Drying device with exhaust heat recovery function

Abstract

The utility model belongs to the technical field of drying equipment, and particularly relates to a drying device with an exhaust heat recovery function, which comprises a drying chamber provided with a chamber air inlet and a chamber air outlet; the exhaust channel comprises an exhaust air inlet, a first heat exchanger, an exhaust fan, an exhaust air outlet and the like which are communicated in sequence; the air inlet channel comprises an air inlet, an air inlet fan, a second heat exchanger, an air inlet outlet and the like which are communicated in sequence; the first water outlet is sequentially communicated with the circulating water pump, the one-way valve and the third water inlet to form closed-loop heat recovery waterway circulation, the second water outlet is divided into two paths, one path is communicated with the first water inlet, and the other path is communicated with a water return pipe and leads to an external heat source to form external heat source waterway circulation. The double functions of waste heat recovery and secondary heating are integrated through the single heat exchanger, and self-regulation and self-control of the control system are combined, so that the effects of simple structure, high waste heat utilization rate and simplicity in control are achieved.

Description

Technical Field

[0001] This utility model belongs to the technical field of drying equipment, and specifically relates to a drying device with exhaust heat recovery. Background Technology

[0002] Most agricultural products require temperature and humidity control during the drying process after harvesting to regulate the drying speed. The drying process demands a gradual increase in temperature and a gradual decrease in humidity, typically involving three stages: a small initial temperature rise and slow dehumidification, a stable temperature and large dehumidification in the middle stage, and a significant temperature rise and small dehumidification in the later stage. During the drying process, heating devices are needed to raise the temperature of the air in the drying chamber, while a portion of the hot and humid air in the drying chamber needs to be continuously discharged, and some dry air needs to be added to prevent excessive humidity in the drying chamber from affecting the drying quality and speed. The discharged hot and humid air has high energy and is valuable for recovery. However, existing technologies use dual heat exchangers, where a heat recovery unit recovers heat from the exhaust gas and uses it to preheat fresh air, and then another heat exchanger reheats the preheated fresh air to meet the inlet temperature requirements of the drying chamber. Dual heat exchangers, due to the use of two independent heat exchange systems, suffer from complex structures, low waste heat utilization efficiency, and difficult control. Utility Model Content

[0003] (a) Technical problems to be solved

[0004] To address the problems of complex structure, low waste heat utilization efficiency, and difficult control in existing dual heat exchanger technologies, this utility model proposes a drying device with exhaust heat recovery. The aim is to achieve a simple structure, high waste heat utilization rate, and easy control by integrating waste heat recovery and secondary heating functions into a single heat exchanger and adding self-regulation of the control system.

[0005] (II) Technical Solution

[0006] This utility model is achieved through the following technical solution: This utility model proposes a drying device with exhaust heat recovery, comprising:

[0007] The drying chamber is equipped with an air inlet and an air outlet.

[0008] Exhaust passage: The exhaust air inlet, the first heat exchanger, the exhaust fan and the exhaust air outlet are connected in sequence. The first heat exchanger is provided with a first water inlet and a first water outlet. A first temperature sensor and a first humidity sensor are installed in the exhaust passage.

[0009] Air intake channel: The air intake port, air intake fan, second heat exchanger and air intake outlet are connected in sequence. A second temperature sensor and a second humidity sensor are installed in the air intake channel.

[0010] The exhaust air inlet is connected to the indoor air outlet; the air intake air inlet is connected to the indoor air inlet.

[0011] Specifically:

[0012] The second heat exchanger is provided with a second inlet, a second outlet, and a third inlet located between the second inlet and the second outlet;

[0013] The second water inlet is connected to the water inlet pipe used to connect to an external heat source, and the water inlet pipe is equipped with an electric valve;

[0014] Heat recovery water circuit: The first outlet is connected in sequence to the circulating water pump, the one-way valve and the third inlet, forming a closed-loop heat recovery water circuit circulation;

[0015] External heat source water circuit: The second outlet is divided into two paths: one path connects to the first inlet, and the other path connects to the return water pipe and leads to the external heat source, forming an external heat source water circuit circulation;

[0016] The above-mentioned synergy also forms a staged heating structure: the second water inlet is connected to an external heat source, and the third water inlet receives and recovers waste heat, realizing the mixed heating of the external heat source and waste water in the heat exchanger.

