A waste heat recovery device for a thermal power plant

Abstract

The application discloses a waste heat recovery device for a thermal power plant, which comprises a bearing frame body with an upper end face, the bearing frame body being composed of two side plates and a bottom end face, a condensing assembly, a lower surface of the condensing assembly being fixedly installed at a side edge of an upper end face of the bearing frame body, one end of the condensing assembly being connected to a top portion of the condensing assembly, a precise fitting structure being formed by a conical injection pipe in the condensing assembly and longitudinally arrayed condensing discs, waste heat is uniformly dispersed to each water flow channel, the contact area of the waste heat and the condensing medium is maximized, the problem of local idling of a traditional heat exchange assembly is avoided, the preliminary waste heat exchange efficiency is improved, on the other hand, an absorption heat pump and a compression heat pump constitute a cascade efficiency improving system, low-grade waste heat is converted into medium-grade heat energy through the absorption heat pump, and then the medium-grade heat energy is deeply improved into high-grade heat energy through the compression heat pump, compared with a single heat pump system, the energy conversion efficiency is improved, the waste heat recovery rate of flue gas of the thermal power plant can be improved, and energy loss is reduced.

Description

Technical Field

[0001] This application relates to the field of waste heat recovery and reuse, and more particularly to a waste heat recovery device for thermal power plants. Background Technology

[0002] A significant portion of the heat generated by boiler combustion in thermal power plants is discharged as waste heat with flue gas. For example, the design value for flue gas temperature in large-capacity bituminous coal boiler units is typically around 125°C, while for lean coal and anthracite boiler units it is typically around 140°C, and for high-moisture lignite boiler units it is typically as high as 150°C. In actual operation, the flue gas temperature is often even higher. In addition, turbine exhaust also contains a large amount of heat, which accounts for more than 60% of the plant's total energy. However, due to its low grade, it is difficult to utilize directly. Waste heat resources in various industrial sectors in my country account for 17%-67% of their total fuel consumption, of which about 60% can be recovered and utilized. The research and promotion of heat recovery technology is an important part of energy conservation and emission reduction, and a key technology for achieving sustainable development of resources and energy. For thermal power plants, improving the efficiency of waste heat recovery and utilization can reduce coal consumption for power generation, increase the power output and operating economy of the units, and reduce thermal pollution to the environment.

[0003] A patent with publication number CN 118746205 A discloses a waste heat recovery and utilization device based on energy conservation and emission reduction in thermal power plants, relating to the field of waste heat recovery and utilization technology in thermal power plants. It includes an ash collection pipe, within which an ash collection mechanism and a waste heat recovery mechanism are installed. The ash collection mechanism includes: an installation chamber installed on the inner side of the top of the ash collection pipe; an arc-shaped seat with a vertical channel at its top, the top of which connects to the bottom of the installation chamber; a hollow cylinder movably and rotatably installed within the arc-shaped seat, with an opening at its top; and a blocking component located on the outer wall of the bottom of the hollow cylinder. This application, by setting up the ash collection mechanism and the waste heat recovery mechanism, enables the blocking component to a certain extent to block solid particles in the gas discharged through the ash collection pipe in a thermal power plant, while simultaneously adsorbing some heat. The heat is conducted to the heat transfer section through liquid circulation, thereby outputting heat and achieving the purpose of waste heat recovery, thus improving environmental protection.

[0004] However, the above technologies often have the following drawbacks: the layout of the device is mostly a fixed structure, which cannot be flexibly adjusted according to the actual parameters of the boiler flue gas. When the flue gas parameters change, the fixed spacing of the heat-conducting plates and the flow channel design are difficult to adapt to the flue gas flow path, which can easily lead to local heat exchange dead zones or excessive flow velocity, resulting in insufficient heat transfer and reduced waste heat recovery efficiency. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, at least one technical problem raised in the background art is solved.

[0006] To achieve the above objectives, this application provides a waste heat recovery device for thermal power plants, comprising a support frame having an upper end face, the support frame being composed of two side plates and a bottom end face, a condensing assembly having its lower surface fixedly installed at one edge of the upper end face of the support frame, a heat carrier heat exchange tube having one end connected to the top of the condensing assembly and placed on the surface of the support frame, an absorption heat pump fixedly installed on the upper surface of the support frame near the condensing assembly, a compression heat pump having one side fixedly installed on one side plate of the support frame, a heat medium water pipeline having one end connected to the absorption heat pump and the other end connected to one side surface of the compression heat pump, and a heat medium return pipeline having one end connected from the compression heat pump to the absorption heat pump. An evaporator is connected to one side surface of the compression heat pump. The surface of the support frame has several threaded holes, and the surface of the condensing assembly is connected to the support frame through these threaded holes.

