阅读说明：本技术 一种太阳能储热干化污泥制备硫铝酸盐水泥的系统和方法 (System and method for preparing sulphoaluminate cement by solar heat storage dried sludge ) 是由 王文龙 张嘉政 毛岩鹏 黄彦敏 于 2021-09-07 设计创作，主要内容包括：本发明属于太阳能利用技术领域,涉及一种太阳能储热干化污泥制备硫铝酸盐水泥的系统和方法,所述系统包括：太阳能聚光器依次与高温熔盐储罐、过热器、预热-蒸发器、低温熔盐储罐连接形成混合熔盐传热-储热循环系统；过热器中的过热蒸汽进入超圆盘干化机,超圆盘干化机依次与储水罐、预热-蒸发器过热器连接形成水传热循环系统；湿污泥仓与超圆盘干化机、干化污泥仓入口连接,干化后的污泥被输送至干化污泥仓储存；水泥生产系统分别与超圆盘干化机废气出口、干化污泥仓出口连接。该系统能够利用谷电对夜间或其他特定时候的热量进行补充,并与水泥窑相耦合,废气通入水泥窑进行烧废,干化后的污泥与其他固废配伍进入水泥窑制备硫铝酸盐水泥。(The invention belongs to the technical field of solar energy utilization, and relates to a system and a method for preparing sulphoaluminate cement by solar heat storage dried sludge, wherein the system comprises: the solar condenser is sequentially connected with the high-temperature molten salt storage tank, the superheater, the preheating-evaporator and the low-temperature molten salt storage tank to form a mixed molten salt heat transfer-storage circulating system; superheated steam in the superheater enters a super-disc drier which is sequentially connected with a water storage tank and a preheater-evaporator superheater to form a water heat transfer circulating system; the wet sludge bin is connected with the super-disc drier and the inlet of the dried sludge bin, and the dried sludge is conveyed to the dried sludge bin for storage; and the cement production system is respectively connected with the waste gas outlet of the super-disc drier and the dried sludge bin outlet. The system can supplement heat at night or other specific times by utilizing the valley electricity, is coupled with the cement kiln, leads waste gas into the cement kiln to burn the waste, and leads the dried sludge and other solid wastes to be compatible and enter the cement kiln to prepare the sulphoaluminate cement.)

1. A system for preparing sulphoaluminate cement by solar heat storage drying sludge is characterized by comprising: the solar condenser is sequentially connected with the high-temperature molten salt storage tank, the superheater, the preheating-evaporator and the low-temperature molten salt storage tank to form a mixed molten salt heat transfer-storage circulating system; superheated steam in the superheater enters a super-disc drier which is sequentially connected with a water storage tank and a preheater-evaporator superheater to form a water heat transfer circulating system; the wet sludge bin is connected with the super-disc drier and the inlet of the dried sludge bin, and the dried sludge is conveyed to the dried sludge bin for storage; and the cement production system is respectively connected with the waste gas outlet of the super-disc drier and the dried sludge bin outlet.

2. The system for preparing sulphoaluminate cement by solar heat-storage drying sludge according to claim 1, wherein the solar condenser is a parabolic trough type solar condenser; or a molten salt pump is also arranged on a connecting pipeline of the mixed molten salt heat transfer-heat storage circulating system; further, the molten salt pump is arranged on a connecting pipeline of the solar condenser and the low-temperature molten salt storage tank.

3. The system for preparing sulphoaluminate cement by solar heat storage and sludge drying, as claimed in claim 1, wherein the mixed molten salt heat transfer-storage circulation system is further provided with an electric cabinet and a molten salt heater, and the mixed molten salt is heated by the electric cabinet and the molten salt heater; or, the mixed molten salt comprises potassium nitrate, sodium nitrate and graphite.

4. The system for preparing sulphoaluminate cement by solar heat-storage drying sludge according to claim 1, wherein the water heat-transfer circulating system is also provided with a circulating water pump; further, the circulating water pump is arranged on a connecting pipeline between the water storage tank and the preheating-evaporating device; or, an automatic water replenishing device with a warning water level is arranged in the water storage tank.

