Steam supply system based on calcium hydroxide thermochemical energy storage and operation method

Abstract

The invention discloses a steam supply system based on calcium hydroxide thermochemical energy storage and an operation method. The system comprises a thermochemical energy storage device, a steam supply device, an electric heating device and a material circulation auxiliary device. The thermochemical energy storage device is a fluidized bed reactor and a solid material storage tank, reversible conversion between high-grade heat energy and chemical energy is achieved through hydration / dehydration reaction, then heat energy storage is achieved, and the thermochemical energy storage device is matched with the auxiliary device to form a closed material circulation loop. The steam supply device integrates multiple paths of steam through a valve and a mixer; the electric heating device serves as a supplementary heat source in the peak regulation stage of the coal-fired heat supply unit. The operation method is divided into a starting stage, a non-peak-shaving stage and a peak-shaving stage, and cooperative control over high-pressure steam extraction heat energy storage and low-temperature water supply evaporation overheating is achieved. The system aims to solve the thermoelectric decoupling problem of the coal-fired heat supply unit, and has the advantages of flexibility, high efficiency, safety, environmental protection, low application cost, high energy storage density, small occupied area and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage, and particularly relates to a steam supply system and an operation method based on calcium hydroxide thermochemical energy storage. Background Art

[0002] Under the background of building a new power system, coal-fired power units need to improve their deep peak shaving and rapid load-changing capabilities in order to support the consumption of a high proportion of new energy and maintain the stability of the power system. However, there is a fundamental contradiction between industrial steam supply demand and the peak shaving ability of the units: the units need to maintain the extraction steam pressure to meet the needs of heat users, resulting in the power generation load being unable to drop to its lowest technical output, forming a "power determined by heat" bottleneck, restricting the peak shaving space of the units and weakening their competitiveness in the power market.

[0003] Thermochemical energy storage technology, with its high energy density, long-term lossless storage, and flexible and adjustable heat release characteristics, provides a new path for the upgrade of the steam supply system of coal-fired units. Taking the calcium hydroxide / calcium oxide system as an example, its raw materials are cheap and easily available, the reaction reversibility is strong, and the thermal stability is excellent. It can efficiently capture the extraction waste heat of coal-fired units, store it across time periods in the form of chemical energy, and accurately match the steam demand during load increase, breaking through the restriction of the traditional "power determined by heat" on the peak shaving ability of the units. However, current research mostly focuses on the reaction kinetics mechanism, and there is a significant lack of coupling between thermochemical energy storage systems and thermal cycles. The long-term operation stability of the integrated heating system for the chemical energy-thermal energy reversible conversion process needs to be evaluated. Summary of the Invention

[0004] In order to solve the problems existing in the above-mentioned prior art, the purpose of the present invention is to propose a steam supply system and an operation method based on calcium hydroxide thermochemical energy storage. The core of the system is as follows: a dual-fluidized bed reactor is used to perform dehydration decomposition and hydration synthesis reactions respectively, and the continuous circulation of materials is realized through a calcium oxide / calcium hydroxide particle storage tank; a double-side steam supply path and a parallel heat storage branch are set up, integrating the double-path steam supply on the heat storage side and the heat release side, high-pressure extraction steam and electric heating for auxiliary heat storage; a time-sharing control strategy is constructed, using extraction steam to drive the heat storage cycle during non-peak shaving periods, and switching to electric heating to compensate for the steam supply gap during peak shaving periods. This system aims to achieve the thermal-electric decoupling of coal-fired units and is suitable for the flexibility transformation of units.

[0005] The technical solution adopted by the present invention to solve its technical problems is:

[0006] (1) The present invention provides a steam supply system based on calcium hydroxide thermochemical energy storage, which includes a thermochemical energy storage device, a steam supply device, an electric heating device, and a material circulation auxiliary device; the thermochemical energy storage device includes a reactor and a material storage tank, the reactor includes a fluidized bed dehydration reactor and a fluidized bed hydration reactor, and the material storage tank includes a calcium oxide particle storage tank and a calcium hydroxide particle storage tank; the steam supply device includes a mixer and a pressure reducing valve; the electric heating device includes an electric heater; the material circulation auxiliary device includes a gas-solid separator, a first discharge valve, a second discharge valve, a first feed valve, a second feed valve, and a throttle valve;

