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

Abstract

The invention provides an electric heating heat storage device and a coal-fired power generation unit. The energy storage efficiency can be improved. The electric heating heat storage device comprises a shell and a heat exchange module located in the shell, the heat exchange module comprises a heat exchange layer, a first conductive cover plate and a second conductive cover plate, the heat exchange layer is made of a metal porous material, and the heat exchange layer is provided with a heat exchange layer top and a heat exchange layer bottom which are distributed in the first direction; the first conductive cover plate covers the top of the heat exchange layer, the second conductive cover plate covers the bottom of the heat exchange layer, and the first conductive cover plate and the second conductive cover plate are each provided with a plurality of through hole structures penetrating in 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, and 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 channel communicating the steam inlet with the steam outlet, and the hole and through hole structure of the heat exchange layer is a part of the steam channel.

Description

Technical Field

[0001] The present application relates to the technical field of coal-fired units, and in particular to an electric heating heat storage device and a coal-fired generator set. Background Art

[0002] Coal-fired units need to have flexibility and load-changing rate to ensure the stable operation of the power system. However, the current load-changing rate of coal-fired 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 superheat (for example, more than 100°C) in a short period of time to enter the steam turbine for power generation, thereby increasing the load-changing rate of the unit.

[0003] To this end, one way is to set up an energy storage device and connect the energy storage device to the power grid to store and release electric energy. Specifically, the valley electricity is used to heat the heating rod or heating tube, and then the heating rod or heating tube heats the heat storage material, but this energy storage method is less efficient. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of this application is to provide an electric heating heat storage device and a coal-fired power generation unit, which can improve the efficiency of energy storage.

[0005] The electric heating heat storage device provided in the present application comprises a shell and a heat exchange module located in the shell, wherein the heat exchange module comprises a heat exchange layer, a first conductive cover plate and a second conductive cover plate, wherein the heat exchange layer is made of a porous metal material, wherein the heat exchange layer has a heat exchange layer top and a heat exchange layer bottom distributed along a first direction, wherein the first conductive cover plate is arranged on the top of the heat exchange layer, and the second conductive cover plate is arranged on the bottom of the heat exchange layer, and wherein 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;

[0006] The heat exchange module further includes a first electrode and a second electrode, 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 shell 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, and the holes 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 cover, the heat exchange layer, the first conductive cover plate and the second conductive cover plate are all installed in the insulating cover, and the insulating cover has a plurality of through-hole structures along the first direction, and the perforated structure is a 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 outer cover includes an annular cover body, an outer cover top cover and an outer cover bottom cover, the outer cover top cover is arranged at one end of the annular cover body along the first direction, the outer cover bottom cover is arranged at the other end of the annular cover body along the first direction, and the outer cover top cover and the outer cover bottom cover are both provided with the perforated structure.

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

[0012] Optionally, the insulating outer cover is made of ceramic material, and the side wall portion of the insulating outer cover and the side wall portion of the shell are welded and connected.

[0013] Optionally, the first conductive cover plate and the second conductive cover plate are both metal cover plates, and the first conductive cover plate and the second conductive cover plate are both 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, 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 also includes a baffle assembly, which includes at least two layers of baffles distributed along the first direction, a gap is provided between the baffle and the side wall of the shell, and when projected along the first direction, the projections of two adjacent baffles partially overlap and partially staggered.

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

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

[0018] Optionally, the inner surface of the shell has an insulating layer, and / or the outer surface of the shell 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 porous metal material. The solid metal areas of the porous metal material are connected to each other, so that during the heat storage period, the current can pass through the entire heat exchange layer to store heat, and the pore structure of the porous metal material allows the passage of steam, which can also achieve steam heating. It can be seen that the electric heating heat storage device can realize direct electric heating of the heat exchange layer, so that the valley electricity can be directly used to heat the porous metal material, and the electrical energy can be directly converted into thermal energy, reducing the number of energy conversions and improving energy utilization efficiency;

[0021] Second, the first conductive cover plate is entirely covered on the top of the heat exchange layer, and the second conductive cover plate is entirely covered on the bottom of the heat exchange layer, that is, the entire end surface of the heat exchange layer can be energized at the same time, so that the current can flow relatively evenly through the metal porous material heat exchange layer, thereby achieving that the metal porous material heat exchange layer 101 can generate heat and store energy evenly.

