Electric heating heat storage device and coal-fired power generating unit

Abstract

The application provides an electric heating heat storage device and a coal-fired power generating unit, and can improve the energy storage efficiency. The electric heating heat storage device comprises a shell and a heat exchange module in the shell. The heat exchange module comprises a heat exchange layer, a first conductive cover plate and a second conductive cover plate. The material of the heat exchange layer is a metal porous material. The heat exchange layer has a heat exchange layer top part and a heat exchange layer bottom part distributed along a first direction. The first conductive cover plate is arranged on the heat exchange layer top part. The second conductive cover plate is arranged on the heat exchange layer bottom part. The first conductive cover plate and the second conductive cover plate are both provided with a plurality of through hole structures penetrating along the first direction. The heat exchange module further comprises a first electrode and a second electrode. The first electrode is connected with the first conductive cover plate. The second electrode is connected with the second conductive cover plate. The shell is further provided with a steam inlet and a steam outlet. The electric heating heat storage device comprises a steam passage connecting the steam inlet and the steam outlet. The holes of the heat exchange layer and the through hole structures are part of the steam passage.

Description

Technical Field

[0001] This application relates to the field of coal-fired power unit technology, specifically to an electric heating thermal storage device and a coal-fired power generation unit. Background Technology

[0002] Coal-fired power units need to be flexible and have a high rate of load change to ensure the stable operation of the power system. However, the current rate of load change of coal-fired power units is relatively low. To achieve the goal of balancing renewable energy, it is necessary to increase the flexibility of power plants, that is, to quickly generate superheated steam with a high degree of superheat (e.g., exceeding 100°C) in a short period of time to enter the steam turbine to generate electricity, thereby increasing the rate of load change of the unit.

[0003] To address this, one approach is to install energy storage devices and connect them to the power grid for energy storage and release. Specifically, this involves heating heating rods or tubes using off-peak electricity, which then heats the energy storage material. However, this energy storage method is relatively inefficient. Summary of the Invention

[0004] To address the aforementioned technical problems, the purpose of this application is to provide an electric heating thermal storage device and a coal-fired power generation unit, which can improve energy storage efficiency.

[0005] The electric heating and heat storage device provided in this application includes a shell and a heat exchange module located inside the shell. The heat exchange module includes a heat exchange layer, a first conductive cover plate, and a second conductive cover plate. The heat exchange layer is made of a porous metal material. The heat exchange layer has a top and a bottom distributed along a first direction. The first conductive cover plate covers the top of the heat exchange layer, and the second conductive cover plate covers the bottom of the heat exchange layer. Both the first conductive cover plate and the second conductive cover plate are provided with a plurality of through holes extending along the first direction.

[0006] The heat exchange module further includes a first electrode and a second electrode, wherein the first electrode is connected to the first conductive cover plate and the second electrode is connected to the second conductive cover plate.

[0007] The housing is also provided with a steam inlet and a steam outlet. The electric heating heat storage device includes a steam passage connecting the steam inlet to the steam outlet. The pores of the heat exchange layer and the through-hole structure are part of the steam passage.

[0008] Optionally, the heat exchange module further includes an insulating outer cover, in which the heat exchange layer, the first conductive cover plate, and the second conductive cover plate are all installed. The insulating outer cover has a plurality of through-hole structures along the first direction, and the through-hole structures are part of the steam passage.

[0009] Optionally, the plurality of through-hole structures and the plurality of perforated structures are evenly distributed.

[0010] Optionally, the insulating cover includes an annular cover body, a top cover, and a bottom cover. The top cover covers one end of the annular cover body along the first direction, and the bottom cover covers the other end of the annular cover body along the first direction. Both the top cover and the bottom cover are provided with the perforated structure.

[0011] Optionally, the top cover of the outer casing abuts against the first conductive cover plate, and the bottom cover of the outer casing abuts against the second conductive cover plate.

[0012] Optionally, the insulating cover is made of ceramic material, and the side wall of the insulating cover and the side wall of the housing are welded together.

[0013] Optionally, both the first conductive cover plate and the second conductive cover plate are metal cover plates, and both the first conductive cover plate and the second conductive cover plate are welded to the heat exchange layer.

[0014] Optionally, the electric heating heat storage device includes at least two heat exchange modules distributed along the first direction, and the side wall of the shell is provided with at least two steam outlets, and the cavity between two adjacent heat exchange modules is connected to a corresponding steam outlet.