[0007] For the fluidized bed dehydration reactor, a first branch and a second branch are connected in parallel on the heat supply side. A pressure reducing valve is connected to the inlet of the first branch, and the outlet is connected to the mixer. An electric heater is provided on the second branch. High-pressure extraction steam is sequentially transported to the mixer through the pressure reducing valve and the fluidized bed dehydration reactor. The gaseous material water at the outlet of the fluidized bed dehydration reactor is transported to the mixer through the gas-solid separator. The outlet of the mixer supplies heat users, forming a steam supply path; low-temperature feed water is supplied to heat users after passing through the fluidized bed hydration reactor (7), forming a steam supply path. The outlet of the solid material calcium oxide of the fluidized bed dehydration reactor is sequentially connected to the calcium oxide particle storage tank through the gas-solid separator and the first discharge valve. The calcium oxide particle storage tank is connected to the fluidized bed hydration reactor through the first feed valve. Low-pressure extraction steam is connected to the fluidized bed hydration reactor through the throttle valve. The low-temperature feed water is heated in the fluidized bed hydration reactor and then supplied to heat users. The fluidized bed hydration reactor is connected to the calcium hydroxide particle storage tank through the second discharge valve. The calcium hydroxide particle storage tank is connected to the fluidized bed dehydration reactor through the second feed valve.

[0008] Preferably, the gas-solid separator adopts a cyclone separator.

[0009] Preferably, the first discharge valve and the second discharge valve adopt J-type valves.

[0010] Preferably, the first feed valve and the second feed valve adopt rotary valves.

[0011] (2) The present invention also provides an operation method for a steam supply system based on calcium hydroxide thermochemical energy storage, and this method includes the following processes:

[0012] S1. Starting stage: Connect the high-pressure extraction steam port of the coal-fired unit to the pressure reducing valve, connect the low-pressure extraction steam port of the coal-fired unit to the throttle valve, connect the outlet of the mixer to the heat user, and connect the low-temperature feed water to the heat user via the outlet of the fluidized bed reactor;

[0013] During the operation period of the coal-fired unit, including the non-peak shaving period and the peak shaving period, the steam supply system always supplies steam with a constant flow rate to the heat user;

[0014] S2. Non-peak shaving period: The electric heater does not work. The high-pressure extraction steam reduces its pressure in the pressure reducing valve, and then releases heat to the fluidized bed dehydration reactor, driving the decomposition of calcium hydroxide. The products are separated by the gas-solid separator. The superheated steam is mixed with the high-pressure extraction steam with reduced temperature in the mixer and then supplied to the heat user. The calcium oxide particles are transported to the fluidized bed hydration reactor through the first discharge valve, calcium oxide particle storage tank, and first feed valve. At the same time, the low-pressure extraction steam is transported to the fluidized bed hydration reactor through the throttle valve. The hydration reaction heats the low-temperature feed water and then supplies it to the heat user. The reaction products are transported to the fluidized bed dehydration reactor through the second discharge valve, calcium hydroxide particle storage tank, and second feed valve;

[0015] S3. Peak shaving period: The mixer and pressure reducing valve do not work. The electric heater drives the decomposition reaction of calcium hydroxide in the fluidized bed dehydration reactor. The products are separated by the gas-solid separator. The superheated steam is supplied to the heat user. The calcium oxide particles are transported to the fluidized bed hydration reactor through the first discharge valve, calcium oxide particle storage tank, and first feed valve. The low-pressure extraction steam is transported to the fluidized bed hydration reactor through the throttle valve. The hydration reaction heats the low-temperature feed water and then supplies it to the heat user. The reaction products are transported to the fluidized bed dehydration reactor through the second discharge valve, calcium hydroxide particle storage tank, and second feed valve.

[0016] Preferably, in the non-peak shaving period, it is preferentially provided by the high-pressure extraction steam and the dehydration reaction products driven by it, and the surplus heat is stored in the fluidized bed dehydration reactor in the form of chemical energy. The remaining steam supply is provided by the low-temperature feed water heated by the fluidized bed hydration reactor;

[0017] High-pressure extraction steam flow rate D0, the theoretical maximum steam supply value that the heat storage side can provide:

[0018]

[0019] In the formula, h gc , h gq are the enthalpies of the high-pressure extraction steam and the supplied steam respectively, ΔH f,ts is the enthalpy of the dehydration reaction, and M H2O is the molar mass of water.

