CN113865361A

CN113865361A - Drying system

Info

Publication number: CN113865361A
Application number: CN202111144091.2A
Authority: CN
Inventors: 曹振; 刘磊; 袁占彪
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2021-09-28
Filing date: 2021-09-28
Publication date: 2021-12-31

Abstract

The invention relates to a drying system, which is connected with a flue gas channel and comprises: the water smoke heat exchange unit is arranged in the smoke channel and is used for exchanging heat with smoke in the smoke channel; the drying unit comprises a drying plate, and the drying plate comprises a main plate body and a heating pipeline accommodated in the main plate body; the heating pipeline is connected between the water outlet end and the water inlet end of the water smoke heat exchange unit through a pipeline. The drying system can be used for primarily utilizing heat in the flue gas with higher energy grade in the flue gas channel, and the drying unit can be used for uniformly drying and heating agricultural products, so that the drying system has a good drying effect.

Description

Drying system

Technical Field

The invention relates to the technical field of drying equipment, in particular to a drying system.

Background

Industrial flue gas discharged by enterprises such as thermal power plants, steel plants and the like contains a large amount of waste heat, and is high-grade energy with the temperature of 120-170 ℃, and the industrial waste gas is directly discharged into the atmosphere, so that not only is huge energy waste generated, but also adverse effects are caused to the surrounding environment.

In order to utilize the energy, a drying system for drying agricultural products (such as mushrooms, corn, rice, wheat, etc.) by using the heat of the smoke is developed. However, when the current agricultural product drying system dries agricultural products, the agricultural products are often dried by introducing hot air into the drying chamber. The drying method has the disadvantages that the windward side is heated more, the temperature is higher, the leeward side and the part far away from the air supply port are heated less, the temperature is lower, and partial area can go mouldy and breed bacteria, thereby causing certain economic loss.

Disclosure of Invention

The invention provides a drying system aiming at the problem of uneven drying and heating of agricultural products, and the drying system can achieve the technical effect of improving the drying uniformity.

According to one aspect of the present application, there is provided a drying system connected to a flue gas channel, comprising:

the water smoke heat exchange unit is arranged in the smoke channel and is used for exchanging heat with smoke in the smoke channel; and

the drying unit comprises a drying plate, and the drying plate comprises a main plate body and a heating pipeline accommodated in the main plate body;

the heating pipeline is connected between the water outlet end and the water inlet end of the water smoke heat exchange unit through a pipeline.

In one embodiment, the drying unit includes a plurality of drying plates, and the plurality of drying plates are sequentially arranged at intervals.

In one embodiment, the drying system further comprises a water diversion unit and a water collection unit, the water diversion unit is connected between the water outlet end of the hookah heat exchange unit and the water inlet ends of the heating pipelines, and the water collection unit is connected between the water outlet ends of the heating pipelines and the water inlet end of the hookah heat exchange unit.

In one embodiment, the drying system further comprises a water mixing unit connected between the water outlet end of the hookah heat exchange unit and the water inlet end of the drying unit and connected to the water outlet end of the drying unit, and the water mixing unit is used for mixing water flowing out of the water outlet end of the hookah heat exchange unit and the water outlet end of the drying unit and conveying the water to the water inlet end of the drying unit.

In one embodiment, the drying system further comprises a water replenishing pipeline, and the water replenishing pipeline is connected to the water inlet end of the water smoke heat exchange unit.

In one embodiment, the drying system further comprises:

a drying chamber in which the drying unit is housed;

the fresh air pipe is communicated with the drying chamber and the external environment and is used for conveying air in the external environment into the drying chamber; and

and the exhaust pipe is communicated with the drying chamber and the external environment and is used for exhausting the gas in the drying chamber into the external environment.

In one embodiment, the drying system further comprises:

the first exhaust fan is arranged at one end of the fresh air pipe connected with the drying chamber; and

and the second air exhaust fan is arranged at one end of the air exhaust pipe connected with the drying chamber.

In one embodiment, the drying system further comprises a total heat exchange unit, and the fresh air pipe and the exhaust air pipe exchange heat through the total heat exchange unit.

