station of the utility model;
[0016] In the figure: 1-heat source; 2-primary water supply pipeline; 3-primary return pipeline; 4-plate heat exchanger; 5-secondary water supply pipeline; 6-secondary return pipeline; 7-user end; 8 (a, b, c)-solenoid valve; 9-circulation pump; 10-water supply pump; 11-water supply pipeline; 12-pressure relief solenoid valve; 13-return pipeline; 14-water tank; 15-water pump; 16-water inlet pipeline; 17-water source; 18-third pipeline; 19-fourth pipeline; 20-compression heat pump unit; 21-evaporator; 22-compressor; 23-condenser; 24-expansion valve; 25-first pipeline; 26-second pipeline. DETAILED DESCRIPTION
[0017] The technical solution of the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments.
[0018] like Figure 1 , 2 As shown, the heat exchange station uses a compression type temperature difference heat exchange unit, which includes a primary pipe network, a secondary pipe network, a plate heat exchanger 4, a compression type heat pump unit 20, and a control device. The heat source 1 is connected to the plate heat exchanger 4 through the primary pipe network, and the user end 7 is connected to the plate heat exchanger 4 through the secondary pipe network. The primary water supply pipeline 2 and the primary return water pipeline 3 of the primary pipe network are respectively connected to the primary side inlet and the primary side outlet of the plate heat exchanger 4, and the secondary water supply pipeline 5 and the secondary return water pipeline 6 of the secondary pipe network are respectively connected to the secondary side outlet and the secondary side inlet of the plate heat exchanger 4; the compression type heat pump unit 20 includes an evaporator 21, at least two parallel compressors 22, a condenser 23, and an expansion valve 24 connected in sequence through pipelines. The secondary side of the evaporator, the compressor, the primary side of the condenser and the expansion valve form a complete cycle through the refrigerant. The primary side inlet of the evaporator 21 is connected to the primary side of the evaporator 21 through the first pipe 2 5 is connected to the primary return water pipeline 3 of the primary pipeline network and the primary side outlet of the plate heat exchanger 4, the primary side outlet is connected to the primary return water pipeline 3 of the primary pipeline network through the second pipeline 26, the secondary side inlet of the condenser 23 is connected to the secondary water supply pipeline 5 of the secondary pipeline network and the secondary side outlet of the plate heat exchanger 4 through the third pipeline 18, and the secondary side outlet is connected to the secondary water supply pipeline 5 of the secondary pipeline network through the fourth pipeline 19; the primary water supply pipeline 2 of the primary pipeline network, the primary return water pipeline 3, the secondary water supply pipeline 5 of the secondary pipeline network, the secondary return water pipeline 6, the first pipeline 25, the second pipeline 26, the third pipeline 18, and the fourth pipeline 19 are all provided with temperature transmitters, solenoid valves, pressure transmitters, and flow transmitters, and each of the temperature transmitters, solenoid valves, pressure transmitters, flow transmitters, and the compression heat pump unit are all connected to the control device.
[0019] The above-mentioned control device includes a PLC controller, and an analog input module, an analog output module, an RS485 communication module, a DTU wireless transmission module, a touch screen, and a DC power supply connected to the PLC controller. The analog input module is connected to the various temperature transmitters, pressure transmitters, and flow transmitters, and is connected to the feedback signal ends of the various solenoid valves via a relay assembly. The analog output module is connected to the given signal ends of the various solenoid valves via a relay assembly; the DTU wireless transmission module is connected to a cloud server or a monitoring center computer via a wireless network to facilitate remote control; the compression heat pump unit is connected to the PLC controller via an RS485 communication module.
[0020] The above-mentioned DC power supply includes an AC-DC converter, and the 220V AC mains is connected to the primary winding of the isolation transformer. The secondary winding of the isolation transformer includes a first winding and a second winding. The first winding is connected to the input end of the AC-DC converter, and the output end of the AC-DC converter is connected to the power end of the PLC controller to provide a 24V DC power supply for the PLC controller; the second winding outputs 24V AC power to power each solenoid valve.
[0021] A circulation pump 9 and a solenoid valve 8a are provided on the secondary water return pipeline 6 in the secondary pipe network. The circulation pump is connected to the first frequency converter, and the first frequency converter is connected to the PLC controller via an RS485 communication module.
