A distributed heat pump heat and humidity management system and a container tunnel type drying system
By introducing a distributed heat pump thermal and humidity management system into the container drying process, and utilizing refrigerant loops and distributed heat pump devices, the problems of high energy consumption and heat dissipation during container drying are solved, achieving efficient heat recovery and uniform management, and improving energy efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- TONGJI UNIV
- Filing Date
- 2023-07-21
- Publication Date
- 2026-05-22
AI Technical Summary
Existing heat pump drying technology in container drying processes suffers from high energy consumption, severe heat dissipation, and an inability to achieve uniform management of internal heat and humidity, resulting in low energy efficiency.
The distributed heat pump heat and humidity management system is adopted. By arranging a refrigerant loop outside the container drying tunnel and installing a distributed heat pump heat recovery device and a terminal heat supplement device inside the drying tunnel, the heat distribution and management can be optimized to meet the heat demand of different areas.
It significantly reduced energy consumption, improved heat utilization, and achieved thermal and humidity balance and energy efficiency improvement in the container drying process.
Smart Images
Figure CN116951951B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a heat and humidity management system, and more particularly to a distributed heat pump heat and humidity management system and a container tunnel drying system. Background Technology
[0002] A shipping container is a standardized metal box used for transporting and storing goods. It is convenient and fast and is widely used in various fields: (1) In freight transportation, it can greatly improve logistics efficiency and reduce transportation costs; (2) In energy storage, it can be converted into an energy storage box to store energy such as solar energy; (3) In prefabricated buildings, it can be converted into modular buildings, such as temporary houses and offices; (4) In facility agriculture, it can be transformed into a high-efficiency vertical farm and aquarium.
[0003] Containers have wide applications in the Chinese market and play a vital role in domestic and international trade and logistics. For over a decade, China has been the world's largest producer and seller of containers, accounting for more than 90% of global production of standard dry cargo containers. The development of containers is of great significance to China's economic development and the promotion of international trade.
[0004] The painting and drying process of shipping containers is a crucial step in production, enhancing their quality and lifespan. Typically, containers are coated with primer, intermediate coat, and topcoat. The primer strengthens surface adhesion and provides corrosion resistance, while the topcoat enhances the container's appearance and weather resistance. After painting, the containers are placed in a drying chamber and thoroughly dried using high-temperature drying equipment to ensure the coating adheres firmly to the container's surface.
[0005] Currently, container painting and drying processes primarily utilize natural gas heating and drying. For example... Figure 1 As shown, the container enters from one side of the drying tunnel and moves at a constant speed inside. After the surface paint is dried, it slides out from the other side to enter the next process. The drying tunnel is equipped with several natural gas hot air boilers and circulating fans to maintain a relatively uniform medium-high temperature environment (40-60℃) inside, allowing moisture on the container surface to evaporate. When the relative humidity inside the drying tunnel is detected to be too high, the exhaust fan is turned on to expel the hot and humid air, replace it with an equal amount of fresh air, and reheat to continue drying.
[0006] The traditional solution of heating with hot air furnace and dehumidifying fan has low energy utilization and a large amount of heat dissipation, resulting in high energy consumption per container. The main ways of heat loss include: (1) Water vapor evaporated from the paint on the surface of the container contains a large amount of latent heat of vaporization. It is discharged by the dehumidifying fan, so that this part of the heat is completely released into the atmosphere and is not utilized; (2) A single container weighs as much as 2-4 tons, is made of steel, and has a high heat capacity. The temperature difference between the container entering and exiting is more than 30°C, so there is a large heat capacity loss; (3) The air drawn into the container when it enters and exits the drying tunnel, as well as the air carried inside the container, are similar to the function of the dehumidifying fan and also represent part of the exhaust heat loss.
