Waste heat utilization system and control method thereof

Abstract

The present disclosure relates to a waste heat utilization system and a control method thereof, the system comprising: an air-conditioning heater; a main circulation pipeline, in which a heat exchange medium flows and the two ends of which are respectively connected to a medium inlet and a medium outlet of the air-conditioning heater; a first heat exchanger, used for introducing compressed air cooling circulation water with a first temperature to heat the heat exchange medium in the main circulation pipeline; a second heat exchanger, used for introducing steam condensate with a second temperature to heat the heat exchange medium in the main circulation pipeline, the second temperature being higher than the first temperature; a third heat exchanger, used for introducing steam with a third temperature to heat the heat exchange medium in the main circulation pipeline, the third temperature being higher than the second temperature; and a bypass pipeline, both ends of which are connected to the main circulation pipeline and are connected in parallel with the air-conditioning heater, a main bypass valve being provided on the bypass pipeline, the main bypass valve being used for, in an off state, to allow the heat exchange medium to flow through the air-conditioning heater to circulate and provide heat; and in an on state, to allow the heat exchange medium to flow through the bypass pipeline to circulate.

Description

Technical Field

[0001] The present disclosure relates to the technical field of waste heat utilization of industrial plants, and in particular to a waste heat utilization system and a control method thereof. Background Art

[0002] For constant temperature and humidity workshops, hot water heat exchange is used. Compared with steam heat exchange, the heat exchange temperature difference is small, there is no steam-water phase change, and the air conditioning operation is relatively stable. Air conditioning heating mainly includes heating demand in winter and reheating demand after freezing and dehumidification in summer. Both heating demand and reheating demand consume a lot of energy. Summary of the invention

[0003] The present disclosure provides a waste heat utilization system and a control method thereof, which can reduce the energy consumption required for air-conditioning heating.

[0004] The present disclosure provides a waste heat utilization system, comprising:

[0005] An air conditioning heater having a medium inlet and a medium outlet;

[0006] The main circulation pipeline has heat exchange medium flowing inside and its two ends are respectively connected to the medium inlet and the medium outlet;

[0007] A first heat exchanger, used for introducing compressed air cooling circulating water having a first temperature to heat the heat exchange medium in the main circulation pipeline;

[0008] a second heat exchanger, for introducing steam condensate having a second temperature to heat the heat exchange medium in the main circulation pipeline, the second temperature being higher than the first temperature;

[0009] a third heat exchanger for introducing steam having a third temperature to heat the heat exchange medium in the main circulation pipeline, the third temperature being higher than the second temperature; and

[0010] The bypass pipeline is connected to the main circulation pipeline at both ends and is connected in parallel with the air-conditioning heater. A main bypass valve is provided on the bypass pipeline. The main bypass valve is configured to allow the heat exchange medium to circulate through the air-conditioning heater and provide heat when in the off state; and to allow the heat exchange medium to circulate through the bypass pipeline when in the on state.

[0011] In some embodiments, the waste heat utilization system further comprises:

[0012] The first bypass valve is arranged on the main circulation pipeline and is arranged in parallel with the first heat exchanger. The first bypass valve is configured to allow the heat exchange medium to exchange heat with the first heat exchanger in the closed state, and to allow the heat exchange medium to pass directly through the first bypass valve in the connected state.

[0013] In some embodiments, the waste heat utilization system further comprises:

[0014] The second bypass valve is arranged on the main circulation pipeline and is arranged in parallel with the second heat exchanger. The second bypass valve is configured to allow the heat exchange medium to exchange heat with the second heat exchanger in the closed state, and to allow the heat exchange medium to pass directly through the second bypass valve in the connected state.

[0015] In some embodiments, the first heat exchanger has a circulating water inlet and a circulating water outlet, the second heat exchanger has a condensate inlet and a first condensate outlet, and the waste heat utilization system further includes:

[0016] The first check valve is arranged on the pipeline between the first condensate outlet and the circulating water inlet, and only allows the condensate to flow in one direction from the first condensate outlet to the circulating water inlet.

[0017] In some embodiments, the waste heat utilization system further comprises:

[0018] The third bypass valve is arranged on the main circulation pipeline and close to the heat exchange medium inlet of the air conditioning heater, and the third bypass valve is arranged in parallel with the third heat exchanger. The third bypass valve is configured to allow the heat exchange medium to exchange heat with the third heat exchanger in the closed state, and to allow the heat exchange medium to pass directly through the third bypass valve in the connected state.

[0019] In some embodiments, the second heat exchanger has a condensate inlet and a first condensate outlet, the third heat exchanger has a steam inlet and a second condensate outlet, and the waste heat utilization system further includes:

[0020] The second check valve is arranged on the pipeline between the second condensate outlet and the condensate inlet, and only allows the condensate to flow in one direction from the second condensate outlet to the condensate inlet.

[0021] In some embodiments, the first heat exchanger, the second heat exchanger and the third heat exchanger are arranged in sequence along the flow direction of the heat exchange medium.

[0022] In some embodiments, the third heat exchanger is connected to a region of the main circulation pipeline between the bypass pipeline and the air conditioning heater.

[0023] In some embodiments, the waste heat utilization system further comprises:

[0024] A first regulating valve is provided on a first liquid inlet pipeline of the first heat exchanger and is configured to regulate the amount of compressed air cooling circulating water flowing into the first heat exchanger;

[0025] A second regulating valve is provided on a second liquid inlet pipeline of the second heat exchanger and is configured to regulate the amount of condensed water entering the second heat exchanger; and / or

[0026] The third regulating valve is arranged on the third steam inlet pipeline of the third heat exchanger and is configured to regulate the amount of steam passing into the third heat exchanger.

[0027] In some embodiments, the waste heat utilization system also includes a storage container, which is arranged in the main circulation pipeline and is used to store heat exchange medium. The storage container has an inlet and an outlet. The inlet is arranged in the bottom area of ​​the storage container, and the outlet is arranged in the top area of ​​the storage container.

[0028] In some embodiments, the storage container is located near the heat load center of the air conditioning room.

[0029] In some embodiments, the waste heat utilization system further includes a first temperature detection component configured to detect the temperature of the heat exchange medium in the storage container so as to maintain the temperature of the heat exchange medium within a preset temperature range.

[0030] In some embodiments, the waste heat utilization system further includes a first circulation pump, which is disposed on a pipe section in the main circulation pipeline located on a side of the bypass pipeline away from the air conditioning heater.

[0031] In some embodiments, the motor of the first circulation pump has a frequency converter, and the frequency converter is used to adjust the operating frequency of the motor of the first circulation pump, and the operating frequency is configured to be set according to the heat required by the air-conditioning heater.

[0032] In some embodiments, the waste heat utilization system also includes: a cooling tower, an air compression cooler and a second circulating pump. The air compression cooler has a water outlet and a water inlet. The water outlet is connected to the circulating water inlet of the first heat exchanger through a first liquid inlet pipeline. The circulating water outlet of the first heat exchanger is connected to the water inlet through the cooling tower; the second circulating pump is arranged on the first liquid inlet pipeline to drive the cooling water circulation.

[0033] In some embodiments, the circulating water outlet of the first heat exchanger is connected to the cooling tower through a first liquid outlet pipeline, and the waste heat utilization system further includes:

[0034] A second temperature detection component is used to detect the temperature of the cooling water in the first liquid inlet pipeline; and / or

[0035] The third temperature detection component is used to detect the temperature of the cooling water in the first cold liquid outlet pipeline.

