Heat exchanger dead steam waste heat recovery device
By introducing automatic control of flash tanks and PLC controllers in the waste steam recovery system, the existing system has solved the problems of large equipment footprint, low heat exchange efficiency, and serious pollution, and efficient waste heat and water resources utilization, improving the safety and reliability of the system.
Patent Information
- Application Number
- CN202421877639.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-05
- Publication Date
- 2025-05-16
- Estimated Expiration
- 2034-08-05
AI Technical Summary
The existing waste heat recovery system has problems such as large equipment area, low heat exchange efficiency, low waste heat utilization rate, difficulty in separation of soda and water, and serious pollution problems.
A waste heat recovery device for waste steam including a heat exchanger, a flash tank and a PLC controller is designed. The high-pressure waste steam generated by the heat exchanger is reduced through the flash tank to form a low-pressure saturated steam and saturated solution, and the PLC controller is used to realize automated control and remote monitoring.
It significantly improves waste heat utilization and water resource utilization, reduces energy consumption and water resource consumption, reduces equipment footprint, solves white fog and noise pollution problems, and improves the safety and reliability of the system and operating efficiency.
Smart Images
Figure CN222881141U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of waste heat recovery, and in particular relates to a heat exchanger exhaust steam waste heat recovery device which has compact structure, high waste heat utilization rate, safety and reliability, and can be automatically controlled. Background Art
[0002] In the industrial production process of chemical industry, metallurgy, etc., many reactions and smelting processes require long-term heating, so a huge amount of waste heat is discharged with waste gas, waste liquid and waste residue, and the waste heat resources account for about 17-67% of the total fuel consumption, resulting in high production energy consumption and severe environmental pollution. For this reason, waste heat recovery systems are often used to recover waste heat to achieve energy conservation and emission reduction. However, the current waste heat recovery system mainly relies on direct contact or mixing of cold and hot fluids through heat exchangers to transfer heat, and then passes the steam from the heat exchanger into the atmospheric condensation pool, and then is pumped to the waste heat boiler for use through a drain pressure pump. The above-mentioned waste heat recovery system configuration based on heat exchangers not only occupies a large area, but also has difficulty in separating steam and water, resulting in large steam consumption, high energy consumption, and large water resource consumption of the heat exchanger. In addition, the exhaust steam from the heat exchanger is discharged at will, which will cause white fog and noise pollution on site, affecting the working environment of workers on site, and also causing corrosion to surrounding equipment.
[0003] Waste heat from exhaust steam refers to the heat energy carried by steam in industrial steam systems (such as power generation, chemical industry, metallurgy, etc.), which has a lower temperature and pressure after doing work or heat exchange, but still contains a certain amount of heat. Waste heat recovery from exhaust steam is to capture and convert this part of heat energy through various technical means, and use it for preheating, heating, power generation or other industrial processes, thereby achieving cascade utilization and efficient conversion of energy.
[0004] In the prior art, in order to solve the problems existing in the exhaust steam waste heat recovery system mainly based on heat exchangers, there is an exhaust steam waste heat recovery system that sets up a two-stage or even multi-stage heat exchanger to transfer the heat in the exhaust steam to another working medium (such as water, air or heat transfer oil, etc.) step by step to achieve the transfer and utilization of thermal energy; although this technology is simple and reliable, it is limited by the low temperature and low pressure of the exhaust steam, resulting in low heat exchange efficiency and low temperature difference between working media, low utilization rate of waste heat, and large equipment footprint, and difficult separation of steam and water. In addition, there is also an absorption heat pump that uses a circulation process between the absorbent and the refrigerant to upgrade the low-grade thermal energy in the exhaust steam to high-grade thermal energy; although this technology can effectively improve the utilization rate of the exhaust steam waste heat, the system structure is complex and the investment cost is high. In addition, the waste heat of exhaust steam is used to drive thermal machinery such as steam turbines or Stirling engines, generating electricity and heat energy at the same time, realizing cogeneration of heat and power. Although this technology can significantly improve the comprehensive utilization rate of energy, it is necessary to consider system matching and operational stability issues, making operation and maintenance complicated, and the scope of application is also relatively narrow, and there is still a lot of heat that is not utilized. Of course, in the prior art, there is also a flash tank to assist the heat exchanger, reduce the pressure of the high-pressure exhaust steam from the heat exchanger to form low-pressure saturated steam and saturated solution, and then use them separately to improve the utilization rate of heat energy and water resources; however, the existing flash tank auxiliary heat exchanger waste heat recovery system mostly adopts manual or local automatic control, which is not only complicated to operate, but also has serious human influence in the control process, resulting in insufficient safety and reliability. Utility Model Content
[0005] According to the deficiencies of the prior art, the utility model develops a heat exchanger exhaust steam waste heat recovery device which has compact structure, high waste heat utilization rate, safety and reliability, and can be automatically controlled.