5. The system for preparing sulphoaluminate cement by solar heat-storage drying sludge according to claim 1, wherein a spiral conveying device is arranged on a connecting pipeline between the wet sludge bin and the super-disc drying machine; or a condenser is arranged on a connecting pipeline of the cement production system and the waste gas outlet of the super-disc drier.

6. A method for preparing sulphoaluminate cement by solar heat storage drying sludge, which is based on the system for preparing sulphoaluminate cement by solar heat storage drying sludge as claimed in any one of claims 1 to 5, and is characterized by comprising the following steps:

the solar condenser heats the mixed molten salt, one part of the heated high-temperature mixed molten salt flows to the high-temperature molten salt storage tank for storage, and the other part of the heated high-temperature mixed molten salt flows to the superheater and the preheating-evaporator for heat exchange; the mixed molten salt after heat exchange flows to a low-temperature molten salt storage tank and flows into the solar condenser again under the action of the molten salt pump;

superheated steam formed after heat exchange of the superheater enters the super-disc drier to exchange heat with wet sludge, the superheated steam is condensed in the heat exchange process and enters the water storage tank, and water in the water storage tank enters the preheating-evaporator and the superheater again to circulate under the action of a circulating water pump; conveying the dried sludge to a dried sludge bin for storage, and feeding the dried sludge into a cement production system for preparing sulphoaluminate cement after the dried sludge is compatible with solid waste; waste gas formed in the sludge drying process enters a decomposing furnace of a cement production system for incineration.

7. The method for preparing sulphoaluminate cement by using the solar heat-storage dried sludge as claimed in claim 6, wherein the temperature of the heated high-temperature mixed molten salt is 400-500 ℃; or the temperature of the mixed molten salt after heat exchange is 100-200 ℃; or, the temperature of the superheated steam is 180-.

8. The method for preparing sulphoaluminate cement by using the solar heat-storage dried sludge as claimed in claim 6, wherein the wet sludge is flocculated and compressed sludge; further, the flocculation is performed by adopting ferric salt flocculation, and mechanical compression is performed; or the dried sludge and the solid waste have the dry specific gravity of 5-30: 15-40; further, the solid waste is one or a combination of more of waste incineration fly ash, desulfurized gypsum, aluminum ash or carbide slag; furthermore, the dry specific gravity of the dried sludge and the waste incineration fly ash, the desulfurized gypsum, the aluminum ash or the carbide slag is 13-24: 5-30: 18-35: 17-27: 12 to 20.

9. The method for preparing sulphoaluminate cement by using solar heat-storage dried sludge as claimed in claim 6, wherein when the solar illumination intensity is low, the mixed molten salt is heated by utilizing the off-peak electricity at night through the electric cabinet and the molten salt heater, at the moment, valves at two ends of the solar condenser are in a closed state, and the molten salt heater replaces the solar condenser to store heat and supplement the high-temperature molten salt.

10. The system for preparing sulphoaluminate cement by using the solar heat-storage dried sludge as defined in any one of claims 1 to 5 and/or the method for preparing sulphoaluminate cement by using the solar heat-storage dried sludge as defined in any one of claims 6 to 9 in sewage treatment.

Technical Field

The invention belongs to the technical field of solar energy utilization, and relates to a system and a method for preparing sulphoaluminate cement by using solar heat storage dried sludge.

Background

The information in this background section is only for enhancement of understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art that is already known to a person of ordinary skill in the art.

At present, domestic sewage treatment capacity in China is increasing continuously, and sludge with water content of more than 80% is generated continuously, and sludge dehydration is the premise of comprehensive treatment and utilization. The wet sludge has high water content, needs to consume a large amount of energy to carry out drying treatment, can carry out large-scale cooperative treatment in the cement kiln, and simultaneously needs to treat the drying process and the dried odor. At present, the heat consumption of the main sludge dewatering technology is large, and tail gas can be discharged only by treatment. The solar sludge drying technology has the problems of low efficiency, difficult treatment of stink in and around the device and the like by means of the traditional greenhouse drying technology.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides a system and a method for preparing sulphoaluminate cement by utilizing solar heat storage dried sludge, which utilize mixed molten salt to conduct heat transfer and store heat, solve the problem that solar energy can only be generated in a specific time, and are provided with a bypass electric heating system to improve the stability of the system, can utilize valley electricity to supplement heat at night or other specific times, and are coupled with a cement kiln, waste gas is introduced into the cement kiln to burn waste, and dried sludge and other solid waste enter the cement kiln to prepare the sulphoaluminate cement in a compatible manner.

