Regenerative heating device and coal-fired unit

Abstract

The present application provides a thermal energy storage heating device and a coal-fired unit, including a thermal energy storage heater. The thermal energy storage heater includes a housing, and the housing includes an outer shell and an inner tank. The inner tank is located inside the outer shell. The inner cavity of the inner tank is used for introducing steam. There is a gap between the inner tank and the outer shell to form a steam flow channel. The wall of the inner tank has a communication hole, and the communication hole communicates the inner cavity of the inner tank and the steam flow channel. This thermal energy storage heater can be adapted to working conditions of rapid load change and large temperature difference heat transfer.

Description

Technical Field

[0001] The present invention relates to the technical field of coal-fired power generation, and particularly relates to a heat storage heating device and a coal-fired unit. Background Art

[0002] The flexible peak shaving of a coal-fired power station unit can adopt hot water heat storage as an auxiliary means, and the key equipment of the hot water heat storage system can be a heat storage heating device. The heat storage heating device mainly includes a heat storage heater, and a related heat storage heater is, for example, a deaerator, and the deaerator includes a deaerator with a head and a deaerator without a head. The traditional deaerator includes a shell, and steam and cold water are introduced into the shell for heat exchange, and the cold water is heated into hot water. However, the deaerator has limited heat storage capacity and cannot quickly change the load. At present, the requirements for flexible peak shaving of coal-fired units require the hot water heat storage system to quickly store and release heat energy, and require the heat storage heater therein to have the ability to adapt to rapid load change and large temperature difference heat transfer. However, the existing deaerators do not have this ability. Summary of the Invention

[0003] The purpose of the present application is to provide a heat storage heating device and a coal-fired unit, including a heat storage heater, which can adapt to the working conditions of rapid load change and large temperature difference heat transfer.

[0004] The heat storage heater provided by this application includes a shell, and the shell includes an outer shell and a protective inner liner. The inner liner is located inside the outer shell. The inner cavity of the inner liner is used to introduce cold water and steam. There is a gap between the inner liner and the outer shell to form a steam flow channel. The wall of the inner liner has a communication hole, and the communication hole communicates the inner cavity of the inner liner and the steam flow channel.

[0005] Optionally, at least one set of packing heating components is arranged in the inner liner. The packing heating component includes a packing heating layer and a uniform distribution layer located above the packing heating layer. An interface for accessing a steam pipeline is arranged on the side wall of the shell corresponding to the lower part of each set of packing heating components. In the height direction, the communication hole is arranged at the position of the wall of the inner liner corresponding to the lower part of each layer of the uniform distribution layer.

[0006] Optionally, the periphery of the uniform distribution layer includes an annular connecting part, and the connecting part is connected to the inner wall of the inner liner, and the connecting part is not communicated up and down. The communication hole is arranged at the position of the wall of the inner liner corresponding to the position between the uniform distribution layer and the packing heating layer of each set of packing heating components.

[0007] Optionally, at least a part of the periphery of the packing heating layer has a flow-through gap with the inner wall of the inner liner.

[0008] Optionally, in the projection along the height direction, the projection of the flow-through gap is located within the projection of the connecting part.

[0009] Optionally, the regenerative heater further includes a nozzle disposed at the top of the housing, and a communication hole is provided at the top of the inner container.

[0010] Optionally, the regenerative heater includes a spray heating zone located between the filler heating assembly and the nozzle, and an interface for connecting to a steam pipeline is provided at a position on the side wall of the housing corresponding to the spray heating zone.

[0011] Optionally, a filler heating assembly is disposed inside the inner container, and both the filler heating assembly and the inner container are connected to the outer shell.

[0012] Optionally, the filler heating layer or the uniform distribution layer of the filler heating assembly is connected to the outer shell through a first connecting member. The inner container has an avoidance hole for the first connecting member. One end of the first connecting member is connected to the outer shell, and the other end of the first connecting member passes through the avoidance hole and is connected to the filler heating layer or the uniform distribution layer.

[0013] Optionally, the inner container includes a cylindrical side wall. The cylindrical side wall of the inner container is an integral structure formed by winding a thin plate, and the inner container has the avoidance hole; or, the cylindrical side wall of the inner container includes a plurality of plates spliced in the circumferential direction, and avoidance grooves are provided at the edges extending in the height direction of adjacent plates. The avoidance grooves of adjacent two plates are arranged opposite to each other to form the avoidance hole.

[0014] Optionally, the thickness of the outer shell is greater than the thickness of the inner container.

[0015] Optionally, the outer shell is a thick-walled component, and the thickness of the outer shell is not less than 15 mm; the inner container is a thin-walled component, and the thickness of the inner container is 1 mm to 2 mm.

[0016] Optionally, the regenerative heater further includes a hot water tank located below the housing. The hot water tank is in communication with the inner cavity of the inner container, and the hot water tank is provided with an interface for connecting to a steam pipeline.

[0017] This application also provides a coal-fired unit, including the regenerative heating device described in any one of the above.

