A thermal power plant cooling water waste heat recycling device

Abstract

The application provides a thermal power plant cooling water waste heat recycling device, which comprises a mounting rack, at least one heat exchanger is arranged on the mounting rack, heat exchange tube bundles are coiled in the heat exchanger, a plurality of turbulence structures are arranged on the outside of the heat exchange tube bundles along the axial direction of the heat exchanger, and the turbulence structures comprise first turbulence pieces for changing the flow direction of water flow and / or second turbulence pieces provided with variable-diameter structures and used for changing the flow speed of water flow. The device can destroy the fluid by arranging a plurality of first turbulence pieces for changing the flow direction of water flow and / or second turbulence pieces for changing the flow speed of water flow on the inside of the heat exchanger, form a turbulent flow in the ring wall, significantly improve the heat transfer efficiency of the fluid and the heat exchange tube, and / or increase the flow speed of water flow by the second turbulence pieces provided with variable-diameter structures, provide a turbulence effect, and improve the heat exchange efficiency.

Description

Technical Field

[0001] This invention relates to the field of waste heat recovery technology in thermal power plants, and in particular to a device for recovering and utilizing waste heat from cooling water in thermal power plants. Background Technology

[0002] During operation, the exhaust steam from the turbines of thermal power plants dissipates heat through the cooling water system, carrying away a significant amount of heat. If this cooling water is discharged directly without treatment, it not only wastes water resources but also causes thermal pollution. With the growth of global energy demand and increasingly stringent environmental regulations, the recovery and utilization of waste heat from the cooling water of thermal power plants has become an important means of alleviating energy consumption and environmental protection pressures.

[0003] Currently, waste heat recovery from cooling water in thermal power plants mainly adopts heat pump technology to convert low-grade heat energy in circulating cooling water into high-grade heat energy. In this process, the heat exchange effect of the heat pump system directly affects the efficiency of the entire waste heat recovery device. However, existing heat exchangers mostly install heat exchange tube bundles inside the heat exchanger shell, relying solely on increasing the heat exchange area to improve efficiency, which cannot guarantee the heat exchange efficiency. Therefore, in order to improve the efficiency of waste heat recovery and utilization from cooling water in thermal power plants, this invention proposes a waste heat recovery and utilization device for cooling water in thermal power plants. Summary of the Invention

[0004] The purpose of this invention is to provide a waste heat recovery and utilization device for cooling water in thermal power plants, which improves the heat exchange effect and efficiency of cooling water flowing through heat exchange tube bundles.

[0005] In accordance with the above objectives, the present invention provides a waste heat recovery and utilization device for cooling water in thermal power plants, including a mounting frame on which at least one heat exchanger is mounted. The heat exchanger has a heat exchange tube bundle coiled inside. The heat exchanger has multiple flow-disrupting structures spaced axially on the outside of the heat exchange tube bundle inside. The flow-disrupting structures include a first flow-disrupting element for changing the direction of water flow and / or a second flow-disrupting element with a variable diameter structure for changing the flow velocity of water flow.

[0006] Furthermore, the first turbulence element includes a turbulence ring surrounding the heat exchange tube bundle, and the inner side of the turbulence ring is provided with a plurality of guide channels for changing the direction of water flow at intervals along the circumference, and the plurality of coaxially arranged turbulence rings are staggered along the circumference.

[0007] Furthermore, the inner wall of the turbulence ring is uniformly provided with a plurality of turbulence grooves and / or turbulence protrusions along the circumference, and the guide channel includes a first guide channel formed in the turbulence groove and / or a second guide channel formed between adjacent turbulence protrusions.

[0008] Furthermore, at least two equidistant turbulence rings are provided along the axial direction of the heat exchanger, and the corresponding guide channels in adjacent turbulence rings are circumferentially misaligned.

