A hot water type painting exhaust gas waste heat recycling device and an environmental protection heating system

Abstract

The utility model discloses a hot water type coating waste gas waste heat recycling device and environmental protection heating system, including waste gas intake pipe, waste gas outlet pipe, heat pump unit, heat preservation water tank, first circulating water pump, second circulating water pump and phase change heat storage tank, and heat pump unit includes waste heat heat exchanger, the upper end of heat preservation water tank is equipped with water inlet pipe and heating pipe, and the lower end of heat preservation water tank is equipped with first water outlet pipe, second water outlet pipe, first return pipe and second return pipe, heat pump unit, water inlet pipe, heat preservation water tank, first water outlet pipe, first circulating water pump head -tail connection to form first heating cycle system, and second water outlet pipe, second circulating water pump, phase change heat storage tank, second return pipe head -tail connection to form phase change heat storage system. The above -mentioned device is coupled through heat pump unit, heat preservation water tank, phase change heat storage tank and other equipment, and the load fluctuation is buffered, and the host computer frequent start is reduced, realizes the high -quality utilization of waste heat, solves the energy waste and environmental pollution problem in traditional craft.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery technology, specifically to a hot water type waste heat recovery and utilization device and environmentally friendly heating system for industrial waste gas such as waste gas from a coating production line. Background Technology

[0002] During the coating production process, some coating waste gas is emitted, which contains VOCs and waste heat (20-50℃). At such high temperatures, it is not conducive to downstream processes that use zeolite rotors to remove VOCs. Furthermore, the waste gas contains waste heat; direct emission would not only cause environmental pollution but also result in a significant waste of thermal energy. Currently, steam heating of the cleaning fluid is commonly used in coating production lines. Recovering and utilizing the waste heat from the waste gas to heat the cleaning fluid could not only reduce energy consumption and meet the heat requirements for industrial cleaning but also lower the waste gas temperature and improve the efficiency of subsequent VOCs removal.

[0003] A heat pump is a highly efficient and energy-saving device that fully utilizes low-grade heat energy. It's a mechanical device that forces heat from a low-temperature object to a high-temperature object through a reverse circulation process. It consumes only a small amount of net reverse circulation work to obtain a large amount of heat supply, effectively utilizing low-grade heat energy that is difficult to apply, thus achieving energy savings. Currently, waste heat recovery often uses heat pumps to recover heat from exhaust gases and then use their working principle to produce high-temperature hot water or steam. Because industrial cleaning lines require a stable heat source, and the temperature of waste heat emissions is unstable, the outlet temperature of the heat pump is also unstable, affecting the stability of the heating temperature. In existing technologies, water storage tanks are often used to stabilize the heat pump outlet temperature. However, industrial cleaning lines consume a large amount of heat, and the heat storage effect of water storage tanks alone is insufficient for stable heating. There is an urgent need for a process that couples heat pumps and energy storage for industrial waste gas recovery, such as in coating production lines, and to meet the stable heat source requirements of industrial cleaning lines. Utility Model Content

[0004] In order to overcome the shortcomings of the existing technology, one of the objectives of this utility model is to provide a hot water type coating waste gas waste heat recovery and utilization device to solve the above-mentioned traditional problems.

[0005] The second objective of this utility model is to provide an environmentally friendly heating system that utilizes the hot water type coating waste gas waste heat recovery and utilization device.

[0006] One of the objectives of this utility model is achieved through the following technical solution:

[0007] A hot water-type waste heat recovery and utilization device for coating exhaust gas includes an exhaust gas inlet pipe, an exhaust gas outlet pipe, a heat pump unit, an insulated water tank, a first circulating water pump, a second circulating water pump, and a phase change heat storage tank. The heat pump unit includes a waste heat exchanger connected to the exhaust gas inlet pipe and the exhaust gas outlet pipe. The upper end of the insulated water tank is provided with an inlet pipe and a heating pipe, and the lower end of the insulated water tank is provided with a first outlet pipe, a second outlet pipe, a first return pipe, and a second return pipe. The heat pump unit, the inlet pipe, the insulated water tank, the first outlet pipe, and the first circulating water pump are connected end to end to form a first heating circulation system. The heating pipe and the first return pipe are respectively used to connect to the heat-using unit, and the heating pipe is equipped with a third circulating water pump. The second outlet pipe, the second circulating water pump, the phase change heat storage tank, and the second return pipe are connected end to end to form a phase change heat storage system.