[0022] Third, porous metal materials have a higher porosity. The metal solids of porous metal materials occupy a small volume, and a larger steam storage space can be reserved. In situations where immediate steam supply is needed, instant steam supply can be achieved. If the steam production flow rate fluctuates, it can play a buffering and stabilizing 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, so that the heat exchange layer and the incoming saturated steam have a large convection 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 the steam can be heated to a higher temperature by only reducing the heat released by a small temperature.

[0024] The present application also provides a coal-fired power generation unit, including a steam turbine and a steam engine, and also including an electric heating heat storage device arranged between the steam turbine and the steam engine, wherein the electric heating heat storage device is any of the electric heating heat storage devices described above. The coal-fired power generation unit provided by the present application includes the above-mentioned electric heating heat storage device and has the same technical effect as the above-mentioned electric heating heat storage device. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0026] Figure 2 for Figure 1 The structural diagram of the heat exchange module;

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

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

[0029] The following are the descriptions of the reference numerals:

[0030] 10-heat exchange module; 10a-primary heat exchange module; 10b-secondary heat exchange module; 10c-tertiary 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-outer cover top cover; 1042-outer cover bottom cover; 1043-annular cover body; 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-third-level control valve;

[0033] 40-steam inlet valve;

[0034] 50-steam inlet pipe;

[0035] 601-first-stage steam outlet pipeline; 602-second-stage steam outlet pipeline; 603-third-stage steam outlet pipeline; 604-steam main 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 DESCRIPTION

[0038] In order to enable those skilled in the art to better understand the technical solution of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. In the embodiments of the present application, the terms "first" and "second" are only used to distinguish the same or similar features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the 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 embodiment of the present application; Figure 2 for Figure 1 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 steam turbine of the generator set. The steam exhausted from the steam engine can be introduced into the electric heating heat storage device for heating before flowing to the steam turbine. Specifically, the electric heating heat storage device includes a housing 90 and a heat exchange module 10. The housing 90 is as shown in FIG. Figure 1 The vertical structure is shown, and the heat exchange module 10 is located in the shell 90. Figure 1 Three heat exchange modules 10 are arranged from top to bottom in the shell 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 a metal porous structure with multiple holes, that is, the heat exchange layer 101 is made of a metal porous material, similar to a sponge structure. The specific material of the metal porous material is not limited, for example, it can be foam metal, the metal is, for example, pure nickel or nickel-chromium, etc. The metal porous material can also be a structure such as a metal wire mesh, which has a large metal density, specific heat capacity and a large porosity, and can also have good corrosion resistance.

[0041] The first conductive cover plate 102 and the second conductive cover plate 103 may also be made of metal, but are not limited to metal materials, as long as they can conduct electricity. The heat exchange layer 101 has a heat exchange layer top 1011 and a heat exchange layer bottom 1012 distributed along a first direction. Figure 1 That is, the up and down direction, which is also the height direction of the shell 90, wherein the first conductive cover plate 102 is covered on the top 1011 of the heat exchange layer to contact 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 conductively connected, and the second conductive cover plate 103 is covered on the bottom 1012 of the heat exchange layer to contact 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 conductively connected.

[0042] Look again Figure 3 and Figure 4 , Figure 3 for Figure 2 A schematic structural diagram of the first conductive cover plate 102; Figure 4 for Figure 2 Schematic diagram of 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 completely 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 supply. The external power supply is, for example, valley power. That is, when the power consumption is low, the first electrode 105 and the second electrode 106 can be connected to the valley power. 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 valley power circuit and energized.

