Secondary pipe network waste heat recovery system and method based on heat supply system

Abstract

The secondary pipe network waste heat recovery system comprises a heating end, a user end and a heat exchanger, a pipeline communicated with the heating end is a primary pipeline, a pipeline communicated with the user end is a secondary pipeline, and the primary pipeline and the secondary pipeline exchange heat through the heat exchanger. A recovery system is arranged on the secondary pipeline, and the water return section of the secondary pipeline is connected with the water outlet section of the primary pipeline through the recovery system. Low-temperature liquid in the secondary pipeline can absorb heat of the water outlet section in advance before entering the heat exchanger, and due to the fact that low-temperature water in the water outlet section directly returns to the heating end, heat supply of the primary heat exchange section in the heat exchanger cannot be affected by secondary utilization of the heat of the water outlet section; and the temperature of the liquid in the water return section entering the secondary pipeline can be effectively increased, the temperature difference of the liquid in the secondary pipeline is reduced, and the heating efficiency of the heat exchanger is improved.

Description

Technical Field

[0001] The present invention relates to the field of heating technology, and more specifically, to a secondary pipe network waste heat recovery system and method based on a heating system. Background Art

[0002] Heat supply is a necessity for winter life in heating areas, with strong demand. It is an industry that the country focuses on supporting in the field of infrastructure. With the acceleration of urban construction in my country, this industry, as an important aspect of public utilities, has huge market potential, especially in the areas of centralized heating and cogeneration, which are encouraged and supported by the country. It will have a relatively ideal development prospect. As a major coal-consuming industry, reducing heating costs and reducing pollution emissions will become the development direction of this industry.

[0003] The outdoor heating pipe network is mostly a branch network, with heat near and cold far, hydraulic conditions are imbalanced, and there is no effective pressure regulating equipment. In order to ensure the heating standard, large flow rate and overload heating are the only options.

[0004] Indoors, the heating system mostly uses a single-pipe system. Each heat user cannot adjust the flow according to the indoor temperature. Heat users with too high room temperature can only open windows to adjust the room temperature, resulting in a waste of heat energy, while users with too low room temperature cannot meet the design standards.

[0005] During the heating period, the user's return water temperature is low, resulting in a large temperature difference between the user's return water and the user's supply water, and a large power consumption at the heating end. When the heating is about to be stopped, the temperature difference between the user's return water temperature and the user's supply water temperature is not large. In order to avoid heat energy waste caused by users opening windows, the power consumption of the heating end can usually be reduced during the day. However, this will cause a large temperature difference between the inlet and outlet water at the heating end in the evening, and the energy consumption for reheating is also huge. Therefore, how to reduce the temperature difference between the user's supply water and the user's return water, as well as the temperature difference between the inlet and outlet water at the heating end, so as to reduce energy consumption and improve heating efficiency is the technical problem to be solved by the present invention. Summary of the invention

[0006] A series of simplified concepts are introduced in the Summary of the Invention, which will be further described in detail in the Detailed Description of the Invention. The Summary of the Invention does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0007] In order to at least partially solve the above problems, the present invention provides a secondary pipe network waste heat recovery system based on a heating system, comprising: a heating end, a user end, and a heat exchanger, the pipe connected to the heating end is a primary pipe, the pipe connected to the user end is a secondary pipe, the primary pipe and the secondary pipe exchange heat through the heat exchanger, a recovery system is provided on the secondary pipe, and the return water section of the secondary pipe is connected to the outlet water section of the primary pipe through the recovery system.

[0008] Preferably, The primary pipeline consists of a water inlet section, a primary heat exchange section and the water outlet section, the water inlet section is connected to the water outlet section through the primary heat exchange section, an electric valve is provided on the water inlet section, and a primary circulation pump is provided on the water outlet section; The secondary pipeline consists of the return water section, the secondary heat exchange section and the water supply section. The return water section is connected to the water supply section through the secondary heat exchange section. The return water section and the secondary heat exchange section are connected through the recovery system. The return water section is provided with a secondary circulation pump. The primary heat exchange section and the secondary heat exchange section are both located in the heat exchanger; The high-temperature water at the heating end enters the primary heat exchange section from the water inlet section to transfer heat to the secondary heat exchange section. After that, the low-temperature water flows back to the heating end from the water outlet section through the recovery system. The low-temperature water at the user end enters the secondary heat exchange section from the return water section through the recovery system. After being heated in the primary heat exchange section, high-temperature water is provided to the user end by the water supply section.

