A heat exchange system and a control method thereof

Abstract

The present application relates to the oil fume purification technical field, disclose a kind of heat exchange system and its control method, the heat exchange system by setting up mutually independent cold supply unit and heat supply unit, cooperate the heat exchange purification unit of switchable medium passage, realize cooling purification and heating self-cleaning integration;Specifically, control unit can be based on the real-time operation data of state detection unit feedback automatically switch the medium passage of heat exchange fin, without manual intervention can realize on-line grease separation operation without stopping, substantially reduce maintenance manpower cost and equipment downtime, improve equipment operating efficiency and availability;At the same time, a group or multiple groups of heat exchange fin independent switching mode can be executed, clean operation is completed under the premise of ensuring overall cooling purification capacity, avoid the impact of cleaning process on oil fume purification effect, significantly improve the adaptation ability of equipment to high viscosity, strong condensation oil fume working condition, prolong equipment maintenance cycle.

Description

Technical Field

[0001] This invention relates to the field of oil fume purification technology, and in particular to a heat exchange system and its control method. Background Technology

[0002] In applications such as restaurant fume purification and industrial oil mist treatment, purification equipment based on the principle of heat exchange and condensation relies on low-temperature heat exchange plates to condense and separate the grease in the fumes, which is the mainstream pretreatment technology approach.

[0003] However, existing oil fume purification equipment using condensation pretreatment generally only has a single cold water circulation pipe connected to the heat exchanger array. It relies on low-temperature heat exchangers to cool the high-temperature oily fume, promoting the condensation and separation of grease to achieve purification. Under the condition of treating high-viscosity, highly condensable oily fumes, a large amount of condensed grease will accumulate on the surface of the heat exchangers in a short period of time. This will not only increase the heat transfer resistance and weaken the condensation purification effect, but also narrow the airflow cross-section, resulting in a continuous increase in the pressure difference between the inlet and outlet of the equipment and an increase in the operating load of the fan. At present, the conventional maintenance method for the heat exchangers of this type of equipment is to periodically shut down the machine for manual disassembly and cleaning. This not only has high maintenance labor costs and high work intensity, but also causes long-term downtime of the equipment, which significantly reduces production efficiency and equipment availability.

[0004] It is evident that existing technologies still need improvement and enhancement. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a heat exchange system that solves the technical pain point of existing single cold water circuit equipment where heat exchange fins are easily clogged under high viscosity oil fume conditions, requiring manual cleaning after shutdown.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A heat exchange system includes a control unit, and a heat exchange purification unit, a cooling unit, a heating unit, and a status detection unit, all electrically connected to the control unit. The heat exchange purification unit includes multiple heat exchange fins. The cooling end of the cooling unit and the heating end of the heating unit are respectively connected to the water inlet of the multiple heat exchange fins, and the water outlet of the multiple heat exchange fins are respectively connected to the water return end of the cooling unit and the water return end of the heating unit. The control unit is used to control the heat exchange fins to connect to the cooling end of the cooling unit or the heating end of the heating unit based on real-time detection data fed back by the status detection unit, so as to perform oil fume cooling or grease removal operations.

[0007] In the heat exchange system, the heat exchange purification unit further includes a duct shell, an inlet pipe section, and an outlet pipe section. Multiple heat exchange fins are arranged parallel to each other in the airflow direction within the internal cavity of the duct shell. The output end of the inlet pipe section is connected to the inlet end of each of the multiple heat exchange fins, and the input end of the inlet pipe section is connected to the cooling end of the cooling unit and the heating end of the heating unit. The input end of the outlet pipe section is connected to the outlet end of each of the multiple heat exchange fins, and the output end of the outlet pipe section is connected to the return water end of the cooling unit and the return water end of the heating unit.

[0008] In the heat exchange system described above, the inlet-side piping section includes multiple inlet branches and multiple inlet three-way valves electrically connected to the control unit, and the outlet-side piping section includes multiple outlet branches and multiple outlet three-way valves electrically connected to the control unit. Each of the multiple inlet three-way valves, inlet branches, outlet three-way valves, and outlet branches corresponds one-to-one with multiple heat exchange fins. The two inlet passages of each inlet three-way valve are respectively connected to the cooling end of the cooling unit and the heating end of the heating unit. The outlet passage of each inlet three-way valve is connected to the inlet end of the corresponding heat exchange fin via a corresponding inlet branch; the inlet passage of each outlet three-way valve is connected to the outlet end of the corresponding heat exchange fin via a corresponding outlet branch; and the two outlet passages of each outlet three-way valve are respectively connected to the return water end of the cooling unit and the return water end of the heating unit. The control unit independently switches the circulation medium passage of the corresponding heat exchange fin by controlling the conduction state of each inlet three-way valve and outlet three-way valve.

[0009] In the heat exchange system, the cooling unit includes a refrigeration section, a cold water supply main pipe, a cold water return main pipe, and a cooling pump electrically connected to the control unit. The output end of the cold water supply main pipe is connected to the corresponding cold-side inlet passage of each inlet three-way valve, and the input end of the cold water return main pipe is connected to the corresponding cold-side outlet passage of each outlet three-way valve. The refrigeration section is connected to the input end of the cold water supply main pipe and is used to prepare low-temperature cooling water. The cooling pump is installed on the cold water supply main pipe and is used to provide power for the circulation of cooling water.

[0010] In the heat exchange system, the heating unit includes a hot water storage section, a hot water supply main pipe, a hot water return main pipe, and a heat pump electrically connected to the control unit. The output end of the hot water supply main pipe is connected to the corresponding hot-side inlet passage of each inlet three-way valve, and the input end of the hot water return main pipe is connected to the corresponding hot-side outlet passage of each outlet three-way valve. The input end of the hot water storage section is used to obtain and store high-temperature clean hot water, and the output end of the hot water storage section is connected to the input end of the hot water supply main pipe. The heat pump is installed on the hot water supply main pipe and is used to provide power for the circulation of hot water.

[0011] In the heat exchange system, the status detection unit includes a differential pressure detection unit, a temperature detection unit, and a flow rate detection unit, which are electrically connected to the control unit respectively. The differential pressure detection unit is used to collect the static pressure data of the inlet and outlet air of the heat exchange system in real time and generate the inlet and outlet air differential pressure signal. The temperature detection unit is used to collect the temperature data of the circulating medium and the operating temperature data of the heat exchange fins. The flow rate detection unit is used to collect the real-time flow rate data of the circulating medium.

[0012] The present invention also provides a control method for a heat exchange system, the control method being implemented based on any of the heat exchange systems described above, the control method comprising: when performing fume cooling operation, acquiring real-time detection data fed back by a status detection unit, the real-time detection data including the real-time inlet and outlet air pressure difference of the heat exchange system; calculating an equivalent pressure difference based on the real-time inlet and outlet air pressure difference, and acquiring a preset dynamic pressure difference threshold; when the equivalent pressure difference ≥ the preset dynamic pressure difference threshold, calculating the maximum number of synchronous heating elements; acquiring a preset heating rule, and controlling the heat exchange fins to perform grease removal operation in turn based on the maximum number of synchronous heating elements and the heating rule; when it is determined based on the real-time inlet and outlet air pressure difference that a preset cleaning completion condition is met, controlling the heat exchange fins performing the grease removal operation to switch to performing the fume cooling operation.