[0017] Furthermore, the second water inlet is close to the air inlet and outlet, the third water inlet is located in the middle of the second heat exchanger, and the second water outlet is close to the air inlet and outlet.

[0018] Furthermore, the outlet of the one-way valve points to the third inlet to ensure that water flows unidirectionally from the first heat exchanger into the second heat exchanger.

[0019] Furthermore, the first temperature sensor and the first humidity sensor are disposed between the exhaust air inlet and the first heat exchanger; the second temperature sensor and the second humidity sensor are disposed between the air inlet and the second heat exchanger.

[0020] Furthermore, it also includes a control system, which is electrically connected to a first temperature sensor, a first humidity sensor, an exhaust fan, a second temperature sensor, a second humidity sensor, an intake fan, a circulating water pump, and an electric valve. The control system is used to adjust the air volume of the exhaust fan and the intake fan, the flow rate of the circulating water pump, and the water flow distribution ratio of the electric valve based on the temperature and humidity data of the exhaust channel and the intake channel.

[0021] (III) Beneficial Effects

[0022] Compared with the prior art, this utility model has the following advantages:

[0023] This invention integrates waste heat recovery and secondary heating functions into a single heat exchanger, along with the self-regulation of the control system, thereby achieving a simple structure, high waste heat utilization rate, and easy control. Attached Figure Description

[0024] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0025] Figure 1 This is a schematic diagram of the structure of this utility model.

[0026] Figure 2 This is a schematic diagram of the drying chamber of this utility model.

[0027] Figure 3 This is a schematic diagram of the exhaust channel of this utility model.

[0028] Figure 4 This is a schematic diagram of the air intake channel of this utility model.

[0029] The labels in the attached diagram are as follows: 1-Drying chamber, 101-Chamber air outlet, 102-Chamber air inlet, 2-Exhaust passage, 201-Exhaust air inlet, 202-Exhaust air outlet, 203-First heat exchanger, 2031-First water inlet, 2032-First water outlet, 204-Exhaust fan, 205-First temperature sensor, 206-First humidity sensor, 3-Intake passage, 301-Intake air inlet, 302-Intake air outlet, 303-Intake fan, 304-Second heat exchanger, 3041-Second water inlet, 3042-Third water inlet, 3043-Second water outlet, 305-Second temperature sensor, 306-Second humidity sensor, 4-Control system, 5-Circulating water pump, 6-One-way valve, 7-Inlet water pipe, 8-Return water pipe, 9-Electric valve. Detailed Implementation

[0030] In this technical solution:

[0031] 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 merely illustrative of the present utility model and are not intended to limit the present utility model.

[0032] Reference Figure 1 , 2 As shown in Figures 3 and 4, this utility model proposes a drying device with exhaust heat recovery, comprising:

[0033] The drying chamber is equipped with an air inlet and an air outlet.

[0034] Exhaust passage: The exhaust air inlet, the first heat exchanger, the exhaust fan and the exhaust air outlet are connected in sequence. The first heat exchanger is provided with a first water inlet and a first water outlet. A first temperature sensor and a first humidity sensor are installed in the exhaust passage.

[0035] Air intake channel: The air intake port, air intake fan, second heat exchanger and air intake outlet are connected in sequence. A second temperature sensor and a second humidity sensor are installed in the air intake channel.

[0036] The exhaust air inlet is connected to the indoor air outlet; the air intake air inlet is connected to the indoor air inlet.

[0037] Specifically:

[0038] The second heat exchanger is provided with a second inlet, a second outlet, and a third inlet located between the second inlet and the second outlet;

[0039] The second water inlet is connected to the water inlet pipe used to connect to an external heat source, and the water inlet pipe is equipped with an electric valve;

[0040] Heat recovery water circuit: The first outlet is connected in sequence to the circulating water pump, the one-way valve and the third inlet, forming a closed-loop heat recovery water circuit circulation;

[0041] External heat source water circuit: The second outlet is divided into two paths: one path connects to the first inlet, and the other path connects to the return water pipe and leads to the external heat source, forming an external heat source water circuit circulation;

[0042] The above-mentioned synergy also forms a staged heating structure: the second water inlet is connected to an external heat source, and the third water inlet receives and recovers waste heat, realizing the mixed heating of the external heat source and waste water in the heat exchanger.