[0015] Optionally, the electric heating heat storage device further includes a baffle assembly, which includes at least two layers of baffles distributed along the first direction. There is a gap between the baffles and the side wall of the housing, and the baffles are projected along the first direction. The projections of two adjacent baffles partially overlap and partially offset.

[0016] Optionally, the electric heating heat storage device further includes steam pipes connected to each of the steam outlets, and each of the steam pipes is equipped with a control valve.

[0017] Optionally, a discharge pipe is provided at the bottom of the housing, and the discharge pipe is provided with a discharge valve.

[0018] Optionally, the inner surface of the housing has an insulating layer, and / or the outer surface of the housing is covered with a thermal insulation layer.

[0019] The electric heating thermal storage device in this application has the following advantages:

[0020] First, the heat exchange layer of the heat exchange module is made of a porous metal material. Utilizing the interconnected nature of the solid metal regions in this porous material, current can pass through the entire heat exchange layer for heat storage during the heat storage period. Furthermore, the porous structure of the metal material allows steam to pass through, thus enabling steam heating. Therefore, this electric heating heat storage device can directly electric heat the heat exchange layer, thereby directly utilizing off-peak electricity to heat the porous metal material, directly converting electrical energy into heat energy, reducing the number of energy conversion steps, and improving energy utilization efficiency.

[0021] Second, the first conductive cover plate covers the top of the heat exchange layer and the second conductive cover plate covers the bottom of the heat exchange layer. This means that current can be applied to the entire end face of the heat exchange layer at the same time, so that the current can flow relatively evenly through the porous metal heat exchange layer, thereby enabling the porous metal heat exchange layer 101 to generate heat and store energy evenly.

[0022] Third, porous metal materials have high porosity. The solid metal in porous metal materials occupies a small volume, which can reserve a large steam storage space. In situations where immediate steam supply is required, it can achieve the purpose of immediate steam supply. If the steam production flow fluctuates, it can play a buffering and smoothing role to stabilize the steam supply. At the same time, porous metal materials can ensure that the steam flow area is large enough, thereby reducing the steam flow resistance.

[0023] Fourth, the porous metal material of the heat exchange layer also has a large specific surface area, which makes the heat exchange layer and the incoming saturated steam have a large convective heat exchange area, which is conducive to rapid and sufficient heat exchange, thereby quickly completing the heating process from saturated steam to superheated steam. Moreover, the porous metal material has a large heat storage density, and only a small temperature reduction is needed to release heat to a higher temperature.

[0024] This application also provides a coal-fired power generation set, including a steam turbine and a steam engine, and further including an electric heating and heat storage device disposed between the steam turbine and the steam engine, wherein the electric heating and heat storage device is any of the electric heating and heat storage devices described above. The coal-fired power generation set provided by this application includes the above-mentioned electric heating and heat storage device and has the same technical effects as the above-mentioned electric heating and heat storage device. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the electric heating heat storage device in the embodiments of this application;

[0026] Figure 2 for Figure 1 Schematic diagram of the heat exchange module in the middle;

[0027] Figure 3 for Figure 2 A schematic diagram of the structure of the first conductive cover plate;

[0028] Figure 4 for Figure 2 A schematic diagram of the structure of the second conductive cover plate.

[0029] The annotations in the attached figures are explained as follows:

[0030] 10-Heat exchange module; 10a-First-stage heat exchange module; 10b-Second-stage heat exchange module; 10c-Third-stage heat exchange module; 101-Heat exchange layer; 1011-Top of heat exchange layer; 1012-Bottom of heat exchange layer; 102-First conductive cover plate; 103-Second conductive cover plate; 104-Insulating outer cover; 1041-Top cover of outer cover; 1042-Bottom cover of outer cover; 1043-Annular cover; 105-First electrode; 106-Second electrode;

[0031] 20 - Baffle assembly; 201 - First baffle; 202 - Second baffle;

[0032] 301 - Primary control valve; 302 - Secondary control valve; 303 - Tertiary control valve;

[0033] 40 - Steam inlet valve;

[0034] 50 - Steam inlet pipe;

[0035] 601 - Primary steam outlet pipeline; 602 - Secondary steam outlet pipeline; 603 - Tertiary steam outlet pipeline; 604 - Main steam collection pipeline;

[0036] 70 - Discharge valve; 80 - Discharge pipe;

[0037] 90-Shell; 901-Shell body; 902-Insulation layer; 903-Insulation layer; 90a-Primary steam outlet; 90b-Secondary steam outlet; 90c-Tertiary steam outlet; 90d-Steam inlet. Detailed Implementation

[0038] To enable those skilled in the art to better understand the technical solutions of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. In the embodiments of this application, the terms "first" and "second" are used only to distinguish the same or similar features, and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features.