[0036] In some embodiments, the waste heat utilization system further comprises:

[0037] A cooling tower water inlet regulating valve is arranged on the pipeline between the first liquid inlet pipeline and the water inlet of the cooling tower;

[0038] A first regulating valve is disposed on the first liquid inlet pipeline; and

[0039] The controller is configured to, when the detection value of the second temperature detection component is higher than the preset temperature value of the heat exchange medium temperature required by the air-conditioning heater, put the first regulating valve in the on state and put the cooling tower water inlet regulating valve in the off state; and when the detection value of the second temperature detection component is not higher than the preset temperature value of the heat exchange medium temperature required by the air-conditioning heater, or there is no heat exchange demand for the heat exchange medium, put the first regulating valve in the off state and put the cooling tower water inlet regulating valve in the on state.

[0040] In some embodiments, the waste heat utilization system further comprises:

[0041] A first regulating valve is disposed on the first liquid inlet pipeline; and

[0042] The controller is configured to put the first regulating valve in an off state when the detection value of the third temperature detection component is not lower than the detection value of the second temperature detection component; and put the first regulating valve in an on state when the detection value of the third temperature detection component is lower than the detection value of the second temperature detection component.

[0043] Another aspect of the present disclosure provides a control method for the waste heat utilization system based on the above embodiment, comprising:

[0044] Determine the heating requirements of the air conditioner heater;

[0045] Controlling whether the first heat exchanger, the second heat exchanger and the third heat exchanger participate in heat exchange according to the heating demand;

[0046] Among them, the second heat exchanger is used to introduce steam condensate with a second temperature to heat the heat exchange medium in the main circulation pipeline, and the second temperature is higher than the first temperature; the third heat exchanger is used to introduce steam with a third temperature to heat the heat exchange medium in the main circulation pipeline, and the third temperature is higher than the second temperature.

[0047] In some embodiments, the step of controlling the first heat exchanger, the second heat exchanger, and the third heat exchanger to participate in heat exchange includes:

[0048] Prioritize the first heat exchanger to participate in heat exchange;

[0049] When the heat provided by the first heat exchanger cannot meet the heating demand, the second heat exchanger is used to exchange heat;

[0050] When the heat energy provided by the first heat exchanger and the second heat exchanger cannot meet the heating demand, the third heat exchanger is simultaneously used to participate in the heat exchange.

[0051] In some embodiments,

[0052] The waste heat utilization system further includes: a first bypass valve, which is arranged on the main circulation pipeline and is arranged in parallel with the first heat exchanger; and a first regulating valve, which is arranged on the first liquid inlet pipeline of the first heat exchanger; and controlling whether the first heat exchanger participates in heat exchange includes:

[0053] The first bypass valve is in a closed state, and the first regulating valve is in an open state, so that the first heat exchanger participates in heat exchange;

[0054] The first bypass valve is in an on state, and the first regulating valve is in an off state, so that the first heat exchanger does not participate in heat exchange;

[0055] Alternatively, the waste heat utilization system further includes: a second bypass valve, which is arranged on the main circulation pipeline and is arranged in parallel with the second heat exchanger; and a second regulating valve, which is arranged on the second liquid inlet pipeline of the second heat exchanger; and controlling whether the second heat exchanger participates in heat exchange includes:

[0056] The second bypass valve is in a closed state, and the second regulating valve is in an open state, so that the second heat exchanger participates in heat exchange;

[0057] The second bypass valve is in an on state, and the second regulating valve is in an off state, so that the second heat exchanger does not participate in heat exchange;

[0058] Alternatively, the waste heat utilization system further includes: a third bypass valve, which is arranged on the main circulation pipeline and is arranged in parallel with the third heat exchanger; and a third regulating valve, which is arranged on the third steam inlet pipeline of the third heat exchanger; and controlling whether the third heat exchanger participates in heat exchange includes:

[0059] The third bypass valve is in a closed state, and the third regulating valve is in an open state, so that the third heat exchanger participates in heat exchange;

[0060] The third bypass valve is in an on state, and the third regulating valve is in an off state, so that the third heat exchanger does not participate in heat exchange.

[0061] In some embodiments, the waste heat utilization system further includes: a storage container and a first circulation pump arranged in the main circulation pipeline for storing the heat exchange medium, and the control method further includes:

[0062] Keep the first circulation pump running continuously.

[0063] In some embodiments, the control method further comprises:

[0064] Obtaining the temperature of the heat exchange medium in the storage container;

[0065] The operating frequency of the motor of the first circulation pump is adjusted according to the temperature of the heat exchange medium so that the temperature of the heat exchange medium is maintained within a preset temperature range.

[0066] In some embodiments, the waste heat utilization system includes: a third bypass valve, which is arranged on the main circulation pipeline and close to the heat exchange medium inlet of the air-conditioning heater, and the third bypass valve is arranged in parallel with the third heat exchanger; and a third regulating valve, which is arranged on the third steam inlet pipeline of the third heat exchanger; the control method also includes:

[0067] When the air-conditioning heater does not need heat provided by the heat exchange medium, the main bypass valve is in an on state, and the third bypass valve and the third regulating valve are both in an off state.

[0068] The waste heat utilization system of the disclosed embodiment can fully utilize the existing free low-grade thermal energy in the factory to provide heat for the air conditioner heater, thereby reducing the energy consumption required for air conditioning heating while meeting the production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0070] Figure 1 It is a schematic diagram of the structure of some embodiments of the waste heat utilization system disclosed in the present invention.

[0071] Figure 2 This is a schematic diagram of air compression cooling circulating water. DETAILED DESCRIPTION

[0072] The technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present disclosure and its application or use. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without carrying out creative work are within the scope of protection of the present disclosure.

[0073] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0074] In the description of the present disclosure, it is necessary to understand that the terms "center", "lateral", "longitudinal", "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present invention.

[0075] In the description of the present disclosure, it should be understood that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present disclosure.

[0076] The present disclosure provides a waste heat utilization system, such as Figure 1 and Figure 2 As shown, including:

[0077] The air conditioning heater 1 has a medium inlet 1A and a medium outlet 1B;

[0078] The main circulation pipeline has heat exchange medium flowing inside and its two ends are respectively connected to the medium inlet 1A and the medium outlet 1B;

[0079] The first heat exchanger 3 is used to introduce compressed air cooling circulating water with a first temperature to heat the heat exchange medium in the main circulation pipeline;

[0080] The second heat exchanger 4 is used to introduce steam condensate having a second temperature to heat the heat exchange medium in the main circulation pipeline, and the second temperature is higher than the first temperature;

[0081] a third heat exchanger 5, for introducing steam having a third temperature to heat the heat exchange medium in the main circulation pipeline, the third temperature being higher than the second temperature; and

[0082] The bypass pipeline 10 is connected to the main circulation pipeline at both ends and is connected in parallel with the air-conditioning heater 1. A main bypass valve 11 is provided on the bypass pipeline 10. The main bypass valve 11 is configured to allow the heat exchange medium to circulate through the air-conditioning heater 1 and provide heat in the off state; and to allow the heat exchange medium to circulate through the bypass pipeline 10 in the on state.

[0083] Among them, one or more air conditioning heaters 1 can be set to supply heating for factory air conditioning boxes, and multiple air conditioning heaters 1 can be set in parallel. Due to different regions, the working scenes of each air conditioning heater 1 are different and change over time.

[0084] The heat exchange medium flowing inside the main circulation pipeline can be liquid such as water, or can also be gas, which is used to flow to the air conditioner heater 1 to provide heat thereto.

[0085] The first heat exchanger 3 may be a plate heat exchanger, and has a circulating water inlet 3A, a circulating water outlet 3B, a first inlet 3C and a first outlet 3D. The circulating water inlet 3A is connected to the first liquid inlet pipeline 25, the circulating water outlet 3B is connected to the first liquid outlet pipeline 27, and the circulating water inlet 3A is connected to the circulating water outlet 3B; the first inlet 3C is connected to the first outlet 3D, and both are connected to the main circulation pipeline. The heat exchange medium can enter the first inlet 3C and flow out from the first outlet 3D, and absorb the heat in the compressed air cooling circulating water in the process of entering the first heat exchanger 3.