In one embodiment, the drying system further comprises an air source heat pump subsystem, and the air source heat pump subsystem is used for performing heat exchange between the flue gas in the flue gas channel and the gas in the fresh air pipe.

In one embodiment, the air source heat pump subsystem comprises:

the evaporation unit is accommodated in the smoke channel;

the condensing unit is accommodated in the fresh air pipe;

a compressor connected between an outlet end of the evaporation unit and an inlet end of the condensation unit; and

and the throttling unit is connected between the outlet end of the condensing unit and the inlet end of the evaporating unit.

Above-mentioned drying system can carry out the primary use to the heat in the higher flue gas of energy grade in the flue gas passageway, and drying unit can carry out even stoving heating to agricultural product, has good drying effect.

Drawings

FIG. 1 is a schematic diagram of a drying system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a dryer panel of the dryer system of FIG. 1;

FIG. 3 is a schematic diagram of a control unit of the drying system of FIG. 1;

the reference numbers illustrate:

100. a drying system; 121. the water smoke heat exchange unit; 122. a water circulating pump; 123. a drying unit; 1232. drying the plate; 1232a, a main board body; 1232b, a heating conduit; 124. a water diversion unit; 125. a water collection unit; 126. a water mixing unit; 127. a water replenishing pipeline; 128. a ball valve; 141. a drying chamber; 142. a fresh air duct; 143. an exhaust duct; 144. a first exhaust fan; 145. a second exhaust fan; 146. a total heat exchange unit; 161. a compressor; 163. a condensing unit; 165. an evaporation unit; 167. a throttling unit; 181. a control panel; 182. a drying chamber temperature sensor; 183. a dry plate temperature sensor; 184. a fresh air supply temperature sensor; 185. a compressor controller; 186. a water mixing unit controller;

200. a flue gas channel.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

Referring to fig. 1 to 3, in one embodiment of the present invention, a drying system 100 is provided, in which the drying system 100 is connected to a flue gas channel 200 for exhausting industrial flue gas from a thermal power plant, a steel plant, or the like, and is used for recycling heat in the industrial flue gas to dry agricultural products (such as mushrooms, corn, rice, wheat, or the like). It is to be understood that the application scope of the drying system 100 is not limited thereto, and in other embodiments, the drying system 100 may be used for drying other objects to fully utilize the heat in the industrial flue gas.

The drying system 100 comprises a control unit, a hookah heat exchange subsystem, a ventilation subsystem and an air source heat pump subsystem, wherein under the control of the control unit, the hookah heat exchange subsystem is used for bearing to dry agricultural products, and the ventilation subsystem and the air source heat pump subsystem are used for providing hot air for the environment where the agricultural products are located, so that the agricultural products are heated more uniformly.

Specifically, in some embodiments, the hookah heat exchange subsystem includes a hookah heat exchange unit 121, a circulating water pump 122, a drying unit 123, a water diversion unit 124, and a water collection unit 125. The water outlet end of the hookah heat exchange unit 121, the circulating water pump 122, the water distribution unit 124, the drying unit 123, the water collection unit 125 and the water inlet end of the hookah heat exchange unit 121 are connected in sequence through a pipeline, so that a complete loop is formed.

Specifically, the hookah heat exchange unit 121 is disposed in the smoke channel 200 and located at the upstream of the smoke channel 200, and the hookah heat exchange unit 121 is configured to exchange heat with smoke in the smoke channel 200 to obtain heat in the smoke. The water inlet end of the circulating water pump 122 is connected to the water outlet end of the hookah heat exchange unit 121, and the water outlet end of the circulating water pump 122 is connected to the water diversion unit 124, and is used for providing power for the flow of water in the hookah heat exchange subsystem.