[0039] Please refer to Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the structure of the electric heating heat storage device in the embodiments of this application; Figure 2 for Figure 1 A schematic diagram of the structure of the heat exchange module 10.

[0040] The electric heating heat storage device in this embodiment can be used in conjunction with the steam engine and turbine of a generator set. Steam discharged from the steam engine can be introduced into the electric heating heat storage device for heating before flowing to the turbine. Specifically, the electric heating heat storage device includes a housing 90 and a heat exchange module 10. The housing 90 is as follows... Figure 1 The diagram shows a vertical structure, with the heat exchange module 10 located inside the housing 90. Figure 1 The housing 90 contains three heat exchange modules 10 arranged from top to bottom. Each heat exchange module 10 includes a heat exchange layer 101, a first conductive cover plate 102, and a second conductive cover plate 103. The heat exchange layer 101 is a porous metal structure with multiple pores, that is, the heat exchange layer 101 is made of a porous metal material, similar to a sponge structure. The specific material of the porous metal is not limited, such as foam metal, or the metal itself, such as pure nickel or nickel-chromium. The porous metal material can also be a metal mesh structure, which has a large metal density, specific heat capacity, and large porosity, and can also have good corrosion resistance.

[0041] The first conductive cover plate 102 and the second conductive cover plate 103 can be made of metal, but are not limited to metal, as long as they are conductive. The heat exchange layer 101 has a top heat exchange layer 1011 and a bottom heat exchange layer 1012 distributed along a first direction. Figure 1 The middle refers to the vertical direction, which is also the height direction of the shell 90. The first conductive cover plate 102 is covered on the top 1011 of the heat exchange layer to make contact with the top 1011 of the heat exchange layer, so that the first conductive cover plate 102 and the top 1011 of the heat exchange layer can be electrically connected. The second conductive cover plate 103 is covered on the bottom 1012 of the heat exchange layer to make contact with the bottom 1012 of the heat exchange layer, so that the second conductive cover plate 103 and the bottom 1012 of the heat exchange layer can be electrically connected.

[0042] Let's look again. Figure 3 and Figure 4 , Figure 3 for Figure 2 Schematic diagram of the structure of the first conductive cover plate 102; Figure 4 for Figure 2 The diagram shows the structure of the second conductive cover plate 103. The structures of the first conductive cover plate 102 and the second conductive cover plate 103 can be set to be exactly the same.

[0043] The heat exchange module 10 in this embodiment also includes a first electrode 105 and a second electrode 106. The first electrode 105 is connected to the first conductive cover plate 102, and the second electrode 106 is connected to the second conductive cover plate 103. The first electrode 105 and the second electrode 106 are used to connect to an external power source, such as off-peak electricity. That is, when electricity consumption is low, the first electrode 105 and the second electrode 106 can be connected to the off-peak electricity. The first electrode 105, the first conductive cover plate 102, the heat exchange layer 101, the second conductive cover plate 103, and the second electrode 106 are connected in series to the off-peak electricity circuit for power supply.

[0044] As can be seen, during heat storage, the first conductive cover plate 102 in the heat exchange module 10 can be energized through the first electrode 105, and the second conductive cover plate 103 can be energized through the second electrode 106 to an external power source. The porous metal material has good conductivity and thermal resistance. When current passes through the heat exchange layer 101 made of the porous metal material, due to the resistance of the metal, off-peak electrical energy is directly converted into heat energy, meaning the heat exchange layer 101 is directly heated and stores energy. This results in high energy utilization and reduced waste. Furthermore, thanks to the large specific heat capacity of the metal material, sufficient heat storage is ensured without causing the metal temperature to overheat. In the circuit design, when the heat exchange layer 101 reaches a specified temperature, the power can be automatically cut off, i.e., the first electrode 105, the second electrode 106, and the power source are automatically disconnected to ensure system safety.

[0045] During heat release, in this embodiment, saturated steam is introduced into the shell 90 and heated by the heat exchange module 10. During heat release, the first electrode 105 and the second electrode 106 are de-energized; that is, the entire electric heating and heat storage device is de-energized during heat release in this embodiment to ensure the safety of the steam flowing within the shell 90. It is understood that when the steam flows into the shell 90, it needs to pass through the heat exchange module 10. The heat exchange layer 101 is made of a porous metal material, and its multiple pore structure allows the steam to pass smoothly along the first direction.