Specifically, the invention is realized by the following technical scheme:

in a first aspect of the present invention, a system for preparing sulphoaluminate cement by solar heat storage drying sludge comprises: the solar condenser is sequentially connected with the high-temperature molten salt storage tank, the superheater, the preheating-evaporator and the low-temperature molten salt storage tank to form a mixed molten salt heat transfer-storage circulating system; superheated steam in the superheater enters a super-disc drier which is sequentially connected with a water storage tank and a preheater-evaporator superheater to form a water heat transfer circulating system; the wet sludge bin is connected with the super-disc drier and the inlet of the dried sludge bin, and the dried sludge is conveyed to the dried sludge bin for storage; and the cement production system is respectively connected with the waste gas outlet of the super-disc drier and the dried sludge bin outlet.

In a second aspect of the invention, a method for preparing sulphoaluminate cement by using solar heat storage dried sludge, a system for preparing sulphoaluminate cement based on the solar heat storage dried sludge, comprises:

the solar condenser heats the mixed molten salt, one part of the heated high-temperature mixed molten salt flows to the high-temperature molten salt storage tank for storage, and the other part of the heated high-temperature mixed molten salt flows to the superheater and the preheating-evaporator for heat exchange; the mixed molten salt after heat exchange flows to a low-temperature molten salt storage tank and flows into the solar condenser again under the action of the molten salt pump;

superheated steam formed after heat exchange of the superheater enters the super-disc drier to exchange heat with wet sludge, the superheated steam is condensed in the heat exchange process and enters the water storage tank, and water in the water storage tank enters the preheating-evaporator and the superheater again to circulate under the action of a circulating water pump; conveying the dried sludge to a dried sludge bin for storage, and feeding the dried sludge into a cement production system for preparing sulphoaluminate cement after the dried sludge is compatible with solid waste; waste gas formed in the sludge drying process enters a decomposing furnace of a cement production system for incineration.

In a third aspect of the invention, the system for preparing sulphoaluminate cement by using the solar heat-storage dried sludge and/or the method for preparing sulphoaluminate cement by using the solar heat-storage dried sludge are/is applied to sewage treatment.

One or more embodiments of the present invention have the following advantageous effects:

(1) the solar energy is converted into heat energy by means of the solar condenser and the mixed molten salt, and the sludge is dried by integrating heat transfer and heat storage, so that the energy consumption is reduced, and the efficiency is improved.

(2) When solar energy heat storage is carried out, an electric heating system is arranged to carry out emergency treatment on various conditions, the system is guaranteed to operate safely and stably, and the problem that solar energy generates in a specific time is solved.

(3) The sludge drying system is matched with a cement production system, sludge is dried, and meanwhile, harmless treatment and utilization of the sludge are realized, so that sulphoaluminate cement is produced.

(4) In adverse weather such as extremely low illumination intensity or continuous rainfall in winter, the bypass system can be used for heat supplement, and the reheat steam in the waste heat boiler of the cement production system is used for heating the molten salt; the cement production line without the waste heat boiler can be provided with the fused salt electric heater for heat supplement so as to deal with the influence of extreme weather, and when the heat needs to be supplemented at night, valley electricity can be fully utilized.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. Embodiments of the invention are described in detail below with reference to the attached drawing figures, wherein:

FIG. 1: the system for preparing the sulphoaluminate cement by using the solar heat-storage dried sludge in the embodiment 1, wherein 1, a solar condenser; 2. a molten salt heater; 3. an electric cabinet; 4. a high-temperature molten salt storage tank; 5. a molten salt pump; 6. a superheater; 7. a pre-heater-evaporator; 8. a low-temperature molten salt storage tank; 9. a super-disc drier; 10. a water storage tank; 11. a water circulating pump; 12. a wet sludge bin; 13. a screw conveying device; 14. drying the sludge bin; 15. a condenser; 16. a cement production system.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The experimental procedures, in which specific conditions are not noted in the following examples, are generally carried out according to conventional conditions or according to conditions recommended by the manufacturers.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

At present, the heat consumption of the main sludge dewatering technology is large, and tail gas can be discharged only by treatment. The solar sludge drying technology has the problems of low efficiency, difficult treatment of stink in and around the device and the like by means of the traditional greenhouse drying technology. Therefore, the invention provides a system and a method for preparing sulphoaluminate cement by using solar heat storage dried sludge.

