Drying apparatus and control method thereof

Abstract

The application discloses a drying device and a control method thereof, wherein the drying device comprises a drying box, a heat pump system, the heat pump system comprises a compressor, a four-way valve, a condenser and a dehumidification evaporator, and the drying device further comprises an auxiliary heat exchanger which is located outside the drying box, one end of the auxiliary heat exchanger is connected with the four-way valve, the other end of the auxiliary heat exchanger is connected with a first connecting point on a pipeline between the condenser and the dehumidification evaporator, and the auxiliary heat exchanger is used for being connected with part of refrigerant discharged by the compressor and then being connected with the dehumidification evaporator after heat exchange, so as to be connected with the dehumidification evaporator when the drying device is in a dehumidification mode of the drying box; and a waterway heat exchange system which is connected with the auxiliary heat exchanger and is used for absorbing heat energy of the auxiliary heat exchanger to prepare hot water. The application solves the problem of heat waste in the drying process in the prior art, and improves the energy utilization rate of the drying process.

Description

Technical Field

[0001] This invention relates to the field of drying technology, and more specifically, to a drying apparatus and its control method. Background Technology

[0002] Air source heat pump dryers are gradually replacing traditional coal-fired boilers, especially in agricultural product processing and manufacturing. The drying process requires achieving two air conditioning goals: heating and dehumidification. Dehumidification can be achieved through either fresh air replacement or evaporator condensation dehumidification, both of which involve significant energy loss. For example, during fresh air replacement, the high-temperature, high-humidity air discharged from the drying chamber also releases heat. During condensation dehumidification, the condenser continuously releases heat during operation, causing the temperature inside the drying chamber to rise continuously. Excess heat needs to be discharged from the drying chamber, resulting in heat loss as well. Therefore, any heat transfer will result in heat loss and waste.

[0003] There is currently no effective solution to the problem of heat waste during the drying process in related technologies. Summary of the Invention

[0004] This invention provides a drying device and its control method to at least solve the problem of heat waste in the drying process in the prior art.

[0005] To address the aforementioned technical problems, according to one aspect of the present invention, a drying apparatus is provided, comprising a drying chamber and a heat pump system. The heat pump system includes a compressor, a four-way valve, a condenser, and a dehumidifying evaporator. The drying apparatus further includes: an auxiliary heat exchanger located outside the drying chamber, one end of which is connected to the four-way valve, and the other end of which is connected to a first connection point on a pipeline located between the condenser and the dehumidifying evaporator, for exchanging heat with a portion of the refrigerant discharged from the compressor when the drying apparatus is in the dehumidification mode of the drying chamber, and then introducing it into the dehumidifying evaporator; and a water heat exchange system connected to the auxiliary heat exchanger for absorbing the heat energy of the auxiliary heat exchanger to prepare hot water.

[0006] Furthermore, the drying device also includes a drying chamber heating mode. In the drying chamber heating mode, the auxiliary heat exchanger is used as an evaporator, and after exchanging heat with the refrigerant discharged from the condenser, it is introduced into the compressor.

[0007] Furthermore, in the drying oven heating mode, the dehumidifying evaporator also functions as a condenser, and the auxiliary heat exchanger exchanges heat with the refrigerant discharged from the condenser and dehumidifying evaporator before it is introduced into the compressor.

[0008] Furthermore, it also includes: a first electronic expansion valve, located on the pipeline between the dehumidifying evaporator and the first connection point, used for throttling in the dehumidification mode of the drying chamber and fully opening or closing in the heating mode of the drying chamber; and a second electronic expansion valve, located on the pipeline between the first connection point and the auxiliary heat exchanger, used for fully opening in the dehumidification mode of the drying chamber and throttling in the heating mode of the drying chamber.

[0009] Furthermore, the water heat exchange system includes: a water storage tank, the outlet of which is connected to the inlet of the auxiliary heat exchanger, and the inlet of the water storage tank is connected to the outlet of the auxiliary heat exchanger; and a first stop valve located on the pipeline between the inlet of the water storage tank and the outlet of the auxiliary heat exchanger.