[0046] You can continue to refer to this. Figure 3 and Figure 4 , Figure 3 for Figure 2 Schematic diagram of the structure of the first conductive cover plate 102; Figure 4 for Figure 2 A schematic diagram of the structure of the second conductive cover plate 103.

[0047] In this embodiment, both the first conductive cover plate 102 and the second conductive cover plate 103 are provided with multiple through-hole structures extending along a first direction. These through-hole structures are connected to the holes in the heat exchange layer 101. The through-hole structure of the first conductive cover plate 102 can be defined as the first through-hole structure 102a, and the through-hole structure of the second conductive cover plate 103 can be defined as the second through-hole structure 103a. The first through-hole structure 102a and the second through-hole structure 103a are used for the passage of steam. It should be understood that the heat exchange module 10 is located in the steam flow path. With the through-hole structures provided, steam can pass through the first conductive cover plate 102, the second conductive cover plate 103, and the heat exchange layer 101.

[0048] Figure 1 In the shell 90, a steam inlet 90d and a steam outlet are also provided. The steam inlet 90d is used to connect to the steam inlet pipe 50, which can transport saturated steam into the interior of the shell 90. The electric heating heat storage device includes a steam passage, which connects the steam inlet 90d and the steam outlet. In this embodiment, the holes in the heat exchange layer 101 and the first through-hole structure 102a and the second through-hole structure 103a are all part of the steam passage, that is, saturated steam can flow through the heat exchange module 10 to... Figure 1 From the perspective of steam inlet 90d, which is located below heat exchange module 10, saturated steam can pass through the second through hole structure 103a of the second conductive cover plate 103, the holes of the heat exchange layer 101, and the first through hole structure 102a of the first conductive cover plate 102 in sequence from bottom to top.

[0049] That is, after the electric heating and heat storage device stores heat, when heat needs to be released, the connection between the heat exchange module 10 and the external power supply can be disconnected, the entire electric heating and heat storage device will be de-energized, and then saturated steam will be sent into the shell from the steam inlet 90d. The saturated steam can flow through the heat exchange module 10, and the heat exchange layer 101 in the heat exchange module 10 exchanges heat with the saturated steam 90d. The heat stored in the heat exchange layer 101 can heat the saturated steam, making the saturated steam superheated, and then it will be released from the steam outlet ( Figure 1 The diagram shows the flow of superheated steam from the primary steam outlet 90a, the secondary steam outlet 90b, and the tertiary steam outlet 90c.

[0050] The electric heating heat storage device in this embodiment has the following advantages:

[0051] First, in this embodiment, the heat exchange layer 101 of the heat exchange module 10 is made of a porous metal material. Utilizing the interconnected solid metal regions of the porous metal material, current can pass through the entire heat exchange layer 101 to store heat during the heat storage period. Furthermore, the porous structure of the metal material allows steam to pass through, thus enabling steam heating. Therefore, this electric heating heat storage device can directly electric heat the heat exchange layer 101, thereby directly utilizing off-peak electricity to heat the porous metal material, directly converting electrical energy into heat energy, reducing the number of energy conversions, and improving energy utilization efficiency.

[0052] Secondly, if the electrodes are directly connected to the heat exchange layer 101, the porous metal structure will cause uneven current distribution in the heat exchange layer 101, making it difficult to effectively generate and store heat. However, the heat exchange module 10 in this embodiment includes a first conductive cover plate 102 and a second conductive cover plate 103 covering the top 1011 and bottom 1012 of the heat exchange layer, respectively. The first conductive cover plate 102 completely covers the top 1011, and the second conductive cover plate 103 completely covers the bottom 1012. This allows for simultaneous energization across the entire end face of the heat exchange layer 101, enabling relatively uniform current flow through the porous metal heat exchange layer 101, thus achieving uniform heat generation and energy storage. According to the formula Q=I... 2 As can be seen from Rt, Q is heat, I is current, R is resistance, and t is time. When the current and pressure are the same, the heat generation is the same. Since the solid metal regions of the porous metal material are evenly distributed, the heat generation in each region of the heat exchange layer 101 is also basically the same.

[0053] Third, in this embodiment, the heat exchange layer 101 is made of a porous metal material. Porous metal materials have high porosity and a small volume of solid metal, allowing for ample steam storage space. This enables immediate steam supply when needed, and buffers fluctuations in steam flow to stabilize the supply. Furthermore, the porous metal material ensures a sufficiently large steam flow area, reducing flow resistance. In other words, the use of a porous metal material in the heat exchange layer 101 allows the stored heat to be directly used to heat steam, specifically saturated steam, to generate the required superheated steam.