[0008] Preferably, the waste heat exchanger is a copper tube aluminum fin heat exchanger.

[0009] Preferably, the heat pump unit further includes a compressor, a condenser, an expansion valve, and an evaporator, wherein the evaporator and the waste heat exchanger are connected in parallel.

[0010] Preferably, the insulated water tank is further provided with a first tap water supply pipe, a first level gauge and a first temperature sensor. The first tap water supply pipe is provided with a first control valve, the inlet pipe is provided with a first automatic return water valve, the first return water pipe is provided with a second automatic return water valve, and the second return water pipe is provided with a third automatic return water valve.

[0011] Preferably, the phase change energy storage box is equipped with a phase change energy storage material and a heat exchange coil, wherein the phase change energy storage material is one of solid-liquid phase change material, solid-solid phase change material, and gas-liquid phase change material.

[0012] Preferably, the hot water type coating waste gas waste heat recovery and utilization device further includes a waste gas collection device and a waste gas emission treatment device, one end of the waste gas collection device is connected to the waste gas inlet pipe, and the waste gas emission treatment device is connected to the waste gas outlet pipe.

[0013] Preferably, the hot water type coating waste gas waste heat recovery and utilization device further includes a bypass flue pipe, which is connected to the waste gas emission treatment device and the waste gas inlet pipe respectively.

[0014] Preferably, the exhaust gas inlet pipe is provided with a first air valve, the exhaust gas outlet pipe is provided with a second air valve, and the bypass flue pipe is provided with a third air valve.

[0015] Preferably, the hot water type coating exhaust gas waste heat recovery and utilization device further includes a water storage tank. The upper end of the water storage tank is provided with a third water outlet pipe and a fourth water outlet pipe. The third water outlet pipe is provided with a fourth circulating water pump and the fourth water outlet pipe is provided with a fifth circulating water pump. The middle part of the water storage tank is provided with a second tap water supply pipe. The lower end of the water storage tank is provided with a third water return pipe. The third water return pipe is provided with a fourth automatic return water valve. The water storage tank, the third water outlet pipe, the fourth circulating water pump, the phase change heat storage tank, and the third water return pipe are connected end to end to form a second heating circulation system.

[0016] The second objective of this utility model is achieved by the following technical solution:

[0017] An environmentally friendly heating system includes the aforementioned hot water type waste heat recovery and utilization device for painting exhaust gas.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] 1. The waste heat recovery and utilization device of this utility model buffers load fluctuations and reduces the frequent start-up of the main unit by coupling equipment such as heat pump unit, insulated water tank, and phase change heat storage box, thereby realizing high-quality utilization of waste heat and solving the problems of energy waste and environmental pollution in traditional processes.

[0020] 2. The waste heat recovery and utilization device of this utility model, through the coupling of equipment such as water storage tank and phase change heat storage tank, can reduce the impact of fluctuations in hot water supply in other places on the stability of heat used in industrial cleaning lines and ensure stable system operation. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the hot water type coating waste gas waste heat recovery and utilization device of this utility model;

[0022] Figure 2 for Figure 1 The diagram shows the process structure of a heat pump.

[0023] In the diagram: 10. Exhaust gas inlet pipe; 11. Exhaust gas inlet pipe; 12. Bypass flue gas pipe; 20. Heat pump unit; 21. Waste heat exchanger; 22. Compressor; 23. Condenser; 24. Expansion valve; 25. Evaporator; 30. Insulated water tank; 31. First circulating water pump; 32. Second circulating water pump; 33. Inlet pipe; 34. Heating pipe; 35. First outlet pipe; 36. Second outlet pipe; 37. First return pipe; 38. Second return pipe; 39. Third circulating water pump; 40. Phase change heat storage tank; 50. Water storage tank; 51. Third outlet pipe; 52. Fourth outlet pipe; 53. Fourth circulating water pump; 54. Fifth circulating water pump; 55. Third return pipe. Detailed Implementation

[0024] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0025] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0026] In the description of this utility model, it should be understood that when an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be intermediate elements present. Conversely, when an element is referred to as being "directly" connected to another element, there are no intermediate elements.