[0020] Actual steam supply of the heat storage side:

[0021] D cr,1 =min{D cr,max , D}

[0022] Actual steam supply of the heat release side:

[0023] D sr,1 =max{(D - D cr,max ), 0}

[0024] Net heat storage (expressed in amount of substance):

[0025]

[0026] where γ ts is the conversion rate of the dehydration reaction, and γ sh is the conversion rate of the hydration reaction, h gs is the feed water enthalpy value, and ΔH f,sh is the hydration reaction enthalpy.

[0027] Preferably, during the peak shaving period, the low-temperature feed water heated by the fluidized bed hydration reactor is preferentially used to meet the heat user demand, and the remaining steam volume is provided by the reaction products of the electro-heated fluidized bed dehydration reactor and the hydration reactants supplemented to the calcium oxide particle storage tank.

[0028] The theoretical maximum steam supply value that the heat release side can provide:

[0029]

[0030] where τ is the ratio of the duration of non-peak shaving to peak shaving.

[0031] The actual steam supply volume of the heat storage side:

[0032]

[0033] The required electro-heating power:

[0034]

[0035] The actual steam supply volume of the heat release side:

[0036] D sr,2 = D - D cr,2 .

[0037] Based on the above system and operation method of the present invention, the advantages are as follows:

[0038] First, by using the thermochemical energy storage device, the surplus heat energy of the high-temperature extraction steam of the unit is stored during the non-peak shaving period, and only low-temperature extraction steam is required to release heat during the peak shaving period, realizing the thermal and power decoupling of the unit; second, by using the variable thermochemical reaction temperature and the electric heater, the flexible and stable operation of the steam supply system is realized; third, the reaction products participate in the steam supply, realizing the reasonable utilization of energy cascade, reducing the number of material storage tanks and the occupied volume of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic structural diagram of the steam supply system based on calcium hydroxide thermochemical energy storage of the present invention.

[0040] Figure 2 is a schematic diagram of the operation of the steam supply system based on calcium hydroxide thermochemical energy storage of the present invention during the non-peak shaving period;

[0041] Figure 3This is a schematic diagram of the operation during the peak shaving period of the steam supply system based on the thermochemical energy storage of calcium hydroxide in the present invention;

[0042] In the figure, 1 is a fluidized bed dehydration reactor, 2 is an electric heater, 3 is a gas-solid separator, 4 is a first discharge valve, 5 is a calcium oxide particle storage tank, 6 is a first feed valve, 7 is a fluidized bed hydration reactor, 8 is a second discharge valve, 9 is a calcium hydroxide particle storage tank, 10 is a second feed valve, 11 is a mixer, 12 is a pressure reducing valve, and 13 is a throttle valve. Specific implementation method

[0044] Combined with Figures 1 to 3 , an embodiment of the present invention provides a steam supply system based on the thermochemical energy storage of calcium hydroxide, including a thermochemical energy storage device, a steam supply device, an electric heating device, and a material circulation auxiliary device; the thermochemical energy storage device includes a reactor and a material storage tank, the reactor includes a fluidized bed dehydration reactor 1 and a fluidized bed hydration reactor 7, and the material storage tank includes a calcium oxide particle storage tank 5 and a calcium hydroxide particle storage tank 9; the steam supply device includes a mixer 11 and a pressure reducing valve 12; the electric heating device includes an electric heater 2; the material circulation auxiliary device includes a gas-solid separator 3, a first discharge valve 4, a second discharge valve 8, a first feed valve 6, a second feed valve 10, and a throttle valve 13;