The drying unit 123 includes a plurality of drying plates 1232, the plurality of drying plates 1232 are sequentially arranged at intervals along the gravity direction, and the agricultural products can be spread on each drying plate 1232 for drying. Specifically, as shown in fig. 2, the drying plate 1232 includes a main plate 1232a and a heating duct 1232b, the main plate 1232a has a square plate-shaped structure, and the heating duct 1232b extends zigzag in a zigzag shape so as to uniformly heat each region of the main plate 1232 a. It can be understood that the number, shape and arrangement of the drying panels 1232 are not limited, and can be set as required to meet different drying requirements.

The water diversion unit 124 comprises a water inlet end and a plurality of water outlet ends, the water inlet end of the water diversion unit 124 is connected to the water outlet end of the circulating water pump 122, and each water outlet end of the water diversion unit 124 is correspondingly connected to the water inlet end of the heating pipeline 1232b of the drying plate 1232. The water collecting unit 125 comprises a plurality of water inlet ends and a water outlet end, each water inlet end of the water collecting unit 125 is correspondingly connected with the water outlet end of the heating pipeline 1232b of one drying plate 1232, and the water outlet end of the water collecting unit 125 is connected with the water inlet end of the water smoke heat exchanging unit 121. In this way, the water flowing out of the circulating water pump 122 is divided by the water dividing unit 124 and flows into the plurality of drying plates 1232 at the same time, and the water in the plurality of drying plates 1232 is collected by the water collecting unit 125 and returns to the hookah heat exchanging unit 121 to recover heat.

In some embodiments, the drying system 100 further includes a water mixing unit 126, the water mixing unit 126 is connected between the water outlet end of the hookah heat exchange unit 121 and the drying unit 123 and is connected to the water outlet end of the drying unit 123, the water mixing unit 126 is configured to mix the hot water output from the water outlet end of the hookah heat exchange unit 121 and the return water output from the water outlet end of the drying unit 123 and deliver the mixed water to the drying unit 123, and since the temperature of the return water output from the water outlet end of the drying unit 123 is lower than the temperature of the hot water output from the water outlet end of the hookah heat exchange unit 121, the temperature of the water delivered to the drying unit 123 can be adjusted by adjusting the water mixing ratio. In this way, when different types of agricultural products are dried or in different drying stages, the opening degree of the water mixing unit 126 can be adjusted according to the required temperature to adjust the temperature of the drying plate 1232.

Specifically, the water mixing unit 126 is a water mixing valve, and includes a first water mixing inlet, a second water mixing inlet and a water mixing outlet which are communicated with each other. The first mixed water inlet is connected to the water outlet end of the circulating water pump 122, the second mixed water inlet is connected to the water outlet end of the water collecting unit 125, and the mixed water outlet is connected to the water outlet end of the water dividing unit 124.

In this way, the high-temperature water flowing into the water mixing unit 126 from the circulating water pump 122 and the return water flowing into the water mixing unit 126 from the water collecting unit 125 are mixed by the water mixing unit 126 and then flow into the water diversion unit 124 through the mixed water outlet. The ratio of the high-temperature water to the low-temperature water can be adjusted by adjusting the opening degree of the water mixing unit 126, so as to adjust the temperature of the water flowing out of the water mixing unit 126. When the opening degree of the water mixing unit 126 is increased, the flow rate of the low-temperature return water flowing from the water collecting unit 125 into the water mixing unit 126 is increased, thereby reducing the temperature of the water flowing out of the water mixing unit 126, and further reducing the temperature of the drying panel 1232. When the opening degree of the mixing unit 126 is decreased, the flow rate of the low-temperature return water flowing into the mixing unit 126 from the water collecting unit 125 is decreased, thereby increasing the temperature of the water flowing out of the mixing unit 126.

In some embodiments, the hookah heat exchange subsystem further comprises a water replenishing pipe 127 and a ball valve 128, wherein a water inlet end of the water replenishing pipe 127 is connected to an external water source, and a water outlet end of the water replenishing pipe 127 is connected to a water inlet end of the hookah heat exchange unit 121, so as to replenish the hookah heat exchange unit 121. The ball valve 128 is connected between the circulating water pump 122 and the water diversion unit 124 and is used for controlling the on-off of the pipeline.