[0086] The air compressor cooling circulating water is the cooling circulating water generated by the air compressor cooler 28 during the operation of the air compressor. The outlet water temperature of the cooling circulating water is about 40°C. It is low-grade thermal energy and is free waste heat utilization.

[0087] The second heat exchanger 4 can be a plate heat exchanger, etc. The steam condensate is used for heat exchange with steam in other sections of the factory, and the steam condensate of about 100° C. is medium-grade heat energy and is free waste heat utilization.

[0088] The second heat exchanger 4 has a condensate inlet 4A, a first condensate outlet 4B, a second inlet 4C and a second outlet 4D. The condensate inlet 4A is connected to the second liquid inlet pipeline 22, the first condensate outlet 4B is connected to the second liquid outlet pipeline 23, and the condensate inlet 4A is connected to the first condensate outlet 4B; the second inlet 4C and the second outlet 4D are connected, and both are connected to the main circulation pipeline. The heat exchange medium can enter the second inlet 4C and flow out from the second outlet 4D, and absorb the heat in the steam condensate in the process of entering the second heat exchanger 4.

[0089] The third heat exchanger 5 may be a plate heat exchanger, etc. The steam is steam at about 180° C. used in the factory, which is high-grade thermal energy and is a consumer energy used for heating.

[0090] The third heat exchanger 5 has a steam inlet 5A, a second condensate outlet 5B, a third inlet 5C and a third outlet 5D. The steam inlet 5A is connected to the third steam inlet pipeline 35, the second condensate outlet 5B is connected to the third liquid outlet pipeline 38, and the steam inlet 5A is connected to the first condensate outlet 5B; the third inlet 5C is connected to the third outlet 5D, and both are connected to the main circulation pipeline. The heat exchange medium can enter the third inlet 5C and flow out from the third outlet 5D, and absorb the heat in the steam in the process of entering the third heat exchanger 5.

[0091] When multiple air-conditioning heaters 1 are provided, the first heat exchanger 3 and the second heat exchanger 4 can be centrally arranged at the load center between the multiple air-conditioning heaters 1, and the third heat exchanger 5 can be installed close to the corresponding air-conditioning heater 1 and arranged in conjunction with the air-conditioning heater 1.

[0092] The first heat exchanger 3 and the second heat exchanger 4 can be used as basic heating units to meet the usage requirements of most air-conditioning heaters 1 most of the time. When some air-conditioning heaters 1 have high heat, high temperature and rapid response requirements at certain times, the third heat exchanger 5 can simultaneously ensure the heat supply.

[0093] The main bypass valve 11 may be an electric regulating valve, and further, the flow rate may be adjusted in the on state. The main bypass valve 11 is configured to allow the heat exchange medium to circulate through the air conditioner heater 1 and provide heat in the off state; and to allow the heat exchange medium to circulate through the bypass pipeline 10 without passing through the air conditioner heater 1 in the on state.

[0094] An insulation layer can be added to each pipe in the system to reduce heat loss.

[0095] This embodiment can fully utilize the existing free low-grade thermal energy in the factory to provide heat for the air-conditioning heater 1, thereby reducing the energy consumption required for heating the air conditioner while meeting the production process.

[0096] Furthermore, on the basis of utilizing the factory's existing free low-grade compressed air cooling circulating water, the thermal energy of free medium-grade steam condensate water is utilized as a supplement, and the thermal energy of high-grade steam can be introduced as a further guarantee to provide heat for the air-conditioning heater 1. On the premise of meeting the production process, the utilization of waste heat source for the air-conditioning heater 1 is increased, which can minimize the energy consumption required for air-conditioning heating.

[0097] Furthermore, on the basis of utilizing the factory's existing free low-grade compressed air cooling circulating water, the thermal energy of free medium-grade steam condensate is used as a supplement to provide heat for the air-conditioning heater 1, thereby increasing the capacity of providing energy for air-conditioning heating while meeting the production process.

[0098] When recovering waste heat, the first heat exchanger 3 is preferentially involved in heat exchange, and free low-grade compressed air cooling circulating water is used to provide heat; when the heat energy provided by the first heat exchanger 3 cannot meet the heating demand, the second heat exchanger 4 is simultaneously involved in heat exchange, and free medium-grade steam condensate is used to provide heat; when the heat energy provided by the first heat exchanger 3 and the second heat exchanger 4 cannot meet the heating demand, the third heat exchanger 5 is simultaneously involved in heat exchange, and high-grade steam is introduced to provide heat.

[0099] In some embodiments, Figure 1As shown, the waste heat utilization system also includes: a first bypass valve 16, which is arranged on the main circulation pipeline and is arranged in parallel with the first heat exchanger 3. The first bypass valve 16 is configured to allow the heat exchange medium to exchange heat with the first heat exchanger 3 in the closed state, and to allow the heat exchange medium to pass directly through the first bypass valve 16 in the connected state.

[0100] The first bypass valve 16 may be an electric regulating valve, and further, the flow rate may be adjusted in the switched-on state. The first inlet 3C and the first outlet 3D are connected to two ends of the first bypass valve 16 respectively.

[0101] In this embodiment, a bypass pipeline is provided in parallel with the first heat exchanger 3. When the first heat exchanger 3 does not need to participate in heat exchange, the first bypass valve 16 can be turned on, and the heat exchange medium can preferentially pass through the first bypass valve 16, and no or only a small part of the heat exchange medium passes through the first heat exchanger 3 with a larger flow resistance, thereby reducing the pressure loss of the heat exchange medium flow and the power consumption of the first circulation pump 7 driving the heat exchange medium flow; the first regulating valve 26 is turned off to reduce the pressure loss of the circulating water flow and the power consumption of the second circulation pump 29. When the first heat exchanger 3 needs to participate in heat exchange, the first bypass valve 16 is turned off, and the heat exchange medium passes through the first heat exchanger 3 to participate in heat exchange.

[0102] In some embodiments, Figure 1 As shown, the waste heat utilization system also includes: a second bypass valve 17, which is arranged on the main circulation pipeline and is arranged in parallel with the second heat exchanger 4. The second bypass valve 17 is configured to allow the heat exchange medium to exchange heat with the second heat exchanger 4 in the closed state, and to allow the heat exchange medium to pass directly through the second bypass valve 17 in the connected state.

[0103] The second bypass valve 17 may be an electric regulating valve, and further, the flow rate may be adjusted in the switched-on state. The second inlet 4C and the second outlet 4D are connected to two ends of the second bypass valve 17 respectively.

[0104] In this embodiment, a bypass pipeline is provided in parallel with the second heat exchanger 4. When the second heat exchanger 4 does not need to participate in heat exchange, the second bypass valve 17 can be in an on state, and the heat exchange medium preferentially passes through the second bypass valve 17, and does not pass through or only a small part of the heat exchange medium passes through the second heat exchanger 4 with a larger flow resistance, thereby reducing the pressure loss of the heat exchange medium flow and the power consumption of driving the heat exchange medium flow; when the second heat exchanger 4 needs to participate in heat exchange, the second bypass valve 17 is in a closed state, and the steam condensate passes through the second heat exchanger 4 to participate in heat exchange.

[0105] In some embodiments, Figure 1As shown, the first heat exchanger 3 has a circulating water inlet 3A and a circulating water outlet 3B, the second heat exchanger 4 has a condensate inlet 4A and a first condensate outlet 4B, and the waste heat utilization system also includes: a first check valve 24, which is arranged on the pipeline between the first condensate outlet 4B and the circulating water inlet 3A, and only allows condensate to flow in one direction from the first condensate outlet 4B to the circulating water inlet 3A.

