Heat storage and heat release device for heating molten salt through modular electrodes

Abstract

The invention discloses a heat storage and release device for heating molten salt by modular electrodes, which is characterized in that a water supply pump transmits a high-temperature medium in a heat storage module to a heat user, and a low-temperature medium in a water return pump returns to the heat storage module to form a loop; the heat storage module is formed by connecting heat storage modules in series / in parallel, each heat storage module comprises a ceramic shell and a heating electrode plate, the ceramic shell is rectangular, a through round pipe is transversely arranged in the middle of the ceramic shell, and the space in the shell is divided into a closed shell side and a pipe side communicated with the outside; a heat storage medium is contained in the shell side closed space and adopts fused salt, a heat transfer medium is contained in the pipe side through space, heating electrode plates are oppositely arranged on the two end faces in the shell side closed space respectively, and the heating electrode plates penetrate through the ceramic shell, are led out and are connected with an external power source. According to the technical scheme, uniform and rapid heating of the fused salt can be achieved, the heat storage and heat release processes are conducted at the same time, and stable and continuous heat supply is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of heat storage heating, and particularly relates to a heat storage and heat release device for modular electrode heating of molten salt. Background Art

[0002] As a kind of energy storage technology, molten salt heat storage can store the low-valley electricity or abandoned wind and photovoltaic electricity in the power grid in the form of heat energy in molten salt for building heating or industrial heat use. The molten salt single-tank heat storage system stores heat through an electric heater in the tank and releases heat through a built-in coil heat exchanger. Compared with the double-tank heat storage system, the single-tank heat storage system is more simplified, and the cost and floor area are reduced. When heating the molten salt in the tank, compared with the traditional resistance heater, the electrode AC heating method directly uses the heat storage medium as the resistance, removes the indirect heat transfer process between the traditional heater and the heat storage medium, simplifies the heat transfer path, and has the advantages of fast heating speed, high energy utilization efficiency, and uniform temperature distribution. However, in the existing applications of electrode heating of molten salt, limited by its use, container shape, and electrode arrangement position, the overall resistance of the molten salt is small, resulting in a low use voltage, high current, uneven heating of the internal molten salt, leading to problems such as line heating, molten salt deterioration, and fast electrode loss. Summary of the Invention

[0003] In view of the above problems, the present invention provides a heat storage and heat release device for modular electrode heating of molten salt. The heat storage module is heated in the form of electrode heating, and at the same time, the shape of the heat storage module is improved to increase the resistance of the heat storage medium in the module, reduce the line current, and realize uniform heating of the molten salt. It can convert abandoned wind and photovoltaic electricity and low-valley electricity into heat energy and store it in the heat storage module. The return water of the heat user enters the heat storage module to exchange heat with the heat storage medium to extract the heat, and provides a heat transfer medium with stable temperature to the heat user by adjusting the water flow rate, meeting the water use and heating requirements of the heat user, and realizing the comprehensive utilization of low-valley electricity and abandoned wind and photovoltaic energy while reducing the cost.

[0004] To achieve the above object, the present invention provides a heat storage and heat release device for modular electrode heating of molten salt, including: a water supply pump, a heat storage module, and a return water pump;

[0005] The water supply pump is connected to the heat storage module. The water supply pump transports the high-temperature medium in the heat storage module to the heat user. The return water pump is connected to the heat storage module. The return water pump returns the low-temperature medium after the heat user consumes heat to the heat storage module to form a loop;

[0006] The heat storage module is formed by connecting a preset number of heat storage modules in a series / parallel combination. The heat storage module includes a ceramic shell and a heating electrode sheet. The ceramic shell is rectangular and has a through-round tube horizontally arranged in the middle, dividing the space inside the shell into a closed shell side and a tube side communicating with the outside;

[0007] The shell-side closed space is filled with a heat storage medium, and the heat storage medium is molten salt. The tube-side through space is filled with a heat transfer medium. Heating electrode plates are oppositely arranged on both end faces in the shell-side closed space. The heating electrode plates are led out through the ceramic shell and connected to an external power supply.