[0007] Optionally, the absorption heat pump is connected to a generator on one side, and pipes are provided on both sides of one side surface of the generator. The two pipes are respectively connected to the heat medium water pipe and the heat medium return pipe, which are respectively connected to one side and the other side of the compression heat pump.

[0008] Optionally, the condensation assembly includes a top plate with its bottom surface placed on top of the two side plates, and a heat exchange plate fitted onto the bottom surface of the top plate.

[0009] Optionally, a recessed cavity is formed in the upper surface of the top plate, a bottom inlet is formed at one edge of the upper surface of the heat exchange plate, and a partition plate is connected to the upper surface of the top plate corresponding to the inlet.

[0010] Optionally, a medium outlet is provided on one side of the upper surface of the partition plate, and a waste heat pipe is provided on the side of the partition plate near the medium outlet, with one end of the waste heat pipe extending to the top of the inlet.

[0011] Optionally, the waste heat pipeline has a distribution pipe at the bottom of the inner arc surface, and the outer arc surface of the distribution pipe has a diversion port. The distribution pipe is arranged in a conical structure, and the outer arc surface of the distribution pipe is fitted with a condenser fin assembly.

[0012] Optionally, the condenser plate assembly includes condenser discs connected to the bottom of the heat exchange plate, and a baffle plate connected to the lower surface of the condenser discs.

[0013] Optionally, an inlet hole is provided at one edge of the upper surface of the condensation disc, and a fixing point is provided on the side of the condensation disc near the inlet hole.

[0014] Optionally, the number of condensing discs is several, and they are arranged in a longitudinal array vertically on the support frame. The several condensing discs are connected by fixing points. The upper surface of the partition plate has through holes, and the through holes on the upper surface of the partition plate correspond to the inlet holes. A water flow channel is provided between the condensing discs and the partition plate.

[0015] Optionally, the outer arc surface of the dispensing pipe is rubbed into the inner arc surface of the inlet hole, the inner arc surface of the dispensing port is adapted to the water flow channel between the condensing disc and the gasket, and the condensing disc is provided with an outlet hole on the other side away from the inlet hole, and the outlet hole is connected to the heat exchange tube of the heat carrier.

[0016] This application provides a preheating recovery device for thermal power plants. Through a precisely fitted structure formed by conical injection pipes and longitudinally arrayed condenser discs in the condensing assembly, waste heat is evenly distributed to each water flow channel, maximizing the contact area between waste heat and the condensing medium. This avoids the problem of partial idleness in traditional heat exchange components, improving the initial heat exchange efficiency. Furthermore, an absorption heat pump and a compression heat pump constitute a tiered efficiency improvement system. The absorption heat pump converts low-grade waste heat into medium-grade heat energy, which is then further improved into high-grade heat energy by the compression heat pump. Compared to a single heat pump system, the energy conversion efficiency is improved, increasing the recovery rate of previously wasted flue gas waste heat in thermal power plants and reducing energy consumption. The evaporator absorbs low-grade heat from the environment to assist in efficiency improvement, reducing energy consumption compared to traditional heating equipment that relies solely on electricity. Simultaneously, the heat transfer medium forms a closed-loop circulation through the heat transfer medium water pipeline and the heat transfer medium return pipeline, eliminating the need for frequent replenishment of fresh water, improving water resource utilization, and reducing water costs and wastewater treatment costs for thermal power plants. Attached Figure Description

[0017] Figure 1 This is an overall three-dimensional view of the support frame of this application; Figure 2 This is a schematic diagram of the overall structure of the condenser assembly in this application; Figure 3 This is an exploded structural diagram of the disassembled condenser assembly and condenser fin group in this application; Figure 4 This is a head-up view of the water flow channel structure in this application; Figure 5 This is a cross-sectional view of the condenser disc in this application; Figure 6 This is a front view of the compression heat pump and the absorption heat pump in this application; Figure 7 This is a schematic diagram of the structure of a single condenser disk in this application; Figure 8 This is a schematic diagram of the disassembled structure of the condenser disc and the spacer in this application.

[0018] Attached reference numerals: 1. Support frame; 2. Condensation assembly; 21. Top plate; 211. Recessed cavity; 22. Heat exchange plate; 221. Inlet; 23. Divider plate; 231. Medium outlet; 232. Waste heat piping; 24. Distributor pipe; 241. Distribution port; 3. Heat exchanger tubes; 4. Absorption heat pump; 401. Generator; 402. Piping; 5. Compression heat pump; 501. Evaporator; 6. Heat medium water pipeline; 7. Heat medium return pipeline; 8. Condenser plate assembly; 81. Condenser disc; 811. Inlet hole; 812. Fixing point; 813. Outlet hole; 82. Spacing plate; 83. Water flow channel.