[0022] The above-mentioned compression temperature difference heat exchange unit for the heat exchange station also includes a water tank 14. The water outlet provided on the water tank is connected to the secondary return water pipeline 6 in the secondary pipe network through the water supply pipe 11. The water supply pipe is provided with a water supply pump 10 and a solenoid valve 8b. The water supply pump is connected to the second frequency converter. The second frequency converter is connected to the PLC controller through the RS485 communication module. The feedback signal end and the given signal end of the solenoid valve 8b are respectively connected to the analog input module and the analog output module.
[0023] The return water port of the water tank 14 is connected to the secondary return water pipeline 6 in the secondary pipe network through the return water pipe 13. A pressure relief solenoid valve 12 is provided on the return water pipe. The pressure relief solenoid valve is connected to the PLC controller. Preferably, the output end of the PLC controller controls the pressure relief solenoid valve through a relay to relieve pressure on the secondary pipe network, thereby improving the reliability of safe pressure relief.
[0024] The water inlet of the water tank 14 is connected to the external water source 17 through the water inlet pipe 16. A float-type liquid level sensor, a temperature sensor, and a heater are arranged in the water tank. The float-type liquid level sensor is used to monitor the water volume in the water tank, the temperature sensor is used to monitor the water temperature in the water tank, and the heater is used to heat the water in the water tank; a water pump 15 and a solenoid valve 8c are arranged on the water inlet pipe, and the float-type liquid level sensor, the temperature sensor, the heater, the water pump, and the solenoid valve are all connected to the PLC controller. When the float-type liquid level sensor detects that the water level is lower than the set value, the collected signal is transmitted to the PLC controller. After receiving the signal, the PLC controller controls the solenoid valve 8c to open and the water pump 15 to start, and water is injected into the water tank 14; when the temperature sensor detects that the temperature is lower than the set value, the heater is controlled to work to heat the water in the water tank.
[0025] The utility model uses a compression temperature difference heat exchange unit for a heat exchange station. Preferably, the analog input module uses multiple analog input modules of model SM1231; the analog output module uses multiple analog output modules of model SM1232; and the RS485 communication module uses multiple RS485 communication modules of model CM1241.
[0026] The above-mentioned temperature transmitters, pressure transmitters, and flow transmitters are respectively used to detect the water temperature, water pressure, and water flow in the corresponding pipelines and upload signals to the PLC controller. The PLC controller processes and analyzes the collected signals to control the opening of each solenoid valve, the frequency conversion control amount of the circulation pump 9 and the water supply pump 10, and the working state of the compression heat pump unit.
[0027] The specific working process of the compression type temperature difference heat exchange unit for the heat exchange station of the utility model is described below.
[0028] The primary water supply of the primary pipe network enters the plate heat exchanger 4 through the primary water supply pipeline 2 to transfer heat to the secondary return water of the secondary pipe network. The primary return water enters the primary side of the evaporator 21 of the compression heat pump unit 20. The refrigerant on the primary side of the condenser enters the secondary side of the evaporator and exchanges heat with the above-mentioned primary return water on the primary side of the evaporator. After the water is cooled to the required temperature, it flows back to the primary return water pipeline 3 of the primary pipe network through the second pipeline 26. The refrigerant evaporates in the evaporator to extract the residual heat of the primary return water in the primary pipe network. The evaporated refrigerant enters the compressor 22 and is compressed into a high-temperature and high-pressure steam state, and then enters the condenser 23. The condensation releases heat and heats the secondary water supply of the secondary pipe network on the secondary side of the condenser through the third pipeline 18. After the water is heated to the required temperature, it flows back to the secondary water supply pipeline 5 of the secondary pipe network through the fourth pipeline 19. The liquid refrigerant is depressurized by the expansion valve 24 and then sent back to the evaporator 21 to complete the cycle, thereby realizing the step-by-step utilization of heat and meeting the heating demand.
[0029] After the secondary water supply of the secondary pipe network exchanges heat with the primary water supply of the primary pipe network through the plate heat exchanger 4, a part of it absorbs heat through the condenser 23 of the compression heat pump unit 20, and is mixed with the other part of the secondary water supply and then sent to the user end. The flow distribution of the two water routes is an important parameter affecting the entire heating effect, and the PLC controller can achieve precise control and adjustment. It is flexible to use and can start and stop the compression heat pump unit at any time according to the heat source, weather and other conditions, reducing operating costs.