[0008] In the above technical solution, preferably, the heat storage and heat release device for modular electrode heating of molten salt further includes: an outlet header, a water supply mixing tank, an inlet header, and a return water mixing tank;

[0009] The outlet header is arranged at the outlet of the heat storage module. The water supply mixing tank is arranged between the outlet header and the water supply pump. The inlet header is arranged at the inlet of the heat storage module. The return water mixing tank is arranged between the inlet header and the return water pump;

[0010] The outlet header is used to store the high-temperature heat transfer medium output by the heat storage module. The water supply mixing tank is used to provide the heat transfer medium at a preset temperature to the heat user;

[0011] The return water mixing tank is used to store the heat transfer medium output by the heat user. The inlet header is used to send the heat transfer medium in the return water mixing tank back to the heat storage module through the return water pump. The heat transfer medium is water.

[0012] In the above technical solution, preferably, the heat storage and heat release device for modular electrode heating of molten salt further includes a makeup water valve, a pressure relief valve, and a solenoid valve. The makeup water valve is arranged between the outlet of the heat user and the return water mixing tank, and the makeup water valve is used to supplement circulating water into the return water mixing tank;

[0013] The pressure relief valve and the solenoid valve are arranged between the outlet header and the water supply mixing tank. The pressure relief valve is used to automatically relieve pressure when the pipeline pressure exceeds a preset threshold. The solenoid valve is in a normally closed state when energized and opens when de-energized to relieve pressure on the medium that continuously heats the heat storage module.

[0014] In the above technical solution, preferably, the heat storage and heat release device for modular electrode heating of molten salt further includes a return water stop valve and a water supply stop valve;

[0015] The return water stop valve is arranged between the return water mixing tank and the return water pump, and the return water stop valve is used to close the return water delivery of the return water pump to the inlet header;

[0016] The water supply stop valve is arranged between the water supply mixing tank and the water supply pump, and the water supply stop valve is used to close the medium delivery of the water supply pump to the heat user.

[0017] In the above technical solution, preferably, the heat storage and heat release device for modular electrode heating molten salt further includes a control system and a temperature sensor. The control system is respectively connected to the temperature sensor, the return water pump, and the on-off circuit of the heating electrode sheet. The temperature sensors are respectively arranged in the shell-side closed space of the heat storage module, in the outlet header, and in the water supply mixing tank.

[0018] The control system controls the power of the return water pump according to the medium temperature in the outlet header to adjust the flow rate of the heat transfer medium entering the heat storage module, controls the on-off state of the heating electrode sheet according to the temperature of the molten salt in each heat storage module, and controls the on-off state of the electric heating device in the water supply mixing tank according to the medium temperature in the water supply mixing tank.

[0019] In the above technical solution, preferably, both ends of the heat storage module are provided with flange structures, and the heat storage modules are directly connected or connected through flange elbows to form the heat storage module group.

[0020] In the above technical solution, preferably, the heating electrode sheet includes two plate-shaped molybdenum electrodes with circular holes in the center. The two electrodes are respectively horizontally arranged opposite to each other on the end walls of the shell-side closed space, and the electrodes are led out of the ceramic shell through electrode lead-out rods.

[0021] In the above technical solution, preferably, the inner layer of the heat storage module adopts a silicon nitride ceramic material layer, and the outer layer adopts a module insulation layer.

[0022] In the above technical solution, preferably, the maximum adjustable water flow rate of the return water pump is higher than the water flow rate of the heat user, and the minimum value is lower than the water flow rate of the heat user.

[0023] The return water mixing tank and the water supply mixing tank respectively maintain preset liquid level heights. When the water flow rate of the loop is less than the water flow rate of the heat user, the liquid level in the return water mixing tank is raised, and the liquid level in the water supply mixing tank is lowered. When the water flow rate of the loop is greater than the water flow rate of the heat user, the liquid level in the return water mixing tank is lowered, and the liquid level in the water supply mixing tank is raised to realize the normal operation of the loop.

[0024] In the above technical solution, preferably, in the heat storage working mode only, the control system controls the heating electrode sheet to continuously heat the heat storage medium.