[0018] The regenerative heating device provided by this application, the housing includes an outer shell and an inner tank. The steam flow channel between the outer shell and the inner tank is filled with heating steam, and no cold water flows through. The outer shell is heated evenly, and the temperature remains unchanged or changes little. The outer shell only needs to bear the steam pressure of the internal steam flow channel and the structural force; while the inner tank only needs to bear the impact stress of the alternating heat and cold of cold water and steam, and does not need to bear the structural force. That is, the solution of this application separates the components that bear the structural force and the steam pressure, and the components that bear uneven heating and large temperature rise changes, so that the housing structure can bear both a relatively high internal steam pressure and the structural force, and can also bear severe thermal shock. In this way, the regenerative heater in this application can be adapted to working conditions with rapid load change and large temperature difference heat transfer. Because the coal-fired unit includes this regenerative heating device, it has the same technical effect. Brief Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of the regenerative heater in the embodiment of this application;

[0020] Figure 2 is Figure 1 a top view of the uniform distribution layer and the inner tank;

[0021] Figure 3 is Figure 1 a simplified structural diagram of the cooperation between the outer shell and the inner tank in a top view perspective in ;

[0022] Figure 4 is Figure 3 an enlarged view of position A in ;

[0023] Figure 5 is Figure 4 a schematic structural diagram of the first connecting piece equipped with a plug cover in.

[0024] The reference numerals in the above-mentioned drawings are explained as follows:

[0025] 11 - First steam branch pipe; 12 - Second steam branch pipe; 13 - Third steam branch pipe; 14 - Fourth steam branch pipe; 15 - Fifth steam branch pipe; 151 - Bubbling heating pipe;

[0026] 21 - First control valve; 22 - Second control valve; 23 - Third control valve; 24 - Fourth control valve; 25 - Fifth control valve;

[0027] 3 - Housing; 31 - Outer shell; 32 - Inner tank; 321 - Plate; 321a - Avoidance groove; 32a - Communication hole; 33 - Nozzle; 34 - Exhaust nozzle; 35 - Uniform distribution layer; 351 - Connection part; 352 - Grate body; 36 - Packing heating layer; 36a - Flow - through gap; 37 - Hot water tank; 38 - First connector; 39 - Second connector; 310 - Plug cover; 3A - Steam flow channel; 3a - First interface; 3b - Second interface; 3c - Third interface; 3d - Fourth interface. Detailed implementation manner

[0028] To enable those skilled in the art to better understand the solution of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0029] Please refer to Figure 1 , Figure 1 , which is a schematic structural diagram of the heat storage heating device in the embodiment of the present application.

[0030] The heat storage heating device in this embodiment can be applied to the hot water heat storage system of a coal - fired unit for hot water heating and heat storage, that is, it can store the excess heat of the steam generated in the coal - fired unit. When the heat energy is insufficient, the stored heat can be released to meet the requirements of the deep peak - shaving and rapid load - change of the coal - fired unit.

[0031] Specifically, the heat storage heating device includes a heat storage heater. The heat storage heater includes a housing 3. The housing 3 includes an outer shell 31 and an inner tank 32. The inner tank 32 is located inside the outer shell 31, that is, the housing 3 is a double - layer structure. Figure 1 Among them, the outer shell 31 includes a cylindrical main body with a top cover. The inner tank 32 also has a cylindrical main body and a top cover. The inner tank 32 is nested inside the outer shell 31. Among them, the inner tank 32 is used to introduce steam. The steam generated in the coal - fired unit can be transported to the inner tank 32 through a steam pipeline. In this embodiment, multiple steam branch pipes are provided in a total steam pipeline to transport multiple paths of steam to the inner tank 32. Corresponding interfaces are provided on the wall of the inner tank 32, and the steam branch pipes pass through the corresponding interfaces to output steam to the inner cavity of the inner tank 32. In addition, the heat storage heater also transports water into the inner tank 32. As Figure 1 shown, a nozzle 33 is provided at the top of the housing 3 for spraying water into the inner tank 32. Relative to the steam, the sprayed water is cold water, and the water is heated by the steam to become hot water for heat storage.

[0032] It should be noted that in this embodiment, there is a gap between the inner liner 32 and the outer shell 31 of the housing 3 to form a steam flow channel 3A. The steam flow channel 3A includes an annular cavity located between the cylindrical side walls of the inner liner 32 and the outer shell 31, and a cavity located between the top covers of the inner liner 32 and the outer shell 31. Moreover, the wall of the inner liner 32 has a communication hole 32a, and the communication hole 32a penetrates through the wall of the inner liner 32 from the inside to the outside. In this way, the communication hole 32a can connect the inner cavity of the inner liner 32 and the steam flow channel 3A, that is, the steam transported by the steam branch pipe into the inner liner 32 can flow into the steam flow channel 3A through the communication hole 32a, so that a part of the transported steam can flow in the steam flow channel 3A.