[0054] Fourth, the porous metal material of the heat exchange layer 101 also has a large specific surface area, which makes the heat exchange layer 101 and the incoming saturated steam have a large convective heat exchange area, which is conducive to rapid and sufficient heat exchange, thereby quickly completing the heating process from saturated steam to superheated steam. Moreover, the porous metal material has a large heat storage density, and only a small temperature reduction is needed to release heat to a higher temperature.

[0055] Furthermore, in this embodiment, the first conductive cover plate 102 can be provided with multiple uniformly distributed first through-hole structures 102a, and the second conductive cover plate 103 can be provided with multiple uniformly distributed second through-hole structures 103a, making the steam flow field distribution within the porous metal material more uniform, which can further reduce flow resistance and increase heat exchange uniformity. Moreover, the second conductive cover plate 103 and the first conductive cover plate 102 play a role in equalizing steam flow. For example, the impact of the uniformly flowing steam after passing through the second conductive cover plate 103 on the heat exchange layer 101 of the porous metal material is also reduced, which helps to protect the heat exchange layer 101. Under the premise of having a large porosity to reduce the flow resistance loss of steam inside the heat exchange layer 101, the heat exchange layer 101 can maintain its structural stability when a large amount of steam flows through it, without the risk of breakage or decomposition.

[0056] It is evident that this electric heating and heat storage device can achieve the purpose of "peak shaving and valley filling" of the power grid, and has high energy utilization, fast heat exchange, simple structure, and is easy to maintain.

[0057] Furthermore, the heat exchange module 10 in this embodiment uses a porous metal material to directly heat saturated steam, resulting in high energy utilization efficiency and a smaller volume for the heat exchange module 10, thus making the overall electric heating heat storage device relatively small. For example, when a highly flexible coal-fired generator set is performing flexible peak shaving, it needs to provide approximately 8902 kg of steam within 4 minutes to achieve a rapid load increase target. Heating this mass of saturated steam to superheated steam that meets the steam collection parameter requirements requires 5465855 kJ of heat. Using the electric heating heat storage device in this embodiment, the heat exchange layer 101 is made of foamed nickel with a porosity of 0.8. The foamed nickel is heated to 30°C above the superheated steam temperature using off-peak electricity and then heating is stopped. Based on the specific heat capacity of pure nickel being 0.543 kJ / (kg*K), the required volume of foamed nickel is calculated to be only 149 m³. 3 .

[0058] In addition, such as Figure 1 In this embodiment, the heat exchange module 10 further includes an insulating outer cover 104. The aforementioned heat exchange layer 101, the first conductive cover plate 102, and the second conductive cover plate 103 are all installed inside the insulating outer cover 104, and the insulating outer cover 104 has multiple through-hole structures along the first direction. Figure 2The diagram illustrates a first perforated structure 1041a and a second perforated structure 1042a. These perforated structures are also part of the steam passage. The first perforated structure 1041a corresponds to the first through-hole structure 102a, and the second perforated structure 1042a corresponds to the second through-hole structure 103a. Specifically, the projections of the first perforated structure 1041a and the first through-hole structure 102a along the first direction at least partially overlap, and the projections of the second perforated structure 1042a and the second through-hole structure 103a at least partially overlap. In this way, steam can pass through the heat exchange module 10.

[0059] As mentioned earlier, the heat exchange layer 101, the first conductive cover plate 102, and the second conductive cover plate 103 need to be electrically heated for heat storage. Installing these three components inside the insulating outer cover 104 increases the safety of the device. Of course, to ensure steam can pass through the heat exchange module 10, the insulating outer cover 104 is provided with a perforated structure to allow steam to pass through. Specifically, the insulating outer cover 104 includes an annular cover 1043, a top cover 1041, and a bottom cover 1042. The top cover 1041 covers one end of the annular cover 1043 along the first direction, and the bottom cover 1042 covers the other end of the annular cover 1043 along the first direction. The top cover 1041 has a first perforated structure 1041a, and the bottom cover 1042 has a second perforated structure 1042a. The split-type insulating outer cover 104 is easier to manufacture, and the bottom cover 1042 and the top cover 1041 can be welded and fixed to the annular cover 1043. Figure 2 In the middle, the end of the annular cover 1043 is provided with a stepped surface, the outer cover bottom cover 1042 and the outer cover top cover 1041 have cylindrical side walls, and the cylindrical side walls are welded to the stepped surface along the first direction.