[0025] In the heat release only operating mode, the control system controls the heating electrode sheet to cut off power, controls the return water pump to adjust the flow rate of the heat transfer medium entering the heat storage module, and the flow rate continuously decreases as the temperature of the heat storage medium decreases. After the heat transfer medium enters the heat storage module for heat exchange, it is driven by the water supply pump to provide stable heat to the heat user, and returns to the return water mixing tank after consuming heat to form an internal cycle;

[0026] When heat storage and heat release are carried out simultaneously, when the flow rate of the heat transfer medium reaches the minimum or the temperature of the heat storage medium reaches the lower limit and cannot meet the outlet water temperature, the control system controls the heating electrode sheet to be powered on. When the outlet water temperature exceeds the preset temperature, it controls the return water pump to increase the flow rate of the heat transfer medium entering the heat storage module, so that the temperature of the medium entering the water supply mixing tank meets the preset temperature requirements.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] (1) The present invention uses off-peak electricity and abandoned wind and photovoltaic power to heat the heat storage medium to complete heat storage, provides heating and domestic hot water for heat users, and realizes the comprehensive utilization of off-peak electricity and abandoned wind and photovoltaic energy.

[0029] (2) Compared with the single-tank heat storage system, the modular heat storage and heat release device of the present invention can flexibly design the size of the heat storage module and the connection mode of the heat storage modules according to user needs, and at the same time, the installation and maintenance are safer and more convenient.

[0030] (3) The present invention adjusts the water flow rate entering the tube side of the heat storage module through a water pump. When the temperature of the heat storage medium is high, the water flow rate on the tube side is large, and when the temperature of the heat storage medium is relatively low, the water flow rate on the tube side is small. After the water with a constant temperature but different flow rates enters the water supply mixing tank, the water supply pump outputs heating water with a constant temperature and constant flow rate to the user side. Through the continuous adjustment of the water flow rate and the cooperation of the mixing tank, a stable heat output can be provided for heat users.

[0031] (4) The main body of the heat storage module of the present invention is integrally formed of silicon nitride ceramics, realizing simultaneous power-on heating of the molten salt on the shell side and heating of the heating water on the tube side. The structure is simple and there are fewer accessories. Silicon nitride has good insulation performance, strong heat conduction ability, and good thermal shock resistance, meeting the requirements of long-term stable use of the equipment.

[0032] (5) The present invention uses electrode heating, and at the same time improves the molten salt resistance through the shape design of the heat storage module, with a fast heating speed, uniform heat generation of the molten salt, improved heat storage efficiency, reduced internal volume occupation, increased use voltage, reduced line current, reduced power distribution cost, energy saving and environmental protection. Description of the Drawings

[0033] Figure 1Schematic diagram of the structure of a heat storage and heat release device for modular electrode heating molten salt disclosed in an embodiment of the present invention;

[0034] Figure 2 For Figure 1 Front view of the combined structure of the heat storage module and the header shown in the disclosed embodiment;

[0035] Figure 3 For Figure 1 Left view of the combined structure of the heat storage module and the header shown in the disclosed embodiment;

[0036] Figure 4 For Figure 1 Top view of the combined structure of the heat storage module and the header shown in the disclosed embodiment;

[0037] Figure 5 For Figure 2 Partial sectional view of the heat storage module shown in the disclosed embodiment;

[0038] Figure 6 For Figure 5 Cross-sectional view in the A - A direction shown in the disclosed embodiment;

[0039] Figure 7 For Figure 5 Cross-sectional view in the B - B direction shown in the disclosed embodiment.

