Hybrid electric heating heat storage system for full-amount and full-power consumption of renewable energy sources

Abstract

The invention discloses a hybrid electric heating heat storage system for full-amount and full-power consumption of renewable energy sources. The hybrid electric heating heat storage system comprises a quick response part and a slow response part. The quick response part is used for absorbing quick fluctuation power of renewable energy sources and is composed of one or more quick power response electric heaters such as a solid electric heating heat storage device, an electric boiler heat storage device, an induction heating electric heater and a resistance heating electric heater; the slow response part is used for absorbing medium-low speed fluctuation power and is composed of one or more of an electric heating fused salt heat storage device, a heat pump heating heat storage device, a compressed working medium heat storage device and the like. Multi-grade heat energy supply can be achieved at the same time, or the system is used for series cascade heating to supply high-grade heat energy. The functional defect that a single electric heating heat storage system cannot effectively cope with renewable energy power fluctuation or cannot store a large amount of heat is overcome. A solution for full consumption of renewable energy is provided, and the method is particularly suitable for full consumption of off-grid new energy and provides flexible power support for new energy grid connection.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of energy, and particularly relates to a hybrid electric heating and heat storage system for full-capacity and full-power consumption of renewable energy. BACKGROUND

[0002] With the increasing proportion of renewable energy in the terminal energy consumption structure, solving the key technical problems in the application process and improving the consumption capacity of the energy system for renewable energy have become an important research topic. Due to the inherent volatility characteristics of wind and light, the wind and light output presents millisecond-second-minute-day-week-cross-season multi-scale characteristics, and the existing conventional heat storage technology cannot solve the consumption problem of wind and light fluctuation in the whole time scale by using a single energy storage technology, resulting in large-scale wind and electricity abandonment. The existing single long-time energy storage system, such as molten salt heat storage and hydrogen energy storage, cannot effectively cope with the high power fluctuation of renewable energy. Although single flywheel energy storage and electrochemical energy storage can cope with the rapid fluctuation of wind and light, they cannot store a large amount of energy and cannot realize long-time energy storage. The multi-element hybrid energy storage system such as flywheel energy storage plus molten salt heat storage has high cost, and its energy form is diversified and the operation control is complex. Therefore, a new technology of low-cost electric heating and heat storage is urgently needed to realize full-capacity and full-power consumption of wind and light. SUMMARY

[0003] In order to cope with the inherent intermittency and volatility of renewable energy, more effectively realize power tracking and utilization, and meet the green and low-carbon supply of heat energy in the application scene of multiple temperature grades, the application provides a hybrid electric heating and heat storage system for full-capacity and full-power consumption of renewable energy. The hybrid electric heating and heat storage system is combined by heating methods with different response speeds to achieve full-capacity consumption of renewable energy fluctuation power and realize large storage of heat energy. The purpose is to improve the renewable energy access capacity of the electric heating system, improve the energy utilization rate, and realize the mixed supply of multiple grade heat energy.

[0004] This invention is used to fully absorb renewable energy at full power, comprising two parts: a fast response part and a slow response part. The fast response part absorbs the rapidly fluctuating power of renewable energy and consists of one or more electric heaters with fast power response, such as solid-state electric heating thermal storage devices, electric boiler thermal storage devices, induction heating, and resistance heating. The slow response part absorbs medium- and low-speed fluctuating power and consists of one or more electric heating molten salt thermal storage devices, heat pump heating thermal storage devices, and compressed working fluid thermal storage devices, which can be used to store large amounts of thermal energy. The thermal energy stored in the fast response part and the thermal energy stored in the slow response part can be used as a lower-temperature heat source and a higher-temperature heat source, respectively. They can be used independently for different heating needs or in series for cascade heating to supply high-grade thermal energy—that is, the heated material is first heated by a lower-temperature heat source and then by a higher-temperature heat source, thereby achieving optimized utilization of thermal energy.