[0009] Preferably, a climate compensator is included, a return water temperature detection device is provided on the return water section, a supply water temperature detection device is provided on the supply water section, and the climate compensator is electrically connected to the electric valve, the return water temperature detection device, the supply water temperature detection device, and an outdoor temperature detection device located outdoors, respectively.

[0010] Preferably, the recovery system is wrapped around the water outlet section, a hollow cavity is provided inside the recovery system, one end of the recovery system is connected to the return water section, and the other end is connected to the secondary heat exchange section.

[0011] Preferably, the recovery system is in the shape of a spiral tube and is tightly wound around the outside of the water outlet section.

[0012] Preferably, the recovery system consists of a symmetrically arranged first chamber and a second chamber, the first chamber is communicated with the second chamber, the first chamber is provided with a water inlet communicated with the return water section, the second chamber is provided with a water outlet communicated with the secondary heat exchange section, the water inlet and the water outlet are located at opposite ends of the recovery system, an auxiliary device communicated with the heating end and / or the water outlet section is provided at the connection between the first chamber and the second chamber, and the water outlet section is attached to the outer wall of the first chamber and the outer wall of the second chamber.

[0013] Preferably, the cross section of the first chamber is a radial spiral, and the side wall of the first chamber extends downward from the bottom of the auxiliary device and extends radially in a spiral to the top of the auxiliary device; The cross section of the second chamber is a radial spiral, and the side wall of the second chamber extends downward from the bottom of the auxiliary device and extends radially in a spiral to the top of the auxiliary device; An air chamber is provided at the top connection of the first chamber and the second chamber.

[0014] Preferably, the auxiliary device is a hollow strip structure, and a gap is reserved between the side wall of the first chamber and the side wall of the second chamber connected to the bottom of the auxiliary device, the water outlet section is located in the gap and is attached to the outer side walls of the first chamber and the second chamber, the two ends of the auxiliary device are respectively connected to the inner end faces of the recovery system, the auxiliary device is provided with a first air duct and a second air duct connected to the heating end, the first air duct is located in the first chamber, and the second air duct is located in the second chamber, and the top of the auxiliary device is provided with a first air hole connected to the first air duct, and a second air hole connected to the second air duct.

[0015] Preferably, a liquid channel is provided in the auxiliary device, and the liquid channel is located between the first air channel and the second air channel, one end of the liquid channel is connected to the primary heat exchange section, and the other end is connected to the water outlet section.

[0016] The secondary pipe network waste heat recovery method based on the heating system includes: When the water temperature of the return water section is lower than that of the outlet water section, the low-temperature water at the user end first enters the recovery system from the return water section, and the outlet water section transfers the remaining heat to the low-temperature water in the recovery system, so that the water in the recovery system and the outlet water section becomes warm water, recovering the heat of the outlet water section and reducing the temperature difference between the water supply section and the return water section at the user end; When the water temperature in the return water section is higher than that in the outlet water section, the water in the return water section enters the recovery system and transfers the remaining heat to the low-temperature water in the outlet water section, so that the water in the recovery system and the outlet water section becomes warm water, recovering the heat in the return water section, reducing the temperature difference between the inlet and outlet water sections at the heating end, and reducing heating energy consumption.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: Before the low-temperature liquid in the secondary pipeline enters the heat exchanger, it will absorb the heat of the water outlet section in advance. Because the low-temperature water in the water outlet section directly returns to the heating end, the heat of the water outlet section is reused for the second time, which will not affect the heat supply of the primary heat exchange section in the heat exchanger. It can also effectively increase the temperature of the liquid in the return water section when it enters the secondary pipeline, reduce the temperature difference of the liquid in the secondary pipeline, and improve the heating efficiency of the heat exchanger.

[0018] The secondary pipe network waste heat recovery system and method based on the heating system described in the present invention, and other advantages, objectives and features of the present invention will be reflected in part through the following description, and in part will also be understood by technical personnel in the field through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 It is a schematic diagram of the first embodiment of the secondary pipe network waste heat recovery system based on the heating system described in the present invention.

[0020] Figure 2 It is a schematic diagram of a second embodiment of the present invention.

[0021] Figure 3 Schematic diagram of a recovery system in a second embodiment of the present invention.

[0022] Figure 4 for Figure 3 main view.