The working principle of the hookah heat exchange subsystem is as follows:

the water in the hookah heat exchange unit 121 absorbs the heat in the flue gas and then is heated, the heated hot water enters the water mixing unit 126 through the circulating water pump 122, is mixed with the return water flowing into the water mixing unit 126 from the drying unit 123 and then enters the water dividing unit 124 through the ball valve 128, and then flows into the heating pipes 1232b of the drying plates 1232 through the water dividing unit 124, so as to dry the crops on the drying plates. After the water flowing out of the heating pipe 1232b is collected by the water collecting unit 125, a part of the water flows into the water mixing unit 126, and another part of the water returns to the hookah heat exchanging unit 121 to absorb the heat in the smoke.

So, above-mentioned shredded tobacco for water pipes heat transfer subsystem can carry out the primary use to the heat in the higher flue gas of energy grade in flue gas channel 200, and drying unit 123 can carry out even stoving heating to agricultural product, has good drying effect.

With continued reference to fig. 1, the ventilation subsystem includes a drying chamber 141, a fresh air duct 142, an exhaust duct 143, a first exhaust fan 144, and a second exhaust fan 145. The drying chamber 141 is configured to accommodate the drying unit 123 to provide a drying environment independent of an external environment for the drying unit 123. The fresh air pipe 142 communicates the drying chamber 141 with the external environment, and the first exhaust fan 144 is installed at one end of the fresh air pipe 142 connected to the drying chamber 141. The air in the external environment is delivered into the drying chamber 141 through the fresh air duct 142 by the driving of the first exhaust fan 144. The exhaust duct 143 communicates the drying chamber 141 with the external environment, and the second exhaust fan 145 is installed at one end of the exhaust duct 143 connected to the drying chamber 141. Under the driving of the second exhaust fan 145, the air in the drying chamber 141 is exhausted to the external environment through the exhaust pipe 143, thereby realizing the circulation of the air in the drying chamber 141 and ensuring the cleanness of the air in the drying chamber 141.

In some embodiments, the ventilation subsystem further includes a total heat exchange unit 146, and the gas in the fresh air pipe 142 and the gas in the exhaust pipe 143 exchange heat through the total heat exchange unit 146, so that the gas in the fresh air pipe 142 can absorb heat of the gas in the exhaust pipe 143, thereby improving the utilization rate of energy.

The working principle of the ventilation subsystem is as follows:

driven by the first exhaust fan 144, the air in the external environment enters the fresh air pipe 142, then the total heat exchange unit 146 obtains the heat of the air in the exhaust pipe 143, and finally the air enters the drying chamber 141 to dry the agricultural products. Under the driving of the second exhaust fan 145, the air in the drying chamber 141 enters the exhaust duct 143, and then provides heat for the air in the fresh air duct 142 through the total heat exchanger, and finally flows into the external environment.

Referring to fig. 1, the air source heat pump subsystem is connected to the fresh air duct 142 and includes a compressor 161, a condensing unit 163, an evaporating unit 165, and a throttling unit 167, an outlet end of the compressor 161, the condensing unit 163, the evaporating unit 165, the throttling unit 167, and an inlet end of the compressor 161 are connected in sequence for performing heat exchange between the heat of the downstream flue gas of the flue gas channel 200 and the fresh air duct 142, and the air in the fresh air duct 142 obtains the residual heat in the flue gas passing through the flue gas heat exchange unit 121 in the flue gas channel 200 through the air source heat pump subsystem, so as to further improve the utilization rate of the heat in the flue gas.

The low-temperature low-pressure gaseous refrigerant is compressed by the compressor 161 to form a high-temperature high-pressure gaseous refrigerant, the condensing unit 163 is accommodated in one end of the exhaust pipe 143 connected to the drying chamber 141, and the high-temperature high-pressure gaseous refrigerant flows into the condensing unit 163 to be discharged to form a medium-temperature high-pressure liquid refrigerant to provide heat for the drying chamber 141. The medium-temperature high-pressure liquid refrigerant flowing out of the condensing unit 163 flows into the throttling unit 167, and is throttled in the throttling unit 167 to become a low-temperature low-pressure liquid refrigerant. The evaporation unit 165 is accommodated in the flue gas channel 200 and located at the downstream of the hookah heat exchange unit 121, the liquid refrigerant flowing out of the throttling unit 167 flows into the evaporation unit 165, the low-temperature and low-pressure liquid refrigerant in the evaporation unit 165 absorbs heat in the flue gas channel 200 and then becomes a low-temperature and low-pressure gaseous refrigerant, and finally returns to the compressor 161 again.