[0005] This invention overcomes the functional defects of single electric heating thermal storage systems, which cannot effectively cope with the power fluctuations of renewable energy or cannot be used to store large amounts of heat. It can provide a solution for the full absorption of renewable energy, and is particularly suitable for the full absorption of off-grid renewable energy and for providing flexible power support for renewable energy grid connection.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A hybrid electric heating and thermal storage system that fully utilizes renewable energy at full power includes:

[0008] Fast-response electric heating thermal storage unit is used to absorb rapidly fluctuating power from renewable energy sources;

[0009] Slow-response electric heating thermal storage unit is used to absorb medium- and low-speed power fluctuations from renewable energy sources;

[0010] The fast-response electric heating heat storage unit and the slow-response electric heating heat storage unit form a multi-stage heat storage circuit, which respectively supplies heat energy at various temperatures, or heats the heated medium and then outputs it.

[0011] Preferably, the fast-response electric heating heat storage unit is a solid electric heating heat storage device with a serpentine molten salt flow channel arranged inside. The outer wall of the molten salt flow channel is in direct contact with the solid heat storage body, realizing immersion heat exchange between the solid heat storage body and the molten salt.

[0012] Preferably, the fast-response electric heating heat storage unit is an electric boiler, and the hot water / steam outlet of the electric boiler is coupled to the molten salt circuit of the slow-response electric heating heat storage unit through a heat exchanger, so that the heat of the hot water / steam is transferred to the molten salt circuit through the heat exchanger.

[0013] Preferably, the slow response electric heating thermal storage unit is an electric heating molten salt thermal storage unit, and the molten salt network of the fast response electric heating thermal storage unit is directly connected in series with the network of the electric heating molten salt thermal storage unit to form a molten salt single-loop series thermal storage structure.

[0014] Preferably, the slow response electric heating thermal storage unit is a heat pump, and the fast response electric heating thermal storage unit is a solid electric heating thermal storage unit, and the molten salt outlet of the solid electric heating thermal storage unit is connected to the hot water / steam outlet of the heat pump through a primary heat exchanger, and the hot water / steam circuit inlet of the heat pump is connected to the molten salt return port of the solid electric heating thermal storage unit through a secondary heat exchanger to form a molten salt network-hot water / steam network double-loop series heating structure.

[0015] Preferably, the fast response electric heating thermal storage unit is an electric boiler, and the slow response electric heating thermal storage unit is a heat pump, and the steam outlet of the electric boiler and the hot water outlet of the heat pump are connected in parallel to the same steam / hot water main pipe, and the main pipe outlet is connected to an external heat load through a valve and a pump to realize parallel heating of the two heat sources.

[0016] Preferably, the fast response electric heating thermal storage unit is an induction heater, and the slow response electric heating thermal storage unit is a compressed working medium thermal storage unit, and the molten salt outlet of the induction heater is coupled to the steam circuit of the compressed working medium thermal storage unit through a heat exchanger to transfer the molten salt heat to the compressed working medium circuit through the heat exchanger.

[0017] Preferably, the slow response electric heating thermal storage unit is composed of an electric heating molten salt thermal storage unit and a compressed working medium thermal storage unit in parallel, and the molten salt outlet of the fast response electric heating thermal storage unit is connected to the inlet of the electric heating molten salt thermal storage unit and the inlet of the compressed working medium thermal storage unit through a distribution valve to form a multi-path thermal storage circuit.

[0018] Preferably, the fast response electric heating thermal storage unit is composed of an electric boiler and a solid electric heating thermal storage unit in parallel, and the slow response electric heating thermal storage unit is composed of a heat pump and an electric heating molten salt thermal storage unit in parallel, and the parallel outlet of the fast response unit and the parallel inlet of the slow response unit are connected through a main pipe and a valve to form a fast-slow two-stage parallel thermal storage structure.

[0019] Preferably, the fast response electric heating thermal storage unit is an induction heater, and the slow response electric heating thermal storage unit is an electric heating molten salt thermal storage unit, and the molten salt outlet of the induction heater is directly connected in series with the inlet of the electric heating molten salt thermal storage unit to first heat the molten salt rapidly in the induction heater and then complete long-term thermal storage in the electric heating molten salt thermal storage unit.

[0020] Preferably, the fast response electric heating mode is selected for better adaptability to fast fluctuating power, and the slow response electric heating mode is selected for slower fluctuation response but higher power consumption level, and the two modes respectively realize fast adjustment and slow adjustment of heating power.