[0023] Figure 5 for Figure 4 Schematic diagram of the auxiliary device.

[0024] Figure 6 Schematic diagram of a recovery system in a third embodiment of the present invention.

[0025] Figure 7 for Figure 6 main view.

[0026] Figure 8 for Figure 7 Schematic diagram of the auxiliary device.

[0027] Fig. 9 Schematic diagram of water flow mixing in the recovery system.

[0028] In the figure: 1 heat exchanger, 2 water inlet section, 21 electric valve, 3 primary heat exchange section, 4 water outlet section, 41 primary circulation pump, 5 return water section, 51 secondary circulation pump, 52 return water temperature detection device, 6 secondary heat exchange section, 7 water supply section, 71 water supply temperature detection device, 8 recovery system, 81 first chamber, 82 second chamber, 83 air chamber, 9 climate compensator, 91 outdoor temperature detection device, 10 auxiliary device, 101 first air duct, 102 second air duct, 103 liquid channel. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments so that those skilled in the art can implement the invention with reference to the description.

[0030] It should be understood that the terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0031] like Figure 1-Figure 9 As shown, the present invention provides a secondary pipe network waste heat recovery system based on a heating system, including: a heating end, a user end, and a heat exchanger 1. The heating end can be a hot water heating system, a steam heating system, a cogeneration system, a boiler heating system, a ground source heat pump and other existing technologies. The pipeline connected to the heating end is a primary pipeline, and the pipeline connected to the user end is a secondary pipeline. The primary pipeline is mainly used for high-temperature liquid circulation at the heating end. The primary pipeline and the secondary pipeline exchange heat through the heat exchanger 1 to heat up the secondary pipeline. After passing through the heat exchanger 1, the temperature of the primary pipeline will decrease, and it will usually not be lower than the temperature of the return water section 5 of the secondary pipeline (lower than the return water section 5 temperature). The situation is described in detail below). In order to utilize the heat of the water outlet section 4, a recovery system 8 is arranged on the secondary pipeline. The return water section 5 of the secondary pipeline is connected to the water outlet section 4 of the primary pipeline through the recovery system 8, so that the low-temperature liquid in the secondary pipeline will absorb the heat of the water outlet section 4 in advance before entering the heat exchanger 1. Because the low-temperature water of the water outlet section 4 directly returns to the heating end, the heat of the water outlet section 4 is reused for the second time, which will not affect the heat supply of the primary heat exchange section 3 in the heat exchanger 1, and can also effectively increase the temperature of the liquid in the return water section 5 when entering the secondary pipeline, reduce the temperature difference of the liquid in the secondary pipeline, and improve the heating efficiency of the heat exchanger 1.

[0032] The primary pipeline is composed of a water inlet section 2, a primary heat exchange section 3 and a water outlet section 4. The water inlet section 2 is connected to the water outlet section 4 through the primary heat exchange section 3. The water inlet section 2 is provided with an electric valve 21, and the water outlet section 4 is provided with a primary circulation pump 41. The primary circulation pump 41 cooperates with the electric valve 21 to realize liquid circulation in the primary pipeline. The secondary pipeline is composed of the return water section 5, the secondary heat exchange section 6 and the water supply section 7. The return water section 5 is connected to the water supply section 7 through the secondary heat exchange section 6. The return water section 5 and the secondary heat exchange section 6 are connected through the recovery system 8. The return water section 5 is provided with a secondary circulation pump 51, which can realize liquid circulation in the secondary pipeline. The primary heat exchange section 3 and the secondary heat exchange section 6 are both located in the heat exchanger 1; The high-temperature water at the heating end enters the primary heat exchange section 3 from the water inlet section 2 to transfer the heat to the secondary heat exchange section 6, and then the low-temperature water flows back to the heating end from the water outlet section 4 via the recovery system 8, and the low-temperature water at the user end enters the secondary heat exchange section 6 from the return water section 5 via the recovery system 8. The recovery system 8 can recover heat according to the situation between the water outlet section 4 and the return water section 5. The liquid after heat recovery in the return water section 5 is heated in the primary heat exchange section 3 in the secondary heat exchange section 6, and then the water supply section 7 provides high-temperature water to the user end.