[0007] Heat pump drying technology, as a highly efficient heat recovery technology, has been widely used in many industrial and agricultural fields. For example, patent CN 112050618A discloses a heat pump unit suitable for high-volume drying of seaweed / nori, and patent CN107130415A discloses a heat pump drying device in the field of clothing drying, etc. However, these existing heat pump drying technologies all assume that the application scenario has good heat preservation, such as seaweed drying being completed in a well-insulated drying room, and clothing drying boxes having good sealing properties. These conditions suitable for existing heat pump drying technologies to exert their advantages do not exist in container drying processes. As mentioned above, the container drying tunnel, along with the entry and exit of containers, leads to a large amount of heat dissipation, requiring additional heating. Therefore, relying solely on existing heat pump technology, it is impossible to achieve a stable internal heat and humidity balance.
[0008] Another reason why existing heat pump drying technology is unsuitable for container drying processes is that the heat and humidity distribution of the air inside the container drying tunnel is uneven, making it impossible to use a uniform or centralized heat pump for treatment. For example, the front section of the container drying tunnel is mainly used for rapid preheating of the container, while the rear section focuses on the evaporation of moisture from the paint on the container surface. Consequently, the temperature and humidity in the front section are lower, while the temperature and humidity in the rear section are higher. If heat pump drying technology is blindly applied when the temperature and humidity in the front section are both low, it will lead to extremely low energy efficiency and unstable operation.
[0009] In conclusion, it is necessary to upgrade the thermal and humidity management system of the container drying process to achieve significant energy savings. This will enhance the overall level and competitiveness of the container industry and maintain my country's leading position in container production technologies. Summary of the Invention
[0010] The purpose of this invention is to overcome the shortcomings of the existing technology by providing a distributed heat pump heat and humidity management system and a container tunnel drying system. It constructs a connected refrigerant loop, several heat pump heat recovery devices and terminal heat replenishment devices, and completes the transformation of the container drying process through a heat and humidity management system, thereby achieving significant energy savings.
[0011] The applicant believes that during the conceptualization process:
[0012] As the background technology analysis shows, container drying processes have their own unique characteristics. The drying tunnel contains areas where heat can be recovered, including the latent heat of vaporization and sensible heat corresponding to the large amount of water vapor evaporated in the dehumidification section, and the heat storage carried by the dried container in the discharge section, as well as the residual heat from the entrained air. However, the drying tunnel also has areas that require heat, such as the preheating section for new containers at the beginning of the tunnel. The challenge lies in achieving a balance and management between these two aspects.
[0013] This invention proposes a connected thermal and humidity management system. It innovatively arranges a refrigerant loop outside the container drying tunnel and employs a distributed arrangement of heat pump devices for heat and humidity recovery and terminal devices for supplementing heat to the drying tunnel. Both the heat pump heat recovery devices and the terminal heat supplementation devices can be conveniently installed at various points along the refrigerant loop. Through a unified heat management and scheduling system, optimal heat distribution can be achieved, minimizing energy consumption.
[0014] Furthermore, this invention can be easily adjusted for container drying processes with certain differences (such as dry cargo containers and refrigerated containers), by simply changing the connection positions of the heat pump heat recovery device and the terminal supplementary heating device as needed.
[0015] The objective of this invention can be achieved through the following technical solutions:
[0016] The first aspect of this invention provides a distributed heat pump thermal and humidity management system for container tunnel drying processes, comprising a refrigerant loop, a heat pump heat recovery device, and a terminal heat replenishment device, wherein specifically:
[0017] The refrigerant loop is matched with the container drying tunnel, and the refrigerant loop is a closed loop;
[0018] The heat pump heat recovery device and the terminal heat replenishment device are distributed in the refrigerant loop and are respectively connected to the refrigerant loop;
[0019] The heat pump heat recovery device operates in the area within the container drying tunnel where heat can be recovered.
[0020] The end-heating device acts on areas within the container drying tunnel that require heat.
[0021] Furthermore, the area available for heat recovery includes a thorough dehumidification section for the latent heat of vaporization and sensible heat corresponding to the large amount of water vapor evaporated in the container drying tunnel, and a discharge section for the heat storage carried by the container after drying and the waste heat of the entrained air in the container drying tunnel.
