Heat exchange system

Abstract

The utility model provides a kind of heat exchange system, including primary heat recovery device and secondary heat recovery device;The first heat exchange passage and the second heat exchange passage not communicated with each other are provided in the primary heat recovery device;The inlet of the first heat exchange passage is provided with first air inlet pipeline, and the first air inlet pipeline is used to pass into exhaust air;The inlet of the second heat exchange passage is provided with second air inlet pipeline, and the second air inlet pipeline is used to pass into indoor air;The third heat exchange passage and the fourth heat exchange passage not communicated with each other are provided in the secondary heat recovery device;The inlet of the third heat exchange passage is connected with the outlet of the second heat exchange passage by first air outlet pipeline;The inlet of the fourth heat exchange passage is provided with third air inlet pipeline, and the outlet is provided with fourth air outlet pipeline, and the third air inlet pipeline is used to pass into outdoor air.The application is in the form of secondary heat exchange, indoor and outdoor air source respectively to exhaust air heat exchange to make exhaust air cooling, prepare for the subsequent processing of exhaust air.

Description

Technical Field

[0001] This utility model relates to the field of papermaking ventilation technology, and in particular to a heat exchange system. Background Technology

[0002] The exhaust air in the paper mill has a high moisture content. In northern winters, the outdoor temperature is low. After the humid exhaust air is discharged from the hood, the temperature drops rapidly. The water vapor reaches a saturated state and condenses into tiny droplets, which then accumulate to form a visible "white fog".

[0003] In some regions where environmental regulations require exhaust air to be "free of visible plumes," it is necessary to cool and dehumidify the exhaust air, remove excess moisture, and then reheat it to the required temperature before it can be discharged. Therefore, it is essential to design a heat exchange system suitable for exhaust hoods to cool the exhaust air and achieve humidity saturation, facilitating the removal of moisture from the air during subsequent deodorization and cooling processes, thereby reducing the relative moisture content of the exhaust air. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this utility model provides a heat exchange system that employs a two-stage heat exchange process, drawing air from both indoor and outdoor sources to exchange heat with the exhaust air, thereby cooling the exhaust air and preparing it for subsequent treatment. The technical solution adopted by this utility model is as follows: A heat exchange system includes a primary heat recovery device and a secondary heat recovery device; The primary heat recovery device is equipped with a first heat exchange channel and a second heat exchange channel that are not interconnected. A first air inlet pipe is provided at the entrance of the first heat exchange channel, and the first air inlet pipe is used to introduce exhaust air; The second heat exchange channel is provided with a second air inlet pipe at the inlet and a second air outlet pipe at the outlet. The second air inlet pipe is used to introduce indoor air. The secondary heat recovery device is equipped with a third heat exchange channel and a fourth heat exchange channel that are not interconnected. The inlet of the third heat exchange channel is connected to the outlet of the second heat exchange channel through the first air outlet duct, and a third air outlet duct is provided at its outlet. The fourth heat exchange channel is provided with a third air inlet pipe at the inlet and a fourth air outlet pipe at the outlet. The third air inlet pipe is used to introduce outdoor air.

[0005] Furthermore, a first air valve is installed on the second air inlet duct; The outlet of the fourth air outlet duct forms a first branch duct and a second branch duct. The outlet of the second branch duct is connected to the inlet of the second heat exchange channel. A third air valve is installed on the second branch duct.

[0006] Furthermore, a second air valve is installed on the first branch pipeline.

[0007] Furthermore, a first air source fan, a first heater, and a second heater are sequentially arranged on the second air outlet duct.

[0008] Furthermore, the first heater is a condensate heater or a flash steam heater.

[0009] Furthermore, the second heater is a steam heater.

[0010] Furthermore, a first air source filter is installed at the inlet of the second air intake duct.

[0011] Furthermore, a second air source filter is also installed at the inlet of the third air intake duct.

[0012] Advantages of this utility model: Through a primary heat recovery device and a secondary heat recovery device, the primary heat recovery device exchanges heat with the indoor air source to initially reduce the exhaust air temperature, and the secondary heat recovery device exchanges heat with the outdoor air source to further reduce the exhaust air temperature. The air source for heat exchange is directly sourced with no operating cost, resulting in high energy utilization and better economic efficiency.

[0013] Through the second air inlet duct and the first air valve, the first air valve is closed in other seasons and opened in winter. It is closed when there is no white mist in the exhaust air in other seasons. The first-stage heat recovery device is only used as a pipeline. Through the first branch pipeline and the second air valve, the second air valve is closed in other seasons (such as summer) and opened in winter. In winter, after the second air source exchanges heat with the exhaust air and is heated, it can preheat the air source that needs to be heated in the heating air system, thus saving energy consumption. Through the second branch pipe and the third air valve, when the first air valve is closed in other seasons (such as summer), the second air source exchanges heat with the exhaust air and is heated before being introduced into the second air inlet pipe. This is used as preheating of the supply air for the primary heat recovery device, thus saving energy consumption. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structural composition of this utility model.