[0033] In this embodiment, the main functions of the outer shell 31 are as follows. First, it bears the internal steam pressure. Since the outside of the outer shell 31 is at atmospheric pressure and the steam pressure in the steam flow channel 3A is greater than atmospheric pressure, the outer shell 31 needs to bear the steam pressure. Second, the outer shell 31 can provide support for the installation and positioning of internal structural components, that is, the inner liner 32 and other components inside the inner liner 32 can be installed and supported on the outer shell 31, and the inner liner 32 does not need to bear the structural force. Based on the force requirements of steam pressure and structural force, the thickness of the outer shell 31 is set to be relatively thick. Exemplarily, the outer shell 31 of the regenerative heater can be made of Q345 steel with a thickness of about 20 mm. The normal working pressure of the regenerative heater can be 0.9 MPa, which belongs to the first-class pressure vessel. Of course, if the steam pressure is higher, the wall thickness of the outer shell 31 can also be increased, such as 25 mm, 30 mm, etc., which can be determined according to actual requirements and combined with processing costs. However, for the steam use environment of coal-fired units, the wall thickness of the outer shell 31 should usually be more than 15 mm, and the specific thickness is subject to the strength check requirements.

[0034] The main functions of the inner tank 32 are as follows: first, it provides heat insulation to prevent cold water from splashing onto the outer shell 31, thus avoiding the thermal shock caused by the alternating hot and cold, so that the outer shell 31 does not need to bear the thermal shock; second, the inner tank 32 itself can withstand the alternating thermal shock and thermal stress of cold water and steam. The inner cavity of the inner tank 32 and the steam flow channel 3A on the outer side are both filled with steam, and the internal and external pressures are balanced, so the inner tank 32 does not need to bear the steam pressure or structural force. Based on this, the inner tank 32 can be set to be relatively thin, with its thickness less than that of the outer shell 31. Compared with the thick-walled outer shell 31, the inner tank 32 is a thin-walled component, which can be formed by winding a thin plate, such as a thin steel plate with a thickness of about 1 mm to 2 mm. That is, there is a significant difference in thickness between the inner tank 32 and the outer shell 31. In theory, the inner tank 32 only needs to bear the thermal shock. To reduce the stress generated by this thermal shock, the thinner the inner tank 32 is set, the better. However, the steam will flow upward from the bottom in the inner cavity of the inner tank 32. If the inner tank 32 is too thin, it is not conducive to the maintenance of the structure. The inner tank 32 also requires a certain strength, so the thickness of the inner tank 32 can be set between 1 mm and 2 mm. In addition, there can be a gap of about 150 mm between the inner tank 32 and the outer shell 31. This gap is the cross-sectional width of the steam flow channel 3A, which can ensure that there is a sufficient-sized gap to maintain the separation of heat and cold and the balance of steam pressure inside and outside the inner tank 32.

[0035] In the background art, the single-layer housing 3 is prone to damage. After research, the inventor believes that in order to meet the pressure-bearing requirements of structural force and steam pressure, the housing 3 is set to be relatively thick, so the heat transfer path between the inner surface and the outer surface is relatively long. If the inner surface bears the thermal shock, it is difficult for the temperature changes of the inner surface and the outer surface to be consistent, which is prone to generating thermal stress. And on the premise of bearing both structural force and steam pressure at the same time, cracks will occur and then it will be damaged.

[0036] It can be seen that in this embodiment, the housing 3 of the regenerative hybrid heat exchanger is set to two parts, namely the outer shell 31 and the inner tank 32, and a steam flow channel 3A is established between them, which can produce the following technical effects:

[0037] The gap between the outer shell 31 and the protective inner tank 32 is filled with heating steam, and no cold water flows through. The outer shell 31 is evenly heated, and the temperature remains unchanged or changes little. The outer shell 31 only needs to bear the steam pressure and structural force of the internal steam flow channel 3A; while the inner tank 32 only needs to bear the impact stress of the alternating hot and cold of cold water and steam, and does not need to bear the structural force. The inner tank 32 can be set to be relatively thin. Under the thermal shock, the internal and external changes of the inner tank 32 are easy to be consistent, and it can better resist the thermal shock. That is, in this embodiment, the components bearing structural force and steam pressure and the components bearing uneven heat and large temperature rise change are arranged separately, so that the housing 3 structure can not only bear a relatively high internal steam pressure and structural force, but also bear severe thermal shock.

[0038] Such asFigure 1 As shown, in this embodiment, a filler heating assembly is provided inside the inner tank 32 of the regenerative heater. The filler heating assembly includes a filler heating layer 36 and a distribution layer 35 located above the filler heating layer 36. Water is sprayed from above onto the distribution layer 35, which can also be called a water distribution grate and has evenly distributed through-holes. For example, the distribution layer 35 can be composed of staggeredly arranged angle steels or perforated steel plates, etc. The distribution layer 35 evenly distributes the sprayed water or water mist onto the filler heating layer 36 below for heat exchange. The filler heating layer 36 is heated by steam. After the water distributed by the distribution layer 35 falls into the filler heating layer 36, it can obtain a large contact area with the steam in the filler heating layer 36 and be heated. Specifically, the filler heating layer 36 has a large specific surface area and thus has good heat exchange capacity. In this embodiment, the filler heating layer 36 can be, for example, composed of a mesh corrugated filler processed from a stainless steel thin plate, which has the advantages of large throughput, small pressure drop, and not being easily detached. The stainless steel material also has good thermal conductivity. The material of the outer shell 31 in this embodiment can be selected as Q345 (a kind of high-quality carbon steel) or materials of the same grade, and the material of the inner tank 32 can be stainless steel.