[0013] In the control method described above, the step of calculating the equivalent pressure difference based on the real-time inlet and outlet air pressure difference includes: obtaining the rated operating frequency and the current actual operating frequency of the fan in the heat exchange system; and calculating the equivalent pressure difference based on the real-time inlet and outlet air pressure difference, the rated operating frequency, and the current actual operating frequency.

[0014] In the control method described above, calculating the maximum number of synchronous heating elements includes: obtaining the preset total number of heat exchange fins, the rated cooling heat exchange capacity of a single fin in clean state, and the heat release capacity of a single fin under grease removal operation; and obtaining the current flue gas parameters, the maximum allowable outlet flue gas temperature, and the current chilled water operating parameters; calculating the minimum total cooling heat exchange capacity required by the heat exchange system under the current operating conditions based on the current flue gas parameters and the maximum allowable outlet flue gas temperature; correcting the rated cooling heat exchange capacity of a single fin in clean state based on the current chilled water operating parameters to obtain the actual cooling heat exchange capacity of a single fin; calculating the total effective cooling heat exchange capacity of the equipment based on the total number of heat exchange fins, the actual cooling heat exchange capacity of a single fin, and the heat release capacity of a single fin; and deriving the maximum number of synchronous heating elements with the constraint that the total effective cooling heat exchange capacity of the equipment is greater than or equal to the minimum total cooling heat exchange capacity.

[0015] The control method further includes: when a standby shutdown command is received, retrieving the initial inlet and outlet air pressure difference after the current operating cycle reaches a preset thermal stability state, and the real-time inlet and outlet air pressure difference at the end of the current operating cycle, to calculate the pressure difference increment of the current operating cycle; obtaining a preset increment threshold, and when the pressure difference increment is ≥ the preset increment threshold, determining that the standby cleaning conditions are met and executing the standby cleaning operation; grouping all heat exchange fins according to the maximum number of synchronous heating elements, and controlling each group of heat exchange fins to take turns performing grease removal operations; when the preset standby cleaning completion conditions are met, controlling all heat exchange fins to switch to performing fume cooling operations, and after the heat exchange system operates to a preset thermal stability state, executing the shutdown operation of the heat exchange system.

[0016] Beneficial effects: This invention provides a heat exchange system that integrates cooling purification and heating self-cleaning by setting up independent cooling and heating units and cooperating with a heat exchange purification unit with switchable medium paths. Specifically, the control unit can automatically switch the medium path of the heat exchange fins based on real-time operating data fed back by the status detection unit, enabling online grease removal without manual intervention, significantly reducing maintenance labor costs and equipment downtime, and improving equipment operating efficiency and availability. At the same time, it can execute independent switching working modes for single or multiple sets of heat exchange fins, completing the cleaning operation while ensuring the overall cooling and purification capacity, avoiding the impact of the cleaning process on the oil fume purification effect, significantly improving the equipment's adaptability to high-viscosity, highly condensable oil fume conditions, and extending the equipment maintenance cycle. Attached Figure Description

[0017] Figure 1 A structural diagram of the heat exchange system provided by the present invention; Figure 2 A cross-sectional view of the heat exchange system provided by the present invention; Figure 3 The logic flowchart of the control method provided by the present invention.

[0018] Explanation of main component symbols: 11-Heat exchange fins, 12-Inlet water side piping section, 13-Outlet water side piping section, 2-Cooling unit, 21-Refrigeration section, 22-Cold water supply main pipe, 23-Cold water return main pipe, 3-Heating unit, 31-Hot water storage section, 32-Hot water supply main pipe, 33-Hot water return main pipe, 34-Heat pump. Detailed Implementation

[0019] This invention provides a heat exchange system and its control method. To make the objectives, technical solutions and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0020] In the description of this invention, it should be understood that the terms "top," "bottom," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description, and should not be construed as limiting this invention; in addition, the terms "installation," "connection," etc. should be interpreted broadly, and those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0021] like Figures 1 to 3 As shown, the present invention provides a heat exchange system, including a control unit, and a heat exchange purification unit, a cooling unit 2, a heating unit 3, and a status detection unit, all electrically connected to the control unit. The heat exchange purification unit includes multiple heat exchange fins 11. The cooling end of the cooling unit 2 and the heating end of the heating unit 3 are respectively connected to the water inlet of the multiple heat exchange fins 11, and the water outlet of the multiple heat exchange fins 11 are respectively connected to the water return end of the cooling unit 2 and the water return end of the heating unit 3. The control unit is used to control the heat exchange fins 11 to connect to the cooling end of the cooling unit 2 or the heating end of the heating unit 3 according to the real-time detection data fed back by the status detection unit, so as to perform oil fume cooling or grease removal operations.

[0022] This invention discloses a heat exchange system, which is a pre-condensation pretreatment subsystem for oil fume purification equipment. By setting up independent cooling units 2 and heating units 3, and cooperating with a heat exchange purification unit with switchable medium paths, it realizes integrated cooling purification and heating self-cleaning. Specifically, the control unit can automatically switch the medium path of the heat exchange fins 11 based on real-time operating data fed back by the status detection unit, achieving online grease removal without manual intervention, significantly reducing maintenance labor costs and equipment downtime, and improving equipment operating efficiency and availability. At the same time, it can execute independent switching working modes for single or multiple sets of heat exchange fins 11, completing the cleaning operation while ensuring the overall cooling purification capacity, avoiding the impact of the cleaning process on the oil fume purification effect, significantly improving the equipment's adaptability to high-viscosity, highly condensable oil fume conditions, and extending the equipment maintenance cycle.

[0023] In this embodiment, the multiple heat exchange fins 11 in the heat exchange purification unit are arranged in parallel water circuits. The water inlet of each heat exchange fin 11 is connected to the cooling end of the cooling unit 2 and the heating end of the heating unit 3 through branch pipes. The water outlet of each heat exchange fin 11 is connected to the return water end of the cooling unit 2 and the return water end of the heating unit 3 through branch pipes, forming a parallel cold and hot medium path structure. The cooling unit 2 and the heating unit 3 are independent circulation systems, which independently provide cooling medium and heating medium, respectively, without interfering with each other. Through the integrated architecture of the dual medium circuit, the same heat exchange component has both cooling purification and heating self-cleaning functions, without the need for additional independent cleaning mechanisms. Under normal oil fume cooling operation, the control unit serves as the core control unit. The heat exchange purification unit, cooling unit 2, heating unit 3, and status detection unit are all electrically connected to the corresponding input / output ports of the control unit via electrical control circuits, enabling the issuance of control commands and the uploading of detection signals. The control unit controls the connection between the inlet and outlet of all heat exchange fins 11 and the return water of cooling unit 2. Low-temperature cooling water circulates within the heat exchange fins 11. When high-temperature oil fume flows over the surface of the heat exchange fins 11, heat exchange occurs, lowering the oil fume temperature and removing the grease. The components condense and adhere to the surface of the fins, achieving pre-treatment and purification of oil fumes. When the oil on the surface of the heat exchange fin 11 accumulates to a certain extent, the control unit receives the detection data from the status detection unit and determines that the grease removal operation needs to be performed. Then, it controls the corresponding heat exchange fin 11 to switch the medium passage, so that its inlet end is connected to the heating end of the heating unit 3 and its outlet end is connected to the return end of the heating unit 3. High-temperature hot water enters the interior of the heat exchange fin 11 and heats the fin body, so that the grease condensed on the surface is softened, melted and removed by heat, completing online self-cleaning. It can achieve online cleaning without stopping the machine and effectively improve the continuous operation capability of the equipment.