[0019] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0022] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0023] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0024] like Figure 1 , Figure 2 and Figure 6 As shown, this embodiment of the application includes a support frame 1 with an upper end face, the support frame 1 being composed of two side plates and a bottom end face, a condenser assembly 2, the lower surface of which is fixedly installed on one edge of the upper end face of the support frame 1, a heat carrier heat exchange tube 3, one end of which is connected to the top of the condenser assembly 2 and placed on the surface of the support frame 1, an absorption heat pump 4, which is fixedly installed on the upper surface of the support frame 1 near the condenser assembly 2, a compression heat pump 5, one side of which is fixedly installed on one side plate of the support frame 1, and a heat medium water pipe 6, one end of which is connected to the absorption heat pump 4 and the other end of which is connected to the compression heat pump 5. On one side of the heat pump 5, a heat medium return pipe 7 is connected at one end from the compression heat pump 5 to the absorption heat pump 4. An evaporator 501 is connected to one side of the compression heat pump 5. Several threaded holes are opened on the surface of the support frame 1. The surface of the condenser assembly 2 is connected to the support frame 1 through the threaded holes. A generator 401 is connected to one side of the absorption heat pump 4. Pipes 402 are provided on both sides of one side of the generator 401. The two pipes 402 are respectively connected to the heat medium water pipe 6 and the heat medium return pipe 7. The heat medium water pipe 6 and the heat medium return pipe 7 are respectively connected to one side and the other side of the compression heat pump 5.

[0025] The high-temperature waste heat generated by the boiler of the thermal power plant, such as the exhaust waste heat, first enters the system through the waste heat pipeline 232 of the device. One end of the waste heat pipeline 232 is connected to the partition plate 23 on the top plate 21, and the other end corresponds to the bottom inlet 221 of the heat exchange plate 22. The waste heat can be introduced into the condensing component 2. At the same time, the conical injection pipe 24 at the bottom of the inner arc surface of the waste heat pipeline 232 diverts the concentrated waste heat to evenly distribute it into several longitudinally arrayed condensing plates 81, avoiding the problem of uneven heat exchange caused by local waste heat accumulation.

[0026] An absorption heat pump 4 is fixedly installed on the upper surface of the support frame 1 near the condenser assembly 2. It initially enhances the medium and low temperature heat transported by the heat exchange tube 3. A generator 401 connected to one side of the absorption heat pump 4 forms a passage with the heat medium water pipe 6 and the heat medium return pipe 7 through the pipe 402. When the heat medium enters the absorption heat pump 4, the generator 401 uses the waste heat carried by the medium to drive the internal working fluid circulation of the heat pump, converting the low-grade waste heat into medium-grade heat energy, and transferring it to the heat medium water in the heat medium water pipe 6, so that the temperature of the heat medium water initially rises. The heat medium water initially heated by the absorption heat pump 4 enters the compression heat pump 5 through the heat medium water pipe 6. The compression heat pump 5 uses a small amount of electricity to drive the compressor to run, deeply compressing and enhancing the medium-grade heat energy carried by the heat medium water, converting it into high-grade heat energy. After the efficiency improvement is completed, the high-grade heat transfer water can be directly output to the outside, while the low-temperature heat transfer water that has released heat will flow back to the generator 401 of the absorption heat pump 4 through the heat transfer return pipe 7, forming a heat transfer water recycling. At the same time, the evaporator 501 connected to one side of the compression heat pump 5 can absorb low-grade heat in the environment, such as air and cooling water heat, to help improve the efficiency of the heat pump and further reduce energy consumption.