[0045] The fluidized bed dehydration reactor 1 has a first branch and a second branch connected in parallel on the heat supply side. A pressure reducing valve 12 is connected to the inlet of the first branch, and a mixer 11 is connected to the outlet. An electric heater 2 is provided on the second branch. Thus, two heat sources, high-pressure steam or the electric heater 2, can be selected to drive the decomposition of calcium hydroxide in the fluidized bed dehydration reactor 1 to achieve heat storage. The high-pressure extraction steam sequentially passes through the pressure reducing valve 12 and the fluidized bed dehydration reactor 1 and is delivered to the mixer 11. The gaseous material water at the outlet of the fluidized bed dehydration reactor 1 is delivered to the mixer 11 through the gas-solid separator 3. The outlet of the mixer 11 supplies heat users. Part of the reaction products directly participate in steam supply instead of being stored after condensation, reducing the inter-stage heat transfer loss and condensation loss, improving the energy utilization efficiency, and reducing the number of material storage tanks and floor area. The solid material calcium oxide outlet of the fluidized bed dehydration reactor 1 is sequentially connected to the calcium oxide particle storage tank 5 through the gas-solid separator 3 and the first discharge valve 4. The calcium oxide particle storage tank 5 is connected to the fluidized bed hydration reactor 7 through the first feed valve 6. The low-pressure extraction steam is connected to the fluidized bed hydration reactor 7 through the throttle valve 13. Only by ensuring that the low-temperature extraction steam is superheated steam under the reaction pressure after flowing through the throttle valve 13 and without other restrictions, calcium hydroxide can be generated and the reaction temperature can be reached in the fluidized bed hydration reactor 7, generating the required grade of heat energy. The low-temperature feed water is heated in the fluidized bed hydration reactor 7 and then supplied to heat users. Thus, a two-way steam supply path for the heat storage side and the heat release side is formed. While being able to withstand different amounts of high-pressure extraction steam, providing a buffer for the operating conditions fluctuations of the coal-fired unit, and ensuring a stable steam supply, the reaction temperature can also be controlled by adjusting the reaction pressure to meet the needs of different types of heat users. The fluidized bed hydration reactor 7 is connected to the calcium hydroxide particle storage tank 9 through the second discharge valve 8. The calcium hydroxide particle storage tank 9 is connected to the second feed valve 10 and then returns to the fluidized bed dehydration reactor 1, forming a thermochemical material circulation loop.

[0046] The working process of the present invention includes a starting stage, a non-peak shaving period, and a peak shaving period, specifically as follows:

[0047] S1. Starting stage: Connect the high-pressure extraction steam port of the coal-fired unit to the pressure reducing valve 12, connect the low-pressure extraction steam port of the coal-fired unit to the throttle valve 13, connect the outlet of the mixer 11 to the heat user, and connect the low-temperature feed water via the outlet of the fluidized bed reactor 7 to the heat user.

[0048] S2. Non-peak shaving period: First, supply steam through the high-pressure extraction steam and the driven dehydration reaction products, and store the surplus heat in the form of chemical energy. If the rated steam supply amount cannot be reached yet, the remainder is provided by the low-temperature feed water heated by the fluidized bed hydration reactor 7;

[0049] Cut off the second branch connected to the heat supply side of the fluidized bed dehydration reactor 1, that is, the electric heater 2 does not work. The high-pressure extraction steam reduces its pressure in the pressure reducing valve 12 and then releases heat to the fluidized bed dehydration reactor 1. The decomposition products of calcium hydroxide are separated by the gas-solid separator 3. The superheated steam is merged into the mixer 11 and supplied to the heat user. The calcium oxide particles are transported to the calcium oxide particle storage tank 5 through the first discharge valve 4 and then transported to the fluidized bed hydration reactor 7 through the first feed valve 6. At this time, the low-pressure extraction steam is transported to the fluidized bed hydration reactor 7 through the throttle valve 13. The exothermic calcium oxide hydration reaction evaporates and superheats the low-temperature feed water, which is then supplied to the heat user. The reaction products are transported to the calcium hydroxide particle storage tank 9 through the second discharge valve 8 and then transported to the fluidized bed dehydration reactor 1 through the second feed valve 10.

[0050] S3. Peak shaving period: Give priority to supplying steam from the low-temperature feed water heated by the fluidized bed hydration reactor 7. If the rated steam supply volume cannot be reached yet, the remaining amount is provided by the reaction products of the electrically heated fluidized bed dehydration reactor 1 and the additional calcium oxide entering the hydration reactor 7 to further heat the feed water.