[0106] This embodiment connects the condensed water after the steam condensate heat exchange to the first liquid inlet pipe 25 into which the compressed air cooling circulating water flows, which can fully realize the heat utilization and prevent the compressed air cooling circulating water from entering the second liquid outlet pipe 23 from which the condensed water flows out, so as to prevent the low-grade energy hot water from mixing with the high-grade energy hot water.

[0107] In some embodiments, Figure 1 As shown, the waste heat utilization system also includes: a third bypass valve 9, which is arranged on the main circulation pipeline and close to the heat exchange medium inlet 1A of the air-conditioning heater 1, and the third bypass valve 9 is arranged in parallel with the third heat exchanger 5. The third bypass valve 9 is configured to allow the heat exchange medium to exchange heat with the third heat exchanger 5 in the closed state, and to allow the heat exchange medium to pass directly through the third bypass valve 9 in the connected state.

[0108] The third bypass valve 9 may be an electromagnetic on-off valve, and further, the flow rate may be adjusted in the on state. The third inlet 5C and the third outlet 5D may be connected to both ends of the third bypass valve 9 respectively.

[0109] In this embodiment, a bypass pipeline is provided in parallel with the third heat exchanger 5. When the third heat exchanger 5 does not need to participate in heat exchange, the third bypass valve 9 can be in an on state, and the heat exchange medium preferentially passes through the third bypass valve 9, and no or only a small part of the heat exchange medium passes through the third heat exchanger 5, thereby reducing the pressure loss of the heat exchange medium flow and the power consumption of driving the heat exchange medium flow; when the third heat exchanger 5 needs to participate in heat exchange, the third bypass valve 9 is in a closed state, and the heat exchange medium passes through the third heat exchanger 5 to participate in heat exchange.

[0110] Moreover, the third bypass valve 9 can be located on the main circulation pipeline and between the bypass pipeline 10 and the medium inlet 1A. When the air conditioning heater 1 does not need the heat exchange medium to provide heat, the main bypass valve 11 is in the on state, and the third bypass valve 9 and the third regulating valve 18 are both in the off state. The temperature of the heat exchange medium in the storage container 6 is maintained by the operation of the first circulation pump 7. When the air conditioning heater 1 needs to provide heat through the third heat exchanger 5, the main bypass valve 11 and the third bypass valve 9 are in the off state, and the third regulating valve 18 is in the on state.

[0111] In some embodiments, the second heat exchanger 4 has a condensate inlet 4A and a first condensate outlet 4B, the third heat exchanger 5 has a steam inlet 5A and a second condensate outlet 5B, and the waste heat utilization system also includes: a second check valve 19, which is arranged on the pipeline between the second condensate outlet 5B and the condensate inlet 4A, and only allows condensate to flow in one direction from the second condensate outlet 5B to the condensate inlet 4A.

[0112] In this embodiment, the condensate generated after the steam heat exchange is connected to the second liquid inlet pipe 22 where the steam condensate flows in, and is mixed with the steam condensate in the plant area, which can enter the second heat exchanger 4 for waste heat utilization, thereby fully realizing the utilization of heat, and preventing the steam condensate entering the second heat exchanger 4 from entering the third liquid outlet pipe 38 where the condensate flows out, so as to prevent the hot water with medium-grade heat from mixing with the hot water with high-grade heat, and prevent the pressure of the steam condensate pipe in the plant area from causing pressure buildup on the drainage of the steam condensate in the third liquid outlet pipe 38, thereby affecting the heat exchange of the third heat exchanger 5.

[0113] In some embodiments, the first heat exchanger 3, the second heat exchanger 4 and the third heat exchanger 5 are arranged in sequence along the flow direction of the heat exchange medium.

[0114] In some embodiments, the third heat exchanger 5 is connected to a region of the main circulation pipeline between the bypass pipeline 10 and the air conditioning heater 1 .

[0115] This embodiment installs the third heat exchanger 5 at the front end of the air-conditioning heater 1 and adopts high-grade steam for heating, which meets the requirements of large heating amount, high temperature or fast heat exchange speed of individual air-conditioning boxes. Moreover, the third heat exchanger 5 is arranged close to the air-conditioning heater 1, so that the higher heat in the steam can quickly reach the air-conditioning heater 1, thereby improving the response speed of air-conditioning heating.

[0116] In some embodiments, the waste heat utilization system further comprises:

[0117] A first regulating valve 26 is provided on the first liquid inlet pipeline 25 of the first heat exchanger 3 and is configured to regulate the amount of compressed air cooling circulating water flowing into the first heat exchanger 3; and / or

[0118] The second regulating valve 20 is provided on the second liquid inlet pipeline 22 of the second heat exchanger 4 and is configured to regulate the amount of steam condensate entering the second heat exchanger 4; and / or

[0119] The third regulating valve 18 is disposed on the third steam inlet pipeline 35 of the third heat exchanger 5 , and is configured to regulate the amount of steam passing into the third heat exchanger 5 .

[0120] Among them, the first regulating valve 26, the second regulating valve 20 and / or the third regulating valve 18 can be electric regulating valves. The first regulating valve 26 can realize the on-off function of the first liquid inlet pipeline 25, and can adjust the amount of compressed air cooling circulating water introduced by adjusting the opening; the second regulating valve 20 can realize the on-off function of the second liquid inlet pipeline 22, and can realize the amount of steam condensate introduced; the third regulating valve 18 can realize the on-off function of the third steam inlet pipeline 35, and can realize the amount of steam introduced.

[0121] This embodiment can flexibly control whether to introduce air-compressed cooling circulating water, steam condensate or steam, and the flow rate introduced, thereby adjusting the heat provided to the air-conditioning heater 1, which can both meet the heat demand of the air-conditioning heater 1 and prevent heat waste.

[0122] In some embodiments, the waste heat utilization system also includes a storage container 6, which is arranged in the main circulation pipeline for storing heat exchange medium. The storage container 6 has an inlet 6A and an outlet 6B. The inlet 6A is arranged in the bottom area of ​​the storage container 6, and the outlet 6B is arranged in the top area of ​​the storage container 6.

[0123] The inlet 6A and the outlet 6B may be arranged on the side wall of the storage container 6. The storage container 6 also has a liquid replenishing port 6C, which may be connected to the expansion tank 13. The liquid inlet of the expansion tank 13 is provided with a liquid replenishing valve 14 to control whether to introduce heat exchange medium into the expansion tank 13 or to adjust the amount of heat exchange medium replenished. The storage container 6 also has a sewage outlet 6D, and a sewage valve 15 is provided at the sewage outlet 6D to discharge impurities in the storage container 6.

[0124] For example, the storage container 6 may be in the shape of a tank with a large aspect ratio. The liquid temperature is vertically distributed longitudinally. By utilizing the law that the temperature of the liquid is inversely proportional to the density, the liquid has a density difference in the height direction, and the liquid enters at the lower end and exits at the upper end.

[0125] A heat-insulating layer may be provided outside the storage container 6, for example, made of glass wool, to reduce heat loss.

[0126] This embodiment provides a storage container 6 in the main circulation pipeline to stabilize the temperature of the heat exchange medium and partially store heat.

[0127] In some embodiments, the storage container 6 is located near the heat load center of the air-conditioning room.

[0128] This embodiment can shorten the branch line for supplying the heat exchange medium from the storage container 6 to the air-conditioning heater 1, thereby reducing heat loss in the branch line and reducing the cold water section in the branch line.