[0044] It can be seen that when storing heat, 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 and the external power supply. The metal porous material has good electrical conductivity and thermal resistance. When the current passes through the heat exchange layer 101 made of the metal porous material, due to the existence of the metal material resistance, the valley electricity will be directly converted into thermal energy, that is, the heat exchange layer 101 is directly heated to store energy, so that the energy utilization rate is high and waste can be reduced; in addition, thanks to the large specific heat capacity of the metal material, while ensuring that enough heat is stored, the metal temperature will not be too high. When designing the circuit, when the heat exchange layer 101 reaches the specified temperature, the power can be automatically cut off, that is, the first electrode 105, the second electrode 106 and the power supply are automatically cut off to ensure the safety of the system.

[0045] When releasing heat, in this embodiment, saturated steam is sent into the shell 90, and the saturated steam is heated by the heat exchange module 10. During the heat release process, the first electrode 105 and the second electrode 106 are powered off, that is, the entire electric heating heat storage device is powered off when releasing heat in this embodiment to ensure the safety of steam flowing in the shell 90. It can be seen that when the steam flows into the shell 90, it needs to pass through the heat exchange module 10, and the heat exchange layer 101 is made of a porous metal material, and its multiple hole structures allow the steam to pass smoothly along the first direction.

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

[0047] In this embodiment, the first conductive cover plate 102 and the second conductive cover plate 103 are both provided with a plurality of through-hole structures penetrating along the first direction, and the through-hole structures are connected to the holes of 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 known that the heat exchange module 10 is in the flow path of the steam. After the through-hole structure is provided, the 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 embodiment, the shell 90 is also provided with a steam inlet 90d and a steam outlet. The steam inlet 90d is used to connect to the steam inlet pipe 50. The steam inlet pipe 50 can transport saturated steam to the inside of the shell 90. The electric heating heat storage device includes a steam passage. The steam passage is used to connect the steam inlet 90d and the steam outlet. The holes of the heat exchange layer 101 in this embodiment 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 a perspective, the steam inlet 90d is located below the heat exchange module 10, and from bottom to top, the 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.

[0049] That is, after the electric heating heat storage device stores heat, when it needs to release heat, the connection between the heat exchange module 10 and the external power supply can be disconnected, the entire electric heating heat storage device is powered off, and then saturated steam is 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, so that the saturated steam becomes superheated steam, and then it is discharged from the steam outlet ( Figure 1 The primary steam outlet 90a, the secondary steam outlet 90b, and the tertiary steam outlet 90c are schematically shown, that is, superheated steam can be provided.

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

[0051] First, the heat exchange layer 101 of the heat exchange module 10 in this embodiment is made of a porous metal material. The solid metal regions of the porous metal material are connected to each other, so that during the heat storage period, the current can pass through the entire heat exchange layer 101 to store heat, and the pore structure of the porous metal material allows the passage of steam, which can also achieve steam heating. It can be seen that the electric heating heat storage device can achieve direct electric heating of the heat exchange layer 101, so that the valley electricity can be directly used to heat the porous metal material, and the electrical energy can be directly converted into thermal energy, which reduces the number of energy conversions and improves energy utilization efficiency;

[0052] Second, if the electrode is directly connected to the heat exchange layer 101, the structural characteristics of the metal porous material will cause the current distribution of the heat exchange layer 101 to be uneven, making it difficult to effectively generate heat and store energy. The heat exchange module 10 in this embodiment includes a first conductive cover plate 102 and a second conductive cover plate 103 that are covered on the top 1011 of the heat exchange layer and the bottom 1012 of the heat exchange layer, and the first conductive cover plate 102 is entirely covered on the top 1011 of the heat exchange layer, and the second conductive cover plate 103 is entirely covered on the bottom 1012 of the heat exchange layer, that is, the entire end surface of the heat exchange layer 101 can be energized at the same time, so that the current can flow relatively evenly through the metal porous material heat exchange layer 101, thereby achieving that the metal porous material heat exchange layer 101 can generate heat and store energy evenly. According to the formula Q=I 2 Rt shows that 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, and the solid metal area of ​​the metal porous material is evenly distributed, then the heat generation conditions of each area of ​​the heat exchange layer 101 are basically the same.