[0039] In this embodiment, multiple groups of filler heating assemblies are arranged in the inner tank 32 of the outer shell 31 from top to bottom. Figure 1 Three layers of filler heating assemblies are shown. The number of groups of filler heating assemblies can be designed according to the height of the inner tank 32, the actual heat storage requirements, etc. It is possible to set one group or multiple groups.

[0040] Please continue to refer to Figure 2 , Figure 2 for Figure 1 the top view of the distribution layer 35 and the inner tank 32 in

[0041] It should be emphasized that the periphery of the distribution layer 35 includes an annular connecting portion 351, and the connecting portion 351 is connected to the inner wall of the inner tank 32. There is no gap between the distribution layer 35 and the inner wall of the inner tank 32. The connecting portion 351 can be a solid structure or a hollow structure as long as it is not vertically through. The periphery of the distribution layer 35 does not limit the distribution layer 35 to be square, but refers to the entire outer periphery, that is, the connecting portion 351 is an annular structure. Figure 2 In Figure 1 ,the distribution layer 35 includes a grate body 352 and a connecting portion 351 surrounding and connecting to the periphery of the grate body 352. In this way, the water from above cannot pass through the connecting portion 351 around, and can only fall after being evenly distributed through the part of the grate body 352 outside the connecting portion 351. At this time, in Figure 1 、 2As shown, due to the shielding of the connecting portion 351, it is not easy for water to accumulate directly below the connecting portion 351 of the uniform distribution layer 35. Therefore, the communication hole 32a, which is lower than the connecting portion 351 in height, is also not likely to admit water, thus preventing water from entering the steam flow channel 3A and further ensuring a reduction in thermal shock. It can be seen that the communication hole 32a can be arranged as close as possible to the connecting portion 351. For example, the top hole wall of the communication hole 32a can be flush with the bottom wall of the connecting portion 351. The connecting portion 351 acts as a "brim" for the communication hole 32a, providing better shielding to reduce or prevent water from entering the communication hole 32a. Additionally, water will fall onto the packing heating layer 36. Since the height of the communication hole 32a is higher than that of the packing heating layer 36, water on the packing heating layer 36 can be prevented from entering the communication hole 32a. Therefore, the height of the communication hole 32a is between the heights of the packing heating layer 36 and the uniform distribution layer 35.

[0042] Furthermore, at least a part of the periphery of the packing heating layer 36 has a gap with the inner wall of the inner container 32, which can be defined as a flow-through gap 36a. In this way, when the water flow rate is too large and exceeds the flow-through capacity of the packing heating layer 36, the excess water can overflow through the flow-through gap 36a to the lower part, thus avoiding water resistance. As Figure 1 shown, the packing heating layer 36 can have a flow-through gap 36a with the inner wall of the inner container 32 throughout its entire periphery, creating an annular flow-through gap 36a and enhancing the flow-through capacity. At this time, the packing heating layer 36 needs to be supported by a support member or suspended by a suspension member, such as supported at the bottom of the outer shell 31 or suspended from the uniform distribution layer 35. Of course, the packing heating layer 36 can also have a flow-through gap 36a with the inner wall of the inner container 32 at only a part of its periphery. Connecting members can be arranged around the packing heating layer 36, and the connecting members are kept connected to the inner wall of the outer shell 31, which facilitates the installation and arrangement of the packing heating layer 36. It can be seen that when the entire periphery of the packing heating layer 36 has a gap with the inner wall of the inner container 32, the packing heating layer 36 can also be installed and fixed in other ways. For example, the outer shell 31 can also have a bottom, and the packing heating layer 36 is supported by a support member such as a support rod to the bottom of the outer shell 31, etc.

[0043] When setting the flow-through gap 36a, in the projection along the height direction, the projection of the flow-through gap 36a can be located within the projection of the connecting portion 351 of the uniform distribution layer 35. In this way, the connecting portion 351 can shield the flow-through gap 36a from above, preventing water or water mist sprayed from above from falling directly without passing through the packing heating layer 36.

[0044] In this embodiment, a total of three groups of packing heating components are provided. A communication hole 32a is provided on the wall of the inner container 32 corresponding to each layer of the packing heating component, or a group of circumferentially distributed communication holes 32a are provided to allow steam to fully enter the steam flow channel 3A.

[0045] Regarding the filler heating layer 36 and the uniform distribution layer 35, both are connected to the outer shell 31, that is, the outer shell 31 provides installation support. The inner tank 32 does not support the internal components inside the housing 3 such as the filler heating layer 36 and the uniform distribution layer 35. For example, the internal components inside the housing 3 have no connection relationship with the inner tank 32, or have a relationship such as contact, and do not bear or inevitably bear very little, even negligible load. Considering that if a support member extending up and down is provided to support the internal components, it will occupy the space for heat exchange between steam and water up and down, so the cylindrical side wall of the outer shell 31 and the uniform distribution layer 35 or the filler heating layer 36 can be kept connected through the first connecting member 38.