[0027] according to Figure 3 , Figure 4 , Figure 5 , Figure 7 and Figure 8As shown, the condenser assembly 2 includes a top plate 21 with its bottom surface placed on top of the two side plates. A heat exchange plate 22 is fitted onto the bottom surface of the top plate 21. A recessed cavity 211 is formed in the upper surface of the top plate 21. A bottom inlet 221 is formed at one edge of the upper surface of the heat exchange plate 22. A partition plate 23 is connected to the upper surface of the top plate 21 corresponding to the inlet 221. A medium outlet 231 is formed on one side of the upper surface of the partition plate 23. A waste heat pipe 232 is provided on the side of the partition plate 23 near the medium outlet 231. One end of the waste heat pipe 232 extends to the top of the inlet 221. A distribution pipe 24 is located at the bottom of the inner arc surface of the waste heat pipe 232. A branch port 241 is formed on the outer arc surface of the distribution pipe 24. The distribution pipe 24 has a conical structure. A condenser fin assembly 8 is fitted onto the outer arc surface of the distribution pipe 24. The condenser fin assembly 8 includes condenser fins 81 and is connected to the bottom of the heat exchange plate 22. A partition plate 82 is connected to the lower surface of the condensing disc 81. An inlet hole 811 is provided on one edge of the upper surface of the condensing disc 81. A fixing point 812 is provided on the side of the condensing disc 81 near the inlet hole 811. There are several condensing discs 81, which are arranged in a longitudinal array and are perpendicular to the support frame 1. Several condensing discs 81 are connected to each other through the fixing point 812. A through hole is provided on the upper surface of the partition plate 82, which corresponds to the inlet hole 811. A water flow channel 83 is provided between the condensing disc 81 and the partition plate 82. The outer arc surface of the dispensing pipe 24 is inserted into the inner arc surface of the inlet hole 811. The inner arc surface of the dispensing port 241 is adapted to the water flow channel 83 between the condensing disc 81 and the partition plate 82. An outlet hole 813 is provided on the other side of the condensing disc 81 away from the inlet hole 811. The outlet hole 813 is connected to the heat exchange tube 3 of the heat carrier.

[0028] The high-temperature waste heat generated by the boiler in the thermal power plant first enters the condensing assembly 2 through the waste heat pipe 232. One end of the waste heat pipe 232 is connected to the side of the partition plate 23 near the medium outlet 231, and the other end extends to the top of the bottom inlet 221 of the heat exchange plate 22, forming a waste heat introduction channel. The partition plate 23 is fixed on the upper surface of the top plate 21 at the corresponding position of the bottom inlet 221. Its main function is to prevent waste heat from leaking directly from the surface of the top plate 21, and at the same time guide the waste heat to flow along a fixed path to the bottom inlet 221. The bottom surface of the top plate 21 is sleeved with the heat exchange plate 22. The recessed cavity 211 opened on its surface can temporarily store the introduced waste heat, forming a buffer space to prevent excessive local pressure caused by the instantaneous impact of waste heat.

[0029] When the waste heat enters the heat exchange plate 22 through the bottom inlet 221, the branch port 241 on the outer arc surface of the branch pipe 24 at the bottom of the inner arc surface of the waste heat pipeline 232 is adapted to the water flow channel 83 of the condenser plate group 8. Its conical design can use the principle of fluid mechanics to disperse and reduce the pressure of the concentrated waste heat to avoid the local waste heat flow rate being too fast or too slow.

[0030] Specifically, the diameter of the conical distribution pipe 24 gradually changes from the inlet end 221 to the outlet end. Combined with the uniform distribution of multiple diversion ports 241, it can evenly transport the waste heat to the water flow channel 83 formed by each condensing disc 81 and the baffle plate 82, ensuring that all condensing discs 81 can fully contact the waste heat. This solves the problem of local heat exchange saturation and local idleness of traditional heat exchange components, and maximizes the utilization rate of heat exchange area. At the same time, it is composed of several condensing discs 81 and baffle plates 82 stacked alternately. The condensing discs 81 are vertically fixed on the support frame 1 in a longitudinal array through fixing points 812, forming a multi-layer parallel heat exchange channel. The baffle plate 82 is connected to the lower surface of two adjacent condensing discs 81. Its thickness determines the height of the water flow channel 83. At the same time, the through holes opened on the upper surface of the baffle plate 82 correspond to the inlet holes 811 of the condensing discs 81, ensuring that the waste heat after being diverted by the distribution pipe 24 can smoothly enter each water flow channel 83. When the waste heat flows within the water channel 83, it comes into full contact with the surface of the condensing disc 81. The condensing disc 81 is made of a material with a high thermal conductivity, which can quickly transfer the heat from the waste heat to the condensing medium inside the disc. At the same time, the multi-layer structure of the longitudinal array expands the contact time and area between the waste heat and the condensing medium, so that the temperature of the waste heat gradually decreases and the temperature of the condensing medium gradually increases, realizing the conversion of low-grade waste heat into high-grade carrier heat energy. After heat exchange is completed, the cooled waste heat is concentrated and discharged through the outlet hole 813 on the side of the condenser plate 81 away from the inlet hole 811. The outlet hole 813 is directly connected to one end of the heat carrier heat exchange tube 3, while the other end of the heat carrier heat exchange tube 3 is connected to the top of the condenser assembly 2. A stable discharge channel is formed by relying on the support of the support frame 1. At this time, the carrier medium in the heat carrier heat exchange tube 3 is transported to the subsequent absorption heat pump 4 system, completing the closed loop of receiving waste heat from the condenser assembly 2, heat exchange, and heat transfer, providing a stable medium and low temperature heat energy source for the entire waste heat recovery.