[0053] Third, the heat exchange layer 101 in this embodiment is made of porous metal material, which has a high porosity. The metal solid of the porous metal material occupies a small volume, and a large steam storage space can be reserved. In the case of immediate steam supply, the purpose of immediate steam supply can be achieved. If the steam production flow rate fluctuates, it can play a buffering and smoothing role to stabilize the steam supply. At the same time, the porous metal material can ensure that the flow area of ​​the steam is large enough, thereby reducing the flow resistance of the steam. That is, the heat exchange layer 101 in this embodiment is made of porous metal material, and the heat stored in the heat exchange layer 101 can be directly used to heat steam, specifically to heat saturated steam, thereby generating the required superheated steam.

[0054] Fourth, the metal porous material of the heat exchange layer 101 also has a large specific surface area, so that the heat exchange layer 101 and the incoming saturated steam have a large convection 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 the steam can be heated to a higher temperature by only reducing the heat released by a small temperature.

[0055] In addition, the first conductive cover plate 102 in this embodiment can be provided with a plurality of uniformly distributed first through-hole structures 102a, and the second conductive cover plate 103 can be provided with a plurality of uniformly distributed second through-hole structures 103a, so that the steam flow field entering the metal porous material is more uniformly distributed, which can further reduce the flow resistance and increase the uniformity of heat exchange. Moreover, the second conductive cover plate 103 and the first conductive cover plate 102 play a role in equalizing the flow of steam. 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 metal porous material is also reduced, which is beneficial to protecting the heat exchange layer 101, so that the heat exchange layer 101 can maintain its own structural stability when a large amount of steam flows through, without the risk of breakage, decomposition, etc., while having a large porosity to reduce the flow resistance loss of steam inside the heat exchange layer 101.

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

[0057] Moreover, the heat exchange module 10 in the present embodiment adopts a method of directly heating saturated steam with a metal porous material, which has a high energy utilization efficiency, so that the volume of the heat exchange module 10 is also small, and the volume of the entire electric heating heat storage device is also relatively small. For example, when an ultra-flexible coal-fired power generation unit performs flexible peak regulation, in order to achieve the goal of rapid load increase, it is necessary to provide about 8902 kg of steam within 4 minutes. The heat required to heat this mass of saturated steam into superheated steam that meets the steam exchange parameter requirements is 5465855 kJ. The electric heating heat storage device in the present embodiment is used for heating. The heat exchange layer 101 adopts nickel foam with a porosity of 0.8. Valley electricity is used to heat the temperature of the nickel foam to 30°C higher than the superheated steam temperature and then stop heating. According to the specific heat capacity of pure nickel of 0.543 kJ / (kg*K), it is calculated that the required volume of nickel foam is only 149 m 3 .