[0040] In the figure, the correspondence between each component and the reference numeral is as follows:

[0041] 1. Make-up water valve; 2. Return water mixing tank; 3. Return water stop valve; 4. Return water pump; 5. Inlet header; 6. Heat storage module; 601. Ceramic shell; 602. Module insulation layer; 603. Heating electrode plate; 7. Elbow; 8. Outlet header; 9. Pressure relief valve; 10. Solenoid valve; 11. Supply water mixing tank; 12. Supply water stop valve; 13. Supply water pump; 14. Heat user; 15. Control system. Detailed implementation manners

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0043] The present invention will be further described in detail below with reference to the accompanying drawings:

[0044] As Figures 1 to 7As shown in the figure, a heat storage and heat release device for modular electrode heating molten salt according to the present invention includes a water supply water pump 13, a heat storage module group, and a return water pump 4;

[0045] The water supply water pump 13 is connected to the heat storage module group. The water supply water pump 13 transfers the high-temperature medium in the heat storage module group to the heat user 14. The return water pump 4 is connected to the heat storage module group. The return water pump 4 returns the low-temperature medium after the heat user 14 consumes heat to the heat storage module group to form a loop;

[0046] The heat storage module group is formed by connecting a preset number of heat storage modules 6 in a series / parallel combination. The heat storage module 6 includes a ceramic outer shell 601 and a heating electrode sheet 603. The ceramic outer shell 601 is rectangular and has a through-round tube transversely arranged in the middle, dividing the space inside the shell into a closed shell side and a tube side communicating with the outside;

[0047] The closed space on the shell side is filled with a heat storage medium, and the heat storage medium uses molten salt. The through space on the tube side is filled with a heat transfer medium. Heating electrode sheets 603 are respectively arranged opposite to the two end faces in the closed space on the shell side. The heating electrode sheets 603 are led out through the ceramic outer shell 601 and connected to an external power supply.

[0048] In this embodiment, the heat storage module group is heated in the form of electrode heating. At the same time, the shape of the heat storage module group is improved to increase the resistance of the heat storage medium in the module, reduce the line current, and realize uniform heating of the molten salt. It can convert abandoned wind and photovoltaic power and low-valley electricity into heat energy and store it in the heat storage module group. The return water of the heat user 14 enters the heat storage module group to exchange heat with the heat storage medium to extract the heat, and provides a heat transfer medium with stable temperature to the heat user 14 by adjusting the water flow rate, meeting the water use and heating requirements of the heat user 14, and realizing the comprehensive utilization of low-valley electricity and abandoned wind and photovoltaic energy while reducing costs.

[0049] As Figure 5 shown, specifically, the through-round tube arranged in the ceramic outer shell 601 of the heat storage module 6 divides the inside of the shell into two non-communicating parts, namely the shell side and the tube side. The heat transfer medium flows on the tube side and exchanges heat with the heat storage medium in the closed space on the shell side. The heating electrode sheet 603 is used to heat the heat storage medium. The main body of the heat storage module 6 is made of an insulating material, and the heat storage and heat release processes can be carried out simultaneously.

[0050] Among them, the structural design of the external rectangular ceramic outer shell 601 and the internally transversely and independently arranged through-round tube, and the linear structural design of the heating electrode sheets 603 arranged at both ends of the closed space on the shell side relative to the heat storage medium can increase the resistance of the heat storage medium in the container. Under the same heating power, the line voltage increases and the current decreases, reducing line heating, improving the service life of the equipment, and saving energy and protecting the environment.

[0051] During the implementation process, the abandoned wind and photovoltaic power and low-valley electricity can be utilized to apply the alternating current voltage to the heat storage medium (i.e., molten salt) through the heating electrode sheet 603. The ions in the molten salt generate Joule heat under the action of the electric field, realizing the uniform and rapid heating of the internal molten salt, thus saving the heat storage time. When needed, the heat transfer medium is input into the heat storage module for heat exchange, and the heat is taken out. The heated heat transfer medium is transported to the heat user 14 for heat utilization to meet the water use or heating demand of the heat user 14.

[0052] Among them, during the loop flow process, in the case of only heat release, the heat of the heat storage module is continuously consumed. In order to provide a heat transfer medium with a constant temperature to the heat user 14, the inlet water flow rate flowing to the heat storage module can be controlled and reduced by the return water pump 4. Water with the same temperature is uniformly input into the heat user 14 by the water supply pump 13, thus realizing constant temperature heat supply.