[0031] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A waste heat recovery device for thermal power plants, characterized in that, include: The support frame (1) has an upper end face, and the support frame (1) is composed of two side plates and a bottom end face; The condenser assembly (2) is fixedly installed on the lower surface of the upper end face of the support frame (1) at one edge; A heat carrier heat exchange tube (3) is connected at one end to the top of the condenser assembly (2), and the heat carrier heat exchange tube (3) is placed on the surface of the support frame (1); An absorption heat pump (4) is fixedly installed on the upper surface of the support frame (1) on the side near the condenser assembly (2); A compression heat pump (5) is fixedly installed on one side plate of the support frame (1); The heat transfer medium water pipe (6) is connected at one end to the absorption heat pump (4) and at the other end to one side surface of the compression heat pump (5); The heat medium return line (7) is connected at one end to the compression heat pump (5) and the absorption heat pump (4); The compression heat pump (5) has an evaporator (501) connected to one side surface, and the support frame (1) has several threaded holes on its surface. The condenser assembly (2) is connected to the support frame (1) through the threaded holes.

2. The waste heat recovery device for thermal power plants according to claim 1, characterized in that, The absorption heat pump (4) is connected to a generator (401) on one side. The generator (401) has pipes (402) on both sides of one side surface. The two pipes (402) are connected to the heat medium water pipe (6) and the heat medium return pipe (7) respectively. The heat medium water pipe (6) and the heat medium return pipe (7) are connected to one side and the other side of the compression heat pump (5) respectively.

3. The waste heat recovery device for thermal power plants according to claim 1, characterized in that, The condensation assembly (2) includes: The top plate (21) is placed on the top of the two side plates; The heat exchange plate (22) is fitted on the bottom surface of the top plate (21).

4. The waste heat recovery device for thermal power plants according to claim 3, characterized in that, The top plate (21) has a recessed cavity (211) on its upper surface, and the heat exchange plate (22) has a bottom inlet (221) on one side edge of its upper surface. A partition plate (23) is connected to the upper surface of the top plate (21) corresponding to the inlet (221).

5. The waste heat recovery device for thermal power plants according to claim 4, characterized in that, A medium outlet (231) is provided on one side of the upper surface of the partition plate (23), and a waste heat pipe (232) is provided on the side of the partition plate (23) near the medium outlet (231). One end of the waste heat pipe (232) is opened to the top of the inlet (221).

6. The waste heat recovery device for thermal power plants according to claim 5, characterized in that, The waste heat pipeline (232) has a branch pipe (24) at the bottom of the inner arc surface. The branch pipe (24) has a branch port (241) on the outer arc surface. The branch pipe (24) is set in a conical structure. The outer arc surface of the branch pipe (24) is fitted with a condenser plate group (8).

7. The waste heat recovery device for thermal power plants according to claim 6, characterized in that, The condenser plate group (8) includes: A condenser plate (81) is connected to the bottom of a heat exchange plate (22); A partition plate (82) is attached to the lower surface of the condenser plate (81).

8. The waste heat recovery device for thermal power plants according to claim 7, characterized in that, An inlet hole (811) is provided on one edge of the upper surface of the condensing disc (81), and a fixing point (812) is provided on the side of the condensing disc (81) near the inlet hole (811).

9. The waste heat recovery device for thermal power plants according to claim 8, characterized in that, The number of condensing discs (81) is several, and they are arranged in a longitudinal array vertically on the support frame (1). The several condensing discs (81) are connected by fixing points (812). The upper surface of the pad partition (82) is provided with through holes. The through holes on the upper surface of the pad partition (82) correspond to the inlet holes (811). A water flow channel (83) is provided between the condensing discs (81) and the pad partition (82).

10. The waste heat recovery device for thermal power plants according to claim 9, characterized in that, The outer arc surface of the injection pipe (24) is inserted into the inner arc surface of the inlet hole (811). The inner arc surface of the branch port (241) and the water flow channel (83) between the condensing disc (81) and the partition plate (82) are adapted to each other. The condensing disc (81) is provided with an outlet hole (813) on the other side away from the inlet hole (811). The outlet hole (813) is connected to the heat exchange tube (3) of the heat carrier.

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