[0060] The insulating outer cover 104 can be made of ceramic material, which has insulating and high-temperature resistant properties. In this embodiment, the side wall of the insulating outer cover 104 and the side wall of the shell 90 can also be welded together, that is, the outer surface of the annular cover 1043 and the inner surface of the side wall of the shell 90 are welded and fixed. In this way, steam can only pass through the inside of the heat exchange module 10, ensuring the heat exchange effect.

[0061] In this embodiment, both the first conductive cover plate 102 and the second conductive cover plate 103 are metal covers. Both can be welded to the heat exchange layer 101. This further ensures uniform contact between the conductive cover plate and the heat exchange layer 101 across the entire end face, guaranteeing uniform current flow through the heat exchange layer 101 for effective heat generation and storage. Alternatively, the first conductive cover plate 102 and the second conductive cover plate 103 can be pressed onto the heat exchange layer 101. In this embodiment, the outer top cover 1041 and the outer bottom cover 1042 abut against the first conductive cover plate 102 and the second conductive cover plate 103, further pressing them onto the heat exchange layer 101 to ensure sufficient and uniform conductive contact.

[0062] Let's look again. Figure 1 In this embodiment, the electric heating heat storage device includes at least two heat exchange modules 10 distributed along a first direction. The side wall portion of the housing 90 is provided with a steam outlet in the portion corresponding to the two adjacent heat exchange modules 10. The cavity between the two adjacent heat exchange modules 10 is connected to a corresponding steam outlet. The cavity between the two heat exchange modules 10 is obviously also part of the steam passage. Figure 1 The diagram illustrates three heat exchange modules 10 arranged vertically. These three modules 10 can be defined sequentially according to the steam flow direction as a primary heat exchange module 10a, a secondary heat exchange module 10b, and a tertiary heat exchange module 10c. The primary heat exchange module 10a is... Figure 1 The lowest heat exchange module 10 is the secondary heat exchange module 10b, the middle heat exchange module 10 is the tertiary heat exchange module 10c, and the highest heat exchange module 10 is the tertiary heat exchange module 10. Correspondingly, three steam outlets are provided: a primary steam outlet 90a, a secondary steam outlet 90b, and a tertiary steam outlet 90c. The primary steam outlets 90a and 90b are located on the side walls of the shell 90 and are distributed from bottom to top, while the tertiary steam outlet 90c is located on the top wall of the shell 90. Of course, it can also be located on the side walls; locating it on the top wall reduces the height requirement for the shell 90.

[0063] When superheated steam is required, saturated steam can be introduced into the shell 90 through the steam inlet pipe 50. It first passes through the lowest primary heat exchange module 10a. The heated steam enters between the primary heat exchange module 10a and the intermediate secondary heat exchange module 10b. It can flow out through the primary steam outlet 90a or continue to flow to the intermediate secondary heat exchange module 10b. After being heated, it enters between the secondary heat exchange module 10b and the uppermost tertiary heat exchange module 10c. It can flow out through the secondary steam outlet 90b or continue to flow to the uppermost tertiary heat exchange module 10c. The steam heated by the tertiary heat exchange module 10c can flow out through the tertiary steam outlet 90c and enter the main steam collection pipe 604.

[0064] The electric heating and heat storage device also includes steam pipes connected to each steam outlet, and each steam outlet pipe is equipped with a control valve. For example... Figure 1 As shown, the three steam outlets corresponding to the three heat exchange modules 10 are respectively connected to a primary steam outlet pipe 601, a secondary steam outlet pipe 602, and a tertiary steam outlet pipe 603. Each of the three steam outlet pipes is equipped with a primary control valve 301, a secondary control valve 302, and a tertiary control valve 303. Figure 1 The steam inlet pipe 50 is equipped with a steam inlet valve 40. The steam inlet valve 40 and the control valves on each stage of the steam outlet pipe can be shut-off valves, gate valves, electric valves, or other types of valves. This embodiment does not impose specific limitations.

[0065] When the electric heating heat storage device releases heat, the saturated steam first enters the interior of the primary heat exchange module 10a, flows through the second perforated structure 1042a of the outer cover bottom cover 1042 and the second through hole structure 103a of the second conductive cover plate 103, and then uniformly enters the interior of the heat exchange layer 101 and undergoes convective heat exchange with the metal solid region. After absorbing heat, the saturated steam becomes superheated steam, and flows out of the primary heat exchange module 10a through the second through hole structure 102a of the first conductive cover plate 102 at the top of the heat exchange layer 101 and the second perforated structure 1041a on the outer cover top cover 1041.