[0027] Please see Figures 1-2 This invention relates to a preferred embodiment of a hot water-type waste heat recovery device for coating production lines. Specifically, the device includes a waste gas inlet pipe 10, a waste gas outlet pipe 11, a heat pump unit 20, an insulated water tank 30, a first circulating water pump 31, a second circulating water pump 32, and a phase change heat storage tank 40. The heat pump unit 20 includes a waste heat exchanger 21 connected to the waste gas inlet pipe 10 and the waste gas outlet pipe 11. The upper end of the insulated water tank 30 is provided with an inlet pipe 33 and a heating pipe 34, while the lower end of the insulated water tank 30 is provided with a first outlet pipe 35, a second outlet pipe 36, a first return pipe 37, and a second return pipe 38. This pipe arrangement facilitates heat exchange and the output of hot water. The heat pump unit 20 and the inlet pipe... 33. The insulated water tank 30, the first outlet pipe 35, and the first circulating water pump 31 are connected end to end to form the first heating circulation system. The heating pipe 34 and the first return water pipe 37 are respectively used to connect to the heat-using unit. The heating pipe 34 is equipped with a third circulating water pump 39, such as the hot water tank for the first hot water wash, pre-degreasing, degreasing, and second hot water wash of the cleaning line. The second outlet pipe 36, the second circulating water pump 32, the phase change heat storage box 40, and the second return water pipe 38 are connected end to end to form a phase change heat storage system. The high-temperature heat can be transferred to the phase change heat storage box 40, and then the low-temperature water can be exchanged with the heat pump unit 20. At the same time, the hot water coming in from the upper layer continuously exchanges heat with the cold water in the lower layer, accelerating the heat transfer in the tank or transferring heat to the phase change heat storage box 40.

[0028] In one embodiment, the waste heat exchanger 21 is a copper tube aluminum fin heat exchanger. The copper tube has high thermal conductivity and corrosion resistance, while the aluminum fins have a large surface area and an aluminum oxide film on the aluminum surface, which improves its corrosion resistance. The combination of these two materials significantly reduces the corrosion of the exhaust gas while also improving its heat exchange efficiency. In other embodiments, the waste heat exchanger 21 can also use other forms of corrosion-resistant heat exchangers, selected according to requirements, which will not be elaborated further here.

[0029] In this embodiment, the heat pump unit 20 also includes a compressor 22, a condenser 23, an expansion valve 24, and an evaporator 25. The evaporator 25 and the waste heat exchanger 21 are connected in parallel. The condenser 23 is used to heat the system water to high-temperature hot water using the compressed high-temperature refrigerant. The waste heat exchanger 21 is used to heat the low-temperature refrigerant using the waste heat of the high-temperature exhaust gas. Then, the gaseous refrigerant is sent to the compressor 22 for compression to obtain high-temperature refrigerant. This cycle is repeated to recover and utilize the waste heat of the exhaust gas. When the exhaust gas is insufficient, or when it is off-peak electricity hours (night), the heat exchanger 21 is switched to the evaporator 25 for heat exchange. The low-priced electricity during off-peak hours is used to produce more hot water, which is stored in the phase change heat storage tank 40 to provide a stable heat source for the insulated water tank 30 during the day. It is understood that when the insulated water tank 30 has excess heat, the heat energy can also be stored in the phase change heat storage tank 40 for subsequent heat energy utilization and stability.

[0030] In this embodiment, the insulated water tank 30 is also equipped with a first tap water supply pipe, a first level gauge and a first temperature sensor. The first tap water supply pipe is equipped with a first control valve, the inlet pipe 33 is equipped with a first automatic return water valve, the first return water pipe 37 is equipped with a second automatic return water valve, and the second return water pipe 38 is equipped with a third automatic return water valve, so as to realize the automatic control of the insulated water tank 30. In other embodiments, other control instruments and control valves are set according to the situation, which will not be described in detail here.