[0024] In some implementations, such as Figure 1and Figure 2 As shown, the heat exchange and purification unit further includes a duct shell, an inlet pipe section 12, and an outlet pipe section 13. Multiple heat exchange fins 11 are arranged parallel to each other in the airflow direction within the internal cavity of the duct shell. The output end of the inlet pipe section 12 is connected to the inlet end of the multiple heat exchange fins 11, and the input end of the inlet pipe section 12 is connected to the cooling end of the cooling unit 2 and the heating end of the heating unit 3. The input end of the outlet pipe section 13 is connected to the outlet end of the multiple heat exchange fins 11, and the output end of the outlet pipe section 13 is connected to the return water end of the cooling unit 2 and the return water end of the heating unit 3.

[0025] In this embodiment, the heat exchange system is an independent functional module of the fume purification equipment, which is integrated and installed inside the air inlet duct of the fume purification equipment. It is located upstream of the electrostatic adsorption unit, filtration unit, and other subsequent purification units of the fume purification equipment along the airflow direction. The duct shell of the heat exchange system is a closed cavity structure, with both ends sealed and connected to the main air duct of the fume purification equipment to form a continuous fume flow channel. This allows the oily fume gas to undergo pretreatment by flowing through the heat exchange system before entering the subsequent purification units. Multiple heat exchange fins 11 are arranged parallel and equidistantly along the airflow direction and fixed to the duct shell. Inside the internal cavity of the air duct, the plane of the heat exchange fins 11 is parallel to the airflow direction to reduce wind resistance; the water inlet side pipeline section 12 is arranged on the water inlet side end face of the air duct shell section, and its multiple output ends are respectively connected to the water inlet interface of each heat exchange fin 11, and its input ends are respectively connected to the cooling end of the cooling unit 2 and the heating end of the heating unit 3 through the main pipeline; the water outlet side pipeline section 13 is arranged on the water outlet side end face of the air duct shell section, and its multiple input ends are respectively connected to the water outlet interface of each heat exchange fin 11, and its output ends are respectively connected to the return water end of the cooling unit 2 and the return water end of the heating unit 3 through the main pipeline. In actual operation, the fumes enter the internal cavity from the air inlet side of the duct housing, flow evenly through the surface gaps of each heat exchange fin 11, and after heat exchange and grease condensation, flow out from the air outlet side. The water inlet side pipeline 12 uniformly distributes cold and hot media to each heat exchange fin 11, and the water outlet side pipeline 13 uniformly recovers the heat exchanged media and returns it to the cooling unit 2 or the heating unit 3. Through the coordinated cooperation of the pipelines on both sides, the unified distribution and centralized recovery of the media are achieved, ensuring that the media supply to each heat exchange fin 11 is uniform and stable.

[0026] In some implementations, such as Figure 1 and Figure 2As shown, the inlet-side piping section 12 includes multiple inlet branches and multiple inlet three-way valves electrically connected to the control unit. The outlet-side piping section 13 includes multiple outlet branches and multiple outlet three-way valves electrically connected to the control unit. Each of the multiple inlet three-way valves, inlet branches, outlet three-way valves, and outlet branches corresponds one-to-one with multiple heat exchange fins 11. The two inlet passages of each inlet three-way valve are connected to the cooling end of the cooling unit 2 and the heating end of the heating unit 3, respectively. The outlet passage of each of the aforementioned inlet three-way valves is connected to the inlet end of the corresponding heat exchange fin 11 via a corresponding inlet branch; the inlet passage of each of the aforementioned outlet three-way valves is connected to the outlet end of the corresponding heat exchange fin 11 via a corresponding outlet branch; and the two outlet passages of each of the aforementioned outlet three-way valves are respectively connected to the return water end of the cooling unit 2 and the return water end of the heating unit 3; the control unit independently switches the circulation medium passage of the corresponding heat exchange fin 11 by controlling the conduction state of each inlet three-way valve and outlet three-way valve.

[0027] In this embodiment, in the inlet-side pipeline section 12, the inlet three-way valves and inlet branches are arranged in a one-to-one correspondence according to the number of heat exchange fins 11. The coil control terminals of all inlet three-way valves are connected to the control unit via control cables. Each inlet three-way valve has two inlet passages and one outlet passage. The two inlet passages of the inlet three-way valve are respectively connected to the cold water supply main and the hot water supply main, and its outlet passage is connected to the inlet end of the corresponding heat exchange fin 11 via the corresponding inlet branch. In the outlet-side pipeline section 13, the outlet three-way valves and outlet branches are arranged in a one-to-one correspondence according to the number of heat exchange fins 11. The quantities are set one-to-one, and the coil control terminals of all outlet three-way valves are connected to the control unit through control cables. Each outlet three-way valve is equipped with one inlet passage and two outlet passages. The inlet passage of the outlet three-way valve is connected to the outlet end of the corresponding heat exchange fin 11 through the corresponding outlet branch, and its two outlet passages are respectively connected to the cold water return main and the hot water return main. By configuring an independent inlet three-way valve and an outlet three-way valve for each heat exchange fin 11, independent passage control of each heat exchange fin 11 is realized, providing a hardware basis for grouped rotation heating and dynamic adjustment of the heating quantity.

[0028] In actual operation, the control unit can independently control the medium passage of a single heat exchange fin 11 by issuing valve position switching commands to the corresponding inlet and outlet three-way valves: when the inlet and outlet three-way valves are respectively connected to the cold side passage, the heat exchange fin 11 is connected to the cold water circulation loop to perform oil fume cooling operation; when the inlet and outlet three-way valves are respectively connected to the hot side passage, the heat exchange fin 11 is connected to the hot water circulation loop to perform grease removal operation; the passage switching of each heat exchange fin 11 does not affect each other, and the timing of mode switching can be independently controlled to flexibly adapt to the cleaning needs of different degrees of blockage and avoid energy waste caused by indiscriminate cleaning.

[0029] In some implementations, such as Figure 1 and Figure 2 As shown, the cooling unit 2 includes a refrigeration section 21, a cold water supply main pipe 22, a cold water return main pipe 23, and a cooling pump electrically connected to the control unit. The output end of the cold water supply main pipe 22 is connected to the corresponding cold-side inlet passage of each inlet three-way valve, and the input end of the cold water return main pipe 23 is connected to the corresponding cold-side outlet passage of each outlet three-way valve. The refrigeration section 21 is connected to the input end of the cold water supply main pipe 22 and is used to prepare low-temperature cooling water. The cooling pump is installed on the cold water supply main pipe 22 and is used to provide power for the circulation of cooling water.