[0051] Cut off the first branch connected to the heat supply side of the fluidized bed dehydration reactor 1, that is, the mixer 11 and the pressure reducing valve 12 do not work. The electric heater 2 drives the decomposition of calcium hydroxide in the fluidized bed dehydration reactor 1. The products are separated by the gas-solid separator 3. The superheated steam is supplied to the heat user. The calcium oxide particles are transported to the calcium oxide particle storage tank 5 through the first discharge valve 4 and then transported to the fluidized bed hydration reactor 7 through the first feed valve 6. At this time, the low-pressure extraction steam is transported to the fluidized bed hydration reactor 7 through the throttle valve 13. The exothermic reaction evaporates and superheats the low-temperature feed water, which is then supplied to the heat user. The reaction products are transported to the calcium hydroxide particle storage tank 9 through the second discharge valve 8 and then transported to the fluidized bed dehydration reactor 1 through the second feed valve 10.

[0052] During the operation of the above system, the steam supply volume is calculated as follows:

[0053] Continuously supply steam with a flow rate of D to the heat user. During the non-peak shaving period, the steam supply volume on the heat storage side is D cr,1 , and the steam supply volume on the heat release side is D sr,1 ; during the peak shaving period, the steam supply volume on the heat storage side is D cr,2 , and the steam supply volume on the heat release side is D sr,2 ; satisfying D cr,i +D sr,i =D (i = 1 or 2). The high-pressure extraction steam volume is D0, and the power of the electric heater is P; the enthalpy values of the high-pressure extraction steam, steam supply, and feed water are h gc , h gq , h gs ; the conversion rates of the dehydration and hydration reactions are γts and γsh respectively; the enthalpies of the dehydration and hydration reactions are ΔH f,ts , ΔH f,sh ; the molar mass of water is The duration ratio of non-peak shaving to peak shaving is τ.

[0054] During the non-peak shaving period:

[0055]

[0056] D cr,1 = min{D cr,max , D}

[0057] D sr,1 = max{(D - D cr,max ), 0}

[0058]

[0059] During the peak shaving period:

[0060]

[0061] D sr,2 = D - D cr,2 Example 1:

[0062] In this example, the rated steam supply of the steam supply system is D = 15 kg / s. During the non-peak shaving period, the steam supply on the heat storage side is D cr,1 , and the steam supply on the heat release side is D sr,1 ; during the peak shaving period, the steam supply on the heat storage side is D cr,2 , and the steam supply on the heat release side is D sr,2 ; satisfying D cr,i + D sr,i = D (i = 1 or 2). The high-pressure extraction steam volume is 14.5 kg / s, and the power of the electric heater is P; the enthalpies of the high-pressure extraction steam, steam supply, and feed water are 3005.9 kJ / kg, 2815.3 kJ / kg, and 632.2 kJ / kg respectively; the conversion rates of the dehydration and hydration reactions are both 1; the enthalpies of the dehydration and hydration reactions are 109 kJ / mol and -99 kJ / mol respectively; the molar mass of water is 0.018 kg / mol; the duration ratio of non-peak shaving to peak shaving is 5.

[0063] During the non-peak shaving period:

[0064]

[0065] D cr,1 = min{D cr,max , D} = min{14.9, 15} = 14.9 kg / s

[0066] D sr,1 = max{(D - D cr,max ), 0} = max{(15 - 14.9), 0} = 0.1 kg / s

[0067]

[0068] During the peak shaving period:

[0069]

[0070] D sr,2 = D - D cr,2 = 15 - 0.2 = 14.8 kg / s.