Therefore, the compressor 161, the condensing unit 163, the throttling unit 167 and the evaporating unit 165 are sequentially connected to form a heat exchange loop to heat the gas in the heating pipe, so that the residual heat of the flue gas in the flue gas channel 200 can be further utilized to dry crops, and the heat utilization rate of the flue gas is further improved.

In some embodiments, the control unit includes a control panel 181, a drying chamber temperature sensor 182, a drying plate temperature sensor 183, a fresh air supply temperature sensor 184, a compressor controller 185, and a mixing unit controller 186. Wherein, drying chamber temperature sensor 182, drying plate temperature sensor 183, new trend air supply temperature sensor 184 are connected with control panel 181 communication respectively for the temperature signal feedback control panel 181 that will gather. The compressor controller 185 and the water mixing unit controller 186 are respectively in communication connection with the control panel 181, and the control panel 181 can respectively control the working states of the compressor controller 185 and the water mixing unit controller 186 according to the temperature signal, so as to realize accurate adjustment of the indoor air temperature in the drying chamber 141.

Specifically, the compressor controller 185 is used to adjust the compression frequency of the compressor 161 under the control of the control panel 181. As the compression frequency of the compressor 161 is increased, more heat may be provided to the air in the fresh air duct 142, thereby increasing the indoor air temperature of the drying chamber 141.

The mixing unit controller 186 is configured to adjust the opening degree of the mixing unit 126 under the control of the control panel 181, and when the opening degree of the mixing unit 126 is increased, the proportion of the return water flowing out of the drying unit 123 and having a lower temperature flowing into the mixing unit 126 is increased, so as to reduce the temperature of the hot water flowing out of the mixing unit 126, and further reduce the temperature of the drying unit 123. When the opening degree of the water mixing unit 126 is decreased, the ratio of the return water flowing out of the drying unit 123 and having a lower temperature to the water mixing unit 126 is decreased, so that the temperature of the hot water flowing out of the water mixing unit 126 is increased, and the temperature of the drying unit 123 is increased.

The present application further provides a drying control method of the drying system 100, the drying control method including the steps of:

s110: the indoor air temperature in the drying chamber 141 is acquired.

Specifically, under the control of the control panel 181, the drying chamber temperature sensor 182 acquires the indoor air temperature t inside the drying chamber 141 in real time and feeds back the acquired indoor air temperature t to the control panel 181.

S120: the indoor air temperature is compared with the target temperature.

Specifically, the control panel 181 compares the indoor air temperature T with the target temperature T according to the acquired indoor air temperature T.

S130: and adjusting the indoor air temperature according to the indoor air temperature and the target temperature.

Specifically, the control panel 181 adjusts the magnitude of the indoor air temperature T according to the magnitudes of the indoor air temperature T and the target temperature T. When the indoor air temperature T is less than T- Δ T, the compressor controller 185 increases the compression frequency of the compressor 161 and the mixing unit controller 186 decreases the opening degree of the mixing valve under the control of the control panel 181, thereby increasing the indoor air temperature T of the drying chamber 141. When the indoor air temperature T is greater than the target temperature T + Δ T, the compressor controller 185 decreases the compression frequency of the compressor 161 and the water mixing unit 126 controls to increase the opening degree of the water mixing unit 126 under the control of the control panel 181, thereby decreasing the indoor air temperature T of the drying chamber 141. When the indoor air temperature T is greater than or equal to T- Δ T and less than or equal to T + Δ T, the control panel 181 controls the drying system 100 to maintain the original state.