[0006] The utility model is implemented as follows: comprising a heat exchanger and a steam main pipe, wherein the steam inlet of the heat exchanger is connected to the steam main pipe, and a steam inlet main valve is also arranged on the steam main pipe;
[0007] It is characterized in that it also includes a flash tank and a PLC controller, the steam condensate outlet of the heat exchanger is connected with the condensate inlet of the flash tank through a pipeline, the flash steam outlet of the flash tank is connected with a subsequent device through a pipeline, and the flash condensate outlet of the flash tank is connected with a waste heat boiler through a pipeline; a condensate inlet regulating valve is arranged on the pipeline connected with the condensate inlet, a flash steam outlet regulating valve is arranged on the pipeline connected with the flash steam outlet, a flash condensate outlet regulating valve is arranged on the pipeline connected with the flash condensate outlet, and the flash tank is also provided with a pressure sensor, and the steam inlet main valve, condensate inlet regulating valve, flash steam outlet regulating valve, flash condensate outlet regulating valve and pressure sensor are electrically connected to the PLC controller respectively.
[0008] Furthermore, the heat exchanger is a shell and tube heat exchanger, and the heat exchanger exhaust steam waste heat recovery device includes a plurality of heat exchangers connected in parallel and / or in series, and the heat exchangers connected in parallel and / or in series are connected through steam connecting pipes and control valves. A total flow meter electrically connected to a PLC controller is also provided on the steam main pipe, and the control valve is electrically connected to the PLC controller.
[0009] Furthermore, a three-way valve is provided on the pipeline connected to the flash steam outlet of the flash tank, a first outlet of the three-way valve is connected to a subsequent device through a pipeline, a second outlet is connected to a screw compressor through a pipeline, the outlet of the screw compressor is connected to a thermal compensator through a pipeline, and the outlet of the thermal compensator is connected to the steam inlet of the heat exchanger through a pipeline.
[0010] Furthermore, a heater capable of heating the flash chamber is disposed at the lower portion of the flash tank, a temperature sensor is disposed on the flash tank, and the heater and the temperature sensor are electrically connected to the PLC controller respectively.
[0011] Furthermore, the flash tank is a vertical tower tank, the condensed water inlet is arranged in the middle of the flash tank, the flash steam outlet is arranged at the top of the flash tank, and the flash condensed water outlet is arranged at the lower part and / or bottom of the flash tank.
[0012] Furthermore, a liquid level sensor is also provided in the flash tank, and the liquid level sensor is electrically connected to the PLC controller.
[0013] Furthermore, a flow meter I is provided on the pipeline connected to the condensed water inlet, a flow meter II is provided on the pipeline connected to the flash steam outlet, and a flow meter III is provided on the pipeline connected to the flash condensed water outlet. The flow meters I, II and III are electrically connected to the PLC controller respectively.
[0014] Furthermore, the flash tank is also provided with a pressure safety valve connected to the flash chamber, and the PLC controller is also electrically connected to an alarm system.
[0015] Compared with the prior art, the beneficial effects of the utility model are:
[0016] 1. The utility model sets a flash tank at the steam condensate outlet of the heat exchanger to replace the conventional atmospheric condensate pool and drain booster pump. The high-pressure exhaust steam generated by the heat exchanger is reduced in pressure through the flash tank to form low-pressure saturated steam and saturated solution, and then the saturated steam and saturated solution are respectively transported to related equipment, thereby realizing the comprehensive recovery and utilization of the exhaust steam waste heat and water resources generated by the heat exchanger, which can significantly reduce the energy consumption and water resource consumption required for production, and can also effectively reduce the floor space of the equipment, and can also completely solve the problems of white fog and noise pollution, and improve the on-site working environment.