[0066] If the steam flow rate is small and the required heat exchange is small, and the steam temperature after heat exchange with the primary heat exchange module 10a has reached the required superheat, then the primary control valve 301 is opened, and the secondary control valve 302 and the tertiary control valve 303 are closed. The steam flows through the primary steam outlet pipe 601 to the main steam collection pipe 604 and can enter the steam turbine. If the steam flow rate is large and the required heat exchange is large, and the steam temperature after heat exchange with the primary heat exchange module 10a has not reached the required superheat, then the secondary control valve 302 is opened, and the primary control valve 301 and the tertiary control valve 303 are closed. The steam will then continue to enter the secondary heat exchange module 10b for heat exchange. If the steam usage parameters are still not met after heat exchange in the secondary heat exchange module 10b, the tertiary control valve 303 is opened, and the primary control valve 301 and the tertiary control valve 303 are closed. The steam that has passed through the primary heat exchange module 10a, the secondary heat exchange module 10b and the tertiary heat exchange module 10c flows through the tertiary steam outlet pipe 603 to the main steam collection pipe 604, and finally flows from the main steam collection pipe 604 to the steam turbine to do work.

[0067] Therefore, the electric heating and heat storage device in this embodiment integrates multi-stage heating into one unit, which can simplify the structure, save space, avoid making the process too complicated, achieve precise control, and facilitate maintenance.

[0068] In this embodiment, temperature sensors can be installed in the steam inlet pipe 50 and each stage of the steam outlet pipes. These sensors monitor the temperature changes of the inlet and outlet steam to determine whether steam enters the next stage heat exchange module 10, thus determining the number of heat exchange modules 10 required to heat the steam, and controlling the opening and closing of the corresponding control valves. Pressure sensors and flow sensors can also be installed on each stage of the steam outlet pipes to monitor changes in pressure and flow rate, facilitating better control of the steam flow.

[0069] Please continue to refer to this. Figure 1 In this embodiment, a baffle assembly 20 is also included between two adjacent heat exchange modules 10. The baffle assembly 20 includes at least two layers of baffles distributed along the first direction. Figure 1 The diagram illustrates a first baffle 201 and a second baffle 202. Each baffle has a gap between itself and the side wall of the housing 90, allowing steam to continue flowing downstream to another heat exchange module 10 through the gap between the baffle and the side wall. Furthermore, projected along the first direction, the projections of adjacent baffles partially overlap and partially offset, meaning the baffle assembly 20 forms a labyrinth structure. This creates resistance to steam flow through the baffle assembly 20. When the steam outlet pipe of the housing 90 corresponding to the baffle assembly 20 is connected, steam mainly flows out from the corresponding outlet pipe and does not flow downstream after passing through the baffle assembly 20. In other words, the baffle assembly 20 serves to control steam flow as needed. Specifically, the baffle assembly 20 can cooperate with a control valve to control the opening and closing of the passage between adjacent heat exchange modules 10.

[0070] Of course, even without the baffle assembly 20, the steam will flow to multiple heat exchange modules 10, but most of it will still flow out from the corresponding steam outlet pipe according to demand. The baffle assembly 20 simply makes the steam flow rate and direction more controllable.

[0071] In addition, such as Figure 1 As shown, a discharge pipe 80 is provided at the bottom of the shell 90, and a discharge valve 70 is provided in the discharge pipe 80. As mentioned above, in this embodiment, saturated steam is directly introduced into the shell 90. After being heated, the saturated steam flows out as superheated steam. However, it cannot be ruled out that after the heat release stage, a trace amount of steam may become liquid. To avoid affecting the power supply during the heat storage stage, the discharge pipe 80 at the bottom of the shell 90 can discharge liquid water and impurities such as dust that may be carried in the saturated steam, thereby improving the safety factor.

[0072] Let's look again. Figure 1In this embodiment, the housing 90 includes a housing body 901. The inner surface of the housing body 901 has an insulating layer 903. Because it is necessary to supply power to the heat exchange module 10 inside the housing 90 during the heat storage stage, the insulating layer 903 is provided on the entire inner surface of the housing body 901 for insulation treatment, which can improve the safety performance of the entire device. In addition, the outer surface of the housing 90 can be covered with a heat insulation layer 902. The heat insulation layer 902 is located on the outermost layer of the housing 90 and can be tightly attached to the housing body 901. The heat insulation layer 902 can reduce heat loss caused by heat dissipation of the device. The material and thickness of the heat insulation layer 902 can be determined according to the environmental conditions of the location where the electric heating heat storage device is used, the preset temperature drop, and the heat dissipation. For example, in this embodiment, the material of the heat insulation layer 902 can be rock wool or polyurethane foam.