[0015] In the diagram: 100 - Primary heat recovery device, 110 - First air inlet duct, 120 - First air outlet duct, 130 - Second air inlet duct, 131 - First air valve, 140 - Second air outlet duct, 141 - First air source fan, 142 - First heater, 143 - Second heater, 200 - Secondary heat recovery device, 210 - Third air outlet duct, 220 - Third air inlet duct, 230 - Fourth air outlet duct, 231 - First branch duct, 232 - Second air valve, 233 - Second branch duct, 234 - Third air valve. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0017] Please see the appendix Figure 1 This application proposes a heat exchange system, including a primary heat recovery device 100 and a secondary heat recovery device 200; the structures of the primary heat recovery device 100 and the secondary heat recovery device 200 refer to the heat recovery in the prior art, and their structural details will not be repeated here.

[0018] The primary heat recovery device 100 is provided with a first heat exchange channel and a second heat exchange channel that are not interconnected; a first air inlet pipe 110 is provided at the entrance of the first heat exchange channel, and the first air inlet pipe 110 is used to introduce exhaust air; a second air inlet pipe 130 is provided at the entrance of the second heat exchange channel and a second air outlet pipe 140 is provided at the outlet, the second air inlet pipe 130 is used to introduce indoor air, and a first air valve 131 is provided on the second air inlet pipe 130.

[0019] The first air inlet duct 110, the first heat exchange channel, and the first air outlet duct 120 provide a complete heat exchange path for the exhaust air from the hood. The second air inlet duct 130, the second heat exchange channel, and the second air outlet duct 140 provide a complete heat exchange path for the indoor air. When the first air valve 131 is open, the primary heat recovery device 100 performs heat exchange. When the first air valve 131 is closed, the primary heat recovery device 100 stops working. Adjusting the flow rate of the first air valve 131 can adjust the heat exchange temperature.

[0020] The secondary heat recovery device 200 is equipped with a third heat exchange channel and a fourth heat exchange channel that are not interconnected. The inlet of the third heat exchange channel is connected to the outlet of the second heat exchange channel via a first air outlet duct 120, and a third air outlet duct 210 is provided at its outlet. The inlet of the fourth heat exchange channel is provided with a third air inlet duct 220, and the outlet is provided with a fourth air outlet duct 230. The third air inlet duct 220 is used to introduce outdoor air. Exhaust air enters the third heat exchange channel through the first outlet duct 120 for heat exchange and cooling, and then exits through the third outlet duct 210 to enter the subsequent deodorizing spray system. Outdoor air enters the fourth heat exchange channel through the third inlet duct 220 to exchange heat with the exhaust air in the third heat exchange channel; after the outdoor air exchanges heat with the exhaust air and is heated, it is discharged through the fourth outlet duct 230. The secondary heat recovery device 200 and the primary heat recovery device 100 work together to perform two heat exchange and cooling processes on the exhaust air, preparing it for subsequent treatment.

[0021] In a specific heat exchange process, the temperature of the indoor air entering the second heat exchange channel is not affected by the season and is approximately 20℃-30℃. After heat exchange between the indoor air and the exhaust air, the temperature is approximately 55℃-65℃. After the initial heat exchange, the exhaust air temperature is approximately 55℃-70℃, and the humidity is approximately 100-180 g(H2O) / kg(Air). The exhaust air continues to enter the secondary heat recovery device 200 for heat exchange. The outdoor air temperature entering the fourth heat exchange channel is approximately -20℃ to 5℃ in winter and approximately 20℃-30℃ in other seasons (taking summer as an example). After heat exchange in other seasons, the exhaust air temperature is approximately 55℃-60℃, and after heat exchange in winter, the exhaust air temperature is approximately 45℃-55℃. The exhaust air humidity is approximately 65-95 g(H2O) / kg(Air). After two heat exchanges, the moisture content of the exhaust air reaches saturation. After heat exchange in other seasons, the outdoor air temperature is approximately 30℃-40℃, and in winter, it is approximately 40℃-50℃. After two heat exchanges, the exhaust temperature and humidity are stabilized and controlled. Using indoor and outdoor air as the air source for the two heat recovery devices is more economical, as the air source is directly sourced and there are no operating costs, resulting in higher energy utilization.

[0022] In one embodiment, the outlet of the fourth air outlet duct 230 forms a first branch duct 231 and a second branch duct 233. The outlet of the second branch duct 233 is connected to the inlet of the second heat exchange channel, and a third air valve 234 is provided on the second branch duct 233.