[0021] Preferably, the fast-responding heat storage stage can be solid electric heating heat storage or electric boiler or induction heating or resistance heating; the slow-responding heat storage stage can be electric heating molten salt heat storage or heat pump heating heat storage or compressed working medium heat storage. Each heating stage can also be a combination of multiple heating methods.

[0022] Preferably, the fast-responding solid electric heating heat storage and the slow-responding electric heating molten salt heat storage can constitute a hybrid heating system; the fast-responding electric boiler and the slow-responding electric heating molten salt heat storage can constitute a hybrid heating system; the fast-responding solid electric heating heat storage and the slow-responding heat pump heating can constitute a hybrid heating system; the fast-responding electric boiler and the slow-responding heat pump heating can constitute a hybrid heating system; the fast-responding induction heating and the slow-responding compressed working medium heat storage can constitute a hybrid heating system. Each fast-responding heating method can be mixed with one slow-responding heating method.

[0023] Preferably, the present application can use renewable energy to supply power directly, or can use power grid to supply power. When using renewable energy to supply power, the fast-responding heating part and the slow-responding heating part absorb fast and low-speed fluctuating power respectively.

[0024] Preferably, the present application can supply heat energy of multiple grades through series cascade heat supply and separate heat supply. It can be used independently for different heat supply demands, or used for series cascade heating to supply high-grade heat energy, that is, the heated substance is heated by a lower-temperature heat source first, and then heated by a higher-temperature heat source, so as to achieve optimal utilization of heat energy.

[0025] Preferably, the present application realizes full consumption of renewable energy by power coordination and configuration of multiple heating methods with different response speeds.

[0026] Advantages:

[0027] 1. The present application uses a hybrid electric heating method, uses the fast-responding heating part to absorb the fast fluctuating power of renewable energy, and uses the slow-responding part to absorb the remaining low-speed fluctuating power, so as to better adapt to the direct access of renewable energy.

[0028] 2. The fast-responding wind-solar fluctuation energy storage and heat storage of the present application can be flexibly configured to adapt to different wind-solar fluctuation characteristics, reduce system cost, and solve the problem that a single electric heating heat storage system cannot effectively respond to renewable energy power fluctuation or cannot be used for storing a large amount of heat, which has obvious economic advantages.

[0029] 3. The present application has fast frequency regulation and peak regulation capacity, can fully consume renewable energy power, solves the problem of difficulty in full power consumption of general hybrid energy storage systems, and can provide flexible support for the power grid.

[0030] 4、The application provides multiple grades of heat energy by means of series cascade heat supply and separate heat supply, can meet the heat demand of various types of heat load, realizes the optimized utilization of heat energy, has rich application range and has wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a schematic diagram of a solid-molten salt mixed electric heating heat storage system of the first embodiment of the application;

[0032] Figure 2 It is a structural diagram of a solid-molten salt mixed electric heating heat storage device;

[0033] Figure 3 It is a schematic diagram of an electric boiler-molten salt mixed electric heating heat storage system of the second embodiment of the application;

[0034] Figure 4 It is a schematic diagram of a solid-heat pump mixed electric heating heat storage system of the third embodiment of the application;

[0035] Figure 5 It is a schematic diagram of an electric boiler-heat pump mixed electric heating heat storage system of the fourth embodiment of the application;

[0036] Figure 6 It is a schematic diagram of an induction heating-compressed working medium heat storage mixed system of the fifth embodiment of the application;

[0037] Figure 7 It is a comprehensive system diagram of the mixed electric heating heat storage system.

[0038] Wherein, Figure 1 The reference signs of the first embodiment are as follows: A-1, first new energy power generation system; A-2, first current conversion device; A-3, high-temperature molten salt storage tank; A-4, eighth heat exchanger; A-5, low-temperature molten salt storage tank; A-6, first molten salt valve; A-7, first molten salt pump; A-8, mixed electric heating heat storage device; A-9, controller unit.

[0039] Figure 2 The reference signs of the first embodiment are as follows: A-10, electric heater; A-11, solid heat storage body; A-12, molten salt flow channel; A-13, temperature sensor; A-14, pressure sensor.