In one or more embodiments of the present invention, a system for preparing sulphoaluminate cement by using solar heat-storage dried sludge comprises: the solar condenser is sequentially connected with the high-temperature molten salt storage tank, the superheater, the preheating-evaporator and the low-temperature molten salt storage tank to form a mixed molten salt heat transfer-storage circulating system; superheated steam in the superheater enters a super-disc drier which is sequentially connected with a water storage tank and a preheater-evaporator superheater to form a water heat transfer circulating system; the wet sludge bin is connected with the super-disc drier and the inlet of the dried sludge bin, and the dried sludge is conveyed to the dried sludge bin for storage; and the cement production system is respectively connected with the waste gas outlet of the super-disc drier and the dried sludge bin outlet.

Wherein the mixed molten salt comprises potassium nitrate, sodium nitrate and graphite. Mixed molten salt consisting of potassium nitrate and sodium nitrate is used as a heat transfer medium and a heat storage material, and graphite is added, so that the heat conductivity coefficient of the mixed molten salt is improved, the melting point of the molten salt is reduced to be about 100 ℃,

the solar condenser is a parabolic trough type solar condenser, solar radiation energy is converted into heat energy, the parabolic trough surface of the solar condenser can be adjusted by selecting the best sunlight irradiation angle according to the change of the daily illumination angle and intensity, and the solar condenser can be placed on the roof of a factory building, so that the space is saved, and the situation that no other obstacles block the solar condenser is ensured. The solar condenser can convert low-density solar energy into high-density energy, and the solar energy is converted into heat energy through mixed molten salt, so that the temperature of the mixed molten salt reaches 400-500 ℃;

a molten salt pump is also arranged on a connecting pipeline of the mixed molten salt heat transfer-heat storage circulating system; further, the molten salt pump is arranged on a connecting pipeline of the solar condenser and the low-temperature molten salt storage tank. When the illumination is sufficient, one part of the generated high-temperature fused salt is subjected to heat exchange with water countercurrent in the superheater and the preheating-evaporator to generate superheated steam, the other part of the generated high-temperature fused salt is stored with the heat-absorbed high-temperature fused salt through the high-temperature fused salt storage tank, and when the illumination is insufficient, the stored high-temperature fused salt in the high-temperature fused salt storage tank sequentially flows into the three heat exchangers under the action of the fused salt pump to supplement heat.

The mixed molten salt heat transfer-heat storage circulating system is also provided with an electric cabinet and a molten salt heater, the mixed molten salt is heated by the electric cabinet and the molten salt heater, heat transfer and storage are carried out by utilizing the mixed molten salt, the problem that solar energy can only be generated in a specific time is solved, a bypass electric heating system is arranged to improve the stability of the system, heat at night or in other specific times can be supplemented by utilizing valley electricity, the system is coupled with a cement production system, waste gas is introduced into the cement production system to burn waste, and dried sludge and other solid waste are mixed and enter the cement production system to prepare the sulphoaluminate cement. The stability of the solar sludge drying system is improved by arranging the molten salt storage tank and the standby electric heating system.

A circulating water pump is also arranged in the water heat transfer circulating system; further, the circulating water pump is arranged on a connecting pipeline between the water storage tank and the preheating-evaporating device; or, an automatic water replenishing device with a warning water level is arranged in the water storage tank.

A spiral conveying device is arranged on a connecting pipeline of the wet sludge bin and the super-disc drier; or a condenser is arranged on a connecting pipeline of the cement production system and the waste gas outlet of the super-disc drier.