[0010] Furthermore, the water heat exchange system also includes: a water supply device, the outlet of which is connected to the inlet of the auxiliary heat exchanger, and the outlet of the auxiliary heat exchanger is also connected to the inlet of the water supply device; and a second stop valve located on the pipeline between the outlet of the auxiliary heat exchanger and the inlet of the water supply device.

[0011] Furthermore, the water heat exchange system also includes: a water supply pump located at the outlet of the water supply device; and a water purification device located on the pipeline between the water supply pump and the inlet of the auxiliary heat exchanger.

[0012] According to another aspect of the present invention, a drying device control method is provided, applied to the drying device as described above, the method comprising: determining an operating mode of the drying device; wherein the operating mode includes at least: a drying chamber dehumidification mode and a drying chamber heating mode; and controlling the operation of an auxiliary heat exchanger and a water circuit heat exchange system according to the operating mode.

[0013] Furthermore, the operation of the auxiliary heat exchanger and the water heat exchange system is controlled according to the operating mode, including: when the operating mode is the drying box dehumidification mode, the first electronic expansion valve is controlled to throttle and the second electronic expansion valve is fully opened, while the first stop valve of the water heat exchange system is opened and the second stop valve of the water heat exchange system is closed; when the operating mode is the drying box heating mode, the opening and closing of the first electronic expansion valve is controlled according to the outlet water temperature of the water supply device, and the second electronic expansion valve is controlled to throttle, while the first stop valve of the water heat exchange system is closed and the second stop valve of the water heat exchange system is opened.

[0014] Furthermore, controlling the opening and closing of the first electronic expansion valve based on the outlet water temperature of the water supply device includes: determining whether the outlet water temperature of the water supply device is greater than a preset temperature threshold; if so, controlling the first electronic expansion valve to fully open; otherwise, controlling the first electronic expansion valve to close.

[0015] According to another aspect of the present invention, a storage medium containing computer-executable instructions is provided, which, when executed by a computer processor, are used to perform the drying apparatus control method as described above.

[0016] This invention provides a drying device that improves energy utilization. It employs a dehumidifying evaporator within a heat pump system for dehumidification. In addition, an auxiliary heat exchanger is installed outside the drying chamber. During dehumidification, the auxiliary heat exchanger is essentially connected in parallel with the condenser. A portion of the refrigerant discharged from the compressor enters the condenser, while the remaining portion enters the auxiliary heat exchanger. After heat exchange, the refrigerant flows through the dehumidifying evaporator and then returns to the compressor. This auxiliary heat exchanger diverts some of the refrigerant from the condenser to regulate the condenser's heat exchange capacity, balance the heat within the drying chamber, and prevent overheating. Simultaneously, a water-based heat exchange system absorbs the heat energy from the auxiliary heat exchanger to prepare hot water, thus avoiding heat waste during the drying process and improving energy efficiency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of an optional structure of a drying apparatus according to an embodiment of the present invention;

[0018] Figure 2 This is a refrigerant flow diagram of the drying apparatus according to an embodiment of the present invention in the drying chamber heating mode;

[0019] Figure 3 This is an optional flowchart of a drying apparatus control method according to an embodiment of the present invention;

[0020] Figure 4 This is another optional flowchart of the drying apparatus control method according to an embodiment of the present invention.

[0021] Explanation of reference numerals in the attached figures:

[0022] 1. Compressor; 2. Four-way valve; 3. Condenser; 4. Dehumidifying evaporator; 5. Auxiliary heat exchanger; 6. First electronic expansion valve; 7. Second electronic expansion valve; 8. Water storage tank; 9. First stop valve; 10. Water supply device; 11. Second stop valve; 12. Make-up water pump; 13. Water purification device; 14. Circulating fan; 15. Gas-liquid separator; 16. Three-way valve; 17. Domestic water supply. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0024] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.

[0025] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0026] It should be understood that although the terms first, second, third, etc., may be used to describe controllers in embodiments of the present invention, these controllers should not be limited to these terms. These terms are only used to distinguish controllers connected to different devices. For example, without departing from the scope of embodiments of the present invention, a first controller may also be referred to as a second controller, and similarly, a second controller may also be referred to as a first controller.