[0043] The second water inlet is close to the air inlet and outlet, the third water inlet is located in the middle of the second heat exchanger, and the second water outlet is close to the air inlet and outlet.

[0044] The outlet of the one-way valve points to the third inlet to ensure that water flows unidirectionally from the first heat exchanger into the second heat exchanger.

[0045] The first temperature sensor and the first humidity sensor are disposed between the exhaust air inlet and the first heat exchanger; the second temperature sensor and the second humidity sensor are disposed between the air inlet and the second heat exchanger.

[0046] It also includes a control system, which is electrically connected to a first temperature sensor, a first humidity sensor, an exhaust fan, a second temperature sensor, a second humidity sensor, an intake fan, a circulating water pump, and an electric valve. The control system is used to adjust the air volume of the exhaust fan and the intake fan, the flow rate of the circulating water pump, and the water flow distribution ratio of the electric valve based on the temperature and humidity data of the exhaust channel and the intake channel.

[0047] Working principle:

[0048] When the drying device is running, the high-temperature and high-humidity exhaust gas discharged from the drying chamber enters the exhaust channel through the chamber outlet and flows through the first heat exchanger and the exhaust fan in sequence. The first heat exchanger absorbs the residual heat in the exhaust gas through internal circulating water. The circulating water after heat absorption is pressurized by the circulating water pump and directionally transported to the third water inlet of the second heat exchanger (located in the middle of the heat exchanger) through a one-way valve, forming a closed-loop heat recovery water circuit. At this time, the low-temperature fresh air introduced from the outside enters from the air inlet and flows through the second heat exchanger under the drive of the air inlet fan.

[0049] The above implementation involves two stages:

[0050] Waste heat preheating stage: Fresh air first comes into contact with the recovered waste hot water injected through the third water inlet, absorbing low-temperature heat energy to achieve initial temperature rise;

[0051] External heat source heating stage: The preheated airflow continues to flow to the high temperature zone of the second heat exchanger (near the second water inlet), where it undergoes secondary heat exchange with the high temperature water injected by the external heat source. Finally, the dry hot air that reaches the target temperature is sent into the drying chamber from the air inlet and outlet.

[0052] The mixed water discharged from the second heat exchanger is circulated in two paths: one path returns to the first heat exchanger to continue absorbing waste heat from the exhaust gas and maintain heat recovery efficiency; the other path flows back to the external heat source system to achieve cascaded energy utilization. The entire process is dynamically regulated by the control system, as follows:

[0053] Temperature and humidity monitoring: The original exhaust gas status is captured in real time by a first temperature sensor and a first humidity sensor set between the exhaust air inlet and the first heat exchanger; the second temperature sensor and the second humidity sensor set between the air inlet and the second heat exchanger monitor the unheated fresh air data.

[0054] Intelligent adjustment: Based on sensor feedback, the control system synchronously adjusts the air volume of the exhaust and intake fans (controlling the dehumidification intensity), the flow rate of the circulating water pump (adjusting the waste heat recovery rate), and the opening of the electric valve (allocating the ratio of external heat source to waste heat) to ensure the temperature and humidity requirements of different drying stages (slow dehumidification / high dehumidification / high temperature dehumidification).

[0055] In this utility model:

[0056] By using a single heat exchanger with three interfaces (second inlet, third inlet, and second outlet), the traditionally separate waste heat recovery and fresh air heating functions are integrated into a single device. The layout of the second inlet being close to the high-temperature air outlet area and the third inlet being centrally located achieves the effect of spatial graded heating with priority utilization of low-temperature waste heat and precise compensation from high-temperature external heat sources. Compared with the dual heat exchanger solution, it can reduce more than 40% of the pipe interfaces, significantly reducing leakage risk and maintenance costs.

[0057] By using a one-way valve to force water flow from the first heat exchanger into the second heat exchanger, backflow interference under high pressure conditions of external heat sources is eliminated, ensuring continuous recovery of waste heat and improving waste heat utilization efficiency.

[0058] The second outlet diversion design allows some hot water to return to the first heat exchanger for heat absorption, while the other part flows back to the external heat source, forming an energy efficiency optimization chain of "recovery-utilization-recovery".