[0031] In this embodiment, the phase change thermal storage box 40 is equipped with a phase change energy storage material and a heat exchange coil (not shown). The phase change energy storage material is one of solid-liquid phase change materials, solid-solid phase change materials, or gas-liquid phase change materials. In one embodiment, the solid-liquid phase change material is paraffin wax, fatty acids, polyols, polyethylene glycol, hydrated salts (such as sodium sulfate decahydrate, magnesium chloride hexahydrate), molten salts, etc., and the solid-solid phase change material is a metal alloy (such as a eutectic alloy), polymer, or sugar alcohol (such as erythritol), etc. Preferably, the phase change energy storage material is molten salt, paraffin wax, etc. Heat exchange is performed between the hot water and the phase change energy storage material through the heat exchange coil, transferring the heat from the hot water to the phase change energy storage material for storage. The heat is then released later. The phase change thermal storage box 40 is equipped with a second temperature sensor to detect the temperature inside the phase change thermal storage box 40 and adjust the heat storage or heating state according to the temperature.

[0032] In one embodiment, the waste heat recovery and utilization device further includes a waste gas collection device (not shown) and a waste gas emission treatment device. One end of the waste gas collection device is connected to the waste gas inlet pipe 10 for collecting and then uniformly transporting the collected coating waste gas. The waste gas emission treatment device is connected to the waste gas outlet pipe 11 and is equipped with VOCs treatment equipment such as zeolite rotor adsorption. In this embodiment, the waste heat recovery and utilization device also includes a bypass flue pipe 12, which is connected to the waste gas emission treatment device and the waste gas inlet pipe 10. The waste gas inlet pipe 10 is equipped with a first air valve, the waste gas outlet pipe 11 is equipped with a second air valve, and the bypass flue pipe 12 is equipped with a third air valve. The air valves control the entry and exit of the flue gas. The air valves can be manual or automatic. Optionally, the waste gas inlet pipe 10 is equipped with a flue gas flow sensor, a flue gas pressure sensor, and a flue gas temperature sensor for detecting the condition of the waste gas.

[0033] The waste heat recovery and utilization device also includes a water storage tank 50. The upper end of the water storage tank 50 is provided with a third outlet pipe 51 and a fourth outlet pipe 52. The third outlet pipe 51 is provided with a fourth circulating water pump 53, and the fourth outlet pipe 52 is provided with a fifth circulating water pump 54. One end of the fourth outlet pipe 52 is used to connect to a heat-using unit such as a cleaning tank. The middle part of the water storage tank 50 is provided with a second tap water supply pipe, and the lower end of the water storage tank 50 is provided with a third return water pipe 55. The third return water pipe 55 is provided with a fourth return water automatic opening and closing valve. The water storage tank 50, the third outlet pipe 51, the fourth circulating water pump 53, the phase change heat storage tank 40, and the third return water pipe 55 are connected end to end to form a second heating circulation system. The water storage tank 50 is provided with a second level gauge and a third temperature sensor to realize the automatic control of the water storage tank 50. In other embodiments, other control instruments and control valves are set as appropriate, which will not be described in detail here.

[0034] In other embodiments, the insulated water tank 30 and the water storage tank 50 can also exchange heat through heat exchange coils to achieve the corresponding heating function.

[0035] The working principle of the above device is as follows:

[0036] Waste gas is collected. Based on the temperature and flow rate of the waste gas, the heat pump unit 20 is started. If an evaporator 25 and / or waste heat exchanger 21 are used, the first circulating water pump 31 is started to form a first heating cycle system to heat the insulated water tank 30 and produce hot water. According to the hot water temperature requirements of the heat-using unit, the third circulating water pump 39 is started to supply hot water to the heat-using unit. When the temperature requirement of the insulated water tank 30 exceeds that of the heat-using unit (or during off-peak electricity hours when the heat-using unit uses less heat), the second circulating water pump 32 is started to form a phase change heat storage system to heat the phase change heat storage box 40 and store the heat energy in the phase change heat storage box 40. When the heat pump unit 20 is insufficient to heat the insulated water tank 30... (Or during peak electricity hours when the heat-using unit consumes more heat) At this time, the temperature of the phase change heat storage tank 40 is higher than that of the insulated water tank 30. The second circulating water pump 32 is started to transfer heat energy to the insulated water tank 30 to heat it. When the cleaning tank needs heat, the fourth circulating water pump 53 is started to form a second heating cycle system to heat the water storage tank 50. When the temperature of the water storage tank 50 reaches the heat demand, the fifth circulating water pump 54 is started to supply hot water to the cleaning tank. In the above operations, if there is no heat demand when the temperatures of the phase change heat storage tank 40, the insulated water tank 30, and the water storage tank 50 reach the requirements, the heat pump unit 20 is stopped (appropriate adjustments can be made according to specific needs).