In one or more embodiments of the present invention, a method for preparing sulphoaluminate cement by solar heat storage drying sludge, a system for preparing sulphoaluminate cement based on the solar heat storage drying sludge, comprises:

the solar condenser heats the mixed molten salt, one part of the heated high-temperature mixed molten salt flows to the high-temperature molten salt storage tank for storage, and the other part of the heated high-temperature mixed molten salt flows to the superheater and the preheating-evaporator for heat exchange; the mixed molten salt after heat exchange flows to a low-temperature molten salt storage tank and flows into the solar condenser again under the action of the molten salt pump;

superheated steam formed after heat exchange of the superheater enters the super-disc drier to exchange heat with wet sludge, the superheated steam is condensed in the heat exchange process and enters the water storage tank, and water in the water storage tank enters the preheating-evaporator and the superheater again to circulate under the action of a circulating water pump; conveying the dried sludge to a dried sludge bin for storage, and feeding the dried sludge into a cement production system for preparing sulphoaluminate cement after the dried sludge is compatible with solid waste; waste gas formed in the sludge drying process enters a decomposing furnace of a cement production system for incineration.

Wherein, the heated high-temperature mixed molten salt stores the heat of solar energy, and the temperature reaches 400-500 ℃ due to low melting point and high heat transfer coefficient of the mixed molten salt. However, the mixed molten salt after heat exchange transfers heat to water in the evaporator to form superheated steam, and the temperature of the mixed molten salt is reduced to 200 ℃ for 100 ℃ and 250 ℃ for 180 ℃.

In order to improve the solid content of the sludge, the wet sludge is flocculated and compressed sludge; further, the flocculation is performed by using ferric salt flocculation and mechanical compression.

The sludge after flocculation and mechanical compression enters the super-disc drier to exchange heat with superheated steam generated by the superheater to realize further drying treatment, the dried sludge can be adjusted in water content according to different requirements and can be reduced to below 5% at least, the superheated steam and the sludge exchange heat indirectly in the super-disc drier and are not in direct contact with each other, water after heat exchange can be recycled, waste gas generated after drying is condensed and then can be introduced into a decomposing furnace to be burned, and the waste gas can be treated and utilized by a waste gas treatment system of a cement production line.

The dried sludge can be mixed with desulfurization gypsum, aluminum ash, carbide slag, waste incineration fly ash and other solid wastes to prepare the sulphoaluminate cement. In order to fully utilize the dried sludge, the proportion is very important to control during compatibility. Therefore, the dry specific gravity of the dried sludge and the solid waste is 5-30: 15-40.

Wherein the solid waste is one or a combination of more of waste incineration fly ash, desulfurized gypsum, aluminum ash or carbide slag; furthermore, the dry specific gravity of the dried sludge and the waste incineration fly ash, the desulfurized gypsum, the aluminum ash or the carbide slag is 13-24: 5-30: 18-35: 17-27: 12 to 20. At this ratio, it is advantageous to improve the utilization rate.

When the solar illumination intensity is low, the mixed molten salt is heated by utilizing the valley electricity at night through the electric cabinet and the molten salt heater, valves at two ends of the solar condenser are in a closed state, and the molten salt heater replaces the solar condenser to store and supplement the high-temperature molten salt. The process carries out emergency treatment on various conditions, ensures the safe and stable operation of the system and solves the problem of solar energy generated in specific time.

In one or more embodiments of the invention, the system for preparing sulphoaluminate cement by using the solar heat-storage dried sludge and/or the method for preparing sulphoaluminate cement by using the solar heat-storage dried sludge are/is applied to sewage treatment.

The present invention is described in further detail below with reference to specific examples, which are intended to be illustrative of the invention and not limiting.