[0053] Specifically, the water flow on the tube side in the heat storage module 6 can be adjusted by the return water pump 4. When the temperature of the heat storage medium is high, the water flow rate on the tube side is large; when the temperature of the heat storage medium is relatively low, the water flow rate on the tube side is small. By continuously adjusting the water flow rate, the outlet water temperature can be accurately controlled, and in cooperation with the water supply mixing tank 11 and the return water mixing tank 2, stable and continuous heat supply can be realized.

[0054] During the implementation process, the heat user 14 is the heating end or the domestic hot water end.

[0055] During the implementation process, the number of heat storage modules 6 used and the connection method are determined by the on-site conditions and the rated load.

[0056] As Figures 2 to 4 shown, in the above-mentioned implementation manner, preferably, the heat storage and heat release device for modular electrode heating of molten salt further includes: an outlet header 8, a water supply mixing tank 11, an inlet header 5, and a return water mixing tank 2;

[0057] The outlet header 8 is arranged at the outlet of the heat storage module, the water supply mixing tank 11 is arranged between the outlet header 8 and the water supply pump 13, the inlet header 5 is arranged at the inlet of the heat storage module, and the return water mixing tank 2 is arranged between the inlet header 5 and the return water pump 4;

[0058] The outlet header 8 is used to store the high-temperature heat transfer medium output by the heat storage module, and the water supply mixing tank 11 is used to provide the heat transfer medium with a preset temperature to the heat user 14;

[0059] The return water mixing tank 2 is used to store the heat transfer medium output by the heat user 14, and the inlet header 5 is used to return the heat transfer medium in the return water mixing tank 2 to the heat storage module through the return water pump 4. The heat transfer medium is water.

[0060] During the implementation process, through the collaborative action of the above-mentioned outlet header 8, water supply mixing tank 11, inlet header 5, and return water mixing tank 2 relative to the water supply pump 13, heat storage module, and return water pump 4, the normal and effective operation of the loop between the heat storage module and the heat user 14 can be achieved.

[0061] In the above-mentioned embodiment, preferably, the heat storage and heat release device for modular electrode heating molten salt further includes a makeup water valve 1, a pressure relief valve 9, and a solenoid valve 10. The makeup water valve 1 is arranged between the outlet of the heat user 14 and the return water mixing tank 2, and the makeup water valve 1 is used to supplement circulating water into the return water mixing tank 2.

[0062] The pressure relief valve 9 and the solenoid valve 10 are arranged between the outlet header 8 and the water supply mixing tank 11. The pressure relief valve 9 is used to automatically relieve pressure when the pipeline pressure exceeds a preset threshold value. The solenoid valve 10 is in a normally closed state when energized and opens when powered off to relieve pressure on the medium that continuously heats the heat storage module.

[0063] During the implementation process, a bypass is arranged on the inlet pipeline of the heat storage module, and the makeup water valve 1 is installed to supplement circulating water. Two bypasses are arranged on the outlet pipeline of the heat storage module. One bypass is installed with a pressure relief valve 9, which automatically opens for pressure relief when the internal pressure of the pipeline exceeds the preset threshold value, and the other bypass is installed with a solenoid valve 10.

[0064] When the equipment is powered off, the return water pump 4 stops working. The water remaining in the tube side of the heat storage module as the heat transfer medium is continuously heated and becomes steam, which will cause the pressure in the pipeline to rise and there is a risk of explosion. Therefore, the solenoid valve 10 is set to automatically open for draining and pressure relief to ensure safety when powered off. In addition, when heating the molten salt for the first time and introducing heating water into the tube side of the heat storage module 6, a certain amount of steam will be generated. At this time, the solenoid valve 10 needs to be opened to discharge the steam-water mixture in the tube side of the heat storage module 6 until the normal heat exchange in the tube side and the outlet temperature is stable, and then the solenoid valve 10 can be closed.

[0065] In the above-mentioned embodiment, preferably, the heat storage and heat release device for modular electrode heating molten salt further includes a return water stop valve 3 and a water supply stop valve 12;

[0066] The return water stop valve 3 is arranged between the return water mixing tank 2 and the return water pump 4, and the return water stop valve 3 is used to close the return water delivery of the return water pump 4 to the inlet header 5;

[0067] The water supply stop valve 12 is arranged between the water supply mixing tank 11 and the water supply pump 13, and the water supply stop valve 12 is used to close the medium delivery of the water supply pump 13 to the heat user 14.