[0059] By placing temperature and humidity sensors in the front (close to the air inlet), the collected data is ensured to be unaffected by the heat exchange process, providing the control system with raw environmental parameters. Based on this, a multi-actuator linkage mechanism (fan + pump + valve) is implemented, with the following logic:

[0060] Early stage of drying: Reduce fan speed, increase the proportion of waste heat, and meet the need for slow temperature rise;

[0061] Mid-drying stage: Maximize exhaust volume, balance the ratio of residual heat to external heat source, and adapt to high humidity dehumidification requirements;

[0062] Later stage of drying: Reduce the electric valve to decrease waste heat recovery and enhance high-temperature compensation of external heat source;

[0063] The above-mentioned control is based on the control system and does not require too much operation, achieving a simple operation effect. The control system can be directly implemented based on a microcontroller or computer, and the corresponding program can be directly written and input. This is existing technology and will not be described in detail.

[0064] The graded heating structure of this invention allows the fresh air to undergo a gradual heating process of "low-temperature waste heat preheating → high-temperature external heat source supplementary heating", avoiding the hardening of material surface caused by sudden temperature rise in traditional solutions. The control system accurately tracks the three-stage temperature and humidity curves, effectively suppressing material cracking, discoloration and other losses.

[0065] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0066] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0067] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0068] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0069] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A drying device with exhaust heat recovery, comprising: The drying chamber (1) is provided with a chamber air inlet (102) and a chamber air outlet (101). Exhaust passage (2): an exhaust air inlet (201), a first heat exchanger (203), an exhaust fan (204) and an exhaust air outlet (202) are connected in sequence. The first heat exchanger (203) is provided with a first water inlet (2031) and a first water outlet (2032). A first temperature sensor (205) and a first humidity sensor (206) are provided in the exhaust passage. Air intake channel (3): connected in sequence to the air intake port (301), the air intake fan (303), the second heat exchanger (304) and the air intake outlet (302), and a second temperature sensor (305) and a second humidity sensor (306) are installed in the air intake channel. The exhaust air inlet (201) is connected to the room air outlet (101); the air inlet (301) is connected to the room air inlet (102); Its features are: The second heat exchanger (304) is provided with a second inlet (3041), a second outlet (3043) and a third inlet (3042) located between the second inlet and the second outlet. The second water inlet (3041) is connected to the water inlet pipe (7) used to connect to an external heat source, and the water inlet pipe is equipped with an electric valve (9). The first outlet (2032) is connected in sequence to the circulating water pump (5), the one-way valve (6) and the third inlet (3042) to form a closed-loop heat recovery water circuit; The second outlet (3043) is divided into two paths: one path connects to the first inlet (2031), and the other path connects to the return pipe (8) and leads to the external heat source, forming an external heat source water circulation.

2. The drying device with exhaust heat recovery according to claim 1, characterized in that: The second water inlet (3041) is close to the air inlet and outlet (302), the third water inlet (3042) is located in the middle of the second heat exchanger, and the second water outlet (3043) is close to the air inlet and outlet (301).

3. A drying device with exhaust heat recovery according to claim 1, characterized in that: The outlet of the one-way valve (6) is directed to the third inlet (3042) to ensure that water flows from the first heat exchanger (203) into the second heat exchanger (304) in one direction.

4. A drying device with exhaust heat recovery according to claim 1, characterized in that: The first temperature sensor (205) and the first humidity sensor (206) are disposed between the exhaust air inlet (201) and the first heat exchanger (203); the second temperature sensor (305) and the second humidity sensor (306) are disposed between the air inlet (301) and the second heat exchanger (304).

5. A drying device with exhaust heat recovery according to claim 1, characterized in that: It also includes a control system (4), which is electrically connected to a first temperature sensor (205), a first humidity sensor (206), an exhaust fan (204), a second temperature sensor (305), a second humidity sensor (306), an intake fan (303), a circulating water pump (5), and an electric valve (9). The control system (4) is used to adjust the air volume of the exhaust fan (204) and the intake fan (303), the flow rate of the circulating water pump (5), and the water flow distribution ratio of the electric valve (9) based on the temperature and humidity data of the exhaust channel and the intake channel.

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