[0027] Depending on the context, the words “if” or “suppose” as used here can be interpreted as “when” or “in response to determination” or “in response to detection.” Similarly, depending on the context, the phrases “if determination” or “if detection (of the stated condition or event)” can be interpreted as “when determination” or “in response to determination” or “when detection (of the stated condition or event)” or “in response to detection (of the stated condition or event).”

[0028] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.

[0029] The optional embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0030] Example 1

[0031] In a preferred embodiment 1 of the present invention, a drying apparatus is provided, specifically... Figure 1 A schematic diagram of an alternative structure of the drying device is shown, such as... Figure 1 As shown, the drying device includes:

[0032] Drying oven and heat pump system, the heat pump system includes compressor 1, four-way valve 2, condenser 3 and dehumidifying evaporator 4; Figure 1 The upper left frame shows the drying chamber, where the condenser 3 and dehumidifying evaporator 4 are located. A circulating fan 14 is also installed inside the drying chamber, causing airflow within the chamber. Figure 1 As shown. Furthermore, as... Figure 1 As shown, the heat pump system also includes a gas-liquid separator 15 located between the compressor 1 and the four-way valve 2. During condensation dehumidification, the condenser 3 continuously releases heat during operation, causing the temperature inside the drying oven to rise continuously. Excess heat needs to be discharged from the drying oven, resulting in heat loss.

[0033] To address the above issues, the drying device also includes:

[0034] The auxiliary heat exchanger 5 is located outside the drying box. One end is connected to the four-way valve 2, and the other end is connected to the first connection point on the pipeline between the condenser 3 and the dehumidifying evaporator 4. It is used to exchange heat with part of the refrigerant discharged by the compressor 1 when the drying device is in the dehumidifying mode of the drying box and then pass it into the dehumidifying evaporator 4.

[0035] The water heat exchange system is connected to the auxiliary heat exchanger 5 and is used to absorb the heat energy of the auxiliary heat exchanger 5 to prepare hot water.

[0036] In the above embodiments, a drying device with improved energy utilization is provided. Dehumidification is achieved using a dehumidifying evaporator in a heat pump system. In addition, an auxiliary heat exchanger is installed outside the drying chamber. During dehumidification, the auxiliary heat exchanger is essentially connected in parallel with the condenser. Part of the refrigerant discharged from the compressor enters the condenser, and the other part enters the auxiliary heat exchanger. After heat exchange, it flows through the dehumidifying evaporator and then returns to the compressor. The auxiliary heat exchanger diverts some of the refrigerant from the condenser to regulate the heat exchange capacity of the condenser, balance the heat within the drying chamber, and prevent excessive temperature. Simultaneously, a water-based heat exchange system absorbs the heat energy from the auxiliary heat exchanger to prepare hot water, thus avoiding heat waste during the drying process and improving the energy utilization rate of the drying process.

[0037] In addition to being used as a parallel condenser, the auxiliary heat exchanger 5 can also be used as an evaporator. When the drying device is in the drying chamber heating mode, that is, when the temperature inside the drying chamber needs to be increased, the auxiliary heat exchanger 5 is used as an evaporator, exchanging heat with the refrigerant discharged from the condenser 3 before being fed into the compressor 1. Figure 2 The diagram shows the refrigerant flow path of the drying device in the drying chamber heating mode. After being compressed by the compressor 1, the refrigerant becomes a high-temperature and high-pressure refrigerant. After exiting the exhaust port of the compressor 1, it enters the condenser 3, or enters the condenser 3 and the dehumidifying evaporator 4, and then enters the auxiliary heat exchanger 5 before returning to the compressor 1.

[0038] like Figure 1 As shown, it also includes: a first electronic expansion valve 6, located on the pipeline between the dehumidifying evaporator 4 and the first connection point, used for throttling in the dehumidification mode of the drying box and fully opening or closing in the heating mode of the drying box; and a second electronic expansion valve 7, located on the pipeline between the first connection point and the auxiliary heat exchanger 5, used for fully opening in the dehumidification mode of the drying box and throttling in the heating mode of the drying box.

[0039] like Figure 1 As shown, the water heat exchange system includes: a water storage tank 8, the outlet of the water storage tank 8 is connected to the inlet of the auxiliary heat exchanger 5, and the inlet of the water storage tank 8 is connected to the outlet of the auxiliary heat exchanger 5; and a first stop valve 9, located on the pipeline between the inlet of the water storage tank 8 and the outlet of the auxiliary heat exchanger 5.

[0040] In addition, the water heat exchange system also includes: a water supply device 10, the outlet of which is connected to the inlet of the auxiliary heat exchanger 5, and the outlet of the auxiliary heat exchanger 5 is also connected to the inlet of the water supply device 10; as shown in the figure, the outlet of the water supply device 10 is connected to the inlet of the auxiliary heat exchanger 5 through a three-way valve 16, and the other end of the three-way valve is connected to the outlet of the water storage tank 8. A second stop valve 11 is also provided in the water heat exchange system, located on the pipeline between the outlet of the auxiliary heat exchanger 5 and the inlet of the water supply device 10. Further, the water heat exchange system also includes: a makeup water pump 12, located at the outlet of the water supply device 10; and a water purification device 13, located on the pipeline between the makeup water pump 12 and the inlet of the auxiliary heat exchanger 5. The water in the water storage tank 8 is used for domestic water use 17.

[0041] Figure 1The refrigerant flow path during dehumidification is also shown. After being compressed by compressor 1, the refrigerant becomes a high-temperature, high-pressure refrigerant. After exiting the exhaust port of compressor 1, part of it enters condenser 3, becoming a high-temperature, high-pressure liquid. After being throttled by the first electronic expansion valve 6 into a low-temperature, low-pressure liquid, it enters dehumidifying evaporator 4. The other part of the refrigerant passes through auxiliary heat exchanger 5, and after being throttled by the second electronic expansion valve 7 (fully open without throttling) and the first electronic expansion valve 6 into a low-temperature, low-pressure liquid, it enters dehumidifying evaporator 4. The refrigerant exiting dehumidifying evaporator 4 returns to compressor 1 to complete one refrigeration cycle. In this mode, after the auxiliary heat exchanger 5 exchanges heat with water from the water source, the excess heat is discharged. At this time, the cold water from the water source becomes hot water after heat exchange by the plate heat exchanger. The second stop valve 11 is closed, and the first stop valve 9 is opened. The hot water enters the water storage tank 8 through the return water pipe for storage. When needed, the water storage tank 8 supplies domestic water. The water in the water storage tank 8 can be circulated and heated through auxiliary heat exchanger 5. Simultaneously with the refrigerant circulation process, a circulating fan provides power for air circulation. Air drawn into the dryer first passes through the dehumidifying evaporator 4. As the high-temperature, high-humidity air flows over the outer wall of the dehumidifying evaporator 4, water vapor in the air condenses into water droplets on the outer wall and is discharged. After condensation and dehumidification, the air enters the condenser 3, is heated, and then enters the drying chamber to complete the air circulation. In the drying operation mode, the temperature can be adjusted via the first electronic expansion valve 6 to meet the drying temperature requirements for commonly used high-temperature resistant materials.

[0042] When the drying device turns on the drying chamber heating mode, such as Figure 2 As shown, the refrigerant, after being compressed by compressor 1, becomes a high-temperature, high-pressure refrigerant. It exits from the compressor 1's exhaust port and enters condenser 3, becoming a high-temperature, high-pressure liquid. To accelerate heating and ensure system reliability, the opening and closing of the electronic expansion valves are determined based on the supply water temperature: when the supply water temperature is high, the evaporation capacity is poor, and the condenser 3 has a high heat exchange demand; the first electronic expansion valve 6 is fully open, and the second electronic expansion valve 7 is throttled. In this case, the dehumidifying evaporator 4 also functions as the condenser 3. When the source water temperature is low, the evaporation capacity is strong, and the evaporator needs to be protected against freezing. Compressor 1 needs to limit its output capacity. In this case, the condenser 3 has a low heat exchange demand; the first electronic expansion valve 6 is closed, and the refrigerant, after being throttled by the second electronic expansion valve 7 into a low-temperature, low-pressure liquid, enters the auxiliary heat exchanger 5. The refrigerant cannot pass through the dehumidifying evaporator 4. During this process, the first stop valve 9 is closed, and the second stop valve 11 is opened. The cold water from the auxiliary heat exchanger 5, after exchanging heat with the source water, returns to the source water via the return pipe.

[0043] In the above implementation, an evaporator is used for dehumidification and heat absorption, and an auxiliary heat exchanger is added to utilize water to exchange heat with excess hot gas, balancing the load demand of the drying chamber and preventing excessive temperature. Simultaneously, the hot water produced by the plate heat exchanger can be used for domestic hot water. Furthermore, the use of a water-based heat exchange system, unlike conventional fan exhaust, eliminates the need for an external fan in the drying chamber, significantly reducing equipment noise. Additionally, during heating operation, the number of condensers in the system can be adjusted according to the evaporator's output capacity, flexibly adapting to various operating conditions and achieving energy-saving operation.

[0044] Example 2

[0045] In a preferred embodiment 2 of the present invention, a drying device control method is provided, which is applied to the drying device in embodiment 1 above. Specifically, Figure 3 An optional flowchart of the method is shown, such as Figure 3 As shown, the method includes the following steps S302-S304:

[0046] S302: Determine the operating mode of the drying device; wherein, the operating mode includes at least: drying chamber dehumidification mode and drying chamber heating mode;

[0047] S304: Control the operation of the auxiliary heat exchanger and water heat exchange system according to the operating mode.

[0048] In the above embodiments, a drying device with improved energy utilization is provided. Dehumidification is achieved using a dehumidifying evaporator in a heat pump system. In addition, an auxiliary heat exchanger is installed outside the drying chamber. During dehumidification, the auxiliary heat exchanger is essentially connected in parallel with the condenser. Part of the refrigerant discharged from the compressor enters the condenser, and the other part enters the auxiliary heat exchanger. After heat exchange, it flows through the dehumidifying evaporator and then returns to the compressor. The auxiliary heat exchanger diverts some of the refrigerant from the condenser to regulate the heat exchange capacity of the condenser, balance the heat within the drying chamber, and prevent excessive temperature. Simultaneously, a water-based heat exchange system absorbs the heat energy from the auxiliary heat exchanger to prepare hot water, thus avoiding heat waste during the drying process and improving the energy utilization rate of the drying process.

[0049] Specifically, the operation of the auxiliary heat exchanger and the water heat exchange system is controlled according to the operating mode, including: when the operating mode is the drying box dehumidification mode, the first electronic expansion valve is controlled to throttle and the second electronic expansion valve is fully opened, while the first stop valve of the water heat exchange system is opened and the second stop valve of the water heat exchange system is closed.

[0050] When the operating mode is the drying chamber heating mode, the opening and closing of the first electronic expansion valve is controlled according to the outlet water temperature of the water supply device, and the throttling of the second electronic expansion valve is controlled. Simultaneously, the first stop valve of the water heat exchange system is closed, and the second stop valve of the water heat exchange system is opened. Further, controlling the opening and closing of the first electronic expansion valve according to the outlet water temperature of the water supply device includes: determining whether the outlet water temperature of the water supply device is greater than a preset temperature threshold; if so, controlling the first electronic expansion valve to fully open; otherwise, controlling the first electronic expansion valve to close.

[0051] In a preferred embodiment 2 of the present invention, another method for controlling the drying device is also provided, specifically... Figure 4 An optional flowchart of the method is shown, such as Figure 4 As shown, the method includes the following steps S401-S406:

[0052] S401: Detect unit status;

[0053] S402: Determine whether dehumidification is needed based on the unit status; if yes, proceed to step S403, otherwise proceed to step S404.

[0054] S403: Controls the first electronic expansion valve to throttle, the second electronic expansion valve to fully open, the first stop valve to open, and the second stop valve to close; (e.g., ...) Figure 1 The diagram illustrates the refrigerant flow path during dehumidification. After being compressed by the compressor, the refrigerant becomes a high-temperature, high-pressure refrigerant. Part of it exits the compressor's exhaust port and enters the condenser, becoming a high-temperature, high-pressure liquid. This liquid is then throttled by the first electronic expansion valve to a low-temperature, low-pressure state before entering the dehumidification evaporator. The other part of the refrigerant passes through the auxiliary heat exchanger, then through the second electronic expansion valve (fully open, no throttling), and again through the first electronic expansion valve to a low-temperature, low-pressure state before entering the dehumidification evaporator. The refrigerant exiting the dehumidification evaporator returns to the compressor, completing one refrigeration cycle. In this mode, the auxiliary heat exchanger exchanges heat with water from the water source and dissipates excess heat. The cold water from the water source becomes hot water after heat exchange through the plate heat exchanger. The second stop valve is closed, and the first stop valve is opened. The hot water flows through the return pipe into the storage tank for storage. When needed, the water in the storage tank is supplied as domestic water. The water in the storage tank can be circulated and heated by the auxiliary heat exchanger. During the refrigerant circulation process described above, a circulating fan provides power for air circulation. Air drawn into the dryer first passes through a dehumidifying evaporator. As the hot, humid air flows over the outer wall of the dehumidifying evaporator, water vapor in the air condenses into water droplets and is discharged. After condensation and dehumidification, the air enters the condenser, is heated, and then enters the drying chamber to complete the air circulation. In drying mode, the temperature can be adjusted via the first electronic expansion valve to meet the drying equipment temperature requirements for commonly used high-temperature resistant materials.

[0055] S404: Determine if the source water temperature is greater than t (preset temperature threshold). If yes, proceed to step S406; otherwise, proceed to step S405.

[0056] S405: Controls the first electronic expansion valve to close, the second electronic expansion valve to throttle, the first stop valve to close, and the second stop valve to open;

[0057] S406: Controls the first electronic expansion valve to be fully open, the second electronic expansion valve to be throttled, the first stop valve to be closed, and the second stop valve to be opened.

[0058] When the drying device turns on the drying chamber heating mode, such as Figure 2 As shown, the refrigerant, after being compressed by the compressor, becomes a high-temperature, high-pressure refrigerant. It exits the compressor's exhaust port and enters the condenser, becoming a high-temperature, high-pressure liquid. To accelerate heating and ensure system reliability, the opening and closing of the electronic expansion valve is determined by the supply water temperature: when the supply water temperature is high, the evaporation capacity is poor, and the condenser's heat exchange demand is high; the first electronic expansion valve is fully open, and the second electronic expansion valve is throttled. In this case, the dehumidifying evaporator also functions as a condenser. When the source water temperature is low, the evaporation capacity is strong, and the evaporator needs to be protected against freezing, requiring the compressor to limit its output. In this case, the condenser's heat exchange demand is low, the first electronic expansion valve is closed, and the refrigerant, after being throttled by the second electronic expansion valve into a low-temperature, low-pressure liquid, enters the auxiliary heat exchanger. The refrigerant cannot pass through the dehumidifying evaporator. During this process, the first stop valve is closed, and the second stop valve is opened. The cold water from the auxiliary heat exchanger, after heat exchange with the source water, returns to the source water via the return pipe.

[0059] Example 3

[0060] Based on the drying device control method provided in Embodiment 2 above, in a preferred embodiment 3 of the present invention, a storage medium containing computer-executable instructions is also provided, which, when executed by a computer processor, are used to execute the drying device control method as described above.

[0061] In the above embodiments, a drying device with improved energy utilization is provided. Dehumidification is achieved using a dehumidifying evaporator in a heat pump system. In addition, an auxiliary heat exchanger is installed outside the drying chamber. During dehumidification, the auxiliary heat exchanger is essentially connected in parallel with the condenser. Part of the refrigerant discharged from the compressor enters the condenser, and the other part enters the auxiliary heat exchanger. After heat exchange, it flows through the dehumidifying evaporator and then returns to the compressor. The auxiliary heat exchanger diverts some of the refrigerant from the condenser to regulate the heat exchange capacity of the condenser, balance the heat within the drying chamber, and prevent excessive temperature. Simultaneously, a water-based heat exchange system absorbs the heat energy from the auxiliary heat exchanger to prepare hot water, thus avoiding heat waste during the drying process and improving the energy utilization rate of the drying process.

[0062] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not invented by the invention. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0063] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A drying apparatus, comprising a drying chamber and a heat pump system, said heat pump system comprising a compressor (1), a four-way valve (2), a condenser (3), and a dehumidifying evaporator (4), characterized in that, The drying device further includes: An auxiliary heat exchanger (5) is located outside the drying box. One end is connected to the four-way valve (2), and the other end is connected to the first connection point on the pipeline between the condenser (3) and the dehumidifying evaporator (4). It is used to exchange heat with part of the refrigerant discharged by the compressor (1) when the drying device is in the dehumidifying mode of the drying box and then pass it into the dehumidifying evaporator (4). A water heat exchange system is connected to the auxiliary heat exchanger (5) and is used to absorb the heat energy of the auxiliary heat exchanger (5) to prepare hot water; The drying device also includes a drying chamber heating mode. In the drying chamber heating mode, the auxiliary heat exchanger (5) is used as an evaporator and exchanges heat with the refrigerant discharged from the condenser (3) before being fed into the compressor (1). The dehumidifying evaporator (4) is also used as a condenser. The auxiliary heat exchanger (5) exchanges heat with the refrigerant discharged from the condenser (3) and the dehumidifying evaporator (4) before being fed into the compressor (1).

2. The drying apparatus according to claim 1, characterized in that, Also includes: The first electronic expansion valve (6) is located on the pipeline between the dehumidifying evaporator (4) and the first connection point, and is used to throttle the drying box in dehumidification mode and to be fully open or closed in heating mode of the drying box. The second electronic expansion valve (7) is located on the pipeline between the first connection point and the auxiliary heat exchanger (5) and is used to be fully open in the dehumidification mode of the drying box and to be throttled in the heating mode of the drying box.

3. The drying apparatus according to claim 1, characterized in that, The water heat exchange system includes: Water storage tank (8), the outlet of the water storage tank (8) is connected to the inlet of the auxiliary heat exchanger (5), and the inlet of the water storage tank (8) is connected to the outlet of the auxiliary heat exchanger (5). The first stop valve (9) is located on the pipeline between the inlet of the water storage tank (8) and the outlet of the auxiliary heat exchanger (5).

4. The drying apparatus according to claim 3, characterized in that, The water heat exchange system also includes: Water supply device (10), the outlet of the water supply device (10) is connected to the inlet of the auxiliary heat exchanger (5), and the outlet of the auxiliary heat exchanger (5) is also connected to the inlet of the water supply device (10). The second stop valve (11) is located on the pipeline between the outlet of the auxiliary heat exchanger (5) and the inlet of the water supply device (10).

5. The drying apparatus according to claim 4, characterized in that, The water heat exchange system also includes: A water supply pump (12) is located at the outlet of the water supply device (10); The water purification device (13) is located on the pipeline between the water supply pump (12) and the inlet of the auxiliary heat exchanger (5).

6. A drying apparatus control method, applied to the drying apparatus as described in any one of claims 1 to 5, characterized in that, The method includes: The operating mode of the drying device is determined; wherein the operating mode includes at least: a drying chamber dehumidification mode and a drying chamber heating mode; The operation of the auxiliary heat exchanger and the water heat exchange system is controlled according to the operating mode.

7. The method according to claim 6, characterized in that, Controlling the operation of the auxiliary heat exchanger and the water heat exchange system according to the aforementioned operating mode includes: When the operating mode is the dehumidification mode of the drying box, the first electronic expansion valve is controlled to throttle and the second electronic expansion valve is fully opened. At the same time, the first stop valve of the water heat exchange system is controlled to open and the second stop valve of the water heat exchange system is closed. When the operating mode is the drying chamber heating mode, the opening and closing of the first electronic expansion valve is controlled according to the outlet water temperature of the water supply device, and the throttling of the second electronic expansion valve is controlled. At the same time, the first stop valve of the water circuit heat exchange system is controlled to close, and the second stop valve of the water circuit heat exchange system is controlled to open.

8. The method according to claim 7, characterized in that, Controlling the opening and closing of the first electronic expansion valve based on the outlet water temperature of the water supply device includes: Determine whether the outlet water temperature of the water supply device is greater than a preset temperature threshold; If so, then control the first electronic expansion valve to fully open; Otherwise, the first electronic expansion valve is closed.

9. A storage medium containing computer-executable instructions, characterized in that, The computer-executable instructions, when executed by a computer processor, are used to perform the drying apparatus control method as described in any one of claims 6 to 8.

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