[0030] In this embodiment, the refrigeration unit 21 adopts a vapor compression chiller structure, including a compressor, condenser, throttling element, evaporator, and temperature control module, which is independently installed in the equipment room. The outlet of the evaporator is connected to the input end of the chilled water supply main pipe 22, and the return end of the evaporator is connected to the output end of the chilled water return main pipe 23, forming a closed heat exchange loop. This allows for precise control of the chilled water supply temperature, ensuring the low-temperature heat exchange conditions required for grease condensation and adapting to different temperatures and concentrations of oil fume. The cooling pump is connected in series on the chilled water supply main pipe 22 near the outlet side of the refrigeration unit 21. On the pipeline, the motor control terminal is electrically connected to the control unit via a control cable; the cold water supply main pipe 22 is laid parallel to the inlet side end face of the heat exchange purification unit, and its pipe body has branch interfaces corresponding to the number of heat exchange fins 11, with each branch interface connecting to the cold side inlet passage of the corresponding inlet three-way valve; the cold water return main pipe 23 is laid parallel to the outlet side end face of the heat exchange purification unit, and its pipe body has corresponding branch interfaces connecting to the cold side outlet passage of each outlet three-way valve, with the end of the cold water return main pipe 23 flowing back to the return side of the refrigeration unit 21.

[0031] The refrigeration unit 21 continuously cools the circulating water to the set temperature through a vapor compression cycle of refrigerant compression, condensation, throttling, and evaporation. In normal refrigeration mode, the cold water supply temperature is controlled within the range of 5-15℃, and under rated operating conditions, the supply temperature is stable at 10±2℃. It can be dynamically adjusted within this range according to the oil fume load and the inlet oil fume temperature to ensure the low-temperature heat exchange conditions required for grease condensation. After the control unit starts the cooling pump, the low-temperature cooling water is delivered along the cold water supply main pipe 22 to each inlet three-way valve under the drive of the cooling pump. It enters the heat exchange fins 11 in cooling mode, absorbs the heat of the flue gas, cools the oil fume, and causes grease to condense. The cooling water that has been heated by heat exchange flows into the cold water return main pipe 23 through the outlet three-way valve and flows back to the refrigeration unit 21 for recooling, completing the cycle. The control unit can adjust the cooling water circulation flow rate by adjusting the operating speed of the cooling pump to match the cooling requirements under different operating conditions, thereby reducing operating energy consumption while ensuring the purification effect.

[0032] In some implementations, such as Figure 1 and Figure 2 As shown, the heating unit 3 includes a hot water storage section 31, a hot water supply main pipe 32, a hot water return main pipe 33, and a heat pump 34 electrically connected to the control unit. The output end of the hot water supply main pipe 32 is connected to the corresponding hot-side inlet passage of each inlet three-way valve, and the input end of the hot water return main pipe 33 is connected to the corresponding hot-side outlet passage of each outlet three-way valve. The input end of the hot water storage section 31 is used to obtain and store high-temperature clean hot water, and the output end of the hot water storage section 31 is connected to the input end of the hot water supply main pipe 32. The heat pump 34 is installed on the hot water supply main pipe 32 and is used to provide power for the circulation of hot water.

[0033] In this embodiment, the hot water storage section 31 is an insulated water tank structure, which is equipped with an electric heating component, a liquid level protection element, and a temperature control module. It is installed next to the oil fume purification equipment and can stably store a sufficient amount of high-temperature hot water to ensure the stability of the heat source supply when multiple heat exchange fins 11 are heated simultaneously, and to avoid large fluctuations in water temperature during the heating process that would weaken the oil removal effect. The input end of the hot water storage section 31 can be connected to an external water supply pipeline, its output end is connected to the input end of the hot water supply main pipe 32, and its return end is connected to the output end of the hot water return main pipe 33. The heat pump 34 is installed in series with the hot water supply main pipe 32. On the pipe near the outlet side of the hot water storage unit 31, the motor control terminal is electrically connected to the control unit via a control cable; the hot water supply main pipe 32 is laid parallel to the inlet side end face of the heat exchange purification unit, and its pipe body has branch interfaces corresponding to the number of heat exchange fins 11, with each branch interface connecting to the hot side inlet passage of the corresponding inlet three-way valve; the hot water return main pipe 33 is laid parallel to the outlet side end face of the heat exchange purification unit, and its pipe body has corresponding branch interfaces connecting to the hot side outlet passage of each outlet three-way valve, with the end of the hot water return main pipe 33 flowing back to the return side of the hot water storage unit 31; In actual operation, the hot water storage unit 31 heats the water and maintains it within a set temperature range through a built-in electric heating component. Specifically, in the heating and cleaning mode, the temperature of the cleaning hot water is controlled between 60-80℃, and the rated operating temperature is stable at 70±2℃. This temperature range allows common animal and vegetable oils to soften and melt fully, while avoiding excessive temperature that could cause carbonization and coking of the oils, and also reducing the thermal fatigue loss of the heat exchange fins. When oil removal is required, the control unit controls the heat pump 34 to start, and the high-temperature hot water is driven by the heat pump 34 to flow along... Hot water supply main pipe 32 delivers water to the corresponding inlet three-way valve, entering the heat exchange fins 11 in heating mode. Through heat conduction, the fin body is heated, causing the grease on the surface to soften and fall off. The hot water, after heat exchange and cooling, flows through the outlet three-way valve into the hot water return main pipe 33, returning to the hot water storage section 31 for reheating and temperature rise, completing the cycle. The control unit can adjust the hot water circulation flow rate by adjusting the speed of the heat pump 34, controlling the heating rate and heating temperature of the fins, which can balance grease dissolution efficiency and operational safety, avoiding grease carbonization or equipment damage.

[0034] In some embodiments, the status detection unit includes a differential pressure detection unit, a temperature detection unit, and a flow rate detection unit, which are electrically connected to the control unit respectively; the differential pressure detection unit is used to collect the static pressure data of the inlet and outlet air of the heat exchange system in real time and generate the inlet and outlet air differential pressure signal; the temperature detection unit is used to collect the temperature data of the circulating medium and the operating temperature data of the heat exchange fins 11; the flow rate detection unit is used to collect the real-time flow rate data of the circulating medium.

[0035] In this embodiment, the differential pressure detection unit includes two static pressure sensors, which are respectively installed on the airflow stabilization section pipe wall on the air inlet and air outlet sides of the duct housing. These sensors are used to collect the static pressure values ​​on the air inlet and air outlet sides in real time. The difference between the two values ​​is the real-time air inlet and outlet pressure difference, which can directly reflect the change in air resistance caused by oil blockage on the surface of the heat exchange fins. The temperature detection unit includes six temperature sensors, which are respectively installed at the inlet and outlet ends of the cold water supply main pipe 22 and the hot water supply main pipe 32, as well as at the airflow stabilization point on the air inlet and air outlet sides of the duct housing. These sensors are used to detect the inlet and outlet temperatures of cold water, hot water, and inlet and outlet flue gas. The inlet and outlet temperatures of cold water and hot water are used to calculate the heat exchange capacity and control the heating process, while the inlet and outlet flue gas temperatures are used to verify the cooling effect and constrain the maximum number of heating fins. In addition, the control unit calculates the real-time circulating flow rate based on the linear correspondence between the pump speed and the rated flow rate.