[0009] Furthermore, the second turbulence element includes turbulence plates arranged alternately with the turbulence ring. A flow guide channel for changing the water flow velocity is provided on one side and / or on the plate body of the turbulence plate. The flow guide channel has a variable diameter structure that gradually narrows from the inlet end to the outlet end.

[0010] Furthermore, the baffle plate includes a flow guiding slope, and the flow guiding channel includes a first flow guiding channel formed between the flow guiding slope and the inner wall of the heat exchanger shell.

[0011] Furthermore, the spoiler plate is provided with a variable diameter spoiler hole, and the flow guiding channel includes a second flow guiding channel formed inside the variable diameter spoiler hole.

[0012] Furthermore, at least two baffles are equidistantly arranged along the axial direction of the heat exchanger, and adjacent baffles are staggered circumferentially.

[0013] Furthermore, the heat exchange tube bundle includes multiple heat exchange tubes, each heat exchange tube including an inlet section, an arc-shaped connecting section and an outlet section connected in sequence, the inlet section of the heat exchange tube at least partially penetrates one of the two adjacent baffles, and the outlet section of the heat exchange tube at least partially penetrates the other of the two adjacent baffles.

[0014] Furthermore, the mounting frame includes two columns and a mounting plate fixed between the columns. The mounting plate has arc-shaped mounting grooves at both the top and bottom ends to accommodate the heat exchanger, and fixing plates are installed on both sides of the columns.

[0015] The technical solution of the present invention provides a plurality of first turbulence-inducing elements for changing the direction of water flow and / or second turbulence-inducing elements for changing the velocity of water flow by spaced intervals inside the heat exchanger. The first turbulence-inducing elements can disrupt the fluid and form turbulence on the annular wall. Turbulence can significantly improve the heat transfer efficiency between the fluid and the heat exchange tube, and / or the second turbulence-inducing elements with variable diameter structures can increase the velocity of water flow, provide a turbulence effect, and improve the efficiency of heat exchange. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure when the two heat exchangers of the present invention are stacked and installed.

[0018] Figure 2This is a schematic diagram of the installation structure of the heat exchanger on the mounting bracket in this invention.

[0019] Figure 3 This is an exploded view of the present invention.

[0020] Figure 4 This is a schematic diagram of the heat exchange tube bundle of the present invention.

[0021] Figure 5 This is a cross-sectional view of the heat exchanger shell of the present invention.

[0022] Figure 6 This is a schematic diagram of the structure of the turbulence ring of the present invention.

[0023] Figure 7 This is a schematic diagram of the spoiler structure of the present invention.

[0024] Explanation of reference numerals in the attached drawings: Mounting bracket-1; Column-11; Mounting plate-12; Mounting groove-13; Fixing plate-14; Heat exchanger-2; Heat exchange tube bundle-20; Turbulence structure-21; Turbulence ring-22; Turbulence groove-221; Turbulence boss-222; Turbulence plate-23; Guide slope-231; Variable diameter turbulence hole-232; Inlet pipe section-24; Arc-shaped connection section-25; Outlet pipe section-26. Detailed Implementation

[0025] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] Please see Figures 1-2 As shown, the present invention provides a waste heat recovery and utilization device for cooling water in thermal power plants, including a mounting frame 1 and a heat exchanger 2 assembled and installed by the mounting frame 1. The mounting frame 1 includes two columns 11 and a mounting plate 12 fixed between the two columns 11. The upper and lower ends of the mounting plate 12 are provided with arc-shaped mounting grooves 13 for accommodating the heat exchanger 2. Fixing plates 14 are installed on the upper and lower sides of the columns 11. The fixing plates 14 are provided with mounting holes. When installing the heat exchanger 2, first fix the bottom bracket that matches the fixing plate 14 at the position to be installed, and then fix the fixing plate 14 to the bottom bracket with bolts. At this time, the mounting plate 12 can be fixed. Then, the heat exchanger 2 to be installed is fixed in the arc-shaped mounting groove 13. When only one heat exchanger 2 needs to be installed, it can be fixed to the fixing plate 14 on the column 11 by a semi-circular clamp (not shown in the figure) to achieve the fixation of the heat exchanger 2.