[0040] Figure 3 The reference signs of the second embodiment are as follows: B-1, first power grid; B-2, second new energy power generation system; B-3, second current conversion device; B-4, fourth transformer; B-5, electric heating molten salt heat storage device; B-6, second molten salt pump; B-7, first molten salt storage tank; B-8, second molten salt valve; B-9, ninth heat exchanger; B-10, first electric boiler; B-11, fifth water storage tank.

[0041] Figure 4 The reference signs of the figure are: C-1, third new energy power generation system; C-2, third current conversion device; C-3, solid heating heat storage device; C-4, second molten salt storage tank; C-5, third molten salt pump; C-6, third molten salt valve; C-7, fourth molten salt valve; C-8, first heat pump; C-9, first heat exchanger; C-10, second heat exchanger; C-11, fifth condenser.

[0042] Figure 5 The reference signs of the figure are: D-1, fourth new energy power generation system; D-2, fourth current conversion device; D-3, steam / hot water valve; D-4, steam / hot water pump; D-5, second electric boiler; D-6, second heat pump; D-7, fourth condenser; D-8, third water storage tank; D-9, fourth water storage tank.

[0043] Figure 6 The reference signs of the figure are: E-1, second power grid; E-2, third transformer; E-3, fifth current conversion device; E-4, fifth new energy power generation system; E-5, second steam turbine; E-6, second generator; E-7, seventh heat exchanger; E-8, fourth molten salt pump; E-9, fifth molten salt valve; E-10, third molten salt storage tank; E-11, induction heating device; E-12, compressed working medium heat storage device; E-13, third condenser.

[0044] Figure 7 The reference signs of the figure are: 1, first generator; 2, first steam turbine; 3, condensing tower; 4, third power grid; 5, renewable energy grid; 6-1, first heater current converter; 6-2, second heater current converter; 6-3, third heater current converter; 6-4, fourth heater current converter; 7-1, third heat pump; 7-2, third electric boiler; 7-3, electric heating molten salt heat storage device A; 7-4, solid heating heat storage device A; 7-5, compressed working medium heat storage device A; 8-1, high-temperature molten salt heat energy supply; 8-2, medium-temperature steam heat energy supply; 8-3, low-temperature hot water heat energy supply; 9-1, first heat exchanger; 9-2, second heat exchanger; 9-3, third heat exchanger; 9-4, fourth heat exchanger; 9-5, fifth heat exchanger; 9-6, sixth heat exchanger; 10, pump; 11-1, fourth molten salt storage tank; 11-2, fifth molten salt storage tank; 12, valve; 13-1, first transformer; 13-2, second transformer; 14-1, first condenser; 14-2, second condenser; 15-1, first water storage tank; 15-2, second water storage tank. DETAILED DESCRIPTION

[0045] The application is further explained in conjunction with the accompanying drawings and examples.

[0046] As Figure 1As shown, the hybrid electric heating thermal storage system for full and full utilization of renewable energy in Embodiment 1 of the present invention is a solid-molten salt hybrid electric heating thermal storage system, including a first new energy power generation system A-1, a first converter A-2, a high-temperature molten salt storage tank A-3, an eighth heat exchanger A-4, a low-temperature molten salt storage tank A-5, a first molten salt valve A-6, a first molten salt pump A-7, a hybrid electric heating thermal storage device A-8 (solid-molten salt hybrid), and a controller unit A-9. The first new energy power generation system A-1 supplies power to the solid-molten salt hybrid electric heating thermal storage system A-8 via the first converter A-2; the low-temperature molten salt is transported from the low-temperature molten salt storage tank A-5 to the hybrid electric heating thermal storage device A-8 through the first molten salt valve A-6 and the first molten salt pump A-7. The high-temperature molten salt enters the high-temperature molten salt storage tank A-3 and is introduced into the eighth heat exchanger A-4 (molten salt-steam heat exchange), transferring heat to water to generate high-temperature, high-pressure steam or hot water.