[0046] As Figures 3 - 5 shown, Figure 3 it is Figure 1 a structural schematic diagram of the top view of the cooperation between the outer shell 31 and the inner tank 32 in Figure 4 and is Figure 3 an enlarged view of position A in Figure 5 and is Figure 4 a structural schematic diagram of the first connecting member 38 equipped with a plug cover 310 in

[0047] Since the filler heating assembly is arranged inside the inner tank 32, the first connecting member 38 needs to pass through the inner tank 32 in order to establish a connection with the filler heating assembly and the outer shell 31, so the inner tank 32 needs to avoid the first connecting member 38. Figure 4 In

[0048] Considering the convenience of installation, the cylindrical side wall of the inner tank 32 can be a split structure. For example, it includes a plurality of plates 321 distributed circumferentially. The plurality of plates 321 are pieced together circumferentially to form a complete inner tank 32. The top cover of the inner tank 32 can be fixedly connected to the cylindrical side wall of the inner tank 32. When the inner tank 32 is an integral structure formed by winding thin plates, it is also separately arranged and fixedly connected to the top cover. When the inner tank 32 has a cylindrical side wall, the plate 321 is, for example, an arc-shaped plate. When the cylindrical side wall of the inner tank 32 is of other shapes, the shape of the plate 321 also changes accordingly.

[0049] Refer to Figure 3, a total of four first connectors 38 are provided, so the inner tank 32 can be divided into four plates 321. The first connectors 38 and the outer shell 31 or the corresponding filler heating layer 36 and the distribution layer 35 are first installed and fixed. Then, the plate 321 is placed between two adjacent first connectors 38. An avoidance groove 321a is provided at the edge of the plate 321 extending in the height direction. The avoidance grooves 321a of two adjacent plates 321 are arranged oppositely to form an avoidance hole to allow the first connector 38 to pass through. It can be understood that the above-mentioned should minimize the connection between the inner cavity of the inner tank 32 and the external steam flow channel 3A. Then, the avoidance hole and the first connector 38 can be roughly matched to reduce a large gap generated between the hole wall of the avoidance hole and the first connector 38 after fitting. Of course, based on the installation design, there will still be a gap between the avoidance hole and the first connector 38. If it is necessary to further ensure that cold water does not flow from the position of the avoidance hole to the steam flow channel 3A, a plug 310 can be provided. The plug 310 can abut against the inner wall of the inner tank 32 to seal the avoidance hole, or even if it does not contact the inner wall, a labyrinth structure is formed, and water is not easily introduced into the outer steam flow channel 3A. The plug 310 can be provided on the inner side or the outer side of the avoidance hole. It is more convenient to install and operate when provided on the inner side.

[0050] Look at Figure 3 , in this embodiment, the first connector 38 extends inward from the inner wall of the inner tank 32, and the extended part can be used to support the filler heating layer 36 or the distribution layer 35, that is, the filler heating layer 36 or the distribution layer 35 can be directly placed on the first connector 38, and at the same time, bolt and buckle-like structures are matched on the first connector 38 to complete the detachable fixed connection, which is convenient for maintenance and replacement. Of course, the first connector 38 can also be fixedly connected to the filler heating layer 36 or the distribution layer 35 by welding. Similarly, the connection method between the first connector 38 and the outer shell 31 can also be welding or detachable fixed connection through structural parts such as bolts and buckles.

[0051] In this embodiment, a second connector 39 can also be provided. The second connector 39 is used to connect the inner tank 32 and the outer shell 31. In this way, the outer shell 31 also plays a role in connecting and supporting the inner tank 32. The connection method between the second connector 39 and the inner tank 32 and the outer shell 31 can also be welding or detachable fixed connection by fasteners such as bolts and buckles. When the inner tank 32 adopts the split structure of the above-mentioned multiple plates 321, the adjacent plates 321 can also be welded or connected by fasteners.

[0052] In addition, as Figure 1As shown in the figure, the nozzle 33 of the regenerative heater is arranged at the top of the housing 3. The nozzle 33 is inserted into the inner cavity of the inner tank 32 from the outside of the outer shell 31, so as to spray water into the inner tank 32. At this time, a communication hole 32a can also be arranged at the top of the inner tank 32. The nozzle 33 sprays water downward, and the communication hole 32a is arranged around the nozzle 33, and water will not enter the communication hole 32a. In this way, steam can also enter the steam flow channel 3A from the top, so that there is a steam inlet channel in the steam flow channel 3A from top to bottom. The steam is relatively evenly distributed in the steam flow channel 3A, and the steam pressure distribution is also relatively uniform, which is beneficial to the pressure-bearing stability of the outer shell 31.

[0053] The regenerative heater in this embodiment includes a spray heating area, which is located between the packing heating assembly and the nozzle 33. That is, the nozzle 33 has an atomizing function. The nozzle 33 can specifically adopt a disk-type constant-speed nozzle 33, which has the advantages of good atomization effect and good performance under variable working conditions, so as to meet the requirements of large-flow water spraying of the regenerative heater. The nozzles 33 can be arranged at equal intervals around the top of the housing 3, and 2 to 4 nozzles can be arranged according to needs. Among them, the inner cavity of the inner tank 32 is the space between the packing heating assembly and the nozzle 33, which is the spray heating area. The sprayed cold water and water mist directly contact and exchange heat with the steam. The spray heating area is the main heating area of the regenerative heater in this embodiment. The packing heating layer 36 is located below the spray heating area, which can be used for supplementary heating of water under high load, and can also bear a large heating load under low load conditions.