[0068] In the above embodiments, preferably, the heat storage and heat release device for modular electrode heating molten salt further includes a control system 15 and a temperature sensor. The control system 15 is respectively connected to the temperature sensor, the return water pump 4, and the on-off circuit of the heating electrode sheet 603. The temperature sensors are respectively arranged in the shell-side closed space of the heat storage module 6, in the outlet header 8, and in the water supply mixing tank 11.

[0069] The control system 15 controls the power of the return water pump 4 according to the medium temperature in the outlet header 8 to adjust the flow rate of the heat transfer medium entering the heat storage module group, controls the on-off state of the heating electrode sheet 603 according to the temperature of the molten salt in each heat storage module 6, and controls the on-off state of the electric heating device in the water supply mixing tank 11 according to the medium temperature in the water supply mixing tank 11.

[0070] During the implementation process, a molten salt temperature sensor is installed in the shell-side closed space of the inner shell of the ceramic shell 601 of each heat storage module 6, and a water temperature sensor is installed in the outlet header 8. The above temperature sensors are all connected to the control system 15. The control system 15 controls the power of the return water pump 4 based on the temperature of the water temperature sensor, adjusts the water flow rate entering the heat storage module 6, and maintains the stability of the outlet temperature. At the same time, the control system 15 controls the on-off power supply of the heating electrode sheet 603 based on the molten salt temperature sensor of each heat storage module 6. When the molten salt temperature reaches the upper limit, the heating electrode sheet 603 is powered off. When the molten salt temperature is lower than the minimum use temperature, power is supplied to the heating electrode sheet 603 to heat the molten salt. In addition, a temperature sensor is provided in the water supply mixing tank 11 and is connected to the control system 15. When the water temperature in the water supply mixing tank 11 is lower than the rated water supply temperature, electric tracing is started to heat the water in the water supply mixing tank 11 to reach the rated temperature.

[0071] In the above embodiments, preferably, both ends of the heat storage module 6 are provided with flange structures, and the heat storage modules 6 are directly connected or connected through flange elbows 7 to form a heat storage module group.

[0072] During the implementation process, a series / parallel combination connection method can be adopted. It is connected in series into a serpentine tube group by elbows 7 from top to bottom, and multiple serpentine tube groups connected in this way are arranged side by side from front to back. The inlets and outlets are uniformly connected to the inlet header 5 and the outlet header 8 to achieve the diversion and convergence of water.

[0073] In the above embodiments, preferably, the heating electrode sheet 603 includes two plate-shaped molybdenum electrodes with circular holes in the center. The two electrodes are horizontally and oppositely arranged on the end walls of the shell-side closed space, and the electrodes are led out of the ceramic shell 601 through electrode lead rods.

[0074] As Figure 6 and Figure 7 shown, in the above embodiments, preferably, the inner layer of the heat storage module 6 is made of a silicon nitride ceramic material layer, and the outer layer is made of a module insulation layer 602.

[0075] In the above embodiment, the stable outlet water temperature is achieved by controlling the water flow rate into the heat storage module, and the temperature and flow rate of the heating water delivered to the heat user 14 are constant. This results in different flow rates within the loop, and it is necessary to utilize the return water mixing tank 2 and the supply water mixing tank 11 to ensure the normal operation of the loop. Therefore, preferably, the maximum adjustable water flow rate of the return water pump 4 is higher than the water flow rate of the heat user 14, and the minimum value is lower than the water flow rate of the heat user 14.

[0076] The return water mixing tank 2 and the supply water mixing tank 11 should always maintain preset liquid level heights respectively to balance the influence brought by the flow rate change within the loop. When the water flow rate in the heat release section of the loop is less than the water flow rate of the heat user 14, the liquid level in the return water mixing tank 2 is raised, and the liquid level in the supply water mixing tank 11 is lowered. When the water flow rate of the loop is greater than the water flow rate of the heat user 14, the liquid level in the return water mixing tank 2 is lowered, and the liquid level in the supply water mixing tank 11 is raised to achieve the normal operation of the loop.