[0037] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0038] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A hot water type painting exhaust gas waste heat recovery and utilization device characterized by comprising: The system includes an exhaust gas inlet pipe, an exhaust gas outlet pipe, a heat pump unit, an insulated water tank, a first circulating water pump, a second circulating water pump, and a phase change heat storage tank. The heat pump unit includes a waste heat exchanger connected to the exhaust gas inlet pipe and the exhaust gas outlet pipe. The upper end of the insulated water tank is provided with an inlet pipe and a heating pipe, and the lower end of the insulated water tank is provided with a first outlet pipe, a second outlet pipe, a first return pipe, and a second return pipe. The heat pump unit, the inlet pipe, the insulated water tank, the first outlet pipe, and the first circulating water pump are connected end to end to form a first heating circulation system. The heating pipe and the first return pipe are respectively used to connect to the heat-consuming unit, and the heating pipe is equipped with a third circulating water pump. The second outlet pipe, the second circulating water pump, the phase change heat storage tank, and the second return pipe are connected end to end to form a phase change heat storage system.

2. The hot-water type painting exhaust gas waste heat recovery and utilization device according to claim 1, characterized by The waste heat exchanger is a copper tube aluminum fin heat exchanger.

3. The hot-water type painting exhaust gas waste heat recovery and utilization device according to claim 2, characterized by The heat pump unit also includes a compressor, a condenser, an expansion valve, and an evaporator, with the evaporator and the waste heat exchanger connected in parallel.

4. The hot-water type painting exhaust gas waste heat recovery and utilization device according to claim 1, characterized by The insulated water tank is also equipped with a first tap water supply pipe, a first level gauge and a first temperature sensor. The first tap water supply pipe is equipped with a first control valve, the inlet pipe is equipped with a first automatic return water valve, the first return water pipe is equipped with a second automatic return water valve, and the second return water pipe is equipped with a third automatic return water valve.

5. The hot-water type painting exhaust gas waste heat recovery and utilization device according to claim 1, characterized by The phase change energy storage box is equipped with phase change energy storage material and heat exchange coil. The phase change energy storage material is one of solid-liquid phase change material, solid-solid phase change material, and gas-liquid phase change material.

6. The hot-water type painting exhaust gas waste heat recovery and utilization device according to claim 1, characterized by The hot water type coating waste gas waste heat recovery and utilization device also includes a waste gas collection device and a waste gas emission treatment device. One end of the waste gas collection device is connected to the waste gas inlet pipe, and the waste gas emission treatment device is connected to the waste gas outlet pipe.

7. The hot-water type painting exhaust gas waste heat recovery and utilization device according to claim 6, characterized by The hot water type coating waste gas waste heat recovery and utilization device also includes a bypass flue pipe, which is connected to the waste gas emission treatment device and the waste gas inlet pipe respectively.

8. The hot-water type painting exhaust gas waste heat recovery and utilization device according to claim 7, characterized by The exhaust gas inlet pipe is equipped with a first air valve, the exhaust gas outlet pipe is equipped with a second air valve, and the bypass flue gas pipe is equipped with a third air valve.

9. The hot-water type painting exhaust gas waste heat recovery and utilization device according to claim 6, characterized by The hot water type coating waste gas waste heat recovery and utilization device also includes a water storage tank. The upper end of the water storage tank is provided with a third water outlet pipe and a fourth water outlet pipe. The third water outlet pipe is provided with a fourth circulating water pump and the fourth water outlet pipe is provided with a fifth circulating water pump. The middle part of the water storage tank is provided with a second tap water supply pipe. The lower end of the water storage tank is provided with a third return water pipe. The third return water pipe is provided with a fourth return water automatic opening and closing valve. The water storage tank, the third water outlet pipe, the fourth circulating water pump, the phase change heat storage tank, and the third return water pipe are connected end to end to form a second heating circulation system.

10. An environmentally friendly heating system, characterized by Includes the hot water type coating waste gas waste heat recovery and utilization device as described in any one of claims 1-9.

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