Solar high-temperature heat utilization system with multiple layers of heat storage balls

Abstract

The utility model discloses a solar energy high temperature heat utilization system with multiple layers of heat storage balls, which comprises a circulating fan, a heat absorption tower, a heat absorber and a heat storage bin, the heat storage bin is arranged into multiple layers, air flow circulates among the material storage layers, each layer is provided with a plurality of heat storage balls for heat energy storage, and heat absorption and heat carrying media are stored in the heat storage balls. A gap is reserved between every two adjacent heat storage balls. The utility model can effectively avoid the problems of complex fused salt medium system, high freezing and blocking risk and the like. Meanwhile, efficient fluid channels can be formed among the spherical heat storage bodies which are arranged in multiple layers; through special design, the whole process of heat storage and heat release can be completed by adopting a set of circulating fan system, and the temperature distribution that the upper part of the heat storage ball is high and the lower part of the heat storage ball is low is realized. The factors are beneficial to heat exchange between the circulating air and the heat storage ball, and the heat / electricity utilization process of the follow-up process is facilitated. The system can be used as a reasonable choice for solar high-temperature heat utilization.

Description

TECHNICAL FIELD

[0001] The utility model relates to solar energy heat utilization technical field especially relates to a solar high temperature heat utilization system with multilayer heat storage ball. BACKGROUND

[0002] Solar high temperature heat power generation technology is an important direction of solar energy scale utilization, and has far-reaching significance for human beings to solve fossil energy crisis, air pollution and the like. According to the different focusing modes, solar high temperature heat power generation can be divided into three modes of dish type, trough type and tower type, and the working medium used includes water (water vapor), molten salt, air, heat conducting oil, liquid metal, other organic matters and the like. Tower type focusing has the advantages of large capacity and high parameters, and has attracted the attention of many countries in the world.

[0003] Tower type heat power generation technology has been in the initial stage of commercial operation abroad, and large-scale commercial projects built or under construction have almost spread to all continents. Especially the solar heat power generation technology with heat storage has a broad application prospect because of longer power generation time and more stable power output. China's tower type heat power generation industry is currently in the demonstration operation stage, and after the solar heat power generation price is clear and the demonstration project is successfully implemented, China's solar heat power generation industry will enter a period of rapid development.

[0004] In the tower type heat power generation technology route, the most commonly used is water working medium and molten salt working medium technology. Water working medium technology has the advantages of low cost, high safety and low initial investment cost, but has the problems of high working pressure and difficulty in water and steam heat storage. The solar heat power generation system using molten salt working medium has the advantages of high working temperature, low working pressure, easy large-scale heat storage, stable power output and high degree of power grid acceptance, but also has the risks of system complexity and molten salt freezing, which to some extent restricts the large-scale development of the technology. UTILITY MODEL CONTENTS

[0005] To solve the above technical problems, the utility model designs a solar high temperature heat utilization system with multilayer heat storage ball.

[0006] The utility model adopts the following technical scheme:

[0007] The utility model provides a kind of solar high-temperature heat utilization system with multilayer heat storage ball, including circulating fan (or air compressor), heat absorption tower, heat absorber and heat storage bin, heat absorber is installed on heat absorption tower, heat absorber two ends are connected with heat storage bin upper and lower ends respectively by pipeline one and pipeline two, heat storage bin upper end is connected to heat / electricity user end by pipeline three, heat storage bin lower end is connected to self-heating / electricity user end by pipeline four, circulating fan is installed on pipeline four, it is characterized in that, the heat storage bin is set to multilayer, air flow is circulated between each layer storage layer, each layer is arranged with multiple heat storage ball for heat storage, heat storage ball stores heat absorption, heat-carrying medium, gap is reserved between adjacent heat storage ball, heat storage bin lower end is connected to self-heating / electricity user end by pipeline five, switching valve three is installed on pipeline one, switching valve one is installed on pipeline two, switching valve four is installed on pipeline three, switching valve five is installed on pipeline five, switching valve two is installed between heat storage bin lower end and pipeline two and pipeline four, switching valve six is provided at self-heating / electricity user end.The heat absorber on heat absorption tower absorbs sunlight reflected by heliostat, and is transferred to heat storage ball by circulating air.There is a certain gap between adjacent heat storage ball, and circulating air passing through the gap during heat storage process transfers heat to heat storage ball.During heat release process, circulating air passing through the gap carries heat out of heat storage ball and is delivered to heat / electricity user for external heat supply or power generation.