[0073] The above are merely preferred embodiments of this application. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. An electric heating heat storage device, characterized in that, The device includes a housing (90) and a heat exchange module (10) located within the housing (90). The heat exchange module (10) includes a heat exchange layer (101), a first conductive cover plate (102), and a second conductive cover plate (103). The heat exchange layer (101) is made of a porous metal material. The heat exchange layer (101) has a top (1011) and a bottom (1012) distributed along a first direction. The first conductive cover plate (102) covers the top (1011) of the heat exchange layer, and the second conductive cover plate (103) covers the bottom (1012) of the heat exchange layer. Both the first conductive cover plate (102) and the second conductive cover plate (103) are provided with a plurality of through holes that extend along the first direction. The heat exchange module (10) further includes a first electrode (105) and a second electrode (106), wherein the first electrode (105) is connected to the first conductive cover plate (102) and the second electrode (106) is connected to the second conductive cover plate (103). The housing (90) is also provided with a steam inlet (90d) and a steam outlet. The electric heating heat storage device includes a steam passage connecting the steam inlet (90d) to the steam outlet. The holes in the heat exchange layer (101) and the through-hole structure are part of the steam passage.

2. The electric heating heat storage device according to claim 1, characterized in that, The heat exchange module (10) further includes an insulating cover (104), the heat exchange layer (101), the first conductive cover plate (102) and the second conductive cover plate (103) are all installed inside the insulating cover (104), and the insulating cover (104) has a plurality of through perforations along the first direction, the perforations being part of the steam passage.

3. The electric heating heat storage device according to claim 2, characterized in that, The multiple through-hole structures and the multiple perforated structures are evenly distributed.

4. The electric heating heat storage device according to claim 2, characterized in that, The insulating outer cover (104) includes an annular cover (1043), an outer cover top cover (1041), and an outer cover bottom cover (1042). The outer cover top cover (1041) covers one end of the annular cover (1043) along the first direction, and the outer cover bottom cover (1042) covers the other end of the annular cover (1043) along the first direction. Both the outer cover top cover (1041) and the outer cover bottom cover (1042) are provided with the perforated structure.

5. The electric heating heat storage device according to claim 4, characterized in that, The top cover (1041) abuts against the first conductive cover plate (102), and the bottom cover (1042) abuts against the second conductive cover plate (103).

6. The electric heating heat storage device according to claim 2, characterized in that, The insulating cover (104) is made of ceramic material, and the side wall of the insulating cover (104) and the side wall of the housing (90) are welded together.

7. The electric heating and heat storage device according to any one of claims 1-6, characterized in that, Both the first conductive cover plate (102) and the second conductive cover plate (103) are metal covers, and both the first conductive cover plate (102) and the second conductive cover plate (103) are welded to the heat exchange layer (101).

8. The electric heating and heat storage device according to any one of claims 1-6, characterized in that, The electric heating heat storage device includes at least two heat exchange modules (10) distributed along the first direction. The side wall of the shell (90) is provided with at least two steam outlets. The cavity between two adjacent heat exchange modules (10) is connected to a corresponding steam outlet.

9. The electric heating heat storage device according to claim 8, characterized in that, The electric heating and heat storage device further includes a baffle assembly (20), which includes at least two layers of baffles distributed along the first direction. There is a gap between the baffles and the side wall of the housing (90), and the baffles are projected along the first direction. The projections of two adjacent baffles overlap and are partially offset.

10. The electric heating heat storage device according to claim 8, characterized in that, The electric heating and heat storage device also includes steam pipes connected to each of the steam outlets, and each of the steam pipes is equipped with a control valve.

11. The electric heating and heat storage device according to any one of claims 1-6, characterized in that, The bottom of the housing (90) is provided with a discharge pipe (80), and the discharge pipe (80) is provided with a discharge valve (70).

12. The electric heating and heat storage device according to any one of claims 1-6, characterized in that, The inner surface of the housing (90) has an insulating layer (903), and / or the outer surface of the housing (90) is covered with a thermal insulation layer (902).

13. A coal-fired power generation unit, characterized in that, It includes a steam turbine and a steam engine, and further includes an electric heating and heat storage device disposed between the steam turbine and the steam engine, wherein the electric heating and heat storage device is the electric heating and heat storage device according to any one of claims 1-12.

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