Example 1

A system for preparing sulphoaluminate cement by solar heat storage drying sludge specifically comprises: the solar condenser 1 is sequentially connected with a high-temperature molten salt storage tank 4, a superheater 6, a preheating-evaporator 7, a low-temperature molten salt storage tank 9 and a molten salt pump 5 to form a mixed molten salt heat transfer-storage cycle. Meanwhile, in order to improve the stability of the solar energy sludge drying system, the electric cabinet 3 and the molten salt heater 2 are arranged, when the sunlight intensity is low, the molten salt is heated through the electric cabinet 3 and the molten salt heater 2 to replace a solar condenser, and heat storage and supplement are carried out on the high-temperature molten salt. Superheated steam formed in the superheater 6 enters a super-disc drier 9, and the super-disc drier 9 is sequentially connected with a water storage tank 10, a circulating water pump 11, a preheating-evaporating device 7 and the superheater 6 to form a water heat transfer circulating system; the wet sludge bin 12 is connected with a screw conveying device 13 and is used for conveying wet sludge from the wet sludge bin 12, the wet sludge bin 12 is connected with the super-disc drier 9 and an inlet of a dried sludge bin 14, and the dried sludge is conveyed to a dried sludge storage. A condenser 15 is arranged on a waste gas outlet pipeline of the super-disc drier and connected with a cement production system 16, and meanwhile, an outlet of a dried sludge bin 14 is also connected with the cement production system 16, so that waste gas in the super-disc drier 9 is treated by the cement production system 16, and dried sludge and solid waste are combined in the cement production system 16 to prepare sulphoaluminate cement.

Example 2

Based on the system of the embodiment 1, the sludge treatment and the preparation of the sulphoaluminate cement are carried out, and the specific method comprises the following steps:

the solar condenser 1 converts solar radiation energy into heat energy, heats mixed molten salt, the temperature reaches 400-500 ℃, the high-temperature mixed molten salt flows to a high-temperature molten salt storage tank 4 through a valve under the action of a molten salt pump 5, one part of the high-temperature mixed molten salt is stored in the tank, the other part of the high-temperature mixed molten salt flows to a superheater 6 and a preheater-evaporator 7, water and the high-temperature mixed molten salt exchange heat between the superheater and the high-temperature mixed molten salt, liquid water is changed into superheated steam, and the temperature is above 180 ℃; after the heat exchange of the high-temperature molten salt, the temperature is reduced to 150 ℃, the high-temperature molten salt flows to the low-temperature molten salt storage tank 8 under the action of the molten salt pump 5 and flows into the solar condenser 1 again through the valve under the action of the pump, and the heat transfer-heat storage cycle of the mixed molten salt is completed;

superheated steam formed in the superheater 6 enters the supercoiling machine 9 to exchange heat with flocculated and compressed sludge, the superheated steam is condensed into liquid water in the heat exchange process and enters the water storage tank 10 under the action of the circulating water pump 11, the water storage tank 10 is internally provided with an automatic water warning level supplementing device, when the water level is lower than 1/2, automatic water supplementing is performed, and the superheated steam enters the preheating-evaporator 7 and the superheater 6 again under the action of the circulating water pump 11 to finish water heat transfer circulation;

after flocculation and mechanical compression, sludge is conveyed into a wet sludge bin 12, enters a super-disc drier 9 through a screw conveying device 13, is heated by superheated steam, the moisture of the sludge is evaporated, the retention time of the sludge in the super-disc drier can be adjusted according to actual requirements, the moisture content of the sludge is further adjusted, the moisture content of a sludge outlet of a general super-disc drier 9 is set to be 30%, and the dried sludge is conveyed to a dried sludge bin 14 for storage;

during the drying process of the super-disc dryer 9, waste gas generated by the sludge is condensed by a condenser 15, enters a decomposing furnace of a cement production system 16 for incineration treatment, and enters a waste gas treatment system of a cement production line together with waste gas generated during the cement clinker firing process;

the dried sludge and the pretreated waste incineration fly ash, the desulfurized gypsum, the aluminum ash and the carbide slag are subjected to compatibility calculation according to the dry weight ratio: 21.15: 6.02: 30.78: 26.2: 15.85, and the cement clinker enters the cement production system 16 to be fired. The three-rate value of the burnt clinker is as follows: p is 2.04; c is 0.945; n is 3.55. The various solid waste components after pretreatment are shown in table 1:

table 1: various solid waste components (unit:%) after pretreatment

In addition, adverse weather such as extremely low illumination intensity or continuous rainfall in winter exists, the molten salt is heated by utilizing the valley electricity at night through the electric cabinet 3 and the molten salt heater 2, valves at two ends of the solar condenser 1 are in a closed state at the moment, and the molten salt heater 2 replaces the solar condenser 1 to store heat and supplement the high-temperature molten salt.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.