[0033] In order to reduce the energy consumption at the heating end, increase the heating rate of the heat exchanger 1, and reduce energy waste, the present invention generally further includes a climate compensator 9. The return water section 5 is provided with a return water temperature detection device 52 for monitoring the temperature of the liquid in the return water section 5. The water supply section 7 is provided with a water supply temperature detection device 71 for monitoring the temperature of the liquid in the water supply section 7. The climate compensator 9 is electrically connected to the electric valve 21, the return water temperature detection device 52, the water supply temperature detection device 71, and the outdoor temperature detection device 91 located outdoors. The outdoor temperature detection device 91 monitors the outdoor temperature. When it is found that the outdoor temperature continues to warm up and the temperature rises, the climate compensator 9 controls the electric valve 21, thereby controlling the liquid circulation in the primary pipeline, and then controlling the heat provided by the primary heat exchange section 3, reducing the temperature of the water supply section 7, so as to reduce the temperature at the user end and avoid energy waste caused by the user opening the window for heat dissipation. When the temperature continues to rise, especially in the period of time when the heating is about to be stopped, the outdoor temperature and the liquid temperature in the secondary pipeline are not much different. At this time, there is a situation where the primary pipeline does not circulate, and only the secondary pipeline liquid circulates (that is, the water temperature of the return water section 5 mentioned above and below is higher than the water temperature of the outlet water section 4). In the prior art, because there is no recovery system 8, when the primary pipeline does not circulate, the temperature difference between the inlet water section 2 and the outlet water section 4 will be relatively large. When the outdoor temperature drops at night and the primary pipeline needs to be recirculated and heated, the energy consumption of the heating end will increase due to the large temperature difference. In this application, the recovery system 8 is wrapped on the outlet water section 4 to reduce the heat loss of the outlet water section 4 as much as possible and reduce the temperature difference between the outlet water section 4 and the inlet water section 2. The recovery system 8 is provided with a hollow cavity inside for liquid circulation. One end of the recovery system 8 is connected to the return water section 5, and the other end is connected to the secondary heat exchange section 6. By providing a climate compensator 9, the heat supply can be made more flexible and energy consumption can be reduced.

[0034] The secondary pipe network waste heat recovery method based on the heating system includes: When the water temperature of the return water section 5 is lower than that of the water temperature of the outlet water section 4, the low-temperature water at the user end first enters the recovery system 8 from the return water section 5, and the outlet water section 4 transfers the remaining heat to the low-temperature water in the recovery system 8, so that the water in the recovery system 8 and the outlet water section 4 are both converted into warm water, and the heat of the outlet water section 4 is recovered, thereby reducing the temperature difference between the user end water supply section 7 and the return water section 5, and increasing the temperature rise rate of the liquid; When the water temperature of the return water section 5 is higher than that of the water temperature of the outlet water section 4, the water in the return water section 5 enters the recovery system 8, transfers the remaining heat to the low-temperature water in the outlet water section 4, and insulates the non-circulating primary pipeline through the recovery system 8, so that the water in the recovery system 8 and the outlet water section 4 are both converted into warm water, recovering the heat of the return water section 5, reducing the temperature difference between the water inlet section 2 and the outlet water section 4 at the heating end, thereby reducing the heating energy consumption at the heating end when the primary pipeline circulates again.

[0035] In this embodiment, we provide an implementation of a recovery system. The recovery system 8 is in the shape of a spiral tube and is tightly wound around the outside of the water outlet section 4. Figure 1 The recovery system 8 is placed on one side of the outlet section 4 and is spirally wound around the outside of the outlet section 4, so that when the user return water flows through the recovery system 8, the waste heat of the outlet section 4 can be recovered, and the distance from the connection between the recovery system 8 and the return section 5 to the heat exchanger 1 is greater than the distance from the connection between the recovery system 8 and the secondary heat exchange section 6 to the heat exchanger 1, as shown in FIG. Figure 1 As shown, when the liquid flows from the return water section 5 to the secondary heat exchange section 6, the closer it is to the secondary heat exchange section 6, the higher the water temperature in the water outlet section 4 is.

[0036] On the contrary, when the water temperature of the return water section 5 is higher than that of the outlet water section 4, the above-mentioned design method can provide insulation effect for the outlet water section 4 through the spirally wrapped recovery system 8, reduce the temperature difference between the outlet water section 4 and the inlet water section 2, and reduce the temperature difference between the outlet water section 4 and the primary heat exchange section 3, thereby reducing the heat loss rate in the heat exchanger 1.