[0054] At this time, a first interface 3a (including holes opened in the outer shell 31 and the inner tank 32) is arranged on the side wall of the housing 3 corresponding to the spray heating area. The first interface 3a is used to connect to the first steam branch pipe 11. The first steam branch pipe 11 can directly extend into the spray heating area and extend from the position of the first interface 3a to the opposite side of the wall of the inner tank 32. A plurality of upward steam injection holes can be arranged along the length direction of the first steam branch pipe 11 to uniformly inject steam upward. A first control valve 21 can be arranged on the first steam branch pipe 11 to regulate the steam pressure entering the inner tank 32 from the first steam branch pipe 11. The first control valve 21 is, for example, a throttle valve.

[0055] In this embodiment, multiple groups of packing heating assemblies are provided, and corresponding steam branch pipes are arranged below each layer of packing heating assembly. Figure 1Among them, they are defined as the second steam branch pipe 12, the third steam branch pipe 13, and the fourth steam branch pipe 14 from top to bottom. On the side wall of the housing 3, corresponding interfaces are provided below each packing heating component, namely the second interface 3b, the third interface 3c, and the fourth interface 3d, which are respectively used to connect to the corresponding second steam branch pipe 12, third steam branch pipe 13, and fourth steam branch pipe 14. The setting method of the steam branch pipes is roughly the same as that of the above-mentioned first steam branch pipe 11 and can be understood by reference. Second control valves 22, third control valves 23, and fourth control valves 24 are respectively provided for the three steam branch pipes. The control valves can also be throttle valves, which are used to regulate the steam pressure of the corresponding steam branch pipes entering the inner tank 32. Communication holes 32a are provided at positions on the wall of the inner tank 32 corresponding to the lower part of each uniform distribution layer 35. Then, the communication holes 32a are arranged relatively evenly up and down, and the communication holes 32a are distributed in the heating area corresponding to each steam branch pipe, which is beneficial to the balanced flow of steam and reduces or avoids the generation of local steam resistance.

[0056] In this embodiment, the regenerative heater further includes a hot water tank 37. The hot water tank 37 is located below the outer shell 31 and is kept in communication with the inner cavity of the inner tank 32. For example, an interface is provided at the top of the hot water tank 37 and is connected to the bottom of the housing 3 through a communication pipeline, specifically through a flange. An interface is provided at the top of the hot water tank 37, and it can also be directly docked and connected to the interface at the bottom of the housing 3. In this way, the water heated after passing through the upper spray heating area and the packing heating component is heated to hot water and collected in the hot water tank 37 for storage. In this embodiment, the regenerative heater includes a spray heating area and a packing heating area, and has good heating capacity and can heat more hot water. Then, the volume of the hot water tank 37 can be increased according to the demand for hot water storage, and hot water tanks 37 of different specifications and capacities can be selected. The high water level and the lowest water level of the hot water tank 37 can both exceed the limit of the deaerator water level in the prior art, and the effective hot water storage volume can reach more than 50% of the total volume, meeting the intermittent demand for hot water storage and heat release.

[0057] At this time, the hot water tank 37 can be provided with corresponding interfaces for connecting to a steam pipeline. This steam branch pipe can be defined as the fifth steam branch pipe 15, and a fifth control valve 25 can also be provided. The fifth control valve 25 can also be a throttle valve. The part of the fifth steam branch pipe 15 extending into the hot water tank 37 can be a bubbling heating pipeline 151. The steam of the fifth steam branch pipe 15 can deeply heat and keep warm the hot water inside the hot water tank 37. Specifically, the fifth steam branch pipe 15 can extend to the bottom of the hot water tank 37.

[0058] In this embodiment, the regenerative heater includes a spray heating area and a packing heating area, and the working principles of each area are as follows:

[0059] Spray heating zone: The uppermost part of the regenerative heater is the spray heating zone. The heat transfer capacity of the spray heating zone is closely related to the atomization effect of the nozzle 33. Under high load, the water flow rate is close to the designed flow rate of the nozzle 33, the atomization effect is good, the droplet diameter is small, the total heat transfer surface area is larger, and the heat transfer intensity is high. Under low load, the atomization effect deteriorates, the droplet diameter becomes larger, the total heat transfer surface area decreases, and the heat transfer inside the droplet is insufficient, resulting in the deterioration of the heat transfer effect. Therefore, the characteristics of the spray heating zone are strong heat transfer capacity under high load and poor heat transfer capacity under low load.

[0060] Packing heating zone: Below the spray heating zone is the packing heating zone. To ensure the heat transfer effect, more than one layer of packing heating components can be arranged. The heat transfer capacity of the packing heating zone is positively correlated with the specific surface area of the packing. To enhance the heat transfer capacity, the specific surface area of the packing should be increased as much as possible. However, if the specific surface area of the packing is too large, the voids are dense, the flow capacity is poor, and water resistance is likely to occur. Therefore, the selection of the specific surface area of the packing needs to consider both the heat transfer capacity and the flow capacity. The characteristics of the packing heating zone are that the heat transfer capacity is weaker than that of the spray heating zone, but the change in the heat transfer capacity of the packing heating zone with the load is smaller, and it has stronger adaptability to variable working conditions.