[0047] like Figure 2 The diagram shows the structure of a hybrid electric heating thermal storage device A-8. It includes an electric heater A-10 and a solid thermal storage body A-11, with a molten salt channel A-12 arranged within it to achieve direct immersion integrated thermal storage and exchange. Preferably, the molten salt channel A-12 is serpentine, and the electric heater A-10 is a direct immersion type, heating the solid thermal storage body A-11 to complete high-power charging and large-capacity thermal storage. The solid thermal storage body A-11, acting as a solid-side frequency modulation unit, preferentially absorbs / releases power fluctuations on the second-to-minute level, achieving rapid thermal buffering and temperature smoothing. The stored heat is transferred to the molten salt via the molten salt channel A-12, where the molten salt performs peak shaving and energy transfer, providing medium-to-long-cycle energy release and stable supply of steam or hot water within a ten-minute to hour timeframe. Temperature sensor A-13 and pressure sensor A-14 are installed on top of the hybrid electric heating and heat storage device A-8 to provide full-range temperature and pressure monitoring. The controller unit realizes coordinated regulation of power, flow rate and valve position and safety protection mechanism, including over-temperature, over-pressure, minimum flow rate, and leakage shutdown, to ensure the high efficiency and safety of the solid-molten salt hybrid electric heating / heat storage system under long-term high-temperature operation conditions.

[0048] When wind and solar power fluctuate rapidly, controller unit A-9 prioritizes the solid thermal accumulator A-11 to absorb and release transient heat. By adjusting the duty cycle of electric heater A-10 and the flow rate in the internal loop of the hybrid electric heating thermal accumulator A-8, it suppresses rapid fluctuations in output power / temperature, maintaining temperature and pressure limits. Solid thermal accumulator A-11 smooths rapid power fluctuations, while molten salt handles energy transport and output, thereby generating stable, high-quality steam and hot water. When medium- to long-term load changes or peak-valley shift demands occur, controller unit A-9 increases the flow rate of the first molten salt pump A-7 and controls the opening of the first molten salt valve A-6, enabling the molten salt to complete a large-scale energy transfer in a closed loop, continuously supplying heat to the molten salt-steam heat exchanger A-4 and stably producing steam or hot water.

[0049] Preferably, the solid heat storage body A-11 is cast iron or magnesium brick, and the liquid heat carrier is molten salt.

[0050] Preferably, the solid heat storage body A-11 can also be a blocky, dense honeycomb structure of thermally conductive ceramic, which serves as a solid-side frequency modulator to smooth rapid disturbances and maintain temperature and pressure limits. The generated heat is transferred to the molten salt channel A-12 to perform liquid-side peak shaving, and through a closed-loop circulation, it matches the load with the external heat exchange unit to achieve a continuous and stable supply of high-grade steam or hot water. This avoids molten salt infiltration and leakage, and also possesses high structural strength and specific surface area.

[0051] Preferably, the solid heat storage body A-11 can also be a thermally conductive ceramic with a porous foam honeycomb structure. This structure significantly improves the convective heat transfer coefficient and temperature uniformity, which is beneficial for rapid heat charging / discharging and peak-valley regulation.

[0052] like Figure 3 As shown, the hybrid electric heating and thermal storage system for full and full utilization of renewable energy in Embodiment 2 of the present invention is an electric boiler-molten salt hybrid electric heating and thermal storage system, including a fast-response heating section of the electric boiler (first electric boiler B-10) and an electric heating molten salt section (electric heating molten salt thermal storage device B-5). A second new energy power generation system B-2 supplies power to the first electric boiler B-10 through a second converter B-3. The second new energy power generation system B-2 is connected to the first power grid B-1 through a fourth transformer B-4. A second molten salt pump B-6 drives the flow direction of the molten salt network. A second molten salt valve B-8 controls the molten salt bypass circuit to regulate the flow rate and temperature of the high-temperature molten salt through the ninth heat exchanger B-9. Figure 3 The system includes two heat flow networks: a high-temperature molten salt network and a low-temperature steam network. The hybrid electric heating and thermal storage system is powered by either the second new energy power generation system B-2 or the first power grid B-1. The high-temperature molten salt and the medium- and low-temperature steam exchange heat through the ninth heat exchanger B-9. The first molten salt storage tank B-7 stores circulating cold molten salt, and the fifth water storage tank B-11 stores circulating cooling water.