[0077] In the above embodiment, preferably, only during the heat storage operation mode, the control system 15 controls the heating electrode sheet 603 to apply alternating current to the heat storage medium using off-peak electricity, causing the heat storage medium to generate joule heat and its temperature to continuously rise for continuous heating. During the implementation process, according to the design, the heat stored during this period can meet the heat load demand of the next day during non-off-peak electricity.

[0078] Only during the heat release operation mode, the control system 15 controls the heating electrode sheet 603 to cut off the power, controls the return water pump 4 to adjust the flow rate of the heat transfer medium entering the heat storage module, and the flow rate continuously decreases as the temperature of the heat storage medium decreases, delivering heating water with a constant temperature. After the heat transfer medium enters the heat storage module for heat exchange, it is driven by the supply water pump 13 to provide stable heat to the heat user 14. After consuming the heat, the cold water is stored in the return water mixing tank 2, enters the tube side of the heat storage module through the return water pump 4 and the inlet header 5, exchanges heat with the heat storage medium, and then flows out from the outlet header 8 to reach the supply water mixing tank 11, and then is provided with stable heat for the heat user 14 by the supply water pump 13. The cold water after consuming the heat returns to the return water mixing tank 2 again to form an internal circulation.

[0079] When heat storage and heat release are carried out simultaneously, when the flow rate of the heat transfer medium reaches the minimum or the temperature of the heat storage medium reaches the lower limit and cannot meet the outlet water temperature, the control system 15 controls the heating electrode sheet 603 to be powered on. When the outlet water temperature exceeds the preset temperature, it controls the return water pump 4 to increase the flow rate of the heat transfer medium entering the heat storage module, so that the temperature of the medium entering the supply water mixing tank 11 meets the preset temperature requirement, achieving the stable supply water temperature for the heat user 14.

[0080] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A modular electrode heating molten salt heat storage and heat release device, characterized in that, Including: A water supply pump, a heat storage module and a return water pump; The water supply pump is connected to the heat storage module. The water supply pump transports the high-temperature medium in the heat storage module to the heat user. The return water pump is connected to the heat storage module. The return water pump returns the low-temperature medium after the heat user consumes heat to the heat storage module to form a loop; The heat storage module is formed by connecting a preset number of groups of heat storage modules in series / parallel combination. The heat storage module includes a ceramic shell and heating electrode plates. The ceramic shell is rectangular and a through-round tube is horizontally arranged in the middle, dividing the space inside the shell into a closed shell side and a tube side communicating with the outside; The closed space on the shell side is filled with a heat storage medium, and the heat storage medium uses molten salt. The through space on the tube side is filled with a heat transfer medium. The heating electrode plates are respectively arranged opposite to the two end faces in the closed space on the shell side. The heating electrode plates are led out through the ceramic shell and connected to an external power supply.

2. The heat storage and heat release device for modular electrode heating molten salt according to claim 1, characterized in that, It also includes: An outlet header, a water supply mixing tank, an inlet header and a return water mixing tank; The outlet header is arranged at the outlet of the heat storage module. The water supply mixing tank is arranged between the outlet header and the water supply pump. The inlet header is arranged at the inlet of the heat storage module. The return water mixing tank is arranged between the inlet header and the return water pump; The outlet header is used to store the high-temperature heat transfer medium output by the heat storage module. The water supply mixing tank is used to provide the heat transfer medium at a preset temperature to the heat user; The return water mixing tank is used to store the heat transfer medium output by the heat user. The inlet header is used to return the heat transfer medium in the return water mixing tank to the heat storage module through the return water pump. The heat transfer medium uses water.