[0058] In addition, if Figure 1 The heat exchange module 10 in this embodiment further includes an insulating outer cover 104, wherein the heat exchange layer 101, the first conductive cover plate 102 and the second conductive cover plate 103 are all installed in the insulating outer cover 104, and the insulating outer cover 104 has a plurality of through-hole structures along the first direction. Figure 2The first perforated structure 1041a and the second perforated structure 1042a are schematically shown in the figure. The perforated structure is also a 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. That is, the projection of the first perforated structure 1041a and the first through-hole structure 102a along the first direction at least partially overlap, and the projection 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 above, the heat exchange layer 101, the first conductive cover plate 102, and the second conductive cover plate 103 need to be electrically heated to store heat. Installing the three in the insulating outer cover 104 can increase the safety of the device. Of course, in order to ensure that steam can pass through the heat exchange module 10, the insulating outer cover 104 is provided with a perforated structure to facilitate the passage of steam. Specifically, the insulating outer cover 104 includes an annular cover body 1043, an outer cover top cover 1041, and an outer cover bottom cover 1042. The outer cover top cover 1041 is provided at one end of the annular cover body 1043 along the first direction, and the outer cover bottom cover 1042 is provided at the other end of the annular cover body 1043 along the first direction. The outer cover top cover 1041 is provided with a first perforated structure 1041a, and the outer cover bottom cover 1042 is provided with a second perforated structure 1042a. The split insulating outer cover 104 is easier to process. The outer cover bottom cover 1042 and the outer cover top cover 1041 can be welded and fixed to the annular cover body 1043. Figure 2 In the embodiment, a step surface is provided at the end of the annular cover body 1043, and the outer cover bottom cover 1042 and the outer cover top cover 1041 have a cylindrical side wall, which is welded to the step surface along a first direction.

[0060] The insulating cover 104 can be made of ceramic material, which has the properties of insulation and high temperature resistance. The side wall of the insulating cover 104 in this embodiment can also be connected by welding, that is, the outer surface of the annular cover body 1043 and the inner surface of the side wall of the shell 90 are welded and fixed, so that steam can only pass through the inside of the heat exchange module 10, ensuring the heat exchange effect.

[0061] In this embodiment, the first conductive cover plate 102 and the second conductive cover plate 103 are both metal cover plates. The first conductive cover plate 102 and the second conductive cover plate 103 can be welded to the heat exchange layer 101. In this way, it can further ensure that the conductive cover plate and the heat exchange layer 101 are in uniform contact on the entire end surface, and ensure that the current passes through the heat exchange layer 101 evenly, so as to achieve effective power-on heat generation and heat storage. Of course, the first conductive cover plate 102 and the second conductive cover plate 103 can also be pressed on the heat exchange layer 101. In this embodiment, the outer cover top cover 1041 and the outer cover bottom cover 1042 abut the first conductive cover plate 102 and the second conductive cover plate 103, which can play a role in further pressing the first conductive cover plate 102 and the second conductive cover plate 103 onto the heat exchange layer 101, ensuring sufficient and uniform conductive contact.

[0062] Look again Figure 1 The electric heating heat storage device in this embodiment includes at least two heat exchange modules 10 distributed along the first direction. The side wall portion of the shell 90 is provided with a steam outlet at a portion corresponding to the portion between 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 shows three heat exchange modules 10 distributed vertically. The three heat exchange modules 10 can be defined as a primary heat exchange module 10a, a secondary heat exchange module 10b and a tertiary heat exchange module 10c according to the steam flow direction. The primary heat exchange module 10a is Figure 1 The lowermost heat exchange module 10, the secondary heat exchange module 10b is the middle heat exchange module 10, and the tertiary heat exchange module 10c is the uppermost heat exchange module 10. Three steam outlets are provided accordingly, namely, the primary steam outlet 90a, the secondary steam outlet 90b and the tertiary steam outlet 90c, wherein the primary steam outlet 90a and the secondary steam outlet 90b are provided on the side wall of the shell 90 and are distributed from bottom to top, and the tertiary steam outlet 90c is provided on the top wall of the shell 90. Of course, it is also possible to provide it on the side wall, and providing it on the top wall can reduce the height requirement of the shell 90.

[0063] When superheated steam is needed, saturated steam can be introduced into the shell 90 from the steam inlet pipe 50, first passing through the bottom first-stage heat exchange module 10a, and the heated steam enters between the first-stage heat exchange module 10a and the middle second-stage heat exchange module 10b, and can flow out through the first-stage steam outlet 90a, or continue to flow to the middle second-stage heat exchange module 10b. After heating, it enters between the second-stage heat exchange module 10b and the top third-stage heat exchange module 10c, and can flow out through the second-stage steam outlet 90b, or continue to flow to the top third-stage heat exchange module 10c. The steam heated by the third-stage heat exchange module 10c can flow out from the third-stage steam outlet 90c and enter the steam main pipeline 604.