Claims

1. A steam supply system based on thermochemical energy storage of calcium hydroxide, characterized in that: It includes a thermochemical energy storage device, a steam supply device, an electric heating device, and a material circulation auxiliary device; the thermochemical energy storage device includes a reactor and a material storage tank, the reactor includes a fluidized bed dehydration reactor (1) and a fluidized bed hydration reactor (7), and the material storage tank includes a calcium oxide particle storage tank (5) and a calcium hydroxide particle storage tank (9); the steam supply device includes a mixer (11) and a pressure reducing valve (12); the electric heating device includes an electric heater (2); the material circulation auxiliary device includes a gas-solid separator (3), a first discharge valve (4), a second discharge valve (8), a first feed valve (6), a second feed valve (10), and a throttle valve (13); The solid material calcium oxide outlet of the fluidized bed dehydration reactor (1) is sequentially connected to the calcium oxide particle storage tank (5) through the gas-solid separator (3) and the first discharge valve (4), the calcium oxide particle storage tank (5) is connected to the fluidized bed hydration reactor (7) through the first feed valve (6), the low-pressure extraction steam is connected to the fluidized bed hydration reactor (7) through the throttle valve (13), the fluidized bed hydration reactor (7) is connected to the calcium hydroxide particle storage tank (9) through the second discharge valve (8), and the calcium hydroxide particle storage tank (9) is connected to the fluidized bed dehydration reactor (1) through the second feed valve (10) to form a thermochemical material circulation loop; A first branch and a second branch are connected in parallel on the heat supply side of the fluidized bed dehydration reactor (1). A pressure reducing valve (12) is connected to the inlet of the first branch, and a mixer (11) is connected to the outlet. An electric heater (2) is provided on the second branch; On the one hand, the high-pressure extraction steam is sequentially transported to the mixer (11) through the pressure reducing valve (12) and the fluidized bed dehydration reactor (1), and the gaseous material water at the outlet of the fluidized bed dehydration reactor (1) is transported to the mixer (11) through the gas-solid separator (3). The outlet of the mixer (11) supplies heat users to form a steam supply path; On the other hand, the low-temperature feed water is supplied to heat users after passing through the fluidized bed hydration reactor (7) to form a steam supply path.

2. The steam supply system based on calcium hydroxide thermochemical energy storage according to claim 1, wherein: The gas-solid separator (3) adopts a cyclone separator.

3. The steam supply system based on calcium hydroxide thermochemical energy storage according to claim 1, characterized in that: The first discharge valve (4) and the second discharge valve (8) adopt J-type valves.

4. The steam supply system based on calcium hydroxide thermochemical energy storage according to claim 1, characterized in that: The first feed valve (6) and the second feed valve (10) adopt rotary valves.

5. A method for operating a steam supply system based on calcium hydroxide thermochemical energy storage according to any one of claims 1 to 4, characterized in that The system operation stage includes a starting stage, a non-peak shaving period, and a peak shaving period, specifically: S1. Starting stage: Connect the high-pressure extraction steam port of the coal-fired unit to the pressure reducing valve (12), connect the low-pressure extraction steam port of the coal-fired unit to the throttle valve (13), connect the outlet of the mixer (11) to the heat user, and connect the low-temperature feed water to the heat user via the outlet of the fluidized bed reactor (7); S2. Non-peak shaving period: The second branch connected to the heat supply side of the fluidized bed dehydration reactor (1) is cut off, the electric heater (2) does not work, the high-pressure extraction steam reduces its pressure in the pressure reducing valve (12), and then releases heat to the fluidized bed dehydration reactor (1). Calcium hydroxide undergoes a decomposition reaction in the fluidized bed dehydration reactor (1), and the products are separated by the gas-solid separator (3). The superheated steam is merged into the mixer (11) and supplied to the heat user. The calcium oxide particles are transported to the calcium oxide particle storage tank (5) via the first discharge valve (4), and then transported to the fluidized bed hydration reactor (7) via the first feed valve (6). At the same time, the low-pressure extraction steam reaches the parameters required for the reaction in the throttle valve (13) and is transported to the fluidized bed hydration reactor (7). The heat released by the reaction evaporates and superheats the low-temperature feed water, and then it is supplied to the heat user. The reaction products are transported to the calcium hydroxide particle storage tank (9) via the second discharge valve (8), and are transported to the fluidized bed dehydration reactor (1) via the second feed valve (10). S3. Peak shaving period: The first branch connected to the heat supply side of the fluidized bed dehydration reactor (1) is cut off, the mixer (11) and the pressure reducing valve (12) do not work, the electric heater (2) drives the decomposition reaction of calcium hydroxide in the fluidized bed dehydration reactor (1), and the products are separated by the gas-solid separator (3). The superheated steam is supplied to the heat user. The calcium oxide particles are transported to the calcium oxide particle storage tank (5) via the first discharge valve (4), and then transported to the fluidized bed hydration reactor (7) via the first feed valve (6). At the same time, the low-pressure extraction steam reaches the parameters required for the reaction in the throttle valve (13) and is transported to the fluidized bed hydration reactor (7). The heat released by the reaction evaporates and superheats the low-temperature feed water, and then it is supplied to the heat user. The reaction products are transported to the calcium hydroxide particle storage tank (9) via the second discharge valve (8), and are transported to the fluidized bed dehydration reactor (1) via the second feed valve (10).