[0029] In one executable embodiment, reference is made to... Figure 3 and Figure 4As shown, the heat exchanger 2 includes a shell and tube boxes installed at both ends of the shell. A heat exchange tube bundle 20, consisting of multiple heat exchange tubes, is installed in the left tube box and the inner cavity of the shell. Each heat exchange tube includes an inlet tube 24, an arc-shaped connection 25, and an outlet tube 26 connected in sequence. The heat exchange tube bundle 20 has a hollow structure forming an inner heat exchange cavity, and an outer heat exchange cavity is formed between the heat exchange tube bundle 20 and the shell. A refrigerant inlet pipe communicating with the left tube box is installed at the bottom of the left tube box, and a refrigerant outlet pipe communicating with the right tube box is installed at the top of the right tube box. A partition is installed in the middle of the right tube box, evenly dividing the inner cavity of the right tube box into upper and lower parts. The inlet and outlet ends of the heat exchange tube bundle 20 communicate with the lower and upper inner cavities of the right tube box, respectively. The shell has a hollow structure and communicates with the left tube box. A tube box gasket is installed between the right tube box and the shell to prevent liquid in the right tube box from flowing into the shell. The left side of the shell... A cooling water and refrigerant discharge pipe is installed at the bottom, and a cooling water and refrigerant inlet pipe is installed on the upper right side of the shell. During heat exchange in heat exchanger 2, cooling water with waste heat from the thermal power plant is introduced through the cooling water and refrigerant inlet pipe. The cooling water flows from the right side of the shell to the left side. Refrigerant is introduced through the refrigerant inlet pipe. The refrigerant enters the inlet pipe section 24 from the lower half of the inner cavity of the right-side tube box, flows to the outlet pipe section 26 through the arc-shaped connection section 25, and finally flows into the upper half of the inner cavity of the right-side tube box from the outlet pipe section 26. Then it flows out along the refrigerant discharge pipe from the upper half of the inner cavity. During the flow of cooling water, the heat of the cooling water is conducted to the heat exchange tube bundle 20 through the heat exchange tube bundle 20, thereby heating the refrigerant in the heat exchange tube bundle 20. After evaporation, it is discharged to the external compressor through the refrigerant discharge pipe. After compression, the heat is collected and supplied to the boiler in the thermal power plant that needs preheating for preheating or to provide heating for the thermal power plant to complete the waste heat recovery and utilization.

[0030] In one executable embodiment, based on the above embodiment, in order to improve heat exchange efficiency, when multiple heat exchangers 2 need to be installed in series, refer to... Figure 1 and Figure 2 As shown, by replacing the semi-circular clamp in the above embodiment with the mounting bracket 1, stacking the two mounting brackets 1 one on top of the other, and then connecting the two heat exchangers 2 end to end, multiple sets of heat exchangers 2 can be installed.

[0031] In one executable embodiment, reference is made to... Figure 5 and Figure 6As shown, multiple turbulence rings 22 are uniformly arranged inside the external heat exchange cavity. The turbulence rings 22 are annular structures. The figure shows a structural example of four turbulence rings 22. The four turbulence rings 22 are uniformly welded and fixed to the inner wall of the heat exchanger shell 2. Multiple turbulence grooves 221 are uniformly opened on the inner peripheral wall of the turbulence rings 22. The turbulence grooves 221 are S-shaped structures. The S-shaped turbulence grooves 221 are the first guide channels. When the cooling water flows through the turbulence grooves 221 on the turbulence rings 22, the flow direction will be changed due to the S-shaped structure of the turbulence grooves 221, which can destroy the turbulence formed by the fluid on the ring wall. Turbulence can significantly improve the heat transfer efficiency between the fluid and the heat exchange tube.