[0036] like Figure 3 As shown, the present invention also provides a control method for a heat exchange system, the control method being implemented based on any of the heat exchange systems described above, the control method comprising: 101. When performing fume cooling operation, the real-time detection data fed back by the status detection unit is obtained, and the real-time detection data includes the real-time inlet and outlet air pressure difference of the heat exchange system; In this embodiment, after the heat exchange system is powered on, it defaults to the oil fume cooling operation mode. All heat exchange fins 11 are switched to the cooling unit 2 through a three-way valve to perform oil fume condensation and purification. The control unit continuously reads the operating data uploaded by the status detection unit and uses the real-time air pressure difference between the inlet and outlet as the core monitoring indicator, which can directly and quickly reflect the degree of oil accumulation on the surface of the heat exchange fins 11.

[0037] 102. Calculate the equivalent pressure difference based on the real-time inlet and outlet air pressure difference, and obtain a preset dynamic pressure difference threshold; Since the fans of the fume purification equipment are often in variable frequency operation, changes in air volume directly affect the real-time inlet and outlet air pressure difference of the duct shell. Under the same degree of blockage, the larger the air volume, the higher the pressure difference. Therefore, it is necessary to convert the measured pressure difference under different air volumes into the equivalent pressure difference under the rated air volume condition to form a unified benchmark for judging the degree of blockage, so as to avoid the problems of false triggering at low air volume and cleaning lag at high air volume. Among them, the rated air volume condition refers to the standard operating condition under which the equipment reaches the factory-nominated rated processing air volume when the fan is running at the rated frequency and the heat exchange fins 11 are in a clean state under the rated power supply conditions. The dynamic differential pressure threshold is not a fixed value, but a trigger threshold dynamically adjusted based on parameters such as the clean baseline, ambient temperature, and operating time, and stored in the parameter storage area of ​​the control unit. The specific adjustment rules for the dynamic differential pressure threshold are as follows: First, the base threshold is set to 1.3 times the clean baseline differential pressure, where the clean baseline is the equivalent differential pressure value under thermally stable conditions after equipment cleaning. Second, ambient temperature adjustment: with 25℃ as the base temperature, the threshold is lowered by 5% for every 5℃ decrease in ambient temperature and raised by 3% for every 5℃ increase in ambient temperature, adapting to the grease coagulation characteristics at different temperatures. Third, operating time adjustment: for every additional 24 hours of continuous equipment operation, the threshold is lowered by 2% to avoid excessive grease buildup during long-term operation. Through multi-dimensional dynamic threshold adjustment, the grease condensation characteristics of different ambient temperatures and different operating stages can be adapted, making the cleaning triggering timing more consistent with actual working conditions, ensuring cleaning effectiveness while minimizing cleaning energy consumption.

[0038] 103. When the equivalent pressure difference is greater than or equal to the preset dynamic pressure difference threshold, calculate the maximum number of synchronous heating elements; In this embodiment, the control unit compares the real-time calculated equivalent pressure difference with the current dynamic pressure difference threshold. If the equivalent pressure difference is greater than or equal to the preset dynamic pressure difference threshold, it is determined that the oil accumulation on the surface of the heat exchange fins has reached the level requiring cleaning, and then the calculation logic for the maximum number of simultaneous heating fins is initiated. The calculation process takes the outlet flue gas temperature not exceeding the allowable upper limit as the core constraint, and combines the current flue gas parameters, hot and cold medium parameters and fin heat exchange parameters to derive the maximum number of heat exchange fins 11 that can be in heating mode at the same time under the current operating conditions. This ensures that the equipment still has qualified cooling and purification capabilities during the cleaning process, so as to maximize the number of fins that can be cleaned at the same time while ensuring that the oil fume purification effect meets the standard, improve cleaning efficiency, and avoid the problem of insufficient cooling capacity during the cleaning process leading to excessive outlet flue gas temperature and affecting subsequent purification stages.

[0039] 104. Obtain the preset heating rules, and based on the maximum number of synchronous heating elements and the heating rules, control the heat exchange fins 11 to perform grease removal operations in turn; In this embodiment, the preset heating rules are pre-stored in the storage module of the control unit, specifically including: 1. Priority sorting rule, that is, the heat exchange fin 11 with the longest time since the last cleaning is selected first to ensure that the cleaning cycle of each fin is balanced; 2. Spatial distribution constraint rules, namely, the selected heat exchange fins 11 are arranged in an odd-even staggered pattern, and two adjacent fins cannot be in heating mode at the same time to ensure that the temperature field of the air duct section is uniform. 3. Single-group heating time rule: The continuous heating time of a single group of heat exchange fins 11 is set to 4 minutes, which can be adjusted within the range of 3-5 minutes according to the degree of oil contamination. 4. Rotation interval rule: After a single heating group finishes and switches back to cooling mode, it needs to run stably for 30 seconds until the system flow field and temperature field return to stability before switching to the next group of fin heating.

[0040] Therefore, the specific process of the heat exchange fins 11 performing the grease removal operation in turn is exemplified as follows: The control unit selects the first batch of heat exchange fin groups 11 according to the maximum number of synchronous heating fins and preset heating rules, and issues switching commands to the corresponding inlet and outlet three-way valves, so that the heat exchange fin group 11 is connected to the heating unit 3 to start heating; after the set time for a single group is reached, the control unit switches the three-way valve of the group back to the cooling unit 2 and enters the interval stabilization stage; after the interval ends, the second batch of fin groups is selected to perform heating, and this cycle continues until the overall equivalent pressure difference falls back to the qualified range; by taking turns heating in groups, the cleaning of all fins can be completed without interrupting the overall cooling function; in addition, the clear heating rules can ensure that the heating fins are evenly distributed in space, avoid uneven flue gas temperature caused by local heating concentration, and balance the cleaning cycle of each fin, avoid excessive oil accumulation on some fins, and improve the uniformity of overall cleaning and operational reliability.

[0041] 105. When the preset cleaning completion conditions are met based on the real-time inlet and outlet air pressure difference, the heat exchange fins 11 that are performing grease removal are switched to performing fume cooling. In this embodiment, the cleaning completion condition adopts a dual criterion of differential pressure reduction and maximum total cleaning time. The differential pressure reduction criterion is that the equivalent differential pressure drops to within 1.1 times the clean baseline differential pressure, indicating that the grease has been fully dissolved. The maximum total cleaning time refers to the upper limit of the total heating time accumulated from the start of the cleaning program. For conventional equipment with a total of 10 fins, the maximum total cleaning time is set to 10 minutes. If this maximum total cleaning time is reached, even if the equivalent differential pressure has not completely dropped to the target value, the cleaning is terminated and normal cooling operation is started to avoid overheating, which would lead to energy waste and fin thermal fatigue. When either criterion is met, the cleaning is considered complete, and all fins currently in heating mode are switched back to cooling mode. The heat exchange system returns to normal fume cooling operation. Through low-temperature heat exchange, the grease components in the high-temperature fume condense and separate, simultaneously reducing the fume temperature and significantly reducing the processing load and grease adhesion of subsequent purification units. By setting dual criteria, the cleaning effect can be directly verified by the pressure difference drop, avoiding incomplete cleaning due to insufficient heating. At the same time, the energy consumption and thermal damage risk can be constrained by the total time limit, balancing the cleaning effect and the service life of the equipment.