[0064] The electric heating heat storage device further comprises steam pipes connected to the steam outlets, and each steam outlet pipe is provided with a control valve. Figure 1 As shown, the three steam outlets corresponding to the three heat exchange modules 10 are respectively connected to a primary steam outlet pipeline 601, a secondary steam outlet pipeline 602, and a tertiary steam outlet pipeline 603. The three steam outlet pipelines are respectively provided 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 provided with a steam inlet valve 40. The steam inlet valve 40 and the control valves on the steam outlet pipes at each level may be stop valves, gate valves, electric valves and other types of valves, which are not specifically limited in this embodiment.

[0065] When the electric heating heat storage device releases heat, the saturated steam first enters the first-stage 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 evenly enters the heat exchange layer 101 and undergoes convection heat exchange with the metal solid area. After absorbing heat, the saturated steam becomes superheated steam and flows out of the first-stage heat exchange module 10a through the second through-hole structure 102a of the first conductive cover plate 102 on 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 amount of heat exchange required is small, and the steam temperature after heat exchange with the first-level heat exchange module 10a has reached the required superheat, the first-level control valve 301 is opened, and the second-level control valve 302 and the third-level control valve 303 are closed, and the steam flows to the steam main pipeline 604 through the first-level steam outlet pipe 601 and can enter the steam turbine; if the steam flow rate is large and the amount of heat exchange required is large, and the steam temperature after passing through the first-level heat exchange module 10a does not reach the required superheat, the second-level control valve 302 is opened, and the first-level control valve 301 and the third-level control valve 303 are closed, and the steam will continue to enter the second-level heat exchange module 10b for heat exchange. If the steam usage parameters are still not reached 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 passing through the primary heat exchange module 10a, the secondary heat exchange module 10b and the tertiary heat exchange module 10c flows to the steam main pipeline 604 through the tertiary steam outlet pipeline 603, and finally flows from the steam main pipeline 604 to the steam turbine to perform work.

[0067] It can be seen that the electric heating heat storage device in this embodiment integrates multi-stage heating into one, which can simplify the structure, save space, will not cause the process to be overly complicated, and can achieve precise control while facilitating maintenance.

[0068] In this embodiment, temperature sensors can be provided on the steam inlet pipe 50 and the steam outlet pipes at all levels. The temperature sensor monitors the temperature change of the inlet and outlet steam to determine whether the steam enters the lower heat exchange module 10, that is, to determine the number of heat exchange modules 10 that need to participate in heating the steam, so as to control the opening and closing of the corresponding control valve. Pressure sensors and flow sensors can also be provided on the steam outlet pipes at all levels to monitor the changes in pressure and flow, so as to better control the flow of steam.

[0069] Please continue to refer to Figure 1 In this embodiment, a baffle assembly 20 is further provided between two adjacent heat exchange modules 10. The baffle assembly 20 includes at least two layers of baffles distributed along a first direction. Figure 1 The first baffle 201 and the second baffle 202 are schematically shown in the figure. There is a gap between each baffle and the side wall of the shell 90, that is, the steam can continue to flow from the gap between the baffle and the side wall to another heat exchange module 10 downstream. In addition, when projected along the first direction, the projections of two adjacent baffles partially overlap and partially staggered, that is, the baffle assembly 20 forms a maze structure. In this way, the baffle assembly 20 causes a certain resistance to the flow of steam. When the steam pipe of the steam outlet provided on the side wall of the shell 90 corresponding to the baffle assembly 20 is connected, the steam mainly flows out from the corresponding steam outlet pipe and basically does not flow downstream after passing through the baffle assembly 20. That is, the baffle assembly 20 serves the purpose of controlling the flow of steam according to demand. Specifically, the baffle assembly 20 can cooperate with the control valve to realize the on-off control of the passage between adjacent heat exchange modules 10.