[0022] Furthermore, the areas requiring heat supply include the preheating section of the new container that needs rapid preheating at the front of the drying tunnel.
[0023] Furthermore, the heat pump heat recovery device includes an evaporation side at a low temperature stage and a condensation side at a high temperature stage;
[0024] The low-temperature evaporation side is located inside the container drying tunnel, extracts heat from the internal circulating air, and condenses and removes the water vapor therein, thus completing the recovery of sensible heat and latent heat.
[0025] The condenser side of the high-temperature stage is connected to the refrigerant loop on the outside. The high-temperature and high-pressure refrigerant is pumped into the loop for unified management by the compression capacity of the compressor inside the heat pump.
[0026] Furthermore, the terminal heating device connects its refrigerant circuit in series with the refrigerant loop, and the terminal heating device is equipped with a fan.
[0027] After the fan device is turned on, it drives the air at the corresponding local position to circulate through the terminal heating device, and extracts heat from the corresponding local loop section of the refrigerant to achieve heating inside the container drying tunnel.
[0028] The number and installation location of the heat pump heat recovery device and the terminal heating device are not limited, and are determined according to the actual needs of the specific process. Preferably, the terminal heating device is tended to be arranged in the rapid heating section at the front end of the drying tunnel, and the heat pump heat recovery device is tended to be arranged in the fully dehumidified section at the rear end of the drying tunnel, as well as the container heat recovery cooling section formed by the outlet partition.
[0029] The containers to be dried enter from one side of the container drying tunnel. After rapid heating in the front section, the moisture in the paint on the surface gradually evaporates, replenishing the humidity of the surrounding air.
[0030] Furthermore, the heat pump heat recovery device is a distributed heat pump heat recovery unit;
[0031] Once the distributed heat pump heat recovery unit is turned on, it extracts heat from the surrounding hot and humid air, causing the water vapor contained therein to condense, thus completing the dehumidification inside the container drying tunnel and maintaining the humidity balance.
[0032] The distributed heat pump unit obtains a portion of the required flow from the unified refrigerant loop, throttles it to a low-temperature, low-pressure two-phase state through a throttling element, and then flows it through the evaporator side pipe of the dehumidifying evaporator in the container drying tunnel. After absorbing heat from the air, it evaporates into a superheated gas state. This gas is then drawn into the compressor and compressed into a high-temperature, high-pressure refrigerant gas, which is then pumped back into the external unified refrigerant loop to mix with the mainstream.
[0033] The present invention also includes another embodiment in which the heat pump heat recovery device and the terminal heat replenishment device include a modular closed-loop dehumidification and drying heat pump arranged as a unit in the high-humidity local section of the container drying tunnel, so as to realize the local recovery and utilization of heat.
[0034] It also includes a heat recovery heat pump located in the partition area at the outlet of the container drying tunnel. The evaporator side circuit of the heat recovery heat pump is located in the partition area to rapidly cool down the dried container and achieve heat recovery.
[0035] The heat pump heat recovery device also includes a heat recovery heat pump located in the partition area at the outlet of the container drying tunnel, wherein the evaporation side circuit of the heat recovery heat pump is located in the partition area.
[0036] Specifically, the interconnected thermal and humidity management system is broken down into a discrete, distributed arrangement. Firstly, by arranging individual modular closed-loop dehumidification and drying heat pumps in the high-humidity sections of the drying tunnel, localized heat recovery and utilization are achieved. The hot, humid air inside flows through the evaporator side of the dehumidification heat pump for cooling and dehumidification. The recovered heat, along with part of the power consumed by the dehumidification heat pump compressor, is released on the condenser side of the same dehumidification heat pump and reused to heat the dehumidified circulating air. Secondly, by arranging a heat recovery heat pump in the outlet isolation area, the evaporator side loop of the heat recovery heat pump is placed in the isolation area to rapidly cool the dried containers, achieving heat recovery. This recovered heat is transferred to the condenser side loop, which can be arranged in the initial section of the drying tunnel requiring rapid heating, achieving heat transfer and utilization. Compared to the interconnected type, this implementation is structurally simpler and easier to control, but the overall energy balance management effect is worse, and energy efficiency is reduced.