3. The heat storage and heat release device for modular electrode heating molten salt according to claim 2, characterized in that It also includes a makeup water valve, a pressure relief valve and a solenoid valve. The makeup water valve is arranged between the outlet of the heat user and the return water mixing tank. The makeup water valve is used to supplement circulating water into the return water mixing tank; The pressure relief valve and the solenoid valve are arranged between the outlet header and the water supply mixing tank. The pressure relief valve is used to automatically relieve pressure when the pipeline pressure exceeds a preset threshold. The solenoid valve is in a normally closed state when powered on and opens when powered off to relieve pressure on the medium that continuously heats the heat storage module.

4. The heat storage and heat release device for modular electrode heating molten salt according to claim 3, wherein It also includes a return water stop valve and a water supply stop valve; The return water stop valve is arranged between the return water mixing tank and the return water pump. The return water stop valve is used to close the return water delivery of the return water pump to the inlet header; The water supply stop valve is arranged between the water supply mixing tank and the water supply pump. The water supply stop valve is used to close the medium delivery of the water supply pump to the heat user.

5. The heat storage and heat release device for modular electrode heating molten salt according to claim 4, characterized in that, It also includes a control system and temperature sensors. The control system is respectively connected to the temperature sensors, the on-off circuits of the return water pump and the heating electrode plates. The temperature sensors are respectively arranged in the closed space on the shell side of the heat storage module, in the outlet header and in the water supply mixing tank; The control system controls the power of the return water pump according to the medium temperature in the outlet header to adjust the flow rate of the heat transfer medium entering the heat storage module group, controls the switch state of the heating electrode plates according to the temperature of the molten salt in each heat storage module, and controls the switch state of the electric heating device in the water supply mixing tank according to the medium temperature in the water supply mixing tank.

6. The heat storage and heat release device for modular electrode heating molten salt according to any one of claims 1 to 5, characterized in that, Both ends of the heat storage module are provided with flange structures, and the heat storage modules are directly connected or connected through flange elbows to form the heat storage module group.

7. The heat storage and heat release device for modular electrode heating molten salt according to claim 6, characterized in that, The heating electrode plate includes two plate-shaped molybdenum electrodes with round holes in the center. The two electrodes are horizontally and oppositely arranged on the end walls at both ends of the shell-side closed space, and the electrodes are led out of the ceramic shell through electrode lead rods.

8. The heat storage and heat release device for modular electrode heating molten salt according to claim 6, characterized in that, The inner layer of the heat storage module adopts a silicon nitride ceramic material layer, and the outer layer adopts a module insulation layer.

9. The heat storage and heat release device for modular electrode heating molten salt according to claim 6, characterized in that, The maximum adjustable water flow rate of the return water pump is higher than the water flow rate of the heat user, and the minimum value is lower than the water flow rate of the heat user; The return water mixing tank and the water supply mixing tank respectively maintain preset liquid level heights. When the water flow rate in the loop is less than the water flow rate of the heat user, the liquid level in the return water mixing tank is increased, and the liquid level in the water supply mixing tank is decreased. When the water flow rate in the loop is greater than the water flow rate of the heat user, the liquid level in the return water mixing tank is decreased, and the liquid level in the water supply mixing tank is increased to realize the normal operation of the loop.

10. The heat storage and heat release device for modular electrode heating molten salt according to claim 6, characterized in that, In the heat storage working mode only, the control system controls the heating electrode plates to continuously heat the heat storage medium; In the heat release working mode only, the control system controls the heating electrode plates to be powered off, controls the return water pump to adjust the flow rate of the heat transfer medium entering the heat storage module group, and the flow rate continuously decreases as the temperature of the heat storage medium decreases. The heat transfer medium enters the heat storage module group for heat exchange and then provides stable heat to the heat user under the drive of the water supply pump, and returns to the return water mixing tank after consuming heat to form an internal circulation; When heat storage and heat release are carried out simultaneously, when the flow rate of the heat transfer medium reaches the minimum or the temperature of the heat storage medium reaches the lower limit and cannot meet the outlet water temperature, the control system controls the heating electrode plates to be powered on. When the outlet water temperature exceeds the preset temperature, the control system controls the return water pump to increase the flow rate of the heat transfer medium entering the heat storage module group so that the temperature of the medium entering the water supply mixing tank meets the preset temperature requirement.

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