[0017] 2. The utility model arranges a steam inlet main valve on the steam main pipe connected to the steam inlet of the heat exchanger, arranges a condensate inlet regulating valve on the pipeline connected to the condensate inlet of the flash tank, arranges a flash steam outlet regulating valve on the pipeline connected to the flash steam outlet, arranges a flash condensate outlet regulating valve on the pipeline connected to the flash condensate outlet, and arranges a pressure sensor on the flash tank, and electrically connects the above valves and pressure sensors to the PLC controller respectively, so as to realize automatic operation and even remote monitoring, effectively reduce the operating workload and avoid safety hazards caused by human factors, and form a flash tank pressure closed-loop control through each valve and pressure sensor and the PLC controller, which can keep the pressure in the flash tank within a set reasonable range, and effectively improve the flash efficiency.
[0018] 3. The utility model further arranges a plurality of heat exchangers connected in parallel and / or in series, and the heat exchangers connected in parallel and / or in series are connected through steam connecting pipes and control valves, so that the number of heat exchangers connected in parallel and in series can be adjusted in time according to the high-pressure steam flow rate to match, which can effectively improve the heat exchange efficiency of the heat exchanger.
[0019] In summary, the utility model has the characteristics of compact structure, high waste heat utilization rate, safety and reliability, and automatic control. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is one of the schematic diagrams of the arrangement structure of the utility model;
[0021] Figure 2 This is the second schematic diagram of the arrangement structure of the utility model;
[0022] Figure 3 This is a schematic diagram of the flash tank structure of the utility model;
[0023] In the figure: 1-heat exchanger, 2-steam main pipe, 3-steam inlet main valve, 4-flash tank, 41-condensate inlet, 42-flash steam outlet, 43-flash condensate outlet, 51-condensate inlet regulating valve, 52-flash steam outlet regulating valve, 53-flash condensate outlet regulating valve, 54-pressure sensor, 55-three-way valve, 56-flow meter I, 57-flow meter II, 58-flow meter III, 59-pressure safety valve, 6-steam connecting pipe, 7-screw compressor, 8-thermal compensator. DETAILED DESCRIPTION
[0024] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited in any way. Any changes or improvements made based on the teachings of the present invention belong to the protection scope of the present invention.
[0025] like Figure 1 , 2 As shown in FIG. 3 , the utility model comprises a heat exchanger 1 and a steam main pipe 2. The steam inlet of the heat exchanger 1 is connected to the steam main pipe 2. The steam main pipe 2 is also provided with a steam inlet main valve 3.
[0026] It also includes a flash tank 4 and a PLC controller. The steam condensate outlet of the heat exchanger 1 is connected to the condensate inlet 41 of the flash tank 4 through a pipeline, the flash steam outlet 42 of the flash tank 4 is connected to the subsequent device through a pipeline, and the flash condensate outlet 43 of the flash tank 4 is connected to the waste heat boiler through a pipeline; a condensate inlet regulating valve 51 is arranged on the pipeline connected to the condensate inlet 41, a flash steam outlet regulating valve 52 is arranged on the pipeline connected to the flash steam outlet 42, and a flash condensate outlet regulating valve 53 is arranged on the pipeline connected to the flash condensate outlet 43. The flash tank 4 is also provided with a pressure sensor 54. The steam inlet main valve 3, the condensate inlet regulating valve 51, the flash steam outlet regulating valve 52, the flash condensate outlet regulating valve 53 and the pressure sensor 54 are electrically connected to the PLC controller respectively.
[0027] The heat exchanger 1 is a shell and tube heat exchanger. The heat exchanger exhaust steam waste heat recovery device includes a plurality of heat exchangers 1 connected in parallel and / or in series. The heat exchangers 1 connected in parallel and / or in series are connected through a steam connecting pipe 6 and a control valve. A total flow meter electrically connected to a PLC controller is also provided on the steam main pipe 2, and the control valve is electrically connected to the PLC controller.