[0070] Of course, even if the baffle assembly 20 is not provided, even if the steam will flow to multiple heat exchange modules 10, most of it will still flow out from the corresponding steam outlet pipes according to demand. It is just that the baffle assembly 20 is provided to make the flow rate and direction of the steam more controllable.

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

[0072] Look again Figure 1In this embodiment, the shell 90 includes a shell body 901, and the inner surface of the shell body 901 has an insulating layer 903. Because the heat exchange module 10 inside the shell 90 needs to be energized during the heat storage stage, the inner surface of the entire shell body 901 is provided with an insulating layer 903 for insulation treatment, which can improve the safety performance of the entire device. In addition, the outer surface of the shell 90 can be coated with an insulation layer 902, and the insulation layer 902 is located at the outermost layer of the shell 90, and can fit closely with the shell body 901. The insulation layer 902 can reduce the heat loss caused by the heat dissipation of the device. The material and thickness of the insulation layer 902 can be determined according to the environmental conditions of the place where the electric heating heat storage device is used, the preset temperature drop and the heat dissipation. For example, the material of the insulation layer 902 in this embodiment can be rock wool or polyurethane foam.

[0073] The above are only preferred implementations of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. An electric heating heat storage device, characterized in that: The invention comprises a shell (90) and a heat exchange module (10) located in the shell (90), wherein the heat exchange module (10) comprises a heat exchange layer (101), a first conductive cover plate (102) and a second conductive cover plate (103), wherein the heat exchange layer (101) is made of a porous metal material, wherein the heat exchange layer (101) has a heat exchange layer top (1011) and a heat exchange layer bottom (1012) distributed along a first direction, wherein the first conductive cover plate (102) is covered on the heat exchange layer top (1011), and the second conductive cover plate (103) is covered on the heat exchange layer bottom (1012), and the first conductive cover plate (102) and the second conductive cover plate (103) are both provided with a plurality of through-hole structures penetrating along the first direction; The heat exchange module (10) further comprises 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 shell (90) is also provided with a steam inlet (90d) and a steam outlet, the electric heating heat storage device comprises a steam passage connecting the steam inlet (90d) to the steam outlet, and the holes of 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 comprises an insulating outer cover (104), the heat exchange layer (101), the first conductive cover plate (102) and the second conductive cover plate (103) are all installed in the insulating outer cover (104), and the insulating outer cover (104) has a plurality of through-hole structures along the first direction, and the perforated structures are part of the steam passage.

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

4. The electric heating heat storage device according to claim 2, characterized in that: The insulating outer cover (104) comprises an annular cover body (1043), an outer cover top cover (1041) and an outer cover bottom cover (1042); the outer cover top cover (1041) is arranged at one end of the annular cover body (1043) along the first direction, and the outer cover bottom cover (1042) is arranged at the other end of the annular cover body (1043) along the first direction; and 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 outer cover top cover (1041) abuts against the first conductive cover plate (102), and the outer cover 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 outer cover (104) is made of ceramic material, and the side wall portion of the insulating outer cover (104) and the side wall portion of the shell (90) are connected by welding.

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

8. The electric heating heat storage device according to any one of claims 1 to 6, characterized in that: The electric heating heat storage device comprises at least two heat exchange modules (10) distributed along the first direction, the side wall portion of the shell (90) is provided with at least two steam outlets, and 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 heat storage device further comprises a baffle assembly (20), the baffle assembly (20) comprising at least two layers of baffles distributed along the first direction, a gap being provided between the baffles and the side wall portion of the shell (90), and projected along the first direction, the projections of two adjacent baffles partially overlap and partially stagger.

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

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

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

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

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