6. The operating method of a steam supply system based on calcium hydroxide thermochemical energy storage according to claim 5, characterized in that, Since the temperature of the thermochemical reaction is restricted by the reaction pressure, the component parameters of the fluidized bed dehydration reactor (1), the fluidized bed hydration reactor (7), the pressure reducing valve (12), and the throttle valve (13) are adjusted in real time to achieve flexible matching of the heat storage and heat release temperatures to the heat user's needs.

7. The operating method of a steam supply system based on calcium hydroxide thermochemical energy storage according to claim 6, characterized in that Some of the products of the fluidized bed dehydration reactor (1) are low-pressure and high-temperature water vapor, which is directly used for steam supply without the need to be stored after condensation, realizing reasonable utilization of energy, reducing the number of thermochemical cycle material storage tanks and the occupied volume of the system.

8. The operating method of a steam supply system based on calcium hydroxide thermochemical energy storage according to claim 6, characterized in that, Some of the reactants of the fluidized bed hydration reactor (7) are water vapor, which is supplied by the low-pressure extraction steam of the unit after passing through the throttle valve (13). The temperature is not strictly limited, and the rated-grade heat energy is generated through the reaction, which is flexible and efficient and has little impact on the unit performance.

9. According to the operation method of a steam supply system based on calcium hydroxide thermochemical energy storage according to claim 5, characterized in that: It is possible to always supply steam with a constant flow rate to the heat user; During the non-peak shaving period, it is preferentially provided by the high-pressure extraction steam and the driven dehydration reaction products, and the surplus heat is stored in the fluidized bed dehydration reactor (1) in the form of chemical energy. The remaining steam supply is provided by the low-temperature feed water heated by the fluidized bed hydration reactor (7). During the peak shaving period, the heat demand of heat users is preferentially met by the low-temperature feed water heated by the fluidized bed hydration reactor (7), and the remaining steam quantity is provided by the reaction products of the electric-heated fluidized bed dehydration reactor (1) and the hydration reactants replenished to the calcium oxide particle storage tank (5).

10. The operating method of a steam supply system based on calcium hydroxide thermochemical energy storage according to claim 5, characterized in that, Steam with a flow rate of D is continuously supplied to heat users, specifically: During the non-peak shaving period: The high-pressure extraction steam flow rate D0 during the non-peak shaving period, and the theoretical maximum steam supply value D that the heat storage side can provide cr,max : where h gc and h gq are the enthalpy values of high-pressure extraction steam and supply steam respectively, and ΔH f,ts is the enthalpy of dehydration reaction, that is, the heat absorption per mole of reactants, which is a positive value, is the molar mass of water; Actual steam supply volume D on the heat storage side cr,1 : D cr,1 = min{D cr,max , D} Actual steam supply volume D on the heat release side sr,1 : D sr,1 = max{(D - D cr,max ), 0} That is: D sr,1 = D - D cr,1 The net heat storage quantity, expressed in terms of the amount of substance, is: where γ ts is the conversion rate of the dehydration reaction, and γ sh is the conversion rate of the hydration reaction, h gs is the feed water enthalpy value, and ΔH f,sh is the enthalpy of the hydration reaction, that is, the heat released per mole of reactant, which is negative; During the peak shaving period: The theoretical maximum steam supply value D that the heat storage capacity can drive the heat release side to generate sr,max : In the formula, τ is the ratio of the duration of the non-peak shaving period to the peak shaving period; Actual steam supply volume D on the heat storage side cr,2 : The required electric heating power P: Actual steam supply volume D on the heat release side sr,2 : D sr,2 = D - D cr,2 。

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