[0028] A three-way valve 55 is provided on the pipeline connected to the flash steam outlet 42 of the flash tank 4. The first outlet of the three-way valve 55 is connected to the subsequent device through a pipeline, and the second outlet is connected to the screw compressor 7 through a pipeline. The outlet of the screw compressor 7 is connected to the thermal compensator 8 through a pipeline, and the outlet of the thermal compensator 8 is connected to the steam inlet of the heat exchanger 1 through a pipeline. By providing the three-way valve 55 on the pipeline connected to the flash steam outlet 42, low-pressure saturated steam can be introduced according to the needs of the subsequent device, and the low-pressure saturated steam can be pressurized and heated through the screw compressor 7 and the thermal compensator 8 when the subsequent device does not need it, so as to form high-pressure steam and enter the heat exchanger 1 again for heat exchange, which solves the problem that the subsequent device can only discharge saturated steam when it does not need it, resulting in waste of heat and water resources and white fog and noise pollution, and improves the utilization efficiency of heat energy and water resources.
[0029] A heater capable of heating the flash chamber is disposed at the bottom of the flash tank 4, and a temperature sensor is disposed on the flash tank 4. The heater and the temperature sensor are electrically connected to the PLC controller respectively. A temperature closed-loop control is formed by the temperature sensor, the heater and the PLC controller to ensure temperature stability during the flash process.
[0030] The flash tank 4 is a vertical tower tank, the condensed water inlet 41 is arranged in the middle of the flash tank 4, the flash steam outlet 42 is arranged at the top of the flash tank 4, and the flash condensed water outlet 43 is arranged at the lower part and / or the bottom end of the flash tank 4.
[0031] A liquid level sensor is also provided in the flash tank 4, and the liquid level sensor is electrically connected to the PLC controller. The liquid level in the flash tank is monitored by the liquid level sensor to prevent the liquid from overflowing or drying up.
[0032] A flow meter I 56 is provided on the pipeline connected to the condensed water inlet 41, a flow meter II 57 is provided on the pipeline connected to the flash steam outlet 42, and a flow meter III 58 is provided on the pipeline connected to the flash condensed water outlet 43. The flow meters I 56, II 57 and III 58 are electrically connected to the PLC controller respectively. By adjusting the inlet and outlet flow, the flash evaporation process can be ensured to be continuous and stable.
[0033] The flash tank 4 is also provided with a pressure safety valve 59 connected to the flash chamber, and the PLC controller is also electrically connected to an alarm system. By providing a safety valve and an alarm system, measures can be taken in time to prevent safety accidents in abnormal situations.
[0034] The working principle and working process of this utility model:
[0035] like Figure 2 and 3As shown, when in use, the high-pressure steam discharged from the working equipment enters the heat exchanger 1 from the steam main pipe 2 and the steam inlet main valve 3, and the exhaust steam discharged after heat exchange in the heat exchanger 1 enters the flash tank 4 through the condensed water inlet regulating valve 51 and the condensed water inlet 41 for flash evaporation. When the flow rate of the high-pressure steam discharged from the working equipment fluctuates greatly, the PLC controller timely adjusts the number of heat exchangers 1 in parallel and in series by controlling the control valve, thereby matching the steam flow rate, which can effectively improve the heat exchange efficiency of the heat exchanger 1. After flash evaporation, low-pressure saturated steam and saturated solution are formed. The low-pressure saturated steam is passed into the three-way valve 55 through the flash steam outlet 42 and the flash steam outlet regulating valve 52. When the subsequent device needs to pass low-pressure saturated steam, the three-way valve 55 is controlled by the PLC controller to switch, so that the low-pressure saturated steam is passed into the subsequent device for use; when the subsequent device does not need to pass low-pressure saturated steam, the three-way valve 55 is controlled by the PLC controller to switch, so that the low-pressure saturated steam is passed into the screw compressor 7 and the thermal compensator 8 in turn, and the low-pressure saturated steam is pressurized and heated by the screw compressor 7 and the thermal compensator 8 respectively, so as to form high-pressure steam and enter the heat exchanger 1 again for heat exchange. The saturated solution obtained by steam-water separation in the flash tank 4 is passed into the waste heat boiler through the flash condensate outlet 43 and the flash condensate outlet regulating valve 53 for use, thereby improving the utilization rate of the exhaust steam of the heat exchanger 1.