[0053] Fluctuating renewable energy power is decomposed by the control system. Rapidly fluctuating power is absorbed by the first electric boiler B-10, which has a fast response capability, to supply medium- and low-temperature hot steam. Low-speed fluctuations are absorbed by the slow-response electrically heated molten salt thermal storage device B-5, to supply high-temperature hot molten salt. This embodiment can achieve separate supply of heat energy at various temperatures, or the high-temperature molten salt can exchange heat with the low-temperature steam through the ninth heat exchanger B-9, achieving series supply of heat energy.

[0054] like Figure 4As shown, the renewable energy full amount full power consumption mixed electric heating and heat storage system of the third embodiment of the present application is a solid-heat pump mixed electric heating and heat storage system, which comprises a solid heating and heat storage fast response heating part (solid heating and heat storage device C-3) and a heat pump slow response heating part (first heat pump C-8). The power supply part of the mixed electric heating system is a third new energy power generation system C-1 and a third current conversion device C-2. The second molten salt storage tank C-4 is used to store molten salt of the molten salt network. The third molten salt pump C-5 drives the flow direction of the molten salt network. The third molten salt valve C-6 realizes the interconnection of the two molten salt circuits. The fourth molten salt valve C-7 controls the molten salt heat exchange circuit, so as to control the heat exchange between the molten salt network and the hot water / steam network. The solid heating and heat storage device C-3 absorbs the rapid power fluctuation of the renewable energy, heats the molten salt, and heats the circulating hot steam through the primary heat exchanger C-9. The molten salt after heat exchange preheats the circulating water through the secondary heat exchanger C-10. The first heat pump C-8 heats the preheated water to obtain steam with a certain temperature. The steam after secondary heating of the molten salt is supplied to the heat load. The exhaust gas after condensation by the fifth condenser C-11 can supply hot water to the hot water load. In this way, the comprehensive supply of multiple grade heat energy is realized.

[0055] As shown in the figure, Figure 5 As shown, the renewable energy full amount full power consumption mixed electric heating and heat storage system of the fourth embodiment of the present application is an electric boiler-heat pump mixed electric heating and heat storage system, which comprises an electric boiler fast response heating part (second electric boiler D-5) and a heat pump slow response heating part (second heat pump D-6). The fourth new energy power generation system D-1 supplies power to the second electric boiler D-5 through the fourth current conversion device D-2. The steam / hot water valve D-3 is used to control the flow of the heat pump circuit. The steam / hot water pump D-4 drives the flow direction of the steam and hot water network. The fourth condenser D-7 is used to connect the high-temperature steam / hot water network and the low-temperature hot water network, and condense the high-temperature steam to obtain hot water with lower temperature. The third water storage tank D-8 is used to store water of the high-temperature steam / hot water network. The fourth water storage tank D-9 is used to store water of the low-temperature hot water network. Figure 5 The heat supply network is a steam / hot water network, which is heated by the fast response part and the slow response part, and the two parts absorb the rapid fluctuation power and the low-speed fluctuation power of the renewable energy respectively. The supply of hot steam and hot water with different temperatures can be realized.

[0056] As shown in the figure, Figure 6As shown, the renewable energy full amount full power consumption mixed electric heating heat storage system of the fifth embodiment of the present application is an induction heating-compressed working medium heat storage mixed system, which includes an induction heating fast response part (induction heating device E-11) and a compressed working medium heat storage slow response part (compressed working medium heat storage device E-12). The fifth new energy power generation system E-4 supplies power to the compressed working medium heat storage device E-12 through the fifth variable flow device E-3. The fifth new energy power generation system E-4 is connected to the second power grid E-1 through the third transformer E-2. High-temperature steam generates power for the second power grid E-1 through the second steam turbine E-5 and the second generator E-6. The fourth molten salt pump E-8 drives the molten salt network to flow. The fifth molten salt valve E-9 controls the flow of the molten salt network. The third molten salt storage tank E-10 is used to store the molten salt of the molten salt network. Figure 6 The system includes two heat flow networks, namely a molten salt network and a steam network. The induction heating device E-11 absorbs power from the new energy power generation system E-4 or the second power grid E-1 to heat the molten salt network. The molten salt network and the steam network can exchange heat through the seventh heat exchanger E-7. The compressed working medium heat storage device E-12 can absorb slow fluctuation power of renewable energy for heat storage or heat the steam network.