[0032] In one executable embodiment, reference continues to... Figure 5 and Figure 6 As shown, multiple turbulence protrusions 222 are uniformly provided on the inner peripheral wall of the turbulence ring 22. When the cooling water flows through the turbulence protrusions 222 on the turbulence ring 22, a second guide channel is formed between adjacent turbulence protrusions 222. The second guide channel will change the flow direction due to the structure of the turbulence protrusions 222, which can disrupt the turbulence formed by the fluid on the ring wall, thereby improving the heat transfer efficiency between the fluid and the heat exchange tube.

[0033] In further embodiments, refer again to Figure 5 and Figure 6 As shown, the inner peripheral wall of the turbulence ring 22 is uniformly provided with multiple turbulence grooves 221 and turbulence protrusions 222, and the turbulence grooves 221 and turbulence protrusions 222 are spaced apart. Through the combined use of the first guide channel on the turbulence groove 221 and the second guide channel between adjacent turbulence protrusions 222, the turbulence effect can be further improved, resulting in better heat exchange efficiency. It is worth noting that adjacent turbulence rings 22 are staggered, causing the turbulence grooves 221 and turbulence protrusions 222 on adjacent turbulence rings 22 to be misaligned. At this time, the guide channels formed on adjacent turbulence rings 22 will again create a turbulence effect, further improving heat exchange efficiency.

[0034] In a further embodiment, reference is made to... Figure 4 and Figure 7 As shown, multiple baffles 23 are uniformly arranged inside the external heat exchange cavity. The baffle 23 is an example of a structure with four baffles 23 shown in the figure. The baffle 23 is an arc plate structure, which includes an arc surface on one side and a cross section on the other side. The arc surface fits into the inner wall of the shell. Adjacent baffles 23 are staggered on the upper and lower sides of the inner wall of the shell, so that the water flow always flows through the cross section of the baffle 23. It is worth noting that the cross section is set as a guide slope 231. The bottom of the guide slope 231 is the water inlet end and the top is the water outlet end. The first guide channel can be formed by the setting of the guide slope 231.

[0035] In further embodiments, reference continues to be made to... Figure 4 and Figure 7 As shown, a variable diameter turbulence hole 232 is provided through the adjacent turbulence plate 23, forming a second flow guide channel. The inner diameter of the variable diameter turbulence hole 232 can gradually decrease from the water inlet end to the water outlet end, and the variable diameter turbulence holes 232 on the adjacent turbulence plate 23 are circumferentially misaligned, so that the adjacent second flow guide channels are circumferentially misaligned. The variable diameter setting can increase the speed of the water flow in this part, provide a turbulence effect, and improve the efficiency of heat exchange.

[0036] In further embodiments, refer again to Figure 4 and Figure 7 As shown, the spoiler 23 is provided with both a flow guiding slope 231 and a variable diameter spoiler hole 232. The flow guiding slope 231 and the variable diameter spoiler hole 232 are provided to generate a spoiler effect on both parts at the same time. It is worth noting that the flow guiding channels on one side and / or inside the adjacent spoilers 23 are circumferentially misaligned.

[0037] In the structures disclosed above, the spoiler ring 22 can constitute the spoiler structure 21 on its own, and the spoiler plate 23 can also constitute the spoiler structure 21 on its own. Of course, as Figure 6 and Figure 7 The spoiler ring 22 and spoiler plate 23 shown can also be used together to form a spoiler structure 21. When the spoiler structure 21 includes the spoiler ring 22 and spoiler plate 23, the spoiler ring 22 and spoiler plate 23 are arranged in accordance with... Figure 4 The staggered arrangement shown, in this structure, refers to Figure 7 As shown, for the left-side baffle 23, all the inlet pipes 24 and part of the outlet pipes 26 of the heat exchange tubes pass through the left-side baffle 23. For the right-side baffle 23, part of the inlet pipes 24 and all the outlet pipes 26 of the heat exchange tubes pass through the right-side baffle 23. The adjacent baffles 23 can fix the heat exchange tube bundle 20 while turbulent.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for recovering and utilizing waste heat from cooling water in a thermal power plant, characterized in that, The device includes a mounting frame (1), on which at least one heat exchanger (2) is mounted. The heat exchanger (2) has a heat exchange tube bundle (20) coiled inside. The heat exchanger (2) has multiple turbulence structures (21) spaced axially on the outside of the heat exchange tube bundle. The turbulence structure (21) includes a first turbulence element for changing the direction of water flow and / or a second turbulence element with a variable diameter structure for changing the velocity of water flow.