[0129] In some embodiments, the waste heat utilization system further includes a first temperature detection component 12, which is configured to detect the temperature of the heat exchange medium in the storage container 6, so as to keep the temperature of the heat exchange medium within a preset temperature range.

[0130] This embodiment can monitor the temperature of the heat exchange medium in the storage container 6 in real time through the first temperature detection component 12, so as to accurately control whether each heat exchanger participates in heat exchange, and the amount of compressed air cooling circulating water and steam condensate water introduced, thereby ensuring that the temperature of the heat exchange medium in the storage container 6 is maintained within a certain range.

[0131] In some embodiments, the waste heat utilization system further includes a first circulation pump 7, which is disposed on a pipe section of the main circulation pipeline located on a side of the bypass pipeline 10 away from the air conditioning heater 1. Specifically, the first circulation pump 7 is disposed between the outlet 6B of the storage container 6 and the bypass pipeline 10.

[0132] When the third heat exchanger 5 does not participate in heat exchange, the storage container 6, the first circulation pump 7, the first heat exchanger 3, the second heat exchanger 4 and the air-conditioning heater 1 form a closed loop; when the third heat exchanger 5 participates in heat exchange, the storage container 6, the first circulation pump 7, the first heat exchanger 3, the second heat exchanger 4, the third heat exchanger 5 and the air-conditioning heater 1 form a closed loop; when the air-conditioning heater 1 does not need to provide heat, the storage container 6, the first circulation pump 7, the main bypass valve 11, the first bypass valve 16 and the second bypass valve 17 form a closed loop.

[0133] The first circulation pump 7 circulates the heat exchange medium in the storage container 6 to be heated, which is used as a basic waste heat utilization to meet the heating requirements of each air-conditioning heater 1 .

[0134] This embodiment is provided with a first circulation pump 7, which can drive the heat exchange medium in the storage container 6 to flow to the air-conditioning heater 1 or directly flow through the bypass branch 10, so that the heat exchange medium circulates in the main circulation pipeline to form a closed flow loop to supply the basic waste heat utilization of the air-conditioning heater 1.

[0135] In some embodiments, the motor of the first circulation pump 7 has a frequency converter, and the frequency converter is used to adjust the operating frequency of the motor of the first circulation pump 7 , and the operating frequency is configured to be set according to the heat required by the air-conditioning heater 1 .

[0136] Among them, the first circulation pump 7 can operate continuously without interruption. On the one hand, it can enable the first heat exchanger 3, the second heat exchanger 4 and / or the third heat exchanger 5 to continuously input heat into the system; on the other hand, it can maintain the water temperature in the storage container 6 and the system pipeline to prevent the temperature from dropping due to the cessation of the flow of the heat exchange medium in the system pipeline, and avoid the occurrence of cold water sections when the air-conditioning heater 1 needs to use hot water. At this time, the first circulation pump 7 can be set to low-frequency operation.

[0137] This embodiment can adjust the operating frequency of the motor of the first circulation pump 7 according to the heat required by the air-conditioning heater 1. When the required heat is small, the first circulation pump 7 can be operated at a low frequency. On the basis of meeting the air-conditioning heating demand, the energy consumption of the system circulating and transporting the heat exchange medium is reduced at low load.

[0138] In some embodiments, Figure 2 As shown, the waste heat utilization system also includes: a cooling tower 30, an air compression cooler 28 and a second circulation pump 29. The air compression cooler 28 has a water outlet 28A and a water inlet 28B. The water outlet 28A is connected to the circulating water inlet 3A of the first heat exchanger 3 through the first liquid inlet pipeline 25. The circulating water outlet 3B of the first heat exchanger 3 is connected to the water inlet 28B through the cooling tower 30. The second circulation pump 29 is arranged on the first liquid inlet pipeline 25 to drive the cooling water circulation. The air compression cooler 28 is a heat dissipation component arranged in the air compressor.

[0139] The steam condensate is added to the first liquid inlet pipeline 25 for introducing air-compressed cooling circulating water through the first check valve 24 , which can increase the temperature of the cooling circulating water with a relatively low temperature and can be used as water replenishment for the cooling tower 30 .

[0140] The cooling tower 30 may be an open cooling tower or a closed cooling tower.

[0141] This embodiment forms a circulation loop for utilizing the air compressor cooling heat. After the high-temperature air compressor cooling circulating water is used for heat exchange, it can be returned to the cooling tower 30 for cooling, thereby optimizing the cooling effect of the air compressor cooling circulating water and improving the operating energy efficiency of the air compressor. If the temperature of the air compressor cooling circulating water is relatively low when it enters the cooling tower 30, for example, 20°C, the fan of the cooling tower 30 can be stopped, further saving power consumption. At the same time, it prevents the outlet water temperature of the air compressor cooler 28 from being too low due to the cooling water inlet temperature of the air compressor cooler 28 being too low.

[0142] In some embodiments, Figure 2 As shown, the circulating water outlet 3B of the first heat exchanger 3 is connected to the cooling tower 30 via the first liquid outlet pipeline 27, and the waste heat utilization system also includes: a second temperature detection component 36 for detecting the temperature of the cooling water in the first liquid inlet pipeline 25; and / or a third temperature detection component 33 for detecting the temperature of the cooling water in the first liquid outlet pipeline 27.

[0143] This embodiment provides a temperature detection component on the first liquid outlet pipe 27 and / or the first liquid inlet pipe 25 of the first heat exchanger 3, so as to balance the relationship between heating and cooling according to the inlet and outlet water temperatures of the compressed air cooling circulating water, thereby meeting both the heat demand of the air conditioning heater 1 and the cooling demand of the compressed air cooling circulating water.

[0144] The waste heat utilization system of the present disclosure can be installed near the cooling tower 30, the steam condensate water recovery and the air conditioning heater 1 to reduce the heat loss of the system.

[0145] In some embodiments, Figure 2 As shown, the waste heat utilization system also includes:

[0146] A cooling tower water inlet regulating valve 31 is provided on the pipeline between the first liquid inlet pipeline 25 and the water inlet of the cooling tower 30;

[0147] A first regulating valve 26 is provided on the first liquid inlet pipeline 25, and a first check valve 24 is located between the first regulating valve 26 and the first heat exchanger 3; and

[0148] The controller is configured to, when the detection value of the second temperature detection component 36 is higher than the preset temperature value of the heat exchange medium temperature required by the air-conditioning heater 1, put the first regulating valve 26 in the on state and put the cooling tower water inlet regulating valve 31 in the off state; and when the detection value of the second temperature detection component 36 is not higher than the preset temperature value of the heat exchange medium temperature required by the air-conditioning heater 1, or the heat exchange medium has no heat exchange demand, put the first regulating valve 26 in the off state and put the cooling tower water inlet regulating valve 31 in the on state.

[0149] Specifically, considering that the heat exchange temperature difference of the plate-type first heat exchanger 3 is about 1.5°C, when the detection value of the second temperature detection component 36 is higher than the heat exchange medium temperature required by the air-conditioning heater 1 by 1.5°C, it means that the compressed air cooling circulating water currently provided by the factory area can still provide heat to the air-conditioning heater 1. At this time, the first regulating valve 26 can be opened to allow the compressed air cooling circulating water to participate in the heat exchange, and the cooling tower water inlet pipe valve 31 can be closed, that is, the amount of compressed air cooling circulating water directly entering the cooling tower 30 for cooling is reduced. The opening of the first regulating valve 26 and the cooling tower water inlet pipe valve 31 can be determined according to the preset temperature value and the heating demand of the air-conditioning heater 1.

[0150] When the detection value of the second temperature detection component 36 is not higher than 1.5°C of the heat exchange medium temperature required by the air-conditioning heater 1, it means that the compressed air cooling circulating water currently provided by the factory cannot provide heat to the air-conditioning heater 1, or when the air-conditioning heater 1 and the storage container 6 have no heat exchange demand, the cooling tower water inlet pipe valve 31 can be opened and the first regulating valve 26 can be closed, so that the compressed air cooling circulating water flows directly to the cooling tower 30 for cooling.

[0151] This embodiment can determine the opening and closing state and the opening degree of the first regulating valve 26 and the cooling tower water inlet pipe valve 31 according to the inlet and outlet water temperatures of the compressed air cooling circulating water, so as to give priority to meeting the heating demand when the temperature of the compressed air cooling circulating water can provide heat for the air-conditioning heater; it can also meet the heating demand by the cooling tower 30 when the temperature of the compressed air cooling circulating water is higher than that of the second temperature detecting component 36 and the temperature of the compressed air cooling circulating water is insufficient to provide heat for the air-conditioning heater 1; or when the air-conditioning heater 1 has no heat demand.

[0152] In some embodiments, the waste heat utilization system also includes: a first regulating valve 26, which is arranged on the first liquid inlet pipeline 25; and a controller, which is configured to put the first regulating valve 26 in an off state when the detection value of the third temperature detection component 33 is not lower than the detection value of the second temperature detection component 36; and put the first regulating valve 26 in an on state when the detection value of the third temperature detection component 33 is lower than the detection value of the second temperature detection component 36.

[0153] Specifically, when the detection value of the third temperature detection component 33 is not lower than the detection value of the second temperature detection component 36, it means that the residual heat of the steam condensate can meet the heat exchange requirements and there is a surplus. At this time, the heat exchange amount of the second heat exchanger 4 should be reduced, that is, the frequency of the third circulating pump 21 and the opening of the second regulating valve 20 should be reduced. In addition, the high-temperature hot water in the first liquid outlet pipe 27 is discharged through the valve 34 to reduce the heat dissipation load of the cooling tower. When the detection value of the third temperature detection component 33 is lower than the detection value of the second temperature detection component 36, it means that the air-compressed cooling circulating water supplied by the first liquid inlet pipeline 25 plays a role in heat supply. The first regulating valve 26 should be in the on state to supply heat to the system. The water returned from the first liquid outlet pipe 27 can flow into the cooling tower 30 as the supplementary water of the cooling tower 30. Moreover, in this case, the cooling effect of the air-compressed cooling circulating water can be improved, thereby improving the operating energy efficiency of the air compressor. The excess cooling circulating water in the cooling tower 30 can be discharged from the overflow pipe 37.

[0154] Secondly, the present disclosure proposes a control method for the waste heat utilization system based on the above embodiment, which in some embodiments includes:

[0155] Determine the heating demand of air conditioning heater 1;

[0156] Controlling whether the first heat exchanger 3, the second heat exchanger 4 and the third heat exchanger 5 participate in heat exchange according to the heating demand;

[0157] Among them, the second heat exchanger 4 is used to introduce steam condensate with a second temperature to heat the heat exchange medium in the main circulation pipeline, and the second temperature is higher than the first temperature; the third heat exchanger 5 is used to introduce steam with a third temperature to heat the heat exchange medium in the main circulation pipeline, and the third temperature is higher than the second temperature.

[0158] This embodiment utilizes the free low-grade compressed air cooling circulating water available in the factory and utilizes the heat energy of free medium-grade steam condensate as a supplement, and can introduce the heat energy of high-grade steam as a further guarantee to provide heat for the air-conditioning heater 1. Under the premise of meeting the production process, the free heat energy utilization for the air-conditioning heater 1 is increased.

[0159] In some embodiments, the step of controlling the first heat exchanger 3, the second heat exchanger 4 and the third heat exchanger 5 to participate in heat exchange includes:

[0160] Prioritize the first heat exchanger 3 to participate in heat exchange;

[0161] When the heat energy provided by the first heat exchanger 3 cannot meet the heating demand, the second heat exchanger 4 is simultaneously used to participate in the heat exchange;

[0162] When the heat energy provided by the first heat exchanger 3 and the second heat exchanger 4 cannot meet the heating demand, the third heat exchanger 5 is simultaneously used to participate in the heat exchange.

[0163] This embodiment can preferentially make the first heat exchanger 3 participate in heat exchange when recovering waste heat, and use free low-grade compressed air cooling circulating water to provide heat; when the heat energy provided by the first heat exchanger 3 cannot meet the heating demand, the second heat exchanger 4 is simultaneously involved in heat exchange, and free medium-grade steam condensate is used to provide heat; when the heat energy provided by the first heat exchanger 3 and the second heat exchanger 4 cannot meet the heating demand, the third heat exchanger 5 is simultaneously involved in heat exchange, and high-grade steam is introduced to provide heat. This waste heat recovery method can save costs.

[0164] In some embodiments, the waste heat utilization system further includes: a first bypass valve 16, which is arranged on the main circulation pipeline and is arranged in parallel with the first heat exchanger 3; and a first regulating valve 26, which is arranged on the first liquid inlet pipeline 25 of the first heat exchanger 3; controlling whether the first heat exchanger 3 participates in heat exchange includes:

[0165] The first bypass valve 16 is in the closed state, and the first regulating valve 26 is in the open state, so that the first heat exchanger 3 participates in heat exchange;

[0166] The first bypass valve 16 is in an on state, and the first regulating valve 26 is in an off state, so that the first heat exchanger 3 does not participate in heat exchange.

[0167] In this embodiment, a bypass pipeline is provided in parallel with the first heat exchanger 3. When the first heat exchanger 3 does not need to participate in heat exchange, the first bypass valve 16 can be in an on state, and the heat exchange medium does not need to pass through the first heat exchanger 3, thereby reducing the pressure loss of the heat exchange medium flow and reducing the power consumption of the first circulation pump 7 driving the heat exchange medium flow; the first regulating valve 26 is closed to reduce the circulating water transportation distance and pressure loss, and reduce the power consumption of the second circulation pump 29. When the first heat exchanger 3 needs to participate in heat exchange, the first bypass valve 16 is in an off state, and the heat exchange medium passes through the first heat exchanger 3 to participate in heat exchange.

[0168] In some embodiments, the waste heat utilization system further includes: a second bypass valve 17, which is arranged on the main circulation pipeline and is arranged in parallel with the second heat exchanger 4; and a second regulating valve 20, which is arranged on the second liquid inlet pipeline 22 of the second heat exchanger 4; controlling whether the second heat exchanger 4 participates in heat exchange includes:

[0169] The second bypass valve 17 is in the closed state, and the second regulating valve 20 is in the open state, so that the second heat exchanger 4 participates in heat exchange;

[0170] The second bypass valve 17 is in an on state, and the second regulating valve 20 is in an off state, so that the second heat exchanger 4 does not participate in heat exchange.

[0171] This embodiment sets a bypass pipeline in parallel with the second heat exchanger 4. When the second heat exchanger 4 does not need to participate in heat exchange, the second bypass valve 17 can be in an on state, and the heat exchange medium does not pass through the second heat exchanger 4, reducing the pressure loss of the heat exchange medium flow and reducing the power consumption of the first circulation pump 7 that drives the heat exchange medium flow. The second regulating valve 20 is closed, and the steam condensate does not pass through the second heat exchanger 4, reducing the pressure loss of the steam condensate flow and reducing the power consumption of the third circulation pump 21 that drives the steam condensate flow; when the second heat exchanger 4 needs to participate in heat exchange, the second bypass valve 17 is in an off state, and the heat exchange medium and steam condensate pass through the second heat exchanger 4 to participate in heat exchange.

[0172] In some embodiments, the waste heat utilization system further includes: a third bypass valve 9, which is arranged on the main circulation pipeline and is arranged in parallel with the third heat exchanger 5; and a third regulating valve 18, which is arranged on the third steam inlet pipeline 35 of the third heat exchanger 5; controlling whether the third heat exchanger 5 participates in heat exchange includes:

[0173] The third bypass valve 9 is in the closed state, and the third regulating valve 18 is in the open state, so that the third heat exchanger 5 participates in heat exchange;

[0174] The third bypass valve 9 is in an on state, and the third regulating valve 18 is in an off state, so that the third heat exchanger 5 does not participate in heat exchange.

[0175] In this embodiment, a bypass pipeline is provided in parallel with the third heat exchanger 5. When the third heat exchanger 5 does not need to participate in heat exchange, the third bypass valve 9 can be turned on, the third regulating valve 18 is closed, and the steam does not pass through the third heat exchanger 5, thereby reducing the pressure loss of the heat exchange medium flow and the power consumption of the first circulation pump 7 driving the heat exchange medium flow; when the third heat exchanger 5 needs to participate in heat exchange, the third bypass valve 9 is turned off.

[0176] In some embodiments, the waste heat utilization system further includes: a storage container 6 and a first circulation pump 7 arranged in the main circulation pipeline for storing heat exchange medium, and the control method further includes:

[0177] The first circulation pump 7 is kept running.

[0178] On the one hand, this embodiment allows the first heat exchanger 3 and / or the second heat exchanger 4 to continuously input heat into the system; on the other hand, it can maintain the water temperature in the storage container 6 and the system pipeline to prevent the temperature from dropping due to the cessation of the flow of the heat exchange medium in the system pipeline, thereby avoiding the occurrence of a cold water section when the air-conditioning heater 1 needs to use hot water.

[0179] In some embodiments, the control method further comprises:

[0180] Obtaining the temperature of the heat exchange medium in the storage container 6;

[0181] The operating frequency of the motor of the first circulation pump 7 is adjusted according to the temperature of the heat exchange medium so that the temperature of the heat exchange medium is maintained within a preset temperature range.

[0182] This embodiment can adjust the operating frequency of the motor of the first circulation pump 7 according to the heat required by the air-conditioning heater 1 and the temperature of the heat exchange medium in the current storage container 6. When the required heat is small, the first circulation pump 7 can be operated at a low frequency, thereby reducing the energy consumption of the first circulation pump 7 while meeting the air-conditioning heating demand.

[0183] In some embodiments, the waste heat utilization system further includes a third bypass valve 9, which is arranged on the main circulation pipeline and close to the heat exchange medium inlet of the air conditioning heater 1, and the third bypass valve 9 is arranged in parallel with the third heat exchanger 5; and a third regulating valve 18, which is arranged on the third steam inlet pipeline 35 of the third heat exchanger 5; the control method also includes:

[0184] When the air-conditioning heater 1 does not need the heat exchange medium to provide heat, the main bypass valve 11 is in the on state, and the third bypass valve 9 and the third regulating valve 18 are both in the off state.

[0185] This embodiment can keep the main bypass valve 11 in an on state when there is no need to recover waste heat, so that only a small amount of heat exchange medium circulates in the main circulation pipeline, cutting off the connection with each heat exchanger and keeping the heat exchange medium temperature within a preset temperature range.

[0186] The circulation pump, valves (except the check valve) and temperature detection components in the above embodiments can all be made of automatic control instruments and automatically controlled by a controller.

[0187] The controller in the above embodiments of the present disclosure may be a general-purpose processor, a programmable logic controller (PLC), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or any appropriate combination thereof, for performing the functions described in the present disclosure.

[0188] The above description is only an exemplary embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A waste heat utilization system, characterized in that: include: An air conditioning heater (1) having a medium inlet (1A) and a medium outlet (1B); A main circulation pipeline, in which a heat exchange medium flows, and two ends of which are respectively connected to the medium inlet (1A) and the medium outlet (1B); A first heat exchanger (3) having a circulating water inlet (3A) and a circulating water outlet (3B) for introducing compressed air cooling circulating water having a first temperature to heat the heat exchange medium in the main circulation pipeline; A second heat exchanger (4) having a condensate inlet (4A) and a first condensate outlet (4B), for introducing steam condensate having a second temperature to heat the heat exchange medium in the main circulation pipeline, wherein the second temperature is higher than the first temperature; a third heat exchanger (5), having a steam inlet (5A) and a second condensate outlet (5B), for introducing steam having a third temperature to heat the heat exchange medium in the main circulation pipeline, wherein the third temperature is higher than the second temperature; A bypass pipeline (10), both ends of which are in communication with the main circulation pipeline and are connected in parallel with the air-conditioning heater (1); a main bypass valve (11) is provided on the bypass pipeline (10); the main bypass valve (11) is configured to, in an off state, allow the heat exchange medium to flow through the air-conditioning heater (1) to circulate and provide heat; and in an on state, allow the heat exchange medium to flow through the bypass pipeline (10) to circulate; a first check valve (24), which is disposed on the pipeline between the first condensate outlet (4B) and the circulating water inlet (3A) and allows only one-way flow of condensate from the first condensate outlet (4B) to the circulating water inlet (3A); and The second check valve (19) is arranged on the pipeline between the second condensate outlet (5B) and the condensate inlet (4A), and only allows condensate to flow in one direction from the second condensate outlet (5B) to the condensate inlet (4A).

2. The waste heat utilization system according to claim 1, characterized in that: Also includes: A first bypass valve (16) is provided on the main circulation pipeline and is arranged in parallel with the first heat exchanger (3). The first bypass valve (16) is configured to allow the heat exchange medium to exchange heat with the first heat exchanger (3) in an off state, and to allow the heat exchange medium to directly pass through the first bypass valve (16) in an on state.

3. The waste heat utilization system according to claim 1, characterized in that: Also includes: A second bypass valve (17) is provided on the main circulation pipeline and is arranged in parallel with the second heat exchanger (4). The second bypass valve (17) is configured to allow the heat exchange medium to exchange heat with the second heat exchanger (4) in an off state, and to allow the heat exchange medium to directly pass through the second bypass valve (17) in an on state.

4. The waste heat utilization system according to claim 1, characterized in that: Also includes: A third bypass valve (9) is arranged on the main circulation pipeline and close to the heat exchange medium inlet (1A) of the air conditioning heater (1), and the third bypass valve (9) is arranged in parallel with the third heat exchanger (5). The third bypass valve (9) is configured to allow the heat exchange medium to exchange heat with the third heat exchanger (5) in an off state, and to allow the heat exchange medium to directly pass through the third bypass valve (9) in an on state.

5. The waste heat utilization system according to claim 1, characterized in that: The first heat exchanger (3), the second heat exchanger (4) and the third heat exchanger (5) are arranged in sequence along the flow direction of the heat exchange medium.

6. The waste heat utilization system according to claim 1, characterized in that: The third heat exchanger (5) is connected to a region of the main circulation pipeline located between the bypass pipeline (10) and the air-conditioning heater (1).

7. The waste heat utilization system according to claim 1, characterized in that: Also includes: a first regulating valve (26), disposed on the first liquid inlet pipeline (25) of the first heat exchanger (3), and configured to regulate the amount of compressed air cooling circulating water flowing into the first heat exchanger (3); a second regulating valve (20), provided on a second liquid inlet pipeline (22) of the second heat exchanger (4), configured to regulate the amount of steam condensate flowing into the second heat exchanger (4); and / or The third regulating valve (18) is provided on the third steam inlet pipeline (35) of the third heat exchanger (5) and is configured to regulate the amount of steam entering the third heat exchanger (5).

8. The waste heat utilization system according to any one of claims 1 to 7, characterized in that: It also includes a storage container (6) arranged in the main circulation pipeline and used to store the heat exchange medium, the storage container (6) having an inlet (6A) and an outlet (6B), the inlet (6A) being arranged in the bottom area of ​​the storage container (6), and the outlet (6B) being arranged in the top area of ​​the storage container (6).

9. The waste heat utilization system according to claim 8, characterized in that: The storage container (6) is arranged at a location close to the heat load center of the air-conditioning room.

10. The waste heat utilization system according to claim 8, characterized in that: It also includes a first temperature detection component (12) configured to detect the temperature of the heat exchange medium in the storage container (6) so as to keep the temperature of the heat exchange medium within a preset temperature range.

11. The waste heat utilization system according to any one of claims 1 to 7, characterized in that: It also includes a first circulation pump (7), which is arranged in the main circulation pipeline and is located on a pipe section of the bypass pipeline (10) that is away from the air conditioning heater (1).

12. The waste heat utilization system according to claim 11, characterized in that: The motor of the first circulation pump (7) has a frequency converter, and the frequency converter is used to adjust the operating frequency of the motor of the first circulation pump (7), and the operating frequency is configured to be set according to the heat required by the air-conditioning heater (1).

13. The waste heat utilization system according to any one of claims 1 to 7, characterized in that: Also includes: A cooling tower (30), an air-compressed cooler (28) and a second circulating pump (29), wherein the air-compressed cooler (28) has a water outlet (28A) and a water inlet (28B), wherein the water outlet (28A) is connected to the circulating water inlet (3A) of the first heat exchanger (3) via a first liquid inlet pipeline (25), and the circulating water outlet (3B) of the first heat exchanger (3) is connected to the water inlet (28B) via the cooling tower (30); the second circulating pump (29) is arranged on the first liquid inlet pipeline (25) and is used to drive the cooling water circulation.

14. The waste heat utilization system according to claim 13, characterized in that: The circulating water outlet (3B) of the first heat exchanger (3) is connected to the cooling tower (30) via a first liquid outlet pipeline (27), and the waste heat utilization system further comprises: a second temperature detection component (36), used to detect the temperature of cooling water in the first liquid inlet pipeline (25); and / or The third temperature detection component (33) is used to detect the temperature of the cooling water in the first liquid outlet pipeline (27).

15. The waste heat utilization system according to claim 14, characterized in that: Also includes: A cooling tower water inlet regulating valve (31), arranged on the pipeline between the first liquid inlet pipeline (25) and the water inlet of the cooling tower (30); a first regulating valve (26) disposed on the first liquid inlet pipeline (25); and The controller is configured to, when the detection value of the second temperature detection component (36) is higher than the preset temperature value of the heat exchange medium temperature required by the air-conditioning heater (1), place the first regulating valve (26) in an on state and place the cooling tower water inlet regulating valve (31) in an off state; and when the detection value of the second temperature detection component (36) is not higher than the preset temperature value of the heat exchange medium temperature required by the air-conditioning heater (1), or when there is no heat exchange demand for the heat exchange medium, place the first regulating valve (26) in an off state and place the cooling tower water inlet regulating valve (31) in an on state.

16. The waste heat utilization system according to claim 14, characterized in that: Also includes: a first regulating valve (26) disposed on the first liquid inlet pipeline (25); and The controller is configured to, when the detection value of the third temperature detection component (33) is not lower than the detection value of the second temperature detection component (36), place the first regulating valve (26) in an off state; and when the detection value of the third temperature detection component (33) is lower than the detection value of the second temperature detection component (36), place the first regulating valve (26) in an on state.

17. A control method for the waste heat utilization system according to any one of claims 1 to 16, characterized in that: include: Determining the heating capacity requirement of the air conditioning heater (1); Controlling whether the first heat exchanger (3), the second heat exchanger (4) and the third heat exchanger (5) participate in heat exchange according to the heating demand; The second heat exchanger (4) is used to introduce steam condensate having a second temperature to heat the heat exchange medium in the main circulation pipeline, and the second temperature is higher than the first temperature; the third heat exchanger (5) is used to introduce steam having a third temperature to heat the heat exchange medium in the main circulation pipeline, and the third temperature is higher than the second temperature.

18. The control method according to claim 17, characterized in that: The step of controlling the first heat exchanger (3), the second heat exchanger (4) and the third heat exchanger (5) to participate in heat exchange comprises: Prioritizing the first heat exchanger (3) to participate in heat exchange; When the heat energy provided by the first heat exchanger (3) cannot meet the heating demand, the second heat exchanger (4) is simultaneously used for heat exchange; When the heat energy provided by the first heat exchanger (3) and the second heat exchanger (4) cannot meet the heating demand, the third heat exchanger (5) is simultaneously used to participate in the heat exchange.

19. The control method according to claim 17, characterized in that: The waste heat utilization system further comprises: a first bypass valve (16) provided on the main circulation pipeline and arranged in parallel with the first heat exchanger (3); and a first regulating valve (26) provided on the first liquid inlet pipeline (25) of the first heat exchanger (3); controlling whether the first heat exchanger (3) participates in heat exchange comprises: The first bypass valve (16) is in a closed state, and the first regulating valve (26) is in an open state, so that the first heat exchanger (3) participates in heat exchange; The first bypass valve (16) is in an on state, and the first regulating valve (26) is in an off state, so that the first heat exchanger (3) does not participate in heat exchange; Alternatively, the waste heat utilization system further comprises: a second bypass valve (17), which is arranged on the main circulation pipeline and is arranged in parallel with the second heat exchanger (4); and a second regulating valve (20), which is arranged on the second liquid inlet pipeline (22) of the second heat exchanger (4); and controlling whether the second heat exchanger (4) participates in heat exchange comprises: The second bypass valve (17) is in a closed state, and the second regulating valve (20) is in an open state, so that the second heat exchanger (4) participates in heat exchange; The second bypass valve (17) is in an on state, and the second regulating valve (20) is in an off state, so that the second heat exchanger (4) does not participate in heat exchange; Alternatively, the waste heat utilization system further comprises: a third bypass valve (9) provided on the main circulation pipeline and arranged in parallel with the third heat exchanger (5); and a third regulating valve (18) provided on a third steam inlet pipeline (35) of the third heat exchanger (5); controlling whether the third heat exchanger (5) participates in heat exchange comprises: The third bypass valve (9) is in a closed state, and the third regulating valve (18) is in an open state, so that the third heat exchanger (5) participates in heat exchange; The third bypass valve (9) is in an on state, and the third regulating valve (18) is in an off state, so that the third heat exchanger (5) does not participate in heat exchange.

20. The control method according to claim 17, characterized in that: The waste heat utilization system further comprises: a storage container (6) and a first circulation pump (7) arranged in the main circulation pipeline for storing a heat exchange medium, and the control method further comprises: The first circulation pump (7) is kept running.

21. The control method according to claim 20, characterized in that: Also includes: Obtaining the temperature of the heat exchange medium in the storage container (6); The operating frequency of the motor of the first circulation pump (7) is adjusted according to the temperature of the heat exchange medium, so that the temperature of the heat exchange medium is maintained within a preset temperature range.

22. The control method according to claim 17, characterized in that: The waste heat utilization system comprises: a third bypass valve (9) arranged on the main circulation pipeline and close to the heat exchange medium inlet of the air-conditioning heater (1), and the third bypass valve (9) is arranged in parallel with the third heat exchanger (5); and a third regulating valve (18) arranged on the third steam inlet pipeline (35) of the third heat exchanger (5); the control method further comprises: When the air-conditioning heater (1) does not need heat provided by the heat exchange medium, the main bypass valve (11) is in an on state, and the third bypass valve (9) and the third regulating valve (18) are both in an off state.

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