[0057] Preferably, in addition to the above five mixed heating methods, fast response induction heating, resistance heating, etc. and slow response solid electric heating, electric heating molten salt heat storage, compressed working medium heat storage, etc. can also be combined respectively to form a mixed heating system. Each heating method can also be combined by multiple heating methods with similar response speed, for example, fast response induction heating combined with resistance heating and slow response solid electric heating to form a mixed heating system.

[0058] The mixed heating comprehensive system composed of multiple heating methods is as shown in Figure 7 As shown, the fast response part and the slow response part of the system each include multiple heating and heat storage methods, and the fast fluctuation power and the low fluctuation power can be respectively composed of one or more electric heaters. The fast response heating methods are the third electric boiler 7-2 and the solid heating heat storage device A 7-4; the slow response heating method is the third heat pump 7-1, and the long-time energy storage is the electric heating molten salt heat storage device A 7-3 and the compressed working medium heat storage device A 7-5. The electric energy of the system comes from the third power grid 4 and the renewable energy grid 5. The renewable energy grid 5 is connected to the third power grid 4 through the first transformer 13-1. The renewable energy grid 5 supplies power to the third heat pump 7-1 through the first heater variable flow device 6-1, to the electric heating molten salt heat storage device A 7-3 through the second heater variable flow device 6-2, to the solid heating heat storage device A 7-4 through the third heater variable flow device 6-3, and to the compressed working medium heat storage device A 7-5 through the fourth heater variable flow device 6-4.

[0059] The power generation part of the system includes a first generator 1, a first steam turbine 2 and a condenser tower 3. High-temperature steam generated by heating high-temperature molten salt passes through the first steam turbine 2 and the first generator 1, and is boosted in voltage by the second transformer 13-2 to generate power for the third power grid 4.

[0060] The system can supply three different grades of thermal energy, namely high-temperature molten salt thermal energy supply 8-1, medium-temperature steam thermal energy supply 8-2 and low-temperature hot water thermal energy supply 8-3.

[0061] The system includes three types of heat flow networks, namely low-temperature hot water network, medium-temperature steam network and high-temperature molten salt network. The molten salt network and the steam network exchange heat through the first heat exchanger 9-1, the third heat exchanger 9-3, the fourth heat exchanger 9-4 and the fifth heat exchanger 9-5, the molten salt networks exchange heat through the second heat exchanger 9-2, and the steam network is coupled with the hot water network through the first condenser 14-1 and the second condenser 14-2 and exchanges heat through the sixth heat exchanger 9-6. The first condenser 14-1 is connected to the thermal power generation part to cool the working steam. The second condenser 14-2 is used to connect the high-temperature steam / hot water network and the low-temperature hot water network, and condenses the high-temperature steam to obtain hot water at a lower temperature.

[0062] The molten salt network includes a pump 10 for controlling the flow of molten salt, a fourth molten salt storage tank 11-1 and a fifth molten salt storage tank 11-2 for storing and storing heat of molten salt, and a valve 12 for loop control. The pump 10 drives the flow direction of the molten salt network containing the electric heating molten salt heat storage device A 7-3. The valve 12 controls the molten salt bypass loop to adjust the flow and temperature of the high-temperature molten salt through the first heat exchanger 9-1. The fourth molten salt storage tank 11-1 is used to store the molten salt of the electric heating molten salt heat storage device A 7-3. The steam and hot water loop also includes a first water storage tank 15-1, a second water storage tank 15-2 for water storage, and valves and pumps for controlling the flow direction of steam and water. The first water storage tank 15-1 is used to store water in the high-temperature steam / hot water network. The second water storage tank 15-2 is used to store water in the low-temperature hot water network.

[0063] The electric heating molten salt heat storage device A 7-3 and the solid heating heat storage device A 7-4 can be heated in series, first heated by the molten salt electric heater, then exchanged heat to the adjacent molten salt network through the second heat exchanger 9-2, and finally further heated by the solid electric heater. The third heat pump 7-1 and the third electric boiler 7-2 can also be heated in series, first heated by the heat pump, and the hot water obtained is further heated by the electric boiler. The third heat pump 7-1, the third electric boiler 7-2, the electric heating molten salt heat storage device A 7-3, the solid heating heat storage device A 7-4 and the compressed working medium heat storage device A 7-5 can also be heated respectively to supply heat energy at corresponding temperatures.