[0061] Insulation heating zone: The hot water that enters the lower hot water tank 37 after being heated in the inner tank 32 is already relatively close to the saturation temperature corresponding to the heating steam pressure. For example, the temperature difference between the outlet water temperature and this saturation temperature does not exceed 1°C. To ensure the deep heating of the hot water in the hot water tank 37 and the insulation of the hot water tank 37, the fifth steam branch pipe 15 extends to the bottom of the hot water tank 37. Since the temperature rise of the hot water in the hot water tank 37 is very small, the proportion of the bubbling heating and insulation heat transfer amount in the total heat transfer amount is very small, and the proportion of the steam consumption in the total steam consumption is also small.

[0062] The above three heating zones are distributed in sequence from top to bottom. Each heating zone has a corresponding steam branch pipe for input steam and a corresponding control valve. The pressure loss of each control valve is relatively small, and the pressure of the multi-way steam branch pipes can be slightly reduced from bottom to top in turn. For example, there is a pressure difference of about dozens of Pa between adjacent steam branch pipes, that is, the steam is distributed in a stepped manner from bottom to top, so as to form a certain steam pressure gradient inside the inner tank 32, which can ensure the continuous upward flow of the steam inside the regenerative heater and the hot water tank 37. Figure 1 In addition, an exhaust nozzle 34 is provided at the top of the shell 3, and steam can be discharged as needed. In addition, to avoid the frequent operation and adjustment of the control valve and increase the operation and maintenance cost, through the balance calculation of the steam consumption of each steam branch pipe under different working conditions and reasonable value selection, each control valve can be set at a suitable fixed opening degree, and through reasonable steam circulation measures inside the regenerative heater, the heating steam can flow smoothly.

[0063] The regenerative heater in this embodiment can operate under several working conditions such as high load, low load, and rapid variable load. The specific process is as follows:

[0064] High-load heating process: Under high load, the water flow rate is large, approaching the design condition of nozzle 33, and the atomization effect of nozzle 33 is good. The main heating process is completed in the spray heating zone, which accounts for about 90% of the total heat transfer in this embodiment. Of course, according to parameters such as the design of nozzle 33 and the spatial design of the spray heating zone, this proportion and the proportion of heat transfer borne by other heating zones mentioned below can also change. The following packing heating zone serves as a supplementary heating zone, mainly used to ensure that the water outlet of the regenerative heater reaches the saturation temperature. Due to the large water flow rate, there may be overflow in the flow-through gap 36a around the packing heating layer 36, that is, setting the flow-through gap 36a can adapt to the high-load heating condition.

[0065] Low-load heating process: Under low load, the water flow rate is small, deviating significantly from the design flow rate of nozzle 33. The atomization effect of nozzle 33 deteriorates, the droplet diameter becomes larger, and the heat transfer capacity decreases. At this time, the heat transfer in the spray heating zone accounts for about 40% - 60% of the total heat transfer. In this case, the heat load of the packing heating zone increases, undertaking a larger heat transfer load. Through the step-by-step heating of the three layers of heating packing, it can ensure that the water outlet of the regenerative heater basically reaches the saturation temperature.

[0066] Rapid load change process: When the water flow rate changes rapidly from the minimum flow rate to the maximum flow rate, or vice versa, mainly the heat load redistribution occurs between the spray heating zone and the packing heating zone inside the regenerative heater. Through the reasonable configuration and structural layout of the two main heat transfer zones, it can ensure that the water outlet basically reaches the saturation temperature. For example, the temperature difference between the water outlet temperature and the saturation temperature corresponding to the heating steam does not exceed 1°C. This regenerative heater can adapt to the working conditions of large temperature difference heat transfer and large temperature rise rate. Specifically, it can perform large temperature difference heat transfer by heating water from 20°C to about 180°C, and can have the ability of rapid load change from the minimum flow rate to the maximum flow rate within 5 minutes.

[0067] During the rapid load change process, the steam-water cold and heat shocks generated by the internal unsteady heat transfer process are mainly borne by the inner tank 32, and will not cause cold and heat shock effects on the outer shell 31. Therefore, the safety of the equipment can be ensured and no vibration will occur. In addition, in the existing headless deaerator, the steam volume is large, and abnormal conditions such as bubbling vibration and false water level may occur. In this embodiment, the spray heating zone and the packing heating zone have already heated the water relatively sufficiently, and the heating steam in the hot water tank 37 only needs to account for a small proportion. Therefore, the above abnormal problems such as bubbling vibration and false water level can be improved or avoided. In terms of structural layout, the steam flow channel 3A between the outer shell 31 and the inner tank 32 of the regenerative heater realizes balanced flow through the communication hole 32a provided on the inner tank 32, which is beneficial to ensuring that no steam blockage occurs locally during the rapid load change process; the flow-through gap 36a provided between the packing heating layer 36 and the inner tank 32 can make the water flow unobstructed, which is beneficial to ensuring that no water blockage occurs locally during the rapid load change process.