[0042] In some implementations, calculating the equivalent pressure difference based on the real-time inlet and outlet air pressure difference includes: 201. Obtain the rated operating frequency and the current actual operating frequency of the fan in the heat exchange system; In this embodiment, the fan of the heat exchange system refers to the fan installed in the fume purification equipment. Its rated operating frequency is the fan power supply frequency corresponding to the rated operating conditions specified by the equipment manufacturer, which is usually 50Hz. The current actual operating frequency is obtained by reading the real-time feedback data of the fan frequency converter.

[0043] 202. Calculate the equivalent pressure difference based on the real-time inlet and outlet air pressure difference, the rated operating frequency, and the current actual operating frequency; In this embodiment, based on the fluid pipeline resistance characteristics, the pipeline pressure difference is directly proportional to the square of the air volume; and within the high-efficiency operating range of the fan, the air volume is approximately linearly proportional to the operating frequency. Therefore, the formula for calculating the equivalent pressure difference can be derived as follows: Equivalent pressure difference = Real-time inlet and outlet air pressure difference × ; This calculation formula can convert the measured inlet and outlet air pressure difference at any operating frequency into the standard pressure difference value under the rated air volume condition corresponding to the rated frequency, i.e., the equivalent pressure difference value. This makes the determination of the degree of blockage unaffected by the frequency conversion adjustment of the fan, greatly improves the working condition adaptability of the pressure difference triggering mechanism, and ensures the control accuracy of the equipment under variable load operation.

[0044] In some implementations, calculating the maximum number of simultaneous heating elements includes: 301. Obtain the preset total number of heat exchange fins 11, the rated cooling heat exchange of a single fin in clean state, the heat release of a single fin under grease removal operation, and obtain the current flue gas parameters, the maximum allowable outlet flue gas temperature, and the current cold water operating parameters. In this embodiment, the total number of heat exchange fins 11 and the rated cooling heat exchange capacity of a single fin in clean state are inherent parameters calibrated under rated operating conditions before the equipment leaves the factory and are pre-stored in the control unit; the heat release of a single fin is calculated based on the difference between the rated hot water temperature and the rated flue gas temperature and the fin heat transfer coefficient, and is a preset fixed value. The current flue gas parameters include the inlet flue gas temperature and the flue gas mass flow rate. The inlet flue gas temperature is collected by a temperature sensor installed at the air inlet of the duct, and the flue gas mass flow rate is calculated by combining the current fan operating frequency with the rated air volume. The maximum allowable outlet flue gas temperature is set according to the tolerance requirements of the subsequent purification unit of the fume purification equipment. The subsequent purification unit is usually an electrostatic fume purification unit, whose long-term tolerance temperature does not exceed 60℃. Therefore, the maximum allowable outlet flue gas temperature is set to 55℃. The current chilled water operating parameters include the chilled water supply temperature, which is collected in real time by a temperature sensor installed on the chilled water supply main pipe 22, and the circulation flow rate is calculated by converting the chilled water pump speed.

[0045] 302. Based on the current flue gas parameters and the maximum allowable outlet flue gas temperature, calculate the minimum total cooling heat exchange required by the heat exchange system under the current operating conditions; In this embodiment, based on the principle of heat balance, the total heat required for the flue gas to drop from its inlet temperature to its maximum allowable outlet temperature is the minimum total cooling heat exchange required by the heat exchange system. The calculation formula is as follows: Minimum total cooling heat transfer = flue gas mass flow rate × flue gas specific heat capacity at constant pressure × (inlet flue gas temperature - maximum allowable outlet flue gas temperature); The specific heat capacity of flue gas at constant pressure is a preset fixed value of 1005 J / (kg). The minimum total cooling heat exchange is the minimum cooling capacity required to ensure that the outlet flue gas temperature meets the standard. It is the core boundary condition for the heating quantity constraint. It is used to ensure that the cooling and purification capacity of the equipment during the cleaning process is not lower than the qualified standard, to avoid the outlet flue gas temperature exceeding the standard due to too many heating fins, and to ensure the purification efficiency and operational safety of the subsequent electrostatic purification unit.

[0046] 303. Based on the current chilled water operating parameters, the rated cooling heat exchange of a single unit in clean state is corrected to obtain the actual cooling heat exchange of a single unit; In this embodiment, the rated cooling heat exchange capacity of a single unit is the calibrated value under rated chilled water temperature and rated flow rate. Under actual operating conditions, it needs to be corrected using the heat exchange calculation formula, specifically: Actual cooling heat transfer of a single unit = Rated cooling heat transfer of a single unit × (Actual heat transfer temperature difference / Rated heat transfer temperature difference) × ; Among them, the heat transfer temperature difference is the difference between the inlet flue gas temperature and the cold water supply temperature; the flow index of 0.8 is the empirical coefficient of flow rate for tube-fin heat exchangers. Furthermore, a heat transfer efficiency correction coefficient is introduced to characterize the attenuation effect of oil accumulation on heat transfer capacity. This correction coefficient is set based on the ratio of the equivalent pressure difference to the clean baseline: when the equivalent pressure difference equals the clean baseline, the correction coefficient is 1.0; when the equivalent pressure difference is 1.2 times the clean baseline, the correction coefficient is 0.9; and when the equivalent pressure difference is 1.5 times the clean baseline, the correction coefficient is 0.75. The final actual cooling heat exchange of a single unit is the calculated value multiplied by the heat transfer efficiency correction coefficient. Through operating condition correction, the influence of fluctuations in cold water temperature and flow rate on the cooling capacity calculation can be eliminated, making the calculation of the cooling capacity of a single unit more closely match the actual operating conditions. Moreover, by introducing the heat transfer efficiency correction coefficient, the heat exchange attenuation caused by oil can be quantified, further improving the accuracy of the calculation results, avoiding deviations between theoretical calculations and actual operation, and ensuring the effectiveness of cooling constraints.

[0047] 304. Based on the total number of heat exchange fins 11, the actual cooling heat exchange of a single fin, and the heat release of a single fin, calculate the total effective cooling heat exchange of the equipment; In this embodiment, when a number of heat exchange fins 11 are in heating mode, these heat exchange fins 11 no longer provide cooling capacity. If the hot water temperature is higher than the flue gas temperature, they will also release heat to the flue gas. Therefore, the formula for calculating the total effective cooling heat exchange is: Total effective cooling heat exchange = (Total number of heat exchange fins - Number of heating fins) × Actual cooling heat exchange per fin - Number of heating fins × Heat release per fin; The total effective cooling heat exchange represents the net cooling capacity that the heat exchange system can actually provide for the corresponding heating quantity.