[0064] The solid heating and heat storage device A 7-4 outlet exchanges heat with the power generation steam network through the third heat exchanger 9-3, and flows back to the fifth molten salt storage tank 11-2 or enters the hot water / steam network heat exchange loop. The heat exchange loop exchanges heat with the hot water / steam outlet of the heat pump 7-1 and the electric boiler 7-2 through the fourth heat exchanger 9-4, and the hot water / steam loop exchanges heat with the molten salt network through the fifth heat exchanger 9-5.

[0065] In the case of fluctuating renewable energy power supply, the rapid fluctuating power can be absorbed by the rapid heating response part, and the relatively stable power part obtained after absorption can be consumed by the slow response heating part. The stable utilization and control of the system to fluctuating energy can realize the large storage of thermal energy.

[0066] The system can meet the heat demand of various different temperature heat loads. Each heating and heat storage method can supply different grade heat demand as a different temperature heat source, or can be preheated by a low temperature heat source and then heated by a high temperature heat source to realize series heating.

[0067] Preferably, the system can supply high temperature steam and generate electricity through the steam turbine 2, and can realize high temperature molten salt heat energy supply 8-1 and medium temperature steam heat energy supply 8-2, so as to realize the supply of different temperature heat energy in industrial and agricultural production, and can supply low temperature hot water heat energy supply 8-3 to meet the residential heat demand. The system can be initially heated by the third heat pump 7-1 and the third electric boiler 7-2 of the low temperature heat source, and then heated by the electric heating molten salt heat storage device A 7-3 and the solid heating and heat storage device A 7-4 of the high temperature heat source to realize series heating.

[0068] Those skilled in the art will readily understand that the above description is only a preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A hybrid electric heating and heat storage system for full renewable energy full power consumption, characterized in that, The application relates to a multi-stage thermal energy storage system. The application relates to a multi-stage thermal energy storage system. The application relates to a multi-stage thermal energy storage system. The application relates to a multi-stage thermal energy storage system.

2. The hybrid electric heating and thermal storage system of claim 1, wherein, The application relates to a multi-stage thermal energy storage system.

3. The hybrid electric heating and thermal storage system of claim 1, wherein, The application relates to a multi-stage thermal energy storage system.

4. The hybrid electric heating and thermal storage system of claim 1, wherein, The application relates to a multi-stage thermal energy storage system.

5. The hybrid electric heating and thermal storage system of claim 1, wherein, The application relates to a multi-stage thermal energy storage system.

6. The hybrid electric heating and thermal storage system of claim 1, wherein, The application relates to a multi-stage thermal energy storage system.

7. The hybrid electric heating and thermal storage system of claim 1, wherein, The application relates to a multi-stage thermal energy storage system. The application relates to a multi-stage thermal energy storage system. The application relates to a multi-stage thermal energy storage system.

8. The hybrid electric heating and thermal storage system of claim 1-7, wherein, The fast response electric heating and heat storage unit comprises one or more of solid electric heating and heat storage device, electric boiler heat storage device, induction heating, and resistance heating; the slow response electric heating and heat storage unit comprises one or more of electric heating and heat storage device of molten salt, heat pump heating and heat storage device, and compressed working medium heat storage system.

9. The hybrid electric heating and thermal storage system of claim 1-7, wherein, The series and parallel heat storage and heat supply structure comprises: any combination of the fast response electric heating and heat storage unit and the slow response electric heating and heat storage unit to realize parallel supply of multiple temperatures, or any combination of the fast response and slow response electric heating and heat storage units in series to perform step-by-step heating on the heated medium from low to high.

10. The hybrid electric heating and thermal storage system of claim 1, wherein, Renewable energy is directly used for power supply, or the power grid is used for power supply when renewable energy is insufficient; when the power grid is used for power supply, the fast or slow heating part is selected according to the heat load demand.

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