[0068] It can be seen that for the regenerative heater in this embodiment, after adopting measures such as multi-process step-by-step heating, separate arrangement of pressure-bearing and heat-bearing components, and stepped steam distribution, through reasonable integration and optimization of the heating process flow, the steam path and water path can always remain unobstructed under different working conditions and loads, both having good heating performance and variable load adaptability, reducing or avoiding the phenomena of steam resistance and water resistance, so as to adapt to the ultra-flexible operation of the hot water energy storage system configured in the coal-fired unit with rapid load change.

[0069] The embodiment of the present application also provides a coal-fired unit, which includes the regenerative heater described in any of the above embodiments, so it has the same technical effects and will not be elaborated here. That is, the regenerative heater in the above embodiment can belong to the hot water energy storage system configured for the coal-fired unit to adapt to flexible peak shaving operation. The regenerative heater can be connected downstream of the cold water storage tank in the hot water energy storage system. The source of its water can specifically be the condensate from the condenser, and the source of steam can specifically be from the steam extraction system of the steam turbine.

[0070] In this article, specific examples are used to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A thermal storage heating device, characterized in that: The thermal storage heater comprises a shell (3), the shell (3) comprising an outer shell (31) and an inner liner (32), the inner liner (32) being located in the outer shell (31), the inner cavity of the inner liner (32) being used for passing steam, a gap being provided between the inner liner (32) and the outer shell (31) to form a steam flow channel (3A), the wall of the inner liner (32) having a connecting hole (32a), the connecting hole (32a) connecting the inner cavity of the inner liner (32) and the steam flow channel (3A); At least one group of filler heating components is arranged in the inner pot (32), and the filler heating components include a filler heating layer (36) and a uniformly distributed layer (35) located above the filler heating layer (36); the side wall of the shell (3) is provided with an interface for connecting to a steam pipeline below each group of the filler heating components; in the height direction, the wall of the inner pot (32) is provided with the connecting hole (32a) at a position corresponding to the position below each layer of the uniformly distributed layer (35).

2. The thermal storage heating device according to claim 1, characterized in that: The evenly distributed layer (35) comprises an annular connecting portion (351) around its periphery, the connecting portion (351) being connected to the inner wall of the inner liner (32), and the connecting portion (351) being not connected up and down; the wall of the inner liner (32) is provided with the connecting hole (32a) at a position corresponding to the evenly distributed layer (35) and the filling heating layer (36) of each group of the filling heating components.

3. The thermal storage heating device according to claim 2, characterized in that: At least a portion of the surrounding area of ​​the filler heating layer (36) has a flow gap (36a) with the inner wall of the inner container (32).

4. The thermal storage heating device according to claim 3, characterized in that: Projected along the height direction, the projection of the flow gap (36a) is located within the projection of the connecting portion (351).

5. The thermal storage heating device according to claim 1, characterized in that: The thermal storage heater further comprises a nozzle (33), wherein the nozzle (33) is arranged at the top of the shell (3), and the top of the inner tank (32) is provided with the connecting hole (32a).

6. The thermal storage heating device according to claim 5, characterized in that: The thermal storage heater comprises a spray heating zone, the spray heating zone is located between the filler heating assembly and the nozzle (33), and the side wall of the shell (3) is provided with an interface for connecting to a steam pipeline at a position corresponding to the spray heating zone.

7. The thermal storage heating device according to claim 1, characterized in that: A filler heating component is arranged in the inner container (32), and the filler heating component and the inner container (32) are directly or indirectly connected to the outer shell (31).

8. The thermal storage heating device according to claim 7, characterized in that: The filler heating layer (36) or the uniformly distributed layer (35) of the filler heating assembly is connected to the outer shell (31) via a first connecting piece (38); the inner liner (32) has an avoidance hole for avoiding the first connecting piece (38); one end of the first connecting piece (38) is connected to the outer shell (31); and the other end of the first connecting piece (38) passes through the avoidance hole and is connected to the filler heating layer (36) or the uniformly distributed layer (35).

9. The thermal storage heating device according to claim 8, characterized in that: The inner container (32) comprises a cylindrical side wall; The cylindrical side wall of the inner liner (32) is an integral structure formed by winding a thin plate, and the inner liner (32) has the avoidance hole; or, the cylindrical side wall of the inner liner (32) includes a plurality of plates assembled along the circumferential direction, and the edges extending in the height direction of adjacent plates are provided with avoidance grooves, and the avoidance grooves of two adjacent plates are arranged relative to each other to form the avoidance hole.

10. The thermal storage heating device according to any one of claims 1 to 9, characterized in that: The thickness of the outer shell (31) is greater than the thickness of the inner shell (32).

11. The thermal storage heating device according to claim 10, characterized in that: The outer shell (31) is a thick-walled component, and the thickness of the outer shell (31) is not less than 15 mm; the inner liner (32) is a thin-walled component, and the thickness of the inner liner (32) is 1 mm to 2 mm.

12. The thermal storage heating device according to any one of claims 1 to 9, characterized in that: The thermal storage heater further comprises a hot water tank (37), the hot water tank (37) being located below the shell (3), the hot water tank (37) being in communication with the inner cavity of the inner tank (32), and the hot water tank (37) being provided with an interface for accessing a steam pipeline.

13. A coal-fired unit, characterized in that: It comprises the thermal storage heating device as described in any one of claims 1 to 12.

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