Above-mentioned drying system 100, drying plate 1232 through inside heating tube 1232b dries agricultural product, can carry out the preliminary utilization to the heat in the high temperature flue gas, carries out the even heating to agricultural product simultaneously, has effectively avoided the agricultural product in partial region to be heated unevenly and takes place to milden and rot. Also, heat contained in the air discharged from the drying chamber 141 can be recycled by the total heat exchange unit 146, thereby preheating the introduced fresh air. Meanwhile, the preheated fresh air can be further heated by the heat in the flue gas passing through the water-smoke heat exchange subsystem through the air source heat pump subsystem, so that the heat in the flue gas is effectively utilized. In addition, the drying system 100 can also adjust the indoor air temperature by controlling the opening degree of the water mixing unit 126 and the compression frequency of the compressor 161, so that the application range and the drying effect of the drying system 100 are improved.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A drying system connected to a flue gas channel (200), comprising:

the hookah heat exchange unit (121) is arranged in the smoke channel (200), and the hookah heat exchange unit (121) is used for exchanging heat with smoke in the smoke channel (200); and

a drying unit (123), wherein the drying unit (123) comprises a drying plate (1232), and the drying plate (1232) comprises a main plate body (1232a) and a heating pipeline (1232b) accommodated in the main plate body (1232 a);

the heating pipeline (1232b) is connected between the water outlet end and the water inlet end of the hookah heat exchange unit (121) through a pipeline.

2. The drying system according to claim 1, wherein the drying unit (123) comprises a plurality of the drying panels (1232), the plurality of drying panels (1232) being arranged in sequence at intervals.

3. The drying system according to claim 2, further comprising a water diversion unit (124) and a water collection unit (125), the water diversion unit (124) being connected between the water outlet end of the hookah heat exchange unit (121) and the water inlet ends of the plurality of heating pipes (1232b), the water collection unit (125) being connected between the water outlet ends of the plurality of heating pipes (1232b) and the water inlet ends of the hookah heat exchange unit (121).

4. The drying system according to claim 1, further comprising a water mixing unit (126), wherein the water mixing unit (126) is connected between the water outlet end of the hookah heat exchange unit (121) and the water inlet end of the drying unit (123) and is connected to the water outlet end of the drying unit (123), and wherein the water mixing unit (126) is configured to mix water flowing from the water outlet end of the hookah heat exchange unit (121) and from the water outlet end of the drying unit (123) and deliver the water to the water inlet end of the drying unit (123).

5. Drying system according to claim 1, further comprising a water replenishing pipe (127), the water replenishing pipe (127) being connected to the water inlet end of the hookah heat exchange unit (121).

6. The drying system of claim 1, further comprising:

a drying chamber (141), wherein the drying unit (123) is housed in the drying chamber (141);

the fresh air pipe (142) is communicated with the drying chamber (141) and the external environment and is used for conveying air in the external environment into the drying chamber (141); and

and the exhaust pipe (143) is communicated with the drying chamber (141) and the external environment and is used for exhausting the gas in the drying chamber (141) into the external environment.

7. The drying system of claim 6, further comprising:

the first exhaust fan (144) is arranged at one end of the fresh air pipe (142) connected with the drying chamber (141); and

and the second exhaust fan (145) is arranged at one end of the exhaust pipe (143) connected with the drying chamber (141).

8. Drying system according to claim 6, characterized in that the drying system further comprises a total heat exchange unit (146), the fresh air duct (142) and the exhaust air duct (143) exchanging heat through the total heat exchange unit (146).

9. Drying system according to claim 6, further comprising an air source heat pump sub-system for heat exchanging the flue gas in the flue gas channel (200) with the gas in the fresh air duct (142).

10. The drying system of claim 9, wherein the air source heat pump subsystem comprises:

the evaporation unit (165) is accommodated in the smoke channel (200);

a condensing unit (163) housed in the fresh air duct (142);

a compressor (161) connected between an outlet end of the evaporation unit (165) and an inlet end of the condensation unit (163); and

a throttling unit (167) connected between an outlet end of the condensing unit (163) and an inlet end of the evaporating unit (165).