[0036] The above is only a preferred specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.
Claims
1. A heat exchanger exhaust steam waste heat recovery device, comprising a heat exchanger (1) and a steam main pipe (2), wherein a steam inlet of the heat exchanger (1) is connected to the steam main pipe (2), and a steam inlet main valve (3) is also provided on the steam main pipe (2); It is characterized in that The invention also comprises a flash tank (4) and a PLC controller. The steam condensate outlet of the heat exchanger (1) is connected to the condensate inlet (41) of the flash tank (4) through a pipeline. The flash steam outlet (42) of the flash tank (4) is connected to a subsequent device through a pipeline. The flash condensate outlet (43) of the flash tank (4) is connected to a waste heat boiler through a pipeline. A condensate inlet regulating valve (51) is provided on the pipeline connected to the condensate inlet (41). A flash steam outlet regulating valve (52) is provided on the pipeline connected to the flash steam outlet (42). A flash condensate outlet regulating valve (53) is provided on the pipeline connected to the flash condensate outlet (43). The flash tank (4) is also provided with a pressure sensor (54). The steam inlet main valve (3), the condensate inlet regulating valve (51), the flash steam outlet regulating valve (52), the flash condensate outlet regulating valve (53) and the pressure sensor (54) are respectively electrically connected to the PLC controller.
2. The heat exchanger exhaust steam waste heat recovery device according to claim 1, characterized in that: The heat exchanger (1) is a shell-and-tube heat exchanger. The heat exchanger exhaust steam waste heat recovery device comprises a plurality of heat exchangers (1) connected in parallel and / or in series. The heat exchangers (1) connected in parallel and / or in series are connected via a steam connecting pipe (6) and a control valve. A total flow meter electrically connected to a PLC controller is also provided on the steam main pipe (2). The control valve is electrically connected to the PLC controller.
3. The heat exchanger exhaust steam waste heat recovery device according to claim 1, characterized in that: A three-way valve (55) is provided on a pipeline connected to the flash steam outlet (42) of the flash tank (4); a first outlet of the three-way valve (55) is connected to a subsequent device via a pipeline, and a second outlet is connected to a screw compressor (7) via a pipeline; an outlet of the screw compressor (7) is connected to a thermal compensator (8) via a pipeline, and an outlet of the thermal compensator (8) is connected to a steam inlet of the heat exchanger (1) via a pipeline.
4. The heat exchanger exhaust steam waste heat recovery device according to claim 1, characterized in that: A heater capable of heating the flash chamber is arranged at the bottom of the flash tank (4), and a temperature sensor is arranged on the flash tank (4). The heater and the temperature sensor are electrically connected to the PLC controller respectively.
5. The heat exchanger exhaust steam waste heat recovery device according to claim 1, characterized in that: The flash tank (4) is a vertical tower tank, the condensed water inlet (41) is arranged at the middle of the flash tank (4), the flash steam outlet (42) is arranged at the top of the flash tank (4), and the flash condensed water outlet (43) is arranged at the bottom and / or the bottom end of the flash tank (4).
6. The heat exchanger exhaust steam waste heat recovery device according to any one of claims 1 to 5, characterized in that: A liquid level sensor is also provided in the flash tank (4), and the liquid level sensor is electrically connected to the PLC controller.
7. The heat exchanger exhaust steam waste heat recovery device according to claim 6, characterized in that: A flow meter I (56) is provided on the pipeline connected to the condensate inlet (41), a flow meter II (57) is provided on the pipeline connected to the flash steam outlet (42), and a flow meter III (58) is provided on the pipeline connected to the flash condensate outlet (43). The flow meter I (56), flow meter II (57) and flow meter III (58) are electrically connected to the PLC controller, respectively.
8. The heat exchanger exhaust steam waste heat recovery device according to claim 6, characterized in that: The flash tank (4) is also provided with a pressure safety valve (59) connected to the flash chamber, and the PLC controller is also electrically connected to an alarm system.