[0030] The above description is only a preferred embodiment of the present invention, and not a limitation of the present invention. Without departing from the spirit and scope of the present invention, all equivalent changes and modifications made within the scope of the patent application of the present invention shall fall within the scope of patent protection of the present invention.
Claims
1. A compression type temperature difference heat exchange unit for a heat exchange station, comprising a primary pipe network, a secondary pipe network, a plate heat exchanger, a compression type heat pump unit and a control device, wherein the primary water supply pipeline and the primary return water pipeline of the primary pipe network are respectively connected to the primary side inlet and the primary side outlet of the plate heat exchanger, and the secondary water supply pipeline and the secondary return water pipeline of the secondary pipe network are respectively connected to the secondary side outlet and the secondary side inlet of the plate heat exchanger; wherein: The compression heat pump unit includes an evaporator, at least two parallel compressors, a condenser, and an expansion valve connected in sequence through pipelines. The primary side inlet of the evaporator is connected to the primary return water pipeline of the primary pipeline network and the primary side outlet of the plate heat exchanger through a first pipeline, and the primary side outlet is connected to the primary return water pipeline of the primary pipeline network through a second pipeline. The secondary side inlet of the condenser is connected to the secondary water supply pipeline of the secondary pipeline network and the secondary side outlet of the plate heat exchanger through a third pipeline, and the secondary side outlet is connected to the secondary water supply pipeline of the secondary pipeline network through a fourth pipeline; the primary water supply pipeline of the primary pipeline network, the primary return water pipeline, the secondary water supply pipeline of the secondary pipeline network, the secondary return water pipeline, the first pipeline, the second pipeline, the third pipeline, and the fourth pipeline are all provided with temperature transmitters, solenoid valves, pressure transmitters, and flow transmitters, and each of the temperature transmitters, solenoid valves, pressure transmitters, flow transmitters, and the compression heat pump unit are all connected to the control device.
2. The compression type temperature difference heat exchange unit for heat exchange station according to claim 1 is characterized in that: The control device includes a PLC controller, and an analog input module, an analog output module, an RS485 communication module, a DTU wireless transmission module, a touch screen, and a DC power supply connected to the PLC controller. The analog input module is connected to the temperature transmitters, pressure transmitters, and flow transmitters, and is connected to the feedback signal ends of the solenoid valves via a relay assembly. The analog output module is connected to the given signal ends of the solenoid valves via a relay assembly; the DTU wireless transmission module is connected to a cloud server or a monitoring center computer via a wireless network; and the compression heat pump unit is connected to the PLC controller via an RS485 communication module.
3. The compression type temperature difference heat exchange unit for heat exchange station according to claim 2, characterized in that: The DC power supply includes an AC / DC converter, the 220V AC mains power is connected to the input end of the AC / DC converter via an isolation transformer, and the output end of the AC / DC converter is connected to the power supply end of the PLC controller.
4. The compression type temperature difference heat exchange unit for a heat exchange station according to claim 2 is characterized in that: A circulation pump and a solenoid valve are provided on the secondary water return pipeline in the secondary pipe network. The circulation pump is connected to the first frequency converter, and the first frequency converter is connected to the PLC controller via an RS485 communication module.
5. The compression type temperature difference heat exchange unit for a heat exchange station according to claim 2, characterized in that: It also includes a water tank, a water outlet on the water tank is connected to the secondary return water pipeline in the secondary pipe network through a water supply pipe, a water supply pump and a solenoid valve are provided on the water supply pipe, the water supply pump is connected to the second frequency converter, the second frequency converter is connected to the PLC controller through an RS485 communication module, and the feedback signal end and the given signal end of the solenoid valve are respectively connected to the analog input module and the analog output module.
6. The compression type temperature difference heat exchange unit for a heat exchange station according to claim 5, characterized in that: The water return port of the water tank is connected to the secondary water return pipeline in the secondary pipe network through a water return pipeline. A pressure relief solenoid valve is arranged on the water return pipeline, and the pressure relief solenoid valve is connected to the PLC controller.
7. The compression type temperature difference heat exchange unit for a heat exchange station according to claim 5, characterized in that: The water inlet of the water tank is connected to an external water source through a water inlet pipe, and a float-type liquid level sensor, a temperature sensor, and a heater are arranged in the water tank; a water pump and a solenoid valve are arranged on the water inlet pipe, and the float-type liquid level sensor, the temperature sensor, the heater, the water pump, and the solenoid valve are all connected to the PLC controller.