[0023] The specific energy recovery process can be divided into two types. In the first type, the first air valve 131 is open in other seasons, and the third air valve 234 is also open in other seasons. After the outdoor air exchanges heat with the exhaust air and is heated, it is introduced into the second air inlet pipe 130 and used as the indoor air preheating device in the first stage of heat recovery, thus saving energy consumption. In the second type, the first air valve 131 is closed in other seasons, and the third air valve 234 is open in other seasons. After the outdoor air exchanges heat with the exhaust air and is heated, it is introduced into the second air inlet pipe 130 and replaces the indoor air as the first stage of heat exchange for the exhaust air, thus saving energy consumption and avoiding energy waste.

[0024] In one embodiment, a second air valve 232 is provided on the first branch pipe 231. In a specific energy recovery process, the second air valve 232 is opened in winter, and the temperature of the outdoor air after heat exchange and heating with the exhaust air is approximately 40℃-50℃. The outdoor air at this temperature can preheat the air source that needs to be heated in the heating air system, saving energy consumption. Since white fog removal is not required in other seasons, the second air valve 232 is closed in other seasons to avoid energy waste.

[0025] The second air outlet duct 140 is sequentially equipped with a first air source fan 141, a first heater 142, and a second heater 143. After heat exchange, the temperature of the first air source is initially increased, and then it is successively heated by the first heater 142 and the second heater 143, eventually reaching 95℃-105℃. This indoor air can then be delivered to the hood via the second air outlet duct 140 for use as hood ventilation. The first air source fan 141 provides driving force for the first air source. In some specific embodiments, the first heater 142 can be a condensate heater or a flash steam heater, and the second heater 143 can be a steam heater.

[0026] To further ensure the cleanliness of the first air source entering the second air inlet duct 130 and prevent impurities in the air from clogging the heater and affecting its service life, a first air source filter 132 is installed at the inlet of the second air inlet duct 130. Furthermore, a particle size analyzer is installed at the first air source filter 132 to determine the degree of clogging.

[0027] To further ensure the cleanliness of the second air source entering the third air inlet duct 220 and prevent impurities in the air from clogging the heater and affecting its service life, a second air source filter 221 is also installed at the inlet of the third air inlet duct 220. Furthermore, a particle size analyzer is installed at the second air source filter 221 to determine the degree of clogging.

[0028] In summary, this application employs a low-energy-consumption, low-cost heat exchange system to cool the exhaust air and saturate the humidity, preparing it for subsequent treatment. The air source is directly drawn, resulting in no operating costs, high energy utilization, and better economic efficiency.

[0029] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although this utility model has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A heat exchange system, characterized in that: It includes a primary heat recovery unit (100) and a secondary heat recovery unit (200); The primary heat recovery device (100) is provided with a first heat exchange channel and a second heat exchange channel that are not interconnected. A first air inlet pipe (110) is provided at the entrance of the first heat exchange channel, and the first air inlet pipe (110) is used to introduce exhaust air; The second heat exchange channel is provided with a second air inlet pipe (130) at the inlet and a second air outlet pipe (140) at the outlet. The second air inlet pipe (130) is used to introduce indoor air. The secondary heat recovery device (200) is equipped with a third heat exchange channel and a fourth heat exchange channel that are not interconnected. The inlet of the third heat exchange channel is connected to the outlet of the second heat exchange channel through the first air outlet duct (120), and a third air outlet duct (210) is provided at its outlet. The fourth heat exchange channel is provided with a third air inlet pipe (220) at the inlet and a fourth air outlet pipe (230) at the outlet. The third air inlet pipe (220) is used to introduce outdoor air.

2. The heat exchange system as described in claim 1, characterized in that: A first air valve (131) is installed on the second air inlet duct (130); The outlet of the fourth air outlet duct (230) forms a first branch duct (231) and a second branch duct (233). The outlet of the second branch duct (233) is connected to the inlet of the second heat exchange channel. A third air valve (234) is provided on the second branch duct (233).

3. The heat exchange system as described in claim 2, characterized in that: A second air valve (232) is installed on the first branch pipe (231).

4. The heat exchange system as described in claim 1, characterized in that: The second air outlet duct (140) is sequentially equipped with a first air source fan (141), a first heater (142), and a second heater (143).

5. The heat exchange system as described in claim 4, characterized in that: The first heater (142) is a condensate heater or a flash steam heater.

6. The heat exchange system as described in claim 4, characterized in that: The second heater (143) is a steam heater.

7. The heat exchange system according to any one of claims 1-6, characterized in that: A first air source filter (132) is installed at the inlet of the second air inlet duct (130).

8. The heat exchange system according to any one of claims 1-6, characterized in that: A second air source filter (221) is also installed at the inlet of the third air inlet duct (220).

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