[0037] In the first embodiment, although the structure is the simplest and the floor space occupied is the smallest when the equipment is arranged in the factory, the waste heat utilization rate it can provide depends entirely on the length of the spirally wrapped recovery system 8. When the water temperature of the return water section 5 is higher than that of the outlet water section 4, it will also have a greater impact on the liquid temperature in the return water section 5. Therefore, in this embodiment, we provide a second embodiment to solve the above problem. In this embodiment, the recovery system 8 is composed of a symmetrically arranged first chamber 81 and a second chamber 82. The first chamber 81 is connected to the second chamber 82, such as Figure 3 , 4As shown, the first chamber 81 is provided with a water inlet connected to the return water section 5, and the second chamber 82 is provided with a water outlet connected to the secondary heat exchange section 6. The water inlet and the water outlet are located at opposite ends of the recovery system 8. The connection between the first chamber 81 and the second chamber 82 is provided with an auxiliary device 10 connected to the heating end and / or the water outlet section 4. According to actual design requirements, the auxiliary device 10 can be connected to the heating end (usually high-pressure steam introduced into the heating end, or hot water, introduced through the heating end). The medium of the device 10 is not limited), and it can also be connected to the water outlet section 4 (when the water outlet section 4 is connected to the auxiliary device 10, the liquid in the water outlet section 4 can be heat-exchanged with the liquid in the recovery system 8 through the auxiliary device 10, and at the same time, the medium introduced into the auxiliary device 10 from the heating end can also heat and insulate the liquid introduced into the water outlet section 4, so that the liquid in the water outlet section 4 has a sufficient temperature to provide heat for the liquid in the two chambers), or both can be connected, and the water outlet section 4 is attached to the outer wall of the first chamber 81 and the outer wall of the second chamber 82. When the liquid in the water outlet section 4 flows, it can provide heat for the liquid in the two chambers, thereby realizing the recovery and utilization of waste heat. The cross-section of the first chamber 81 is a radial spiral, and the side wall of the first chamber 81 extends downward from the bottom of the auxiliary device 10, and extends radially in a spiral to the top of the auxiliary device 10; The cross section of the second chamber 82 is a radial spiral, and the side wall of the second chamber 82 extends downward from the bottom of the auxiliary device 10 and extends radially in a spiral to the top of the auxiliary device 10; Figure 3 , 4 As shown, the first chamber 81 and the second chamber 82 form a symmetrical "inverted heart shape". In the first chamber 81, with the center point of the water inlet as the center of the circle, and the distance from the center of the circle to the inner wall of the first chamber 81 as the radius, the radius from the center of the circle to the connection between the first chamber 81 and the auxiliary device 10 is the smallest, and the radius from the center of the circle to the connection between the top of the first chamber 81 and the top of the second chamber 82 is the largest. The second chamber 82 is symmetrical to the first chamber 81.

[0038] The top connection of the first chamber 81 and the second chamber 82 is provided with an air chamber 83 for recovering the gas entering the recovery system 8. The gas is guided to the chimney through the air chamber 83 for discharge, or the hot steam is recycled again. The above structural design provides a space for heating and balancing the liquid temperature for the recovery system 8. The water outlet section 4 can be arranged in an S shape on the outer walls of the two chambers and located in the gap between the outer walls of the two chambers of the "inverted heart-shaped" recovery system 8, such as Figure 3 , 4 As shown, the floor space of the equipment is saved and maintenance is convenient. At the same time, the narrow space can also keep the water outlet section 4 warm.

[0039] In this embodiment, the auxiliary device 10 is a hollow strip structure, and a gap is reserved between the side wall of the first chamber 81 and the side wall of the second chamber 82 connected to the bottom of the auxiliary device 10, and the water outlet section 4 is arranged in an S shape in the gap and is attached to the outer side walls of the first chamber 81 and the second chamber 82. Figure 4 As shown. Both ends of the auxiliary device 10 are connected to the inner end surface of the recovery system 8 respectively. The auxiliary device 10 is provided with a first air channel 101 and a second air channel 102 communicating with the heating end. The first air channel 101 is located in the first chamber 81, and the second air channel 102 is located in the second chamber 82. The top of the auxiliary device 10 is provided with a first air hole communicating with the first air channel 101, and a second air hole communicating with the second air channel 102. The steam at the heating end can be directly introduced into the recovery system 8 through the auxiliary device. The auxiliary device 10 is provided with a liquid channel 103, and the liquid channel 103 is located between the first air channel 101 and the second air channel 102. One end of the liquid channel 103 is communicated with the primary heat exchange section 3, and the other end is communicated with the water outlet section 4.

[0040] When the temperature of the return water section 5 is lower than that of the outlet water section 4, the hot steam at the heating end can enter the recovery system 8 through the air holes on the auxiliary device 10. The entering hot steam can push the water located below the two chambers upward. When the water reaches the top of the two chambers, it will sink along the inner walls of the two chambers and accelerate, thereby achieving the temperature increase and mixing of the liquid in the recovery system 8. Fig. 9 As shown, and finally leaves from the water outlet, the steam entering the recovery system 8 will eventually be discharged or reused through the air chamber 83, and the liquid in the water outlet section 4 will move from top to bottom along the S-shaped pipeline direction. The liquid in the water outlet section 4 can be heated or kept warm again in the auxiliary device 10 by the heat provided by the two air passages, and the liquid in the recovery system 8 located between the two air passages can be heated; When the temperature of the return water section 5 is higher than that of the water outlet section 4, the temperature of the recovery system 8 will be higher than that of the water outlet section 4. Because the water outlet section 4 is wrapped in the gap, the water outlet section 4 can be kept warm, and the amount of liquid in the recovery system 8 is much larger than the amount of liquid in the water outlet section 4 (at this time, the liquid in the primary pipeline is basically in a state of long circulation time or no circulation). Usually, the heating end is in standby or low power consumption state at this time, and basically no high-temperature gas such as steam will be supplied to the auxiliary device 10. Therefore, the liquid in the recovery system 8 will be tumbling, mixing, and uniform liquid temperature through the liquid circulation of the water inlet and the water outlet in coordination with the internal structure.

[0041] Because in the second embodiment, the auxiliary device 10 adopts a strip structure design, the water flow area of ​​the liquid channel 103 is small. In order to make full use of the gap between the two chambers and increase the utilization rate of heat recovery, we provide a third embodiment, such as Figure 6-9 As shown, in this embodiment, the strip structure of the auxiliary device 10 is optimized into an "inverted convex" structure, and the liquid channel 103 is adjusted to a shape with a larger flow area according to the size of the gap, and extends to between the water outlet sections 4 attached to the outer side walls of the two chambers. In this embodiment, the liquid channel 103 of the auxiliary device 10 has a larger flow area, which increases the amount of liquid that can be heated by the two air channels, and at the same time fills the space between the water outlet sections 4 attached to the outer side walls of the two chambers, thereby increasing the thermal insulation effect of the gap.

[0042] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0043] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A secondary pipe network waste heat recovery system based on a heating system, characterized in that: include: A heating end, a user end, and a heat exchanger (1); the pipeline connected to the heating end is a primary pipeline, and the pipeline connected to the user end is a secondary pipeline; the primary pipeline and the secondary pipeline exchange heat through the heat exchanger (1); a recovery system (8) is provided on the secondary pipeline; and the return water section (5) of the secondary pipeline is connected to the outlet water section (4) of the primary pipeline through the recovery system (8).

2. The secondary pipe network waste heat recovery system based on the heating system according to claim 1 is characterized in that: The primary pipeline consists of a water inlet section (2), a primary heat exchange section (3) and a water outlet section (4); the water inlet section (2) is connected to the water outlet section (4) via the primary heat exchange section (3); an electric valve (21) is provided on the water inlet section (2); and a primary circulation pump (41) is provided on the water outlet section (4); The secondary pipeline is composed of the return water section (5), the secondary heat exchange section (6) and the water supply section (7); the return water section (5) is connected to the water supply section (7) through the secondary heat exchange section (6); the return water section (5) and the secondary heat exchange section (6) are connected through the recovery system (8); and a secondary circulation pump (51) is provided on the return water section (5); The primary heat exchange section (3) and the secondary heat exchange section (6) are both located in the heat exchanger (1); The high-temperature water at the heating end enters the primary heat exchange section (3) from the water inlet section (2) to transfer heat to the secondary heat exchange section (6), and then the low-temperature water flows back to the heating end from the water outlet section (4) via the recovery system (8). The low-temperature water at the user end enters the secondary heat exchange section (6) from the return water section (5) through the recovery system (8), and after being heated in the primary heat exchange section (3), the water supply section (7) provides high-temperature water to the user end.

3. The secondary pipe network waste heat recovery system based on the heating system according to claim 2 is characterized in that: The invention comprises a weather compensator (9), the return water section (5) is provided with a return water temperature detection device (52), the supply water section (7) is provided with a supply water temperature detection device (71), and the weather compensator (9) is respectively electrically connected to the electric valve (21), the return water temperature detection device (52), the supply water temperature detection device (71), and an outdoor temperature detection device (91) located outdoors.

4. The secondary pipe network waste heat recovery system based on the heating system according to claim 2 is characterized in that: The recovery system (8) is wrapped around the water outlet section (4), a hollow cavity is provided inside the recovery system (8), one end of the recovery system (8) is connected to the water return section (5), and the other end is connected to the secondary heat exchange section (6).

5. The secondary pipe network waste heat recovery system based on the heating system according to claim 4 is characterized in that: The recovery system (8) is in the shape of a spiral tube and is tightly wound around the outside of the water outlet section (4).

6. The secondary pipe network waste heat recovery system based on the heating system according to claim 4 is characterized in that: The recovery system (8) is composed of a first chamber (81) and a second chamber (82) which are symmetrically arranged. The first chamber (81) is connected to the second chamber (82). The first chamber (81) is provided with a water inlet connected to the return water section (5). The second chamber (82) is provided with a water outlet connected to the secondary heat exchange section (6). The water inlet and the water outlet are located at opposite ends of the recovery system (8). An auxiliary device (10) connected to the heating end and / or the water outlet section (4) is provided at the connection point between the first chamber (81) and the second chamber (82). The water outlet section (4) is attached to the outer wall of the first chamber (81) and the outer wall of the second chamber (82).

7. The secondary pipe network waste heat recovery system based on the heating system according to claim 6 is characterized in that: The cross section of the first chamber (81) is in the shape of a radial spiral, and the side wall of the first chamber (81) extends downward from the bottom of the auxiliary device (10) and extends radially in a spiral to the top of the auxiliary device (10); The cross section of the second chamber (82) is in the shape of a radial spiral, and the side wall of the second chamber (82) extends downward from the bottom of the auxiliary device (10) and extends radially in a spiral to the top of the auxiliary device (10); An air chamber (83) is provided at the top connection between the first chamber (81) and the second chamber (82).

8. The secondary pipe network waste heat recovery system based on the heating system according to claim 6 is characterized in that: The auxiliary device (10) is a hollow strip-shaped structure. A gap is reserved between the side wall of the first chamber (81) and the side wall of the second chamber (82) connected to the bottom of the auxiliary device (10). The water outlet section (4) is located in the gap and is attached to the outer side walls of the first chamber (81) and the second chamber (82). The two ends of the auxiliary device (10) are respectively connected to the inner end surface of the recovery system (8). The auxiliary device (10) is provided with a first air channel (101) and a second air channel (102) connected to the heating end. The first air channel (101) is located in the first chamber (81), and the second air channel (102) is located in the second chamber (82). The top of the auxiliary device (10) is provided with a first air hole connected to the first air channel (101), and a second air hole connected to the second air channel (102).

9. The secondary pipe network waste heat recovery system based on the heating system according to claim 8 is characterized in that: A liquid channel (103) is provided in the auxiliary device (10), and the liquid channel (103) is located between the first air channel (101) and the second air channel (102), and one end of the liquid channel (103) is connected to the primary heat exchange section (3), and the other end is connected to the water outlet section (4).

10. A secondary pipe network waste heat recovery method based on a heating system, characterized in that: include: When the water temperature of the return water section (5) is lower than the water temperature of the outlet water section (4), the low-temperature water at the user end first enters the recovery system (8) from the return water section (5), and the outlet water section (4) transfers the remaining heat to the low-temperature water in the recovery system (8), so that the water in the recovery system (8) and the outlet water section (4) are both converted into warm water, and the heat of the outlet water section (4) is recovered, thereby reducing the temperature difference between the water supply section (7) and the return water section (5) at the user end; When the water temperature of the return water section (5) is higher than the water temperature of the outlet water section (4), the water in the return water section (5) enters the recovery system (8) and transfers the remaining heat to the low-temperature water in the outlet water section (4), so that the water in the recovery system (8) and the outlet water section (4) are both converted into warm water, and the heat of the return water section (5) is recovered, thereby reducing the temperature difference between the water inlet section (2) and the water outlet section (4) at the heating end, and reducing the heating energy consumption.

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