[0048] 305. Using the constraint that the total effective cooling heat exchange of the equipment is greater than or equal to the minimum total cooling heat exchange, derive and calculate the maximum number of simultaneous heating elements; In this embodiment, substituting the formula for calculating the total effective cooling heat transfer into the constraint inequality, we obtain: (Total number of heat exchange fins 11 - Number of heating fins) × Actual cooling heat exchange per fin - Number of heating fins × Heat release per fin ≥ Minimum total cooling heat exchange; The number of heating fins is calculated based on the constraint inequality. The calculation result is rounded down to obtain the theoretical maximum number of simultaneous heating fins. This theoretical maximum number of simultaneous heating fins can maximize the number of fins that can be cleaned at the same time while strictly ensuring that the cooling capacity meets the standard, thus taking into account both cleaning efficiency and purification effect. Furthermore, auxiliary constraints are set: under normal operating conditions, the number of synchronous heating elements shall not exceed 1 / 3 of the total number of elements, so as to avoid the heating elements being too concentrated and causing uneven temperature field in the air duct, and to ensure the overall condensation and purification effect of flue gas. Ultimately, the smaller value between the theoretical value and the upper limit of the ratio is taken as the final maximum number of simultaneous heating elements.

[0049] In some embodiments, the control method further includes: 401. When a standby shutdown command is received, retrieve the initial inlet and outlet air pressure difference after the current operating cycle reaches the preset thermal stability state, and the real-time inlet and outlet air pressure difference at the end of the current operating cycle, in order to calculate the pressure difference increment of the current operating cycle. In this embodiment, the standby shutdown command is triggered in two ways: First, the schedule is automatically triggered. The control unit has a built-in clock module that presets daily off-peak periods (such as 14:00-16:00 and 22:00-06:00 the next day for the catering industry). When the clock reaches the start time of the preset period and the current exhaust smoke temperature is below 40℃ for 10 minutes, it is determined to be in a low-load state and automatically generates a standby shutdown command, which can automatically complete the cleaning during non-business off-peak periods. Second, it can be manually triggered, with maintenance personnel issuing shutdown commands through the operation interface; The thermal stability state refers to the situation where, under fixed operating conditions, the heat exchange system operates continuously with the equivalent pressure difference between the inlet and outlet air not exceeding ±3% and the flue gas temperature not exceeding ±2℃ within 10 consecutive minutes. The initial inlet and outlet air pressure difference of the current operating cycle is the equivalent pressure difference value recorded when the system first reaches thermal stability after startup. The real-time inlet and outlet air pressure difference at the end of the current operating cycle is the equivalent pressure difference value at the moment the shutdown command is received. The difference between these two values ​​represents the pressure difference increment for the current operating cycle, reflecting the degree of oil accumulation during the current operating cycle and providing a reliable quantitative basis for standby cleaning decisions.

[0050] 402. Obtain a preset incremental threshold. When the differential pressure increment is greater than or equal to the preset incremental threshold, determine that the standby cleaning conditions are met and execute the standby cleaning operation. In this embodiment, the incremental threshold is a preset critical value for the increase in differential pressure, which is usually set to 20% of the clean baseline differential pressure, representing the minimum level of oil accumulation required for standby cleaning. When the calculated differential pressure increment is greater than or equal to the preset increment threshold, it is determined that there is a large amount of oil accumulation in the current operating cycle. If the machine is stopped directly, the grease will harden and solidify further as the temperature decreases, resulting in increased resistance and cleaning difficulty for the next start-up. Therefore, standby cleaning is triggered to reduce the cleaning pressure in subsequent operation and effectively extend the manual maintenance cycle of the equipment. If the differential pressure increment is less than the preset increment threshold, it is determined that the degree of oil contamination is relatively light, and the normal shutdown procedure can be executed directly.

[0051] 403. Group all heat exchange fins 11 according to the maximum number of synchronous heating elements, and control each group of heat exchange fins 11 to take turns performing grease removal operation. In this embodiment, the oil fume load is significantly reduced under standby conditions, and the fan of the oil fume purification equipment is usually reduced to low speed operation. The mass flow rate of the flue gas is only about 30% of the rated operating condition, and the inlet flue gas temperature is also significantly reduced. Therefore, the minimum total cooling heat exchange required is greatly reduced, which means that the maximum number of synchronous heating elements needs to be recalculated using the aforementioned constraint inequality. Under standby conditions, the maximum number of synchronous heating elements can usually reach 1 / 2 of the total number of heat exchange fins (11), which is higher than the upper limit of 1 / 3 under normal operation, effectively improving cleaning efficiency and shortening the total standby cleaning time. Based on the recalculated maximum number of synchronous heating elements, all heat exchange fins 11 are divided into several groups. Each group of heat exchange fins 11 is switched to heating mode sequentially according to a preset rotation sequence. After completing one group, the next group is switched, until all heat exchange fins 11 have completed one round of grease removal. The preset rotation sequence adopts an alternating odd-even grouping order, that is, all heat exchange fins 11 are numbered according to their physical arrangement order, with odd-numbered fins in the first group and even-numbered fins in the second group, ensuring that the heating fins are evenly distributed on the air duct cross-section. If the total number of fins is large and the number of a single group exceeds the maximum number of synchronous heating elements, it is further subdivided into multiple groups and rotated sequentially according to the numbering order. The alternating odd-even rotation sequence can ensure that the heating fins are evenly distributed and avoid local temperature anomalies. During standby cleaning, the fan maintains low-speed operation, that is, the fan's operating frequency is reduced to 30% / 40% of the rated frequency. Taking the rated frequency of 50Hz as an example, the low-speed operating frequency is set to 15 / 20Hz, which corresponds to an air volume of about 30% of the rated air volume. During standby cleaning, the fan's low-speed operation can not only drive the melted and detached grease to the bottom oil collection structure to avoid secondary grease accumulation, but also significantly reduce the fan's energy consumption during standby, thus balancing cleaning effect and operating economy.

[0052] 404. When the preset standby cleaning completion conditions are met, control all heat exchange fins 11 to switch to perform oil fume cooling operation. After the heat exchange system runs to the preset thermal stability state, execute the shutdown operation of the heat exchange system. In this embodiment, the standby cleaning completion conditions include two aspects: first, the overall equivalent pressure difference drops to within 1.05 times the clean baseline pressure difference; second, all heat exchange fins 11 have completed at least one round of heating cleaning. Meeting either condition determines that the standby cleaning is complete. After standby cleaning, all heat exchange fins 11 are switched back to cooling mode, i.e., switched back to the oil fume cooling operation state, and run continuously for 5-10 minutes to allow the temperature of the heat exchange fins 11 to gradually decrease and the heat exchange system to reach a thermally stable state. After confirming that all operating parameters are normal, the heat pump 34, cooling pump, and fan are shut down sequentially to complete the shutdown operation. Resuming cooling operation before shutdown after standby cleaning allows the fins to return to a low-temperature state before shutdown, preventing the continuous softening and dripping of residual grease on the high-temperature fins. It also reduces the activity of grease on the fin surface after shutdown, minimizing the risk of hardening and caking. Shutting down after thermal stability ensures that the heat exchange system is in a consistent baseline state upon the next startup, facilitating initial parameter calibration and operational status judgment, and improving the consistency and reliability of equipment operation.

[0053] It is understood that those skilled in the art can make equivalent substitutions or changes to the technical solution and inventive concept of the present invention, and all such changes or substitutions should fall within the protection scope of the present invention.