[0008] For tower type heat power generation technology, in order to obtain stable power output and longer heat storage time, a double-tank system using molten salt as heat absorption and heat-carrying medium is usually adopted. The molten salt in the low-temperature molten salt tank first passes through the upper tower pipeline, then flows through the complex heat absorber circuit, absorbs the heat converted by solar energy to become high-temperature molten salt, and then returns to the ground through the lower tower pipeline and is stored in the high-temperature molten salt tank. When power generation is needed, the high-temperature molten salt flows out of the high-temperature tank, passes through the steam generation system to generate steam with the required parameters for power generation, and the cooled molten salt returns to the cold salt tank. The molten salt heat power generation system has complex pipelines, and since the freezing point of molten salt is usually high (the freezing point of commonly used solar salt is more than 200℃), the risk of freezing and blocking is high during the operation of the molten salt system. Especially when freezing and blocking occur on the solar heat absorber, it may cause over-temperature, overheating, and even damage to the heat absorber, which seriously threatens the safe operation of the solar heat power generation system.

[0009] The utility model provides a kind of solar high-temperature heat utilization system with multilayer heat storage ball structure, multilayer heat storage ball is neatly arranged in heat storage bin, adjacent heat storage ball is formed with the through-flow gap with specific law due to the regular shape of ball body;Heat storage ball layer from top to bottom can be selected same or different heat storage medium according to the different heat storage temperature;It can be sensible heat energy storage medium, and it can be composite phase change material mainly using latent heat.The heat-carrying medium used in system is usually air, and can be selected as carbon dioxide, nitrogen etc as heat-carrying medium according to the different heat storage ball material.Heat-carrying medium is driven under circulating fan (or compressor), absorbs heat converted by solar energy in solar heat absorber, and passes through the gap between multilayer heat storage ball and transfers heat to heat storage ball.Circulating air releases heat from heat storage ball when needed, and is used for external heat supply or power generation.

[0010] As preferred, the heat storage ball of different storage layers can be made of different types of materials according to different working temperatures.

[0011] As preferred, the heat storage ball is made of sensible heat storage material or latent heat composite phase change material.This system can eliminate the risk of freezing and blocking of molten salt heat power generation system, and improve the safety of system

[0012] As preferred, the heat-absorbing and heat-carrying medium uses air, carbon dioxide or nitrogen.Using air, carbon dioxide, nitrogen or other as heat-absorbing and heat-carrying medium, the absorbed solar energy is converted into heat energy and stored in multilayer heat storage ball in heat storage bin.

[0013] As preferred, the heat storage bin includes three layers, upper storage layer, middle storage layer and lower storage layer.

[0014] As preferred, the heat storage ball is neatly arranged in storage layer.

[0015] As preferred, the switching valve one, switching valve two, switching valve three, switching valve four, switching valve five and switching valve six use electric control valve.

[0016] The utility model discloses a beneficial effect is: (1), adopt the circulation wind absorption, take away the heat that solar energy generates, and store in the heat storage warehouse that has the multilayer heat storage ball, can avoid the complex system of adopting molten salt as heat absorbing / heat carrying medium, improve the security of system, (2), heat storage ball can be utilize sensible heat heat storage, can also adopt high temperature composite phase change material, if adopted composite phase change material, material usually has higher heat capacity, can reduce the dosage and volume of heat storage material, (3), when the spherical heat storage body is arranged regularly, the fluid passage of curved, changeable, with specific law is formed between heat storage ball, can make the airflow fully contact heat storage ball, strengthen the heat exchange effect between heat carrying fluid and heat storage ball, (4), through the optimization design of circulation wind system, can adopt a set of fan system to realize the heat storage and heat release of heat storage system: when storing heat, hot air enters from the top of heat storage warehouse, and after releasing heat, discharges from the lower part, when releasing heat, cold air enters heat storage warehouse from the lower part, and after absorbing heat, discharges from the top of heat storage warehouse, is transported to heat / electricity user. This design can simplify system, save initial investment. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is the principle schematic drawing of the utility model under heat storage mode,

[0018] Figure 2 It is the principle schematic drawing of the utility model under heat release mode,

[0019] In the drawing: 1, circulation fan, 2, heat absorbing tower, 3, heat absorber, 4, heat storage warehouse, 5, switching valve one, 6, switching valve two, 7, switching valve three, 8, switching valve four, 9, switching valve five, 10, switching valve six, 41, upper heat storage ball, 42, middle heat storage ball, 43, lower heat storage ball. DETAILED DESCRIPTION

[0020] The technical scheme of the utility model will be further concretely described below by specific embodiment and in conjunction with the drawings:

[0021] Embodiment: as Figure 1 And Figure 2As shown, a solar high-temperature heat utilization system with multi-layer heat storage balls includes a circulating fan 1, a heat absorption tower 2, a heat absorber 3, a heat storage bin 4, a switching valve one 5, a switching valve two 6, a switching valve three 7, a switching valve four 8, a switching valve five 9, and a switching valve six 10. The heat absorber is installed on the heat absorption tower, and the heat absorber is connected to the upper and lower ends of the heat storage bin through pipeline one and pipeline two, respectively. The upper end of the heat storage bin is connected to a heat removal / electricity user end through pipeline three, and the lower end of the heat storage bin is connected to a self-heating / electricity user end through pipeline four. The circulating fan is installed on the pipeline four. The lower end of the heat storage bin is connected to the self-heating / electricity user end through pipeline five. The switching valve three is installed on the pipeline one. The switching valve one is installed on the pipeline two. The switching valve four is installed on the pipeline three. The switching valve five is installed on the pipeline five. The switching valve two is installed between the lower end of the heat storage bin and the pipeline two and the pipeline four. The switching valve six is arranged at the self-heating / electricity user end. The heat storage bin 4 is designed to have one or more layers according to actual requirements. In this example, the heat storage bin is designed to have three layers. The air flows between the layers of the heat storage bin. The upper layer heat storage ball 41, the middle layer heat storage ball 42, and the lower layer heat storage ball 43 are arranged in the three layers, respectively. The heat storage balls store heat absorption and heat carrying medium. Gaps are reserved between adjacent heat storage balls. For a complete solar thermal power generation system, it also includes a heliostat, a steam generation system, and a power generation system. However, the above systems are not strongly related to the basic principle of the utility model, and therefore are not described in detail here.

[0022] As shown, Figure 1 in the heat storage mode, the switching valve one 5, the switching valve three 7, and the switching valve five 9 are opened, and the switching valve two 6, the switching valve four 8, and the switching valve six 10 are closed (note: in the Figure 1 , the valves in the closed state are marked in black). The specific working process is described as follows: The circulating wind (usually air, or carbon dioxide, or nitrogen, etc.) with a relatively low temperature is driven by the circulating fan 1, enters the heat absorber 3 at the top of the heat absorption tower 2 through the switching valve one 5, absorbs the heat energy generated by the solar energy in the heat absorber 3, and increases the temperature to a set temperature. The circulating wind flows into the upper part of the heat storage bin 4 through the switching valve three 7, successively flows through the upper layer heat storage ball 41, the middle layer heat storage ball 42, and the lower layer heat storage ball 43, and is discharged from the lower part of the heat storage bin 4 after the temperature gradually decreases. The circulating wind returns to the inlet of the circulating fan 1 through the switching valve five 9, and completes one heat storage cycle of the medium.

[0023] When the heat storage process is completed, the heat storage bin 4 has a temperature distribution of high in the upper layer, medium in the middle layer, and low in the lower layer. This distribution mode can effectively avoid heat convection, reduce the entropy increase in the heat storage ball, and be beneficial to the subsequent heat / electricity process.

[0024] Figure 2 is a principle schematic diagram of the utility model in the heat release mode. In this mode, the switching valve two 6, the switching valve four 8, and the switching valve six 10 are opened, and the switching valve one 5, the switching valve three 7, and the switching valve five 9 are closed (note: in the Figure 2In the middle, the valve in the closed state is marked as black. The specific working process is described as follows: the switching valve six 10 is opened, the circulating air with low temperature (usually air, or carbon dioxide, or nitrogen, etc.) is driven by the circulating fan 1, enters the lower part of the heat storage bin 4 through the switching valve two 6, flows through the lower heat storage ball 43, the middle heat storage ball 42 and the upper heat storage ball 41 in sequence, and then flows out from the upper part of the heat storage bin 4 after the temperature is gradually increased, and then flows to the heat / electricity user through the switching valve four 8, and the heat release process is completed at the user side, and the circulating air returned from the heat / electricity user enters the inlet of the circulating fan 1 again through the switching valve six 10, and the heat release cycle of the medium is completed.

[0025] During the heat storage or heat release process, when the circulating air flows through the gap between the heat storage balls, since the flow channel formed between the heat storage balls has the characteristics of bending, variability and regularity, the degree of turbulence of the fluid can be increased, the boundary layer thickness can be thinned, and the heat exchange effect between the two can be enhanced.

[0026] The molten salt medium system can be effectively avoided, and the problems of complex, frozen blockage risk and the like can be effectively avoided. Meanwhile, the high-efficiency fluid channel can be formed between the multi-layer arranged spherical heat storage bodies; through special design, a set of circulating fan system can complete the whole process of heat storage and heat release, and the temperature distribution of the upper part of the heat storage ball is high and the lower part is low. These factors are beneficial to the heat exchange between the circulating air and the heat storage ball, and are beneficial to the heat / electricity utilization process of the subsequent process. The system can be used as a reasonable choice for high-temperature heat utilization of solar energy.

[0027] The above-described embodiment is only a preferred scheme of the utility model, and does not limit the utility model in any form, and other variants and modifications can be made without exceeding the technical scheme recorded in the claims.

Claims

1. A solar high-temperature thermal utilization system with multi-layer thermal storage balls, comprising a circulating fan, a heat absorption tower, a heat absorber, and a thermal storage chamber, wherein the heat absorber is installed on the heat absorption tower, and both ends of the heat absorber are connected to the upper and lower ends of the thermal storage chamber respectively via pipe one and pipe two; the upper end of the thermal storage chamber is connected to a heat / electricity user end via pipe three, and the lower end of the thermal storage chamber is connected to a self-heating / electricity user end via pipe four; a circulating fan is installed on pipe four, characterized in that... The thermal storