Waste heat recovery system of air compressor

Abstract

The invention provides an air compressor waste heat recovery system which is provided with an air compressor, a heat energy recovery device, a circulating water tank, a circulating water pump, a user water tank, a hot water supply pump, a hot water supply electromagnetic valve, a first controller, a second controller and a third controller. The circulating water pump is arranged in the pipeline structure between the circulating water tank and the heat energy recovery device, the user water tank is connected with the circulating water tank through a pipeline, the hot water supply pump is arranged in the pipeline structure between the user water tank and the circulating water tank, and the hot water supply electromagnetic valve is arranged in the pipeline structure between the user water tank and the circulating water tank. The first controller is in communication connection with the circulating water pump, the second controller is in communication connection with the hot water supply pump, and the third controller is in communication connection with the second controller and the hot water supply electromagnetic valve, so that the heat recovery efficiency of the air compressor is improved, and the water supply temperature and the heat supply efficiency of hot water supply are ensured.

Description

Technical Field

[0001] The present invention relates to the field of waste heat recovery of air compressors, and particularly to a waste heat recovery system for air compressors. Background Art

[0002] Waste heat recovery of air compressors is to recover the discharged heat generated during the operation of air compressors through a heat energy recovery device and convert it into hot water, hot air, etc. for use in industrial production, employee life, plant heating, industrial heating, agricultural greenhouse heating, etc., so as to achieve the purposes of reducing energy consumption, reducing environmental pollution, improving production efficiency, and prolonging the service life of equipment.

[0003] Currently, waste heat recovery of air compressors has been widely used, and different systems can be constituted according to the cooling method of air compressors, different usage environments, different usage purposes, and control requirements. However, there are the following disadvantages in the existing technology: Most waste heat recovery is only suitable for nearby utilization, with low heat recovery efficiency, and it is impossible to ensure the water supply temperature and heating efficiency of hot water for a long time; constant pressure water supply in small systems causes the hot water supply pipe to be under long-term high temperature and high pressure, and the water pump starts and stops frequently; the initial hot water temperature at the end of the hot water supply pipe is relatively low; the heating efficiency of cold makeup water is not high. Summary of the Invention

[0004] The main purpose of the embodiments of the present invention is to propose a waste heat recovery system for air compressors, which can automatically realize the waste heat recovery of air compressors and continuously heat the water supplied to users, improve the heat recovery efficiency, and ensure the water supply temperature and heating efficiency of hot water.

[0005] To achieve the above object, the first aspect of the embodiments of the present invention proposes a waste heat recovery system for air compressors, including: An air compressor; A heat energy recovery device, which is connected to the air compressor through a pipeline, and the heat energy recovery device is used to receive and convert the heat of the air compressor; A circulating water tank, which is connected to the heat energy recovery device through a pipeline; A circulating water pump, which is arranged in the pipeline structure between the circulating water tank and the heat energy recovery device; A user water tank, which is connected to the circulating water tank through a pipeline; A hot water supply pump, which is arranged in the pipeline structure between the user water tank and the circulating water tank, and the hot water supply pump is used to transfer the water in the circulating water tank to the user water tank; A hot water supply solenoid valve, which is arranged in the pipeline structure between the user water tank and the circulating water tank, and the hot water supply solenoid valve is used to control the conduction between the user water tank and the circulating water tank; A first controller, which is respectively communicatively connected to the circulating water pump, and the first controller is used to control the opening and closing of the circulating water pump to transfer the water in the circulating water tank to the heat energy recovery device for heating; A second controller, which is communicatively connected to the hot water supply pump, and is used to control the opening and closing of the hot water supply pump to transfer the water in the circulation water tank to the user water tank; A third controller, which is communicatively connected to the second controller and the hot water supply solenoid valve respectively, and is used to control the opening and closing of the hot water supply solenoid valve.

[0006] Furthermore, in some embodiments, the system further includes a cold water make-up solenoid valve, one end of which is connected to the circulating water pump pipeline, and the other end of which is connected to an external make-up water pipeline; Wherein, the first controller is also communicatively connected to the cold water make-up solenoid valve, and is further used to control the opening and closing of the cold water make-up solenoid valve so that the cold water in the external make-up water pipeline is transferred to the circulating water pump and then transferred to the circulation water tank or the heat recovery device through the opening and closing of the circulating water pump.

[0007] Furthermore, in some embodiments, the pipeline structure between the user water tank and the circulation water tank includes: A long-distance hot water supply pipe, one end of which is connected to the circulation water tank, and the other end of which is connected to the user water tank; A hot water supply circulation pipe, one end of which is connected to the circulation water tank, and the other end of which is connected to the long-distance hot water supply pipe; A hot water circulation pipeline loop is formed among the long-distance hot water supply pipe, the hot water supply circulation pipe and the circulation water tank; Wherein, the hot water supply solenoid valve is arranged in the long-distance hot water supply pipe and close to the user water tank, and the hot water supply pump is arranged in the long-distance hot water supply pipe and close to the circulation water tank.

[0008] Furthermore, in some embodiments, a hot water supply circulation solenoid valve is arranged in the hot water supply circulation pipe, and is used to control the conduction of the hot water circulation pipeline loop; The third controller is also communicatively connected to the hot water supply circulation solenoid valve, and is further used to control the opening and closing of the hot water supply circulation solenoid valve so that the water in the hot water circulation pipeline loop is circularly heated by the circulation water tank when the hot water circulation pipeline loop is in a conductive state.

[0009] Furthermore, in some embodiments, the circulation water tank includes a first temperature detector, a second temperature detector and a first water level detector. The first temperature detector and the first water level detector are respectively communicatively connected to the first controller, the second temperature detector is communicatively connected to the second controller. The first temperature detector is used to send a first temperature control signal of the circulation water tank to the first controller, the second temperature detector is used to send a second temperature control signal of the circulation water tank to the second controller, and the first water level detector is used to send a first water level signal of the circulation water tank to the first controller; The user water tank includes a second water level detector, which is communicatively connected to the third controller. The second water level detector is used to send a second water level signal of the user water tank to the third controller; The pipeline structure between the heat recovery device and the air compressor includes a high-temperature oil pipe. The high-temperature oil pipe is provided with a third temperature detector, which is communicatively connected to the first controller. The third temperature detector is used to send a third temperature control signal of the high-temperature oil pipe to the first controller; The long-distance hot water supply pipe is also provided with a fourth temperature detector, which is communicatively connected to the third controller. The fourth temperature detector is used to send a fourth temperature control signal of the long-distance hot water supply pipe to the third controller.

[0010] Further, in some embodiments, a first control circuit is provided in the first controller. The first control circuit is used to control the opening and closing of the cold makeup water solenoid valve according to the first water level signal; The first control circuit includes a first water level switch, a second water level switch, and a makeup water solenoid valve coil. The first water level switch, the second water level switch, and the makeup water solenoid valve coil are connected in series with each other. The first water level switch is in a normally open state, and the second water level switch is in a normally closed state; The first water level switch is used to self-close to conduct the first control circuit when the first water level signal indicates that the water level in the circulation water tank is less than the first preset water level value, and self-reset after the first control circuit is disconnected; The second water level switch is used to self-open to disconnect the first control circuit when the first water level signal indicates that the water level in the circulation water tank is greater than the second preset water level value, and self-reset after the first control circuit is disconnected; wherein, the first preset water level value is less than the second preset water level value; The makeup water solenoid valve coil is used to control the opening of the cold makeup water solenoid valve to allow the cold water in the external makeup water pipeline to be transmitted to the circulation water pump when the first control circuit is conducted.

[0011] Further, in some embodiments, a second control circuit is also provided in the first controller. The second control circuit is connected in parallel with the first control circuit. The second control circuit is used to control the opening and closing of the circulation water pump according to the first temperature control signal and the third temperature control signal; The second control circuit includes a first temperature control switch, a second temperature control switch, and a second contactor coil. The first temperature control switch, the second temperature control switch, and the second contactor coil are connected in series with each other. The first temperature control switch is in a normally open state, and the second temperature control switch is in a normally closed state; The first temperature control switch is used to self-close to conduct the second control circuit when the third temperature control signal indicates that the oil temperature in the high-temperature oil pipe reaches the first preset temperature value and the first temperature control signal indicates that the water temperature in the circulation water tank has not reached the second preset temperature value, and self-reset after the second control circuit is disconnected; The second temperature control switch is used to self - disconnect to make the second control circuit disconnected when the third temperature control signal indicates that the oil temperature of the high - temperature oil pipe has not reached the first preset temperature value, or the first temperature control signal indicates that the water temperature of the circulating water tank has reached the second preset temperature value, and perform self - reset after the second control circuit is disconnected; The second contactor coil is used to control the operation of the circulating water pump when the second control circuit is conducting.

[0012] Furthermore, in some embodiments, a third control circuit and a first signal transmission circuit are provided in the third controller, and the third control circuit and the first signal transmission circuit are connected in parallel with each other; The third control circuit is used to control the opening and closing of the hot water supply circulation solenoid valve according to the second water level signal and the fourth temperature control signal. The first signal transmission circuit includes a first signal receiver, and the first signal receiver is used to transmit the second water level signal to the second controller; The third control circuit includes a third water level switch, a fourth water level switch, a third temperature control switch, and a third contactor coil. The third water level switch, the fourth water level switch, and the third temperature control switch are connected in series with the third contactor coil. The third water level switch is in a normally open state, the fourth water level switch is in a normally closed state, and the third temperature control switch is in a normally closed state; The third water level switch is used to self - close to make the third control circuit conducting when the second water level signal indicates that the water level of the user water tank is less than the third preset water level value, and perform self - reset after the third control circuit is disconnected; The fourth water level switch is used to self - disconnect to make the third control circuit disconnected when the second water level signal indicates that the water level of the user water tank is greater than the fourth preset water level value, and perform self - reset after the third control circuit is disconnected, where the third preset water level value is less than the fourth preset water level value; The third temperature control switch is used to self - disconnect to make the third control circuit disconnected when the fourth temperature control signal indicates that the water temperature of the long - distance hot water supply pipe has reached the third preset temperature value, and perform self - reset after the third control circuit is disconnected; The third contactor coil is used to control the opening of the hot water supply circulation solenoid valve to make the hot circulation pipeline loop conducting when the third control circuit is conducting.

[0013] Furthermore, in some embodiments, a fourth control circuit is also provided in the third controller. The fourth control circuit is connected in parallel with the third control circuit, and the fourth control circuit is used to control the opening and closing of the hot water supply solenoid valve according to the second water level signal and the fourth temperature control signal; The fourth control circuit includes a fifth water level switch, a sixth water level switch, a fourth temperature control switch, and a fourth contactor coil. The fifth water level switch, the sixth water level switch, and the fourth temperature control switch are connected in series with the fourth contactor coil. The fifth water level switch is in a normally open state, the sixth water level switch is in a normally closed state, and the fourth temperature control switch is in a normally open state; The fifth water level switch is used to self-close to conduct the fourth control circuit when the second water level signal indicates that the water level in the user's water tank is lower than the third preset water level value, and self-reset after the fourth control circuit is disconnected; The sixth water level switch is used to self-open to disconnect the fourth control circuit when the second water level signal indicates that the water level in the user's water tank is higher than the fourth preset water level value, and self-reset after the fourth control circuit is disconnected; The fourth temperature control switch is used to self-close to conduct the fourth control circuit when the fourth temperature control signal indicates that the water temperature in the long-distance hot water supply pipe reaches the third preset temperature value, and self-reset after the fourth control circuit is disconnected; The fourth contactor coil is used to control the opening of the hot water supply solenoid valve to transfer the water in the long-distance hot water supply pipe to the user's water tank when the fourth control circuit is conductive.

[0014] Further, in some embodiments, a fifth control circuit and a second signal transmission circuit are provided in the second controller, and the fifth control circuit and the second signal transmission circuit are connected in parallel with each other; The second signal transmission circuit includes a second signal receiver for receiving the second water level signal transmitted by the third controller, and the fifth control circuit is used to control the opening and closing of the hot water supply pump according to the second temperature control signal and the second water level signal; The fifth control circuit includes a seventh water level switch, an eighth water level switch, a fifth temperature control switch and a fifth contactor coil. The seventh water level switch, the eighth water level switch and the fifth temperature control switch are connected in series with each other. The seventh water level switch is normally open, the eighth water level switch is normally closed, and the fifth temperature control switch is normally open; The seventh water level switch is used to self-close to conduct the fifth control circuit when the second water level signal indicates that the water level in the user's water tank is at the third preset water level value, and self-reset after the fifth control circuit is disconnected; The eighth water level switch is used to self-open to disconnect the fifth control circuit when the second water level signal indicates that the water level in the user's water tank is at the fourth preset water level value, and self-reset after the fifth control circuit is disconnected; The fifth temperature control switch is used to self-close to conduct the fifth control circuit when the second temperature control signal indicates that the water temperature in the circulation water tank reaches the fourth preset temperature value, and self-reset after the fifth control circuit is disconnected; The fifth contactor coil is used to control the operation of the hot water supply pump to transfer the water in the circulation water tank to the long-distance hot water supply pipe when the fifth control circuit is conductive.

[0015] The embodiments of the present invention have the following beneficial effects: By providing an air compressor, a heat recovery device, a circulating water tank, a circulating water pump, a user water tank, a hot water supply pump, a hot water supply solenoid valve, a first controller, a second controller and a third controller, the heat recovery device is connected to the air compressor through a pipeline. The heat recovery device is used to receive and convert the heat of the air compressor. The circulating water tank is connected to the heat recovery device through a pipeline. The circulating water pump is arranged in the pipeline structure between the circulating water tank and the heat recovery device. The user water tank is connected to the circulating water tank through a pipeline. The hot water supply pump is arranged in the pipeline structure between the user water tank and the circulating water tank. The hot water supply pump is used to transfer the water in the circulating water tank to the user water tank. The hot water supply solenoid valve is arranged in the pipeline structure between the user water tank and the circulating water tank. The hot water supply solenoid valve is used to control the conduction between the user water tank and the circulating water tank. The first controller is respectively communicatively connected to the circulating water pump. The first controller is used to control the opening and closing of the circulating water pump to transfer the water in the circulating water tank to the heat recovery device for heating. The second controller is communicatively connected to the hot water supply pump. The second controller is used to control the opening and closing of the hot water supply pump to transfer the water in the circulating water tank to the user water tank. The third controller is respectively communicatively connected to the second controller and the hot water supply solenoid valve. The third controller is used to control the opening and closing of the hot water supply solenoid valve. Furthermore, it can automatically realize the waste heat recovery of the air compressor and continuously heat the water supplied to the user, improving the heat recovery efficiency and ensuring the water supply temperature and heating efficiency of the hot water supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is an optional overall structure diagram of the air compressor waste heat recovery system provided by the embodiment of the present invention; Figure 2 is an optional circuit diagram of the first controller provided by the embodiment of the present invention; Figure 3 is an optional circuit diagram of the third controller provided by the embodiment of the present invention; Figure 4 is an optional circuit diagram of the second controller provided by the embodiment of the present invention.

[0017] BRIEF DESCRIPTION OF THE DRAWINGS: Air compressor 100, heat recovery device 101, circulating water tank 102, circulating water pump 103, user water tank 104, hot water supply pump 105, hot water supply solenoid valve 106, cold makeup water solenoid valve 107, hot water supply circulation solenoid valve 108, long-distance hot water supply pipe 109, hot water supply circulation pipe 110, high-temperature oil pipe 111, first temperature detector 112, second temperature detector 113, third temperature detector 114, fourth temperature detector 115, first water level detector 116, second water level detector 117; The first controller 200, the second controller 201, the third controller 202, the first control circuit 203, the first water level switch 204, the second water level switch 205, the water replenishing solenoid valve coil 206, the second control circuit 207, the first temperature control switch 208, the second temperature control switch 209, the second contactor coil 210, the third control circuit 211, the third water level switch 212, the fourth water level switch 213, the third temperature control switch 214, the third contactor coil 215, the fourth control circuit 216, the fifth water level switch 217, the sixth water level switch 218, the fourth temperature control switch 219, the fourth contactor coil 220, the first signal transmission circuit 221, the first signal receiver 222, the second signal transmission circuit 223, the second signal receiver 224, the fifth control circuit 225, the seventh water level switch 226, the eighth water level switch 227, the fifth temperature control switch 228, the fifth contactor coil 229. Detailed implementation manners

[0018] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] In the description of the present invention, it should be understood that for the orientation descriptions, such as upper, lower, front, rear, left, right, etc., the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation to the present invention.

[0020] It should also be noted that in the description of the present invention, the meaning of several is more than one, the meaning of multiple is more than two, greater than, less than, exceeding, etc. are understood as not including the present number, and above, below, within, etc. are understood as including the present number. If there is a description of first and second, it is only for the purpose of distinguishing technical features and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used herein are only for the purpose of describing the embodiments of the present invention and are not intended to limit the present invention.

[0022] In the description of the present invention, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0023] At present, the waste heat recovery of air compressors has been widely used, and different systems can be formed according to the cooling methods of air compressors, different usage environments, different usage purposes, and control requirements. However, the following disadvantages exist in the prior art: Most waste heat recovery is only suitable for nearby utilization, with low heat recovery efficiency, and it is impossible to ensure the supply water temperature and heating efficiency of hot feed water for a long time; constant pressure water supply in small systems causes the hot feed water pipes to be under long-term high temperature and high pressure, and the water pumps start and stop frequently; the initial temperature of hot feed water at the end of the hot feed water pipe is relatively low; the heating efficiency of cold makeup water is not high.

[0024] Based on this, the embodiments of the present invention provide an air compressor waste heat recovery system, which can automatically realize the waste heat recovery of the air compressor and continuously heat the water supplied to users, improving the heat recovery efficiency and ensuring the supply water temperature and heating efficiency of hot feed water.

[0025] An air compressor waste heat recovery system provided by the embodiments of the present invention will be specifically described through the following embodiments.

[0026] Refer to Figure 1 As shown, Figure 1 is an optional overall structure diagram of the air compressor waste heat recovery system provided by the embodiments of the present invention. The air compressor waste heat recovery system is provided with an air compressor 100, a heat energy recovery device 101, a circulation water tank 102, a circulation water pump 103, a user water tank 104, a hot feed water pump 105, a hot feed water solenoid valve 106, a first controller 200, a second controller 201, and a third controller 202; the heat energy recovery device 101 is connected to the air compressor 100 through a pipeline, the circulation water tank 102 is connected to the heat energy recovery device 101 through a pipeline, the circulation water pump 103 is arranged in the pipeline structure between the circulation water tank 102 and the heat energy recovery device 101, the user water tank 104 is connected to the circulation water tank 102 through a pipeline, the hot feed water pump 105 is arranged in the pipeline structure between the user water tank 104 and the circulation water tank 102, the hot feed water solenoid valve 106 is arranged in the pipeline structure between the user water tank 104 and the circulation water tank 102, the first controller 200 is respectively communicatively connected to the circulation water pump 103, the second controller 201 is communicatively connected to the hot feed water pump 105, and the third controller 202 is respectively communicatively connected to the second controller 201 and the hot feed water solenoid valve 106.

[0027] Among them, the heat recovery device 101 is used to receive and convert the heat of the air compressor 100. The circulating water pump 103 is used to transfer the water in the circulating water tank 102 to the heat recovery device 101 for heating. The hot water supply pump 105 is used to transfer the water in the circulating water tank 102 to the user water tank 104. The hot water supply solenoid valve 106 is used to control the conduction between the user water tank 104 and the circulating water tank 102. Furthermore, the coordinated operation of the circulating water pump 103 and the hot water supply pump 105 ensures that the waste heat of the air compressor 100 can be efficiently transferred and utilized, avoids the loss of the heat recovered by the heat recovery device 101, and through the coordinated operation of the hot water supply pump 105 and the hot water supply solenoid valve 106, it is also possible to quickly adjust the hot water supply according to the demand of the user water tank 104 to ensure that the user can obtain the required hot water at any time.

[0028] Moreover, the first controller 200 is used to control the opening and closing of the circulating water pump 103 to transfer the water in the circulating water tank 102 to the heat recovery device 101 for heating. The second controller 201 is used to control the opening and closing of the hot water supply pump 105 to transfer the water in the circulating water tank 102 to the user water tank 104. The third controller 202 is used to control the opening and closing of the hot water supply solenoid valve 106. Furthermore, based on the first controller 200, the second controller 201, and the third controller 202, the opening and closing of the circulating water pump 103, the hot water supply pump 105, and the hot water supply solenoid valve 106 are respectively controlled, ensuring the automatic operation of the system, reducing the error of manual operation through automatic control, and improving the reliability and stability of the system.

[0029] Furthermore, the air compressor 100 waste heat recovery system is also provided with a cold makeup water solenoid valve 107. One end of the cold makeup water solenoid valve 107 is connected to the pipeline of the circulating water pump 103, and the other end of the cold makeup water solenoid valve 107 is connected to the external makeup water pipeline. This design enables the system to timely supplement the problem of water level drop caused by use or other reasons, ensuring that there is always enough water in the circulating water tank 102 for heat recovery and transmission to maintain the normal operation of the system.

[0030] Among them, the first controller 200 is also communicatively connected to the cold makeup water solenoid valve 107. The first controller 200 is also used to control the opening and closing of the cold makeup water solenoid valve 107 so that the cold water in the external makeup water pipeline is transferred to the circulating water pump 103 and then transferred to the circulating water tank 102 or the heat recovery device 101 through the opening and closing of the circulating water pump 103. When the water level in the circulating water tank 102 reaches the high water level, the first controller 200 controls the cold makeup water solenoid valve 107 to close and stop the makeup water, preventing the water in the tank from overflowing, protecting the normal operation environment of the system, and avoiding the waste of water resources and potential safety hazards.

[0031] In one embodiment, when the water level in the circulating water tank 102 is at a low level, the first controller 200 controls the cold makeup water solenoid valve 107 to open. The cold makeup water directly enters the heat recovery device 101 through the circulating water pump 103 for preheating, improving the heating efficiency. When the circulating water pump 103 is not started, the cold makeup water will directly enter the circulating water tank 102 through the circulating water pump 103. When the water level in the circulating water tank 102 reaches the high level, the first controller 200 controls the cold makeup water solenoid valve 107 to close, stopping the makeup water to prevent the water in the tank from overflowing, protecting the normal operating environment of the system, and avoiding the waste of water resources and potential safety hazards.

[0032] It should be noted that through the collaborative work of the cold makeup water solenoid valve 107 and the first controller 200, unnecessary makeup water and drainage operations are avoided, and the energy consumption caused by frequently starting and stopping equipment such as water pumps is reduced, further improving the energy-saving effect of the system.

[0033] Furthermore, the pipeline structure between the user water tank 104 and the circulating water tank 102 is provided with a long-distance hot water supply pipe 109 and a hot water supply circulation pipe 110. One end of the long-distance hot water supply pipe 109 is connected to the circulating water tank 102, and the other end of the long-distance hot water supply pipe 109 is connected to the user water tank 104. One end of the hot water supply circulation pipe 110 is connected to the circulating water tank 102, and the other end of the hot water supply circulation pipe 110 is connected to the long-distance hot water supply pipe 109. A hot water circulation pipeline loop is formed among the long-distance hot water supply pipe 109, the hot water supply circulation pipe 110, and the circulating water tank 102. Through the hot water circulation pipeline loop, the water flow in the long-distance hot water supply pipe 109 and the hot water supply circulation pipe 110 can flow through the circulating water tank 102 for constant temperature heating, so that the water temperature in the long-distance hot water supply pipe 109 and the hot water supply circulation pipe 110 is kept consistent with the water temperature of the circulating water tank 102, improving the efficiency of hot water supply and avoiding the situation that the water temperature at the end of the long-distance hot water supply pipe 109 is too low.

[0034] It should be noted that the hot water supply solenoid valve 106 is arranged in the long-distance hot water supply pipe 109 and close to the user water tank 104, and the hot water supply pump 105 is arranged in the long-distance hot water supply pipe 109 and close to the circulating water tank 102.

[0035] Further, a hot feed water circulation solenoid valve 108 is provided in the hot feed water circulation pipe 110. The hot feed water circulation solenoid valve 108 is used to control the conduction of the hot circulation pipeline loop. The third controller 202 is also communicatively connected to the hot feed water circulation solenoid valve 108. The third controller 202 is further used to control the opening and closing of the hot feed water circulation solenoid valve 108 so that the water in the hot circulation pipeline loop can be circulated and heated by the circulation water tank 102 when the hot circulation pipeline loop is in conduction. Furthermore, the opening and closing of the hot feed water circulation solenoid valve 108 can be automatically controlled by the third controller 202 to keep the water temperature in the long-distance hot feed water pipe 109 automatically constant, improving the automatic heat preservation ability of the system.

[0036] Further, the circulation water tank 102 includes a first temperature detector 112, a second temperature detector 113, and a first water level detector 116. The first temperature detector 112 and the first water level detector 116 are respectively communicatively connected to the first controller 200. The second temperature detector 113 is communicatively connected to the second controller 201. The first temperature detector 112 is used to send a first temperature control signal of the circulation water tank 102 to the first controller 200. The second temperature detector 113 is used to send a second temperature control signal of the circulation water tank 102 to the second controller 201. The first water level detector 116 is used to send a first water level signal of the circulation water tank 102 to the first controller 200.

[0037] Meanwhile, the user water tank 104 includes a second water level detector. The second water level detector is communicatively connected to the third controller 202. The second water level detector is used to send a second water level signal of the user water tank 104 to the third controller 202.

[0038] Moreover, the pipeline structure between the heat energy recovery device 101 and the air compressor 100 includes a high-temperature oil pipe 111. The high-temperature oil pipe 111 is provided with a third temperature detector 114. The third temperature detector 114 is communicatively connected to the first controller 200. The third temperature detector 114 is used to send a third temperature control signal of the high-temperature oil pipe 111 to the first controller 200.

[0039] It should also be noted that the long-distance hot feed water pipe 109 is further provided with a fourth temperature detector 115. The fourth temperature detector 115 is communicatively connected to the third controller 202. The fourth temperature detector 115 is used to send a fourth temperature control signal of the long-distance hot feed water pipe 109 to the third controller 202.

[0040] Further, referring to Figure 2 shown, Figure 2 is an optional circuit diagram of the first controller provided by an embodiment of the present invention. A first control circuit 203 is provided in the first controller 200. The first control circuit 203 is used to control the opening and closing of the cold makeup water solenoid valve 107 according to the first water level signal.

[0041] The first control circuit 203 includes a first water level switch 204, a second water level switch 205, and a makeup water solenoid valve coil 206. The first water level switch 204, the second water level switch 205, and the makeup water solenoid valve coil are connected in series with each other. The first water level switch 204 is in a normally open state, and the second water level switch 205 is in a normally closed state.

[0042] The first water level switch 204 is configured to self-close to turn on the first control circuit 203 when the first water level signal indicates that the water level in the circulation water tank 102 is lower than the first preset water level value, and self-reset after the first control circuit 203 is turned off; the second water level switch 205 is configured to self-open to turn off the first control circuit 203 when the first water level signal indicates that the water level in the circulation water tank 102 is higher than the second preset water level value, and self-reset after the first control circuit 203 is turned off; the makeup water solenoid valve coil 206 is configured to control the cold makeup water solenoid valve 107 to open when the first control circuit 203 is turned on, so that the cold water in the external makeup water pipeline is transmitted to the circulation water pump 103.

[0043] Wherein, the first preset water level value is less than the second preset water level value.

[0044] In one embodiment, when the water level in the circulation water tank 102 is lower than the first preset water level value (5L), the first water level switch 204 self-closes to turn on the first control circuit 203, and then the makeup water solenoid valve coil 206 controls the cold makeup water solenoid valve 107 to change from closed to open, so that the cold water in the external makeup water pipeline is transmitted to the circulation water pump 103. In one embodiment, when the water level in the circulation water tank 102 is higher than the second preset water level value (15L), the second water level switch 205 self-opens to turn off the first control circuit 203, and then the first water level switch 204 and the second water level switch 205 start to self-reset, and at the same time, the cold makeup water solenoid valve 107 changes from open to closed to interrupt the transmission of cold water in the external makeup water pipeline.

[0045] Further, a second control circuit 207 is also provided in the first controller 200. The second control circuit 207 is connected in parallel with the first control circuit 203. The second control circuit 207 is configured to control the opening and closing of the circulation water pump 103 according to the first temperature control signal and the third temperature control signal.

[0046] Wherein, the second control circuit 207 includes a first temperature control switch 208, a second temperature control switch 209, and a second contactor coil 210. The first temperature control switch 208, the second temperature control switch 209, and the second contactor coil 210 are connected in series with each other. The first temperature control switch 208 is in a normally open state, and the second temperature control switch 209 is in a normally closed state.

[0047] The first temperature control switch 208 is used to self-close to turn on the second control circuit 207 when the third temperature control signal indicates that the oil temperature of the high-temperature oil pipe 111 reaches the first preset temperature value and the first temperature control signal indicates that the water temperature of the circulating water tank 102 does not reach the second preset temperature value, and self-reset after the second control circuit 207 is turned off; the second temperature control switch 209 is used to self-open to turn off the second control circuit 207 when the third temperature control signal indicates that the oil temperature of the high-temperature oil pipe 111 does not reach the first preset temperature value, or the first temperature control signal indicates that the water temperature of the circulating water tank 102 reaches the second preset temperature value, and self-reset after the second control circuit 207 is turned off.

[0048] The second contactor coil 210 is used to control the operation of the circulating water pump 103 when the second control circuit 207 is turned on.

[0049] In one embodiment, when the oil temperature of the high-temperature oil pipe 111 reaches the first preset temperature value (50 °C) and the water temperature of the circulating water tank 102 does not reach the second preset temperature value (70 °C), the first temperature control switch 208 self-closes to turn on the second control circuit 207, thereby enabling the second contactor coil 210 to control the operation of the circulating water pump 103, so that the water in the circulating water tank 102 is transferred to the heat recovery device 101 for heating. In one embodiment, when the oil temperature of the high-temperature oil pipe 111 does not reach the first preset temperature value (50 °C), or the first temperature control signal indicates that the water temperature of the circulating water tank 102 reaches the second preset temperature value (70 °C), the second temperature control switch 209 self-opens to turn off the second control circuit 207, and then the first temperature control switch 208 and the second temperature control switch 209 start to self-reset, and at the same time control the circulating water pump 103 to stop working to interrupt the water transfer of the circulating water tank 102.

[0050] Further, referring to Figure 3 shown, Figure 3 is an optional circuit diagram of the third controller provided by the embodiment of the present invention. The third controller 202 is provided with a third control circuit 211 and a first signal transmission circuit 221, and the third control circuit 211 and the first signal transmission circuit 221 are connected in parallel with each other.

[0051] Among them, the third control circuit 211 is used to control the opening and closing of the hot water supply circulation solenoid valve 108 according to the second water level signal and the fourth temperature control signal. The first signal transmission circuit 221 includes a first signal receiver 222, and the first signal receiver 222 is used to transmit the second water level signal to the second controller 201.

[0052] The third control circuit 211 includes a third water level switch 212, a fourth water level switch 213, a third temperature control switch 214, and a third contactor coil 215. The third water level switch 212, the fourth water level switch 213, and the third temperature control switch 214 are connected in series with the third contactor coil 215. The third water level switch 212 is in the normally open state, the fourth water level switch 213 is in the normally closed state, and the third temperature control switch 214 is in the normally closed state.

[0053] The third water level switch 212 is configured to self-close to turn on the third control circuit 211 when the second water level signal indicates that the water level in the user water tank 104 is less than the third preset water level value, and self-reset after the third control circuit 211 is turned off; the fourth water level switch 213 is configured to self-open to turn off the third control circuit 211 when the second water level signal indicates that the water level in the user water tank 104 is greater than the fourth preset water level value, and self-reset after the third control circuit 211 is turned off; the third temperature control switch 214 is configured to self-open to turn off the third control circuit 211 when the fourth temperature control signal indicates that the water temperature in the long-distance hot water supply pipe 109 reaches the third preset temperature value, and self-reset after the third control circuit 211 is turned off.

[0054] Wherein, the third preset water level value is less than the fourth preset water level value.

[0055] The third contactor coil 215 is configured to control the opening of the hot water supply circulation solenoid valve 108 to turn on the hot water circulation pipeline loop when the third control circuit 211 is turned on.

[0056] In one embodiment, when the water level in the user water tank 104 is less than the third preset water level value (10L), and at this time the water temperature in the long-distance hot water supply pipe 109 has not reached the third preset temperature value (50°C), the third water level switch 212 self-closes to turn on the third control circuit 211, and then the third contactor coil 215 controls the hot water supply circulation solenoid valve 108 to change from closed to open, turning on the hot water circulation pipeline loop, and then allowing the hot water at the end of the long-distance hot water supply pipe 109 to return to the circulation water tank 102 for heating.

[0057] In one embodiment, when the water level in the user water tank 104 is greater than the fourth preset water level value (20L), the fourth water level switch 213 self-opens to turn off the third control circuit 211, and then the third water level switch 212, the fourth water level switch 213, and the third temperature control switch 214 start to self-reset, and the hot water supply circulation solenoid valve 108 changes from open to closed to interrupt the conduction of the hot water circulation pipeline loop.

[0058] In one embodiment, when the water temperature of the long-distance hot water supply pipe 109 reaches the third preset temperature value (50 °C), the third temperature control switch 214 automatically disconnects, causing the third control circuit 211 to disconnect. Then, the third water level switch 212, the fourth water level switch 213, and the third temperature control switch 214 start to self-reset, and the hot water supply circulation solenoid valve 108 switches from the open state to the closed state to interrupt the conduction of the hot water circulation pipeline loop, thereby preventing the constant-pressure hot water supply from keeping the long-distance hot water supply pipe 109 in a high-temperature and high-pressure state for a long time, keeping the water temperature of the long-distance hot water supply pipe 109 constantly below the third preset temperature value, and improving the durability of the system.

[0059] Furthermore, a fourth control circuit 216 is also provided in the third controller 202. The fourth control circuit 216 is connected in parallel with the third control circuit 211, and the fourth control circuit 216 is used to control the opening and closing of the hot water supply solenoid valve 106 according to the second water level signal and the fourth temperature control signal.

[0060] The fourth control circuit 216 includes a fifth water level switch 217, a sixth water level switch 218, a fourth temperature control switch 219, and a fourth contactor coil 220. The fifth water level switch 217, the sixth water level switch 218, and the fourth temperature control switch 219 are connected in series with the fourth contactor coil 220. The fifth water level switch 217 is in the normally open state, the sixth water level switch 218 is in the normally closed state, and the fourth temperature control switch 219 is in the normally open state.

[0061] The fifth water level switch 217 is used to automatically close itself to conduct the fourth control circuit 216 when the second water level signal indicates that the water level of the user water tank 104 is lower than the third preset water level value, and self-reset after the fourth control circuit 216 is disconnected; the sixth water level switch 218 is used to automatically disconnect itself to disconnect the fourth control circuit 216 when the second water level signal indicates that the water level of the user water tank 104 is higher than the fourth preset water level value, and self-reset after the fourth control circuit 216 is disconnected; the fourth temperature control switch 219 is used to automatically close itself to conduct the fourth control circuit 216 when the fourth temperature control signal indicates that the water temperature of the long-distance hot water supply pipe 109 reaches the third preset temperature value, and self-reset after the fourth control circuit 216 is disconnected.

[0062] The fourth contactor coil 220 is used to control the opening of the hot water supply solenoid valve 106 to transfer the water in the long-distance hot water supply pipe 109 to the user water tank 104 when the fourth control circuit 216 is conducting.

[0063] In one embodiment, when the water level in the user water tank 104 is lower than the third preset water level value (10 L), the fifth water level switch 217 closes automatically. At the same time, when the water temperature in the long-distance hot water supply pipe 109 reaches the third preset temperature value (50 °C), the fourth temperature control switch 219 closes automatically. At this time, the fourth control circuit 216 is turned on, and then the fourth contactor coil 220 controls the hot water supply solenoid valve 106 to change from closed to open, so that the hot water in the long-distance hot water supply pipe 109 is transmitted to the user water tank 104, thereby ensuring that the hot water transmitted to the user water tank 104 is always above the third preset temperature value.

[0064] In one embodiment, when the water level in the user water tank 104 is higher than the fourth preset water level value (20 L), the sixth water level switch 218 opens automatically, causing the fourth control circuit 216 to disconnect. Then, the fifth water level switch 217, the sixth water level switch 218, and the fourth temperature control switch 219 start to reset automatically, and the hot water supply solenoid valve 106 changes from open to closed to interrupt the hot water transmission in the long-distance hot water supply pipe 109, thereby ensuring that the water in the user water tank 104 will not overflow due to excessive water transmission.

[0065] Further, referring to Figure 4 shown in Figure 4 FIG. is an optional circuit diagram of the second controller provided by an embodiment of the present invention. A fifth control circuit 225 and a second signal transmission circuit 223 are provided in the second controller 201, and the fifth control circuit 225 and the second signal transmission circuit 223 are connected in parallel with each other; The second signal transmission circuit 223 includes a second signal receiver 224. The second signal receiver 224 is used to receive the second water level signal transmitted by the third controller 202. The fifth control circuit 225 is used to control the opening and closing of the hot water supply pump 105 according to the second temperature control signal and the second water level signal.

[0066] In one embodiment, the communication method between the second signal receiver 224 and the first signal receiver 222 is the LORA wireless communication method.

[0067] The fifth control circuit 225 includes a seventh water level switch 226, an eighth water level switch 227, a fifth temperature control switch 228, and a fifth contactor coil 229. The seventh water level switch 226, the eighth water level switch 227, the fifth temperature control switch 228, and the fifth contactor coil 229 are connected in series with each other. The seventh water level switch 226 is in a normally open state, the eighth water level switch 227 is in a normally closed state, and the fifth temperature control switch 228 is in a normally open state; The seventh water level switch 226 is used to self-close to turn on the fifth control circuit 225 when the second water level signal indicates that the water level in the user water tank 104 is at the third preset water level value, and to self-reset after the fifth control circuit 225 is turned off; the eighth water level switch 227 is used to self-open to turn off the fifth control circuit 225 when the second water level signal indicates that the water level in the user water tank 104 is at the fourth preset water level value, and to self-reset after the fifth control circuit 225 is turned off; the fifth temperature control switch 228 is used to self-close to turn on the fifth control circuit 225 when the second temperature control signal indicates that the water temperature in the circulating water tank 102 reaches the fourth preset temperature value, and to self-reset after the fifth control circuit 225 is turned off.

[0068] The fifth contactor coil 229 is used to control the operation of the hot water supply pump 105 to transfer the water in the circulating water tank 102 to the long-distance hot water supply pipe 109 when the fifth control circuit 225 is turned on.

[0069] In an embodiment, when the water level in the user water tank 104 is less than the third preset water level value (10L), the seventh water level switch 226 self-closes. At the same time, when the water temperature in the circulating water tank 102 reaches the fourth preset temperature value (60°C), the fifth temperature control switch 228 self-closes. At this time, the fifth control circuit 225 is turned on, and then the fifth contactor coil 229 controls the operation of the hot water supply pump 105 to transfer the hot water in the circulating water tank 102 to the end of the long-distance hot water supply pipe 109.

[0070] In an embodiment, when the water level in the user water tank 104 is greater than the fourth preset water level value (20L), the eighth water level switch 227 self-opens to turn off the fifth control circuit 225. Then, the seventh water level switch 226, the eighth water level switch 227, and the fifth temperature control switch 228 start to self-reset, and the hot water supply pump 105 stops working to interrupt the transfer of the hot water in the circulating water tank 102, thereby ensuring that the water in the user water tank 104 will not overflow due to excessive water transfer.

[0071] The embodiments described in the embodiments of the present invention are for more clearly explaining the technical solutions of the embodiments of the present invention, and do not constitute a limitation on the technical solutions provided by the embodiments of the present invention. Those skilled in the art know that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of the present invention are also applicable to similar technical problems.

[0072] The device embodiments described above are merely illustrative. The devices described as separate components may or may not be physically separated, that is, they may be located in one place or distributed to multiple devices. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0073] In the description of the present invention and the above-mentioned accompanying drawings, terms such as "first", "second", "third", "fourth", etc. (if any) are used to distinguish similar objects and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order different from those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that comprises a series of steps or components does not necessarily have to be limited to those steps or components clearly listed, but may include other steps or components not clearly listed or inherent to these processes, methods, products, or devices.

[0074] It should be understood that in the present invention, "at least one (item)" means one or more, and "a plurality" means two or more. "And / or" is used to describe the association relationship of associated objects and indicates that there can be three relationships. For example, "A and / or B" can mean: only A exists, only B exists, and both A and B exist at the same time. Among them, A and B can be singular or plural. The character " / " generally means that the associated objects before and after are in an "or" relationship. "At least one (one) of the following" or its similar expression refers to any combination of these items, including any combination of single item (one) or plural items (ones). For example, at least one (one) of a, b, or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0075] In several embodiments provided by the present invention, it should be understood that the disclosed system can be implemented in other ways. For example, the system embodiments described above are merely illustrative. For example, the division of the above-mentioned components is only a logical function division. In actual implementation, there may be other division methods. For example, multiple components or assemblies can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be an indirect coupling or communication connection through some interfaces, devices or components, and can be in electrical, mechanical or other forms.

[0076] The components described above as separate components may or may not be physically separated. The components shown as components may or may not be physical components, that is, they can be located in one place or distributed to multiple network components. Some or all of the components can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0077] In addition, in each embodiment of the present invention, each functional unit can be integrated in a processor, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0078] The preferred embodiments of the embodiments of the present invention have been described above with reference to the accompanying drawings. This does not limit the scope of the rights of the embodiments of the present invention. Any modifications, equivalent replacements, and improvements made by those skilled in the art without departing from the scope and essence of the embodiments of the present invention shall fall within the scope of the rights of the embodiments of the present invention.

Claims

1. An air compressor waste heat recovery system, characterized in that, Including: Air compressor; Heat recovery device, which is connected to the air compressor through a pipeline, and is used to receive and convert the heat of the air compressor; Circulation water tank, which is connected to the heat recovery device through a pipeline; Circulation water pump, which is arranged in the pipeline structure between the circulation water tank and the heat recovery device; User water tank, which is connected to the circulation water tank through a pipeline; Hot water supply pump, which is arranged in the pipeline structure between the user water tank and the circulation water tank, and is used to transfer the water in the circulation water tank to the user water tank; Hot water supply solenoid valve, which is arranged in the pipeline structure between the user water tank and the circulation water tank, and is used to control the conduction between the user water tank and the circulation water tank; First controller, which is respectively communicatively connected to the circulation water pump, and is used to control the opening and closing of the circulation water pump to transfer the water in the circulation water tank to the heat recovery device for heating; Second controller, which is communicatively connected to the hot water supply pump, and is used to control the opening and closing of the hot water supply pump to transfer the water in the circulation water tank to the user water tank; Third controller, which is respectively communicatively connected to the second controller and the hot water supply solenoid valve, and is used to control the opening and closing of the hot water supply solenoid valve.

2. The air compressor waste heat recovery system according to claim 1, wherein, The system further includes a cold water make-up solenoid valve, one end of which is connected to the circulation water pump through a pipeline, and the other end is connected to an external water make-up pipeline; Wherein, the first controller is also communicatively connected to the cold water make-up solenoid valve, and is also used to control the opening and closing of the cold water make-up solenoid valve so that the cold water in the external water make-up pipeline is transferred to the circulation water pump and then transferred to the circulation water tank or the heat recovery device through the opening and closing of the circulation water pump.

3. The air compressor waste heat recovery system according to claim 2, characterized in that, The pipeline structure between the user water tank and the circulation water tank includes: Long-distance hot water supply pipe, one end of which is connected to the circulation water tank, and the other end is connected to the user water tank; Hot water supply circulation pipe, one end of which is connected to the circulation water tank, and the other end is connected to the long-distance hot water supply pipe; A hot water circulation pipeline loop is formed among the long-distance hot water supply pipe, the hot water supply circulation pipe and the circulation water tank; Wherein, the hot water supply solenoid valve is arranged in the long-distance hot water supply pipe and close to the user water tank, and the hot water supply pump is arranged in the long-distance hot water supply pipe and close to the circulation water tank.

4. The air compressor waste heat recovery system according to claim 3, wherein A hot water supply circulation solenoid valve is arranged in the hot water supply circulation pipe, and is used to control the conduction of the hot water circulation pipeline loop. The third controller is also communicatively connected to the hot feed water circulation solenoid valve, and is further configured to control the opening and closing of the hot feed water circulation solenoid valve so that the water in the hot circulation pipeline loop can be circularly heated by the circulation water tank when the hot circulation pipeline loop is in a conducting state.

5. The waste heat recovery system of an air compressor according to claim 4, characterized in that, The circulation water tank includes a first temperature detector, a second temperature detector, and a first water level detector. The first temperature detector and the first water level detector are respectively communicatively connected to the first controller, and the second temperature detector is communicatively connected to the second controller. The first temperature detector is configured to send a first temperature control signal of the circulation water tank to the first controller, the second temperature detector is configured to send a second temperature control signal of the circulation water tank to the second controller, and the first water level detector is configured to send a first water level signal of the circulation water tank to the first controller; The user water tank includes a second water level detector, and the second water level detector is communicatively connected to the third controller. The second water level detector is configured to send a second water level signal of the user water tank to the third controller; The pipeline structure between the heat recovery device and the air compressor includes a high-temperature oil pipe, and the high-temperature oil pipe is provided with a third temperature detector. The third temperature detector is communicatively connected to the first controller, and the third temperature detector is configured to send a third temperature control signal of the high-temperature oil pipe to the first controller; The long-distance hot water supply pipe is further provided with a fourth temperature detector, and the fourth temperature detector is communicatively connected to the third controller. The fourth temperature detector is configured to send a fourth temperature control signal of the long-distance hot water supply pipe to the third controller.

6. The air compressor waste heat recovery system according to claim 5, wherein, The first controller is internally provided with a first control circuit, and the first control circuit is configured to control the opening and closing of the cold make-up water solenoid valve according to the first water level signal; The first control circuit includes a first water level switch, a second water level switch, and a make-up water solenoid valve coil. The first water level switch, the second water level switch, and the make-up water solenoid valve coil are connected in series with each other. The first water level switch is in a normally open state, and the second water level switch is in a normally closed state; The first water level switch is configured to self-close when the first water level signal indicates that the water level of the circulation water tank is lower than a first preset water level value to make the first control circuit conductive, and self-reset after the first control circuit is disconnected; The second water level switch is configured to self-open when the first water level signal indicates that the water level of the circulation water tank is higher than a second preset water level value to make the first control circuit disconnected, and self-reset after the first control circuit is disconnected; wherein, the first preset water level value is less than the second preset water level value; The make-up water solenoid valve coil is configured to control the opening of the cold make-up water solenoid valve when the first control circuit is conductive so that the cold water in the external make-up water pipeline is transmitted to the circulation water pump.

7. The air compressor waste heat recovery system according to claim 6, wherein, The first controller further includes a second control circuit, which is connected in parallel with the first control circuit and is used to control the opening and closing of the circulating water pump according to the first temperature control signal and the third temperature control signal; The second control circuit includes a first temperature control switch, a second temperature control switch and a second contactor coil. The first temperature control switch, the second temperature control switch and the second contactor coil are connected in series with each other. The first temperature control switch is in a normally open state, and the second temperature control switch is in a normally closed state; The first temperature control switch is used to self-close to conduct the second control circuit when the third temperature control signal indicates that the oil temperature of the high-temperature oil pipe reaches the first preset temperature value and the first temperature control signal indicates that the water temperature of the circulating water tank does not reach the second preset temperature value, and self-reset after the second control circuit is disconnected; The second temperature control switch is used to self-open to disconnect the second control circuit when the third temperature control signal indicates that the oil temperature of the high-temperature oil pipe does not reach the first preset temperature value, or the first temperature control signal indicates that the water temperature of the circulating water tank reaches the second preset temperature value, and self-reset after the second control circuit is disconnected; The second contactor coil is used to control the operation of the circulating water pump when the second control circuit is conducting; 8. The air compressor waste heat recovery system according to claim 5, wherein The third controller is provided with a third control circuit and a first signal transmission circuit, and the third control circuit is connected in parallel with the first signal transmission circuit; The third control circuit is used to control the opening and closing of the hot water supply circulation solenoid valve according to the second water level signal and the fourth temperature control signal. The first signal transmission circuit includes a first signal receiver, which is used to transmit the second water level signal to the second controller; The third control circuit includes a third water level switch, a fourth water level switch, a third temperature control switch and a third contactor coil. The third water level switch, the fourth water level switch, the third temperature control switch and the third contactor coil are connected in series with each other. The third water level switch is in a normally open state, the fourth water level switch is in a normally closed state, and the third temperature control switch is in a normally closed state; The third water level switch is used to self-close to conduct the third control circuit when the second water level signal indicates that the water level of the user water tank is less than the third preset water level value, and self-reset after the third control circuit is disconnected; The fourth water level switch is used to self-open to disconnect the third control circuit when the second water level signal indicates that the water level of the user water tank is greater than the fourth preset water level value, and self-reset after the third control circuit is disconnected, where the third preset water level value is less than the fourth preset water level value; The third temperature control switch is used to self-open to disconnect the third control circuit when the fourth temperature control signal indicates that the water temperature of the long-distance hot water supply pipe reaches the third preset temperature value, and self-reset after the third control circuit is disconnected; The third contactor coil is used to control the opening of the hot feed water circulation solenoid valve when the third control circuit is turned on, so as to turn on the hot circulation pipeline loop.

9. The air compressor waste heat recovery system according to claim 8, characterized in that A fourth control circuit is also provided in the third controller. The fourth control circuit is connected in parallel with the third control circuit. The fourth control circuit is used to control the opening and closing of the hot feed water solenoid valve according to the second water level signal and the fourth temperature control signal. The fourth control circuit includes a fifth water level switch, a sixth water level switch, a fourth temperature control switch, and a fourth contactor coil. The fifth water level switch, the sixth water level switch, and the fourth temperature control switch are connected in series with the fourth contactor coil. The fifth water level switch is in a normally open state, the sixth water level switch is in a normally closed state, and the fourth temperature control switch is in a normally open state. The fifth water level switch is used to self-close when the second water level signal indicates that the water level in the user water tank is lower than the third preset water level value, so as to turn on the fourth control circuit, and self-reset after the fourth control circuit is turned off. The sixth water level switch is used to self-open when the second water level signal indicates that the water level in the user water tank is higher than the fourth preset water level value, so as to turn off the fourth control circuit, and self-reset after the fourth control circuit is turned off. The fourth temperature control switch is used to self-close when the fourth temperature control signal indicates that the water temperature in the long-distance hot feed water pipe reaches the third preset temperature value, so as to turn on the fourth control circuit, and self-reset after the fourth control circuit is turned off. The fourth contactor coil is used to control the opening of the hot feed water solenoid valve when the fourth control circuit is turned on, so as to transfer the water in the long-distance hot feed water pipe to the user water tank.

10. The air compressor waste heat recovery system according to claim 8, characterized in that, A fifth control circuit and a second signal transmission circuit are provided in the second controller. The fifth control circuit is connected in parallel with the second signal transmission circuit. The second signal transmission circuit includes a second signal receiver. The second signal receiver is used to receive the second water level signal transmitted by the third controller. The fifth control circuit is used to control the opening and closing of the hot feed water pump according to the second temperature control signal and the second water level signal. The fifth control circuit includes a seventh water level switch, an eighth water level switch, a fifth temperature control switch, and a fifth contactor coil. The seventh water level switch, the eighth water level switch, and the fifth temperature control switch are connected in series with the fifth contactor coil. The seventh water level switch is in a normally open state, the eighth water level switch is in a normally closed state, and the fifth temperature control switch is in a normally open state. The seventh water level switch is used to self-close when the second water level signal indicates that the water level in the user water tank is at the third preset water level value, so as to turn on the fifth control circuit, and self-reset after the fifth control circuit is turned off. The eighth water level switch is used to self-open when the second water level signal indicates that the water level in the user water tank is at the fourth preset water level value, so as to turn off the fifth control circuit, and self-reset after the fifth control circuit is turned off. The fifth temperature control switch is used to self-close when the second temperature control signal indicates that the water temperature of the circulating water tank reaches the fourth preset temperature value, so as to turn on the fifth control circuit, and self-reset after the fifth control circuit is turned off; The fifth contactor coil is used to control the operation of the hot water supply pump when the fifth control circuit is turned on, so as to transfer the water in the circulating water tank to the long-distance hot water supply pipe.

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