Claims

1. A heat exchange system, characterized in that, The system includes a control unit, and a heat exchange and purification unit, a cooling unit, a heating unit, and a status detection unit, all electrically connected to the control unit. The heat exchange and purification unit includes multiple heat exchange fins. The cooling end of the cooling unit and the heating end of the heating unit are respectively connected to the water inlet of the multiple heat exchange fins, and the water outlet of the multiple heat exchange fins are respectively connected to the water return end of the cooling unit and the water return end of the heating unit. The control unit is used to control the heat exchange fins to connect to the cooling end of the cooling unit or the heating end of the heating unit based on real-time detection data fed back by the status detection unit, so as to perform oil fume cooling or grease removal operations.

2. The heat exchange system according to claim 1, characterized in that, The heat exchange and purification unit further includes a duct shell section, an inlet-side pipeline section, and an outlet-side pipeline section. Multiple heat exchange fins are arranged parallel to each other in the internal cavity of the duct shell section along the airflow direction. The output end of the inlet-side pipeline section is connected to the inlet end of the multiple heat exchange fins, and the input end of the inlet-side pipeline section is connected to the cooling end of the cooling unit and the heating end of the heating unit. The input end of the outlet-side pipeline section is connected to the outlet end of the multiple heat exchange fins, and the output end of the outlet-side pipeline section is connected to the return water end of the cooling unit and the return water end of the heating unit.

3. The heat exchange system according to claim 2, characterized in that, The inlet-side piping section includes multiple inlet branches and multiple inlet three-way valves electrically connected to the control unit. The outlet-side piping section includes multiple outlet branches and multiple outlet three-way valves electrically connected to the control unit. Each of the multiple inlet three-way valves, inlet branches, outlet three-way valves, and outlet branches corresponds one-to-one with multiple heat exchange fins. The two inlet passages of each inlet three-way valve are connected to the cooling end of the cooling unit and the heating end of the heating unit, respectively. The outlet passage of each inlet three-way valve is connected to the inlet end of the corresponding heat exchange fin via the corresponding inlet branch. The inlet passage of each outlet three-way valve is connected to the outlet end of the corresponding heat exchange fin via the corresponding outlet branch. The two outlet passages of each outlet three-way valve are connected to the return water end of the cooling unit and the return water end of the heating unit, respectively. The control unit independently switches the circulation medium passage of the corresponding heat exchange fin by controlling the conduction state of each inlet and outlet three-way valve.

4. The heat exchange system according to claim 3, characterized in that, The cooling unit includes a refrigeration section, a cold water supply main pipe, a cold water return main pipe, and a cooling pump electrically connected to the control unit. The output end of the cold water supply main pipe is connected to the corresponding cold-side inlet passage of each inlet three-way valve, and the input end of the cold water return main pipe is connected to the corresponding cold-side outlet passage of each outlet three-way valve. The refrigeration section is connected to the input end of the cold water supply main pipe and is used to prepare low-temperature cooling water. The cooling pump is installed on the cold water supply main pipe and is used to provide power for the circulation of cooling water.

5. The heat exchange system according to claim 3, characterized in that, The heating unit includes a hot water storage section, a hot water supply main pipe, a hot water return main pipe, and a heat pump electrically connected to the control unit. The output end of the hot water supply main pipe is connected to the corresponding hot-side inlet passage of each inlet three-way valve, and the input end of the hot water return main pipe is connected to the corresponding hot-side outlet passage of each outlet three-way valve. The input end of the hot water storage section is used to obtain and store high-temperature clean hot water, and the output end of the hot water storage section is connected to the input end of the hot water supply main pipe. The heat pump is installed on the hot water supply main pipe and is used to provide power for the circulation of hot water.

6. The heat exchange system according to claim 1, characterized in that, The status detection unit includes a differential pressure detection unit, a temperature detection unit, and a flow rate detection unit, which are electrically connected to the control unit respectively. The differential pressure detection unit is used to collect the static pressure data of the inlet and outlet air of the heat exchange system in real time and generate the inlet and outlet air differential pressure signal. The temperature detection unit is used to collect the temperature data of the circulating medium and the operating temperature data of the heat exchange fins. The flow rate detection unit is used to collect the real-time flow rate data of the circulating medium.

7. A control method for a heat exchange system, characterized in that, The control method is implemented based on the heat exchange system as described in any one of claims 1-6, and the control method includes: When performing fume cooling operations, real-time detection data fed back by the status detection unit is obtained, including the real-time inlet and outlet air pressure difference of the heat exchange system. The equivalent pressure difference is calculated based on the real-time inlet and outlet air pressure difference, and a preset dynamic pressure difference threshold is obtained. When the equivalent pressure difference is greater than or equal to the preset dynamic pressure difference threshold, the maximum number of synchronous heating elements is calculated; Obtain the preset heating rules, and based on the maximum number of synchronous heating elements and the heating rules, control the heat exchange fins to perform grease removal operations in turn; When the preset cleaning completion conditions are met based on the real-time inlet and outlet air pressure difference, the heat exchange fins that were performing the grease removal operation are switched to the oil fume cooling operation.

8. The control method according to claim 7, characterized in that, The calculation of the equivalent pressure difference based on the real-time inlet and outlet air pressure difference includes: Obtain the rated operating frequency and the current actual operating frequency of the fan in the heat exchange system; The equivalent pressure difference is calculated based on the real-time inlet and outlet air pressure difference, the rated operating frequency, and the current actual operating frequency.

9. The control method according to claim 7, characterized in that, The calculation of the maximum number of synchronous heating elements includes: Obtain the preset total number of heat exchange fins, the rated cooling heat exchange capacity of a single fin in clean state, the heat release of a single fin under grease removal operation, and obtain the current flue gas parameters, the maximum allowable outlet flue gas temperature, and the current chilled water operating parameters. Based on the current flue gas parameters and the maximum allowable outlet flue gas temperature, calculate the minimum total cooling heat exchange required by the heat exchange system under the current operating conditions. Based on the current chilled water operating parameters, the rated cooling heat exchange of a single unit in clean state is corrected to obtain the actual cooling heat exchange of a single unit. Calculate the total effective cooling heat exchange of the equipment based on the total number of heat exchange fins, the actual cooling heat exchange of a single fin, and the heat release of a single fin. With the constraint that the total effective cooling heat exchange of the equipment is greater than or equal to the minimum total cooling heat exchange, the maximum number of synchronous heating elements is derived and calculated.

10. The control method according to claim 7, characterized in that, The control method further includes: When a standby shutdown command is received, the initial inlet and outlet air pressure difference after the current operating cycle reaches the preset thermal stability state is retrieved, as well as the real-time inlet and outlet air pressure difference at the end of the current operating cycle, in order to calculate the pressure difference increment of the current operating cycle. Obtain a preset incremental threshold. When the differential pressure increment is greater than or equal to the preset incremental threshold, it is determined that the standby cleaning condition is met, and standby cleaning operation is performed. All heat exchange fins are grouped according to the maximum number of synchronous heating elements, and each group of heat exchange fins is controlled to perform grease removal operation in turn. When the preset standby cleaning completion conditions are met, control all heat exchange fins to switch to perform oil fume cooling operation. After the heat exchange system reaches the preset thermal stability state, execute the shutdown operation of the heat exchange system.

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