[0037] A second aspect of the present invention provides a container tunnel drying system, including a container drying tunnel and the aforementioned distributed heat pump heat and humidity management system.
[0038] Furthermore, the inlet and outlet of the container drying tunnel are equipped with electric roller shutters, which open when a container passes by and close when no container passes by; during stable operation, there are several containers moving at a uniform speed inside the drying tunnel, and their surfaces are coated with paint to be dried.
[0039] The container drying tunnel is also equipped with an intermediate roller shutter door near the exit, forming a partitioned area for heat recovery. After the container leaves the intermediate roller shutter door, the intermediate roller shutter door is closed. The container that has completed paint drying stays in the area between the intermediate roller shutter door and the exit for a preset time (usually 3-6 minutes) to be fully heat recovered before leaving the container drying tunnel from the exit.
[0040] The container drying tunnel is equipped with circulating fans on both sides, and the circulating fans are evenly distributed along the container drying tunnel. The circulating fans are used to circulate the internal air to make its state distribution uniform.
[0041] Hot air furnaces are installed on both sides of the container drying tunnel. These furnaces are used to input heat into the container drying tunnel, especially during the process start-up phase, to help the interior heat up rapidly. The utilization rate of the hot air furnaces is controlled by adjusting the natural gas flow rate, which is adjusted as needed in practical applications.
[0042] Compared with the prior art, the present invention has the following technical advantages:
[0043] 1. Excellent energy efficiency. This invention utilizes a distributed heat and humidity management system based on heat pump heat recovery technology. This system recovers and rebalances the heat from the entire drying tunnel, significantly reducing energy losses caused by exhaust ventilation, dehumidification, and container loading / unloading in traditional solutions. The overall solution exhibits excellent energy efficiency and technical and economic viability.
[0044] 2. High flexibility. This invention proposes a connected distributed thermal and humidity management system. The unified refrigerant loop distributed along the outside of the container plays a good role in energy storage, transfer, distribution, and balancing. The number and installation location of the local heat pump heat recovery devices and terminal heat dissipation devices connected to it are not limited and can be freely arranged in the required area to maximize adaptability to production process conditions.
[0045] 3. Good applicability. Since the shape of the unified refrigerant loop and the corresponding arrangement of the heat pump heat recovery device and the terminal heat dissipation device are not restricted in this invention, it can be easily adjusted for container drying processes with certain differences (such as dry cargo containers and refrigerated containers). The connection positions of the heat pump heat recovery device and the terminal heat replenishment device can be changed as needed.
[0046] 4. This invention also provides a discrete heat and humidity management scheme, which optimizes the spatial distribution of energy and fully considers the quality of energy in the system layout. The closed-loop dehumidification and drying heat pump unit is arranged in stages and sections along the drying tunnel. Through step-by-step point control, differentiated temperature and humidity distribution within the drying tunnel can be achieved, matching the moisture evaporation rate during the container paint drying process, improving drying efficiency, and reducing energy loss. Simultaneously, the sensible heat recovery at the drying tunnel outlet is used for preheating the initial section (rather than for heating the fully dehumidified section), which helps reduce the condensing temperature of the air source heat pump, improves equipment energy efficiency, and facilitates layout. Attached Figure Description
[0047] Figure 1 This is a schematic diagram of a traditional container tunnel drying process production line.
[0048] Figures 2-4 This is a schematic diagram of a distributed heat pump heat and humidity management system (connected type) used in container tunnel drying process in Embodiment 1 of the present invention;
[0049] Figure 5 This is a schematic diagram of a distributed heat pump heat and humidity management system (discrete type) used in container tunnel drying process in Embodiment 2 of the present invention;
[0050] Figure 6 This is a schematic diagram of the distributed heat pump heat and humidity management system (connected type + auxiliary heat) used in the container tunnel drying process in Embodiment 3 of the present invention.
[0051] Figure 7 This is a schematic diagram of the distributed heat pump heat and humidity management system (discrete type + auxiliary heat) used in the container tunnel drying process in Embodiment 4 of the present invention.
[0052] In the diagram: 1. Container tunnel drying tunnel; 2-1, 2-2, ..., 2-N1. Container; 3-1, 3-2, ..., 3-N2. Hot air furnace (gas boiler); 4-1, 4-2, ..., 4-N3. Circulating fan; 5-1, 5-2. Exhaust vent; 6. Inlet; 7. Outlet; 10-1, 10-2, ..., 10-N4. Distributed closed-loop dehumidification and drying heat pump; 11-1, 11-2. Heat recovery heat pump (including A. Evaporator side heat absorption loop, B. Condenser side heat release loop); 12. Intermediate roller shutter door; 20. Connected unified refrigerant loop; 21-1, 21-2, ..., 21-N5. Terminal heat dissipation device; 22-1, 22-2, ..., 22-N6. Heat pump heat recovery device (including C-throttling element, D-dehumidifying evaporator, E-compressor, F-condenser). Detailed Implementation
[0053] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Component models, material names, connection structures, control methods, algorithms, and other features not explicitly described in this technical solution are considered common technical features disclosed in the prior art.
[0054] Example 1
[0055] The distributed heat pump thermal and humidity management system for container tunnel drying process in this embodiment is a connected type, and its structure is described in [reference needed]. Figure 2 .
[0056] In this embodiment, the distributed heat pump heat and humidity management system for container tunnel drying process includes a connected refrigerant loop 20, several heat pump heat recovery devices 22, and terminal heat replenishment devices 21. The refrigerant loop 20 is arranged around the container drying tunnel 1 and is a closed loop, with several heat pump heat recovery devices 22 and terminal heat replenishment devices 21 connected to it.
[0057] In this embodiment, the container tunnel drying tunnel 1 includes an inlet 6 and an outlet 7. Electric roller shutters are installed at the inlet and outlet, opening when a container 2 passes by and closing when no container 2 passes by. During stable operation, several containers 2 move at a uniform speed within the drying tunnel 1, their surfaces coated with paint to be dried.
[0058] The container drying tunnel 1 is also equipped with an intermediate roller shutter door 12 near the exit 7, which can form a partitioned area for heat recovery. After the container 2 leaves the intermediate roller shutter door 12, the intermediate roller shutter door 12 is closed. The container 2, after the paint drying is completed, stays in the area between the intermediate roller shutter door 12 and the exit 7 for a period of time (usually 3-6 minutes) to fully recover heat before leaving the drying tunnel 1 through the exit 7.
[0059] Circulating fans 4 are installed on both sides of the container drying tunnel 1, and are evenly distributed along the drying tunnel 1. The circulating fans 4 are used to circulate the internal air to make its state distribution uniform.
[0060] See Figure 3In this embodiment, the heat pump heat recovery device 22 and the terminal heating device 21 are directly connected to the external main refrigerant loop 20. The heat pump heat recovery device 22 includes a throttling element C, a dehumidifying evaporator D, and a compressor E. The dehumidifying evaporator C is arranged inside the drying tunnel 1, extracting heat from the internal circulating air and condensing and removing the water vapor therein, thus recovering sensible and latent heat. The condensing side of the high-temperature stage of the heat pump heat recovery device 22 is connected to the external refrigerant loop 20. Through the compression capacity of the internal compressor E, the high-temperature and high-pressure refrigerant is pumped into the loop 20 for unified management. The terminal heating device 21 also connects its refrigerant loop in series to the external unified loop 20, which can be in the form of a fan coil unit with a fan installed on it. After the fan is turned on, it drives the air at the corresponding local location to circulate through the terminal heating device 21, extracting heat from the corresponding local refrigerant loop section to achieve heating inside the drying tunnel 1.
[0061] See Figure 4 In this embodiment, the heat pump heat recovery device 22 and the terminal heating device 21 can also be indirectly heated with the external main refrigerant loop 20. The heat pump heat recovery device 22 includes a throttling element C, a dehumidifying evaporator D, a compressor E, and a condenser F. In the condenser F, the high-temperature refrigerant compressed by the compressor E inside the heat pump heat recovery device 22 exchanges heat with the low-temperature refrigerant in the main refrigerant loop 20, inputting the heat obtained by the dehumidifying evaporator D from the inside of the drying tunnel into the main refrigerant loop 20. The terminal heating device 21 also includes its own refrigerant flow path, which is connected to the corresponding local main refrigerant loop in a heat exchange manner, extracting heat from the main refrigerant loop 20 to supplement the drying tunnel 1. The terminal heating device 21 can also be an air-source heat pump, whose low-temperature evaporation side extracts heat from the main refrigerant loop 20 and further increases the energy level locally, supplementing more heat into the drying tunnel 1. Figure 3 Compared to the direct connection to the main refrigerant loop 20, this indirect heat exchange connection method has a lower heat exchange efficiency, but the device is more independent, easier to change location, and the failure of a single device has a smaller impact on the overall system operation.
[0062] In this embodiment, the form of the heat pump heat recovery device 22 is not limited; it can be the simpler form described herein, or a more complex form such as a cascade heat pump or a stepped heat pump.
[0063] In this embodiment, the number and installation location of the heat pump heat recovery device 22 and the terminal heating device 21 are not limited, and are determined according to the actual needs of the specific process. Preferably, the terminal heating device 21 is tended to be arranged in the rapid heating section at the front end of the drying tunnel 1, and the heat pump heat recovery device 22 is tended to be arranged in the fully dehumidified section at the rear end of the drying tunnel 1, as well as the container heat recovery cooling section formed by the outlet 7 partition.
[0064] The distributed heat pump heat and humidity management system for the container tunnel drying process in this embodiment operates as follows: ① Container 2 enters through inlet 6 of drying tunnel 1. After rapid heating in the front section, the moisture in the paint on its surface gradually evaporates, replenishing the humidity of the surrounding air. ② The distributed heat pump heat recovery unit 22 is turned on, extracting heat from the surrounding hot and humid air, causing the water vapor contained therein to condense, completing the dehumidification inside drying tunnel 1 and maintaining humidity balance. The distributed heat pump unit 22 obtains a portion of the required flow from the unified refrigerant loop 20, throttles it to a low-temperature, low-pressure two-phase state through the throttling element C, and flows it through the evaporation side pipe of the dehumidifying evaporator D in the drying tunnel. After extracting heat from the air, it evaporates into a superheated gas state; this gas is drawn into the compressor E and compressed into a high-temperature, high-pressure refrigerant gas, which is then pumped back into the external unified refrigerant loop 20 to mix with the mainstream. Alternatively, the distributed heat pump unit 22 has a separate refrigerant flow path, extracting heat from the drying tunnel through the dehumidifying evaporator D, and completing indirect heat exchange with the external refrigerant flow path 20 through the condenser F. ③ The terminal heating device 21 turns on the fan as needed. The external unified refrigerant circuit 20 directly or indirectly exchanges heat with the internal air flowing through the corresponding terminal heating device section, supplementing the heat into the drying tunnel 1 and maintaining the thermal balance of the drying tunnel 1. The refrigerant entering the terminal heating device 21 completes heat dissipation, and its specific enthalpy decreases after flowing out. It then re-enters the main refrigerant flow path 20, waiting for new heat to be supplemented into the refrigerant loop 20 to complete the thermal balance of the refrigerant loop 20.
[0065] Example 2
[0066] The distributed heat pump thermal and humidity management system for container tunnel drying process in this embodiment is discrete, and its structure is described in [reference needed]. Figure 5 .
[0067] Compared to Embodiment 1, this embodiment breaks down the interconnected heat and humidity management system into a discrete, distributed arrangement. Firstly, by arranging individual modular closed-loop dehumidification and drying heat pumps 10 in the high-humidity local sections of the drying tunnel 1, localized heat recovery and utilization are achieved. The basic form of the closed-loop dehumidification and drying heat pump 10 is a heat pump unit including a throttling element, a dehumidifying evaporator, a compressor, and a condenser. The hot and humid air inside the drying tunnel 1 flows through the evaporator of the dehumidification heat pump 10 for cooling and dehumidification. The recovered heat, along with part of the power consumed by the compressor of the dehumidification heat pump 10, is released together in the condenser of the dehumidification heat pump 10 and reused to heat the dehumidified circulating air. Secondly, by arranging a heat recovery heat pump 11 in the partition area of the outlet 7, the evaporator-side loop of the heat recovery heat pump 11 is placed in the partition area to rapidly cool the dried container 2, achieving heat recovery. This recovered heat is transferred to the condenser-side loop, which can be arranged in the initial section of the drying tunnel 1 where rapid heating is required, achieving heat transfer and utilization.
[0068] In this embodiment, the dehumidification heat pump 10 and the heat recovery heat pump 11 are not limited in form; they can be the basic form, or more complex forms such as cascade heat pumps or stepped heat pumps.
[0069] Compared to the connected type, this embodiment (discrete type) is simpler in structure and easier to control, but the overall energy balance management effect is worse and the energy efficiency is reduced.
[0070] Example 3
[0071] The structure of this embodiment is shown below. Figure 6 The principle is similar to that of Embodiment 1. The main difference is that hot air furnaces 3 can be selectively installed on both sides of the container drying tunnel 1. These hot air furnaces 3 are used to input heat into the drying tunnel 1, especially to help the interior heat up quickly during the process start-up phase. The utilization rate of the hot air furnaces 3 is achieved by adjusting the natural gas flow rate, which is adjusted as needed in practical applications. This embodiment is more convenient to control, operates more stably, and has a faster heating speed, especially during the start-up phase. The disadvantage is that the initial investment cost is slightly higher.
[0072] Example 4
[0073] The structure of this embodiment is shown below. Figure 7 The principle is similar to that of Example 2. The main difference is that hot air furnaces 3 can be selectively installed on both sides of the container drying tunnel 1. These hot air furnaces 3 are used to input heat into the drying tunnel 1, especially to help the interior heat up quickly during the process start-up phase. The utilization rate of the hot air furnaces 3 is achieved by adjusting the natural gas flow rate, which is adjusted as needed in practical applications. This embodiment is more convenient to control, operates more stably, and especially accelerates the heating speed during the start-up phase. The disadvantage is that the initial investment cost is slightly higher.
[0074] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.
Claims
1. A distributed heat pump thermal and humidity management system for container tunnel drying process, characterized in that, include: A refrigerant loop (20) is configured to match the container drying tunnel (1), and the refrigerant loop (20) is a closed loop; The heat pump heat recovery device (22) and the terminal heat replenishment device (21) are distributed in the refrigerant loop (20) and are respectively connected to the refrigerant loop (20); The heat pump heat recovery device (22) operates on the area within the container drying tunnel (1) where heat can be recovered; The end-heating device (21) acts on the area within the container drying tunnel (1) that requires heat; The area available for heat recovery includes a dehumidification section in the container drying tunnel (1) where the latent heat of vaporization and sensible heat corresponding to the large amount of water vapor evaporated are fully dehumidified, and a discharge section in the container drying tunnel (1) where the container carries the heat storage and the air waste heat entrained by the dried container is discharged. The areas requiring heat include the container heating section at the front of the container drying tunnel that requires rapid preheating. The heat pump heat recovery device (22) includes an evaporation side at a low temperature stage and a condensation side at a high temperature stage; The low-temperature evaporation side is located inside the container drying tunnel (1), which extracts heat from the internal circulating air and condenses and removes the water vapor therein, thus completing the recovery of sensible heat and latent heat. The condenser side of the high-temperature stage is connected to the refrigerant loop (20) on the outside. The high-temperature and high-pressure refrigerant is pumped into the refrigerant loop (20) for unified management by the compression capacity of the compressor inside the heat pump. The terminal heating device (21) connects its refrigerant circuit in series with the refrigerant loop (20), and the terminal heating device (21) is equipped with a fan device; After the fan device is turned on, it drives the air circulation flow of the corresponding local position through the terminal heating device (21) to extract heat from the corresponding local loop section of the refrigerant and realize the heating inside the container drying tunnel (1). The container to be dried enters from one side of the container drying tunnel (1). After rapid heating in the front section, the moisture in the paint on its surface gradually evaporates, replenishing the humidity of the surrounding air.
2. A distributed heat pump thermal and humidity management system for container tunnel drying process according to claim 1, characterized in that, The heat pump heat recovery device (22) is a distributed heat pump heat recovery unit; After the distributed heat pump heat recovery unit is turned on, it takes heat from the surrounding hot and humid air, causing the water vapor contained therein to condense, thus completing the dehumidification inside the container drying tunnel (1) and maintaining the humidity balance. The distributed heat pump unit obtains a portion of the refrigerant from the refrigerant loop (20), throttles it to a low-temperature and low-pressure two-phase state through a throttling element, and flows it through the evaporator side pipe of the dehumidifying evaporator in the container drying tunnel (1). After taking heat from the air, it evaporates into a superheated gas state. The superheated gas is drawn into the compressor and compressed into a high-temperature and high-pressure refrigerant gas, which is then pumped back into the refrigerant loop (20) and mixed with the mainstream of the refrigerant loop (20).
3. A distributed heat pump thermal and humidity management system for container tunnel drying process according to claim 1, characterized in that, The heat pump heat recovery device (22) includes a modular closed dehumidification and drying heat pump arranged in a local section of the container drying tunnel (1) with high humidity, so as to realize the local recovery and utilization of heat. The hot and humid air flows through the evaporation side of the dehumidification and drying heat pump to cool and dehumidify. The heat recovered from it, together with part of the power consumption of the dehumidification and drying heat pump compressor, is released on the condensation side of the dehumidification and drying heat pump and reused to heat the dehumidified circulating air.
4. A distributed heat pump thermal and humidity management system for container tunnel drying process according to claim 3, characterized in that, The heat pump heat recovery device (22) also includes a heat recovery heat pump located in the outlet partition area of the container drying tunnel (1). The evaporation side circuit of the heat recovery heat pump is located in the partition area to rapidly cool down the dried container and realize heat recovery.
5. A container tunnel drying system, characterized in that, It includes a container drying tunnel (1) and a distributed heat pump heat and humidity management system as described in any one of claims 1 to 4.
6. A container tunnel drying system according to claim 5, characterized in that, The inlet and outlet of the container drying tunnel (1) are equipped with electric roller shutters. The roller shutters open when a container passes by and close when no container passes by. The container drying tunnel (1) is also equipped with an intermediate roller shutter door at the inner position near the exit, forming a partitioned area for heat recovery. After the container leaves the intermediate roller shutter door, the intermediate roller shutter door is closed. The container that has completed the paint drying stays in the area between the intermediate roller shutter door and the exit for a preset time, and is fully heat recovered before leaving the container drying tunnel (1) from the exit. The container drying tunnel (1) is equipped with circulating fans on both sides, and the circulating fans are evenly distributed along the container drying tunnel (1); Hot air furnaces are provided on both sides of the container drying tunnel (1), and the hot air furnaces are used to input heat into the container drying tunnel (1).