2. The waste heat recovery and utilization device for cooling water in thermal power plants according to claim 1, characterized in that, The first turbulence element includes a turbulence ring (22) surrounding the heat exchange tube bundle (20). The inner side of the turbulence ring (22) is provided with a plurality of guide channels for changing the direction of water flow at intervals along the circumference. The plurality of coaxially arranged turbulence rings (22) are staggered along the circumference.

3. The waste heat recovery and utilization device for cooling water in thermal power plants according to claim 2, characterized in that, The inner wall of the turbulence ring (22) is uniformly provided with a plurality of turbulence grooves (221) and / or turbulence protrusions (222) along the circumferential direction. The guide channel includes a first guide channel formed in the turbulence groove (221) and / or a second guide channel formed between adjacent turbulence protrusions (222).

4. The waste heat recovery and utilization device for cooling water in thermal power plants according to claim 2 or 3, characterized in that, At least two equidistant turbulence rings (22) are provided along the axial direction of the heat exchanger, and the guide channels corresponding to each other in adjacent turbulence rings (22) are circumferentially misaligned.

5. The waste heat recovery and utilization device for cooling water in thermal power plants according to claim 2, characterized in that, The second turbulence element includes a turbulence plate (23) arranged alternately with the turbulence ring (22). A flow guide channel for changing the flow velocity is provided on one side and / or on the plate body of the turbulence plate (23). The flow guide channel has a variable diameter structure that gradually narrows from the inlet end to the outlet end.

6. The waste heat recovery and utilization device for cooling water in thermal power plants according to claim 5, characterized in that, The baffle (23) includes a flow guide slope (231), and the flow guide channel includes a first flow guide channel formed between the flow guide slope (231) and the inner wall of the heat exchanger (2) shell.

7. The waste heat recovery and utilization device for cooling water in thermal power plants according to claim 5 or 6, characterized in that, The spoiler (23) is provided with a variable diameter spoiler hole (232) through it, and the flow channel includes a second flow channel formed inside the variable diameter spoiler hole (232).

8. The waste heat recovery and utilization device for cooling water in thermal power plants according to claim 5, characterized in that, At least two baffles (23) are provided at equal intervals along the axial direction of the heat exchanger, and adjacent baffles (23) are staggered in the circumferential direction.

9. The waste heat recovery and utilization device for cooling water in thermal power plants according to claim 8, characterized in that, The heat exchange tube bundle (2) includes multiple heat exchange tubes, each heat exchange tube including an inlet tube (24), an arc-shaped connection (25) and an outlet tube (26) connected in sequence. The inlet tube (24) of the heat exchange tube passes through one of the two adjacent baffles (23) in at least a portion, and the outlet tube (26) of the heat exchange tube passes through the other of the two adjacent baffles (23) in at least a portion.

10. The waste heat recovery and utilization device for cooling water in thermal power plants according to claim 1, characterized in that, The mounting bracket (1) includes two columns (11) and a mounting plate (12) fixed between the columns (11). The upper and lower ends of the mounting plate (12) are provided with arc-shaped mounting grooves (13) for accommodating the heat exchanger (2). Fixing plates (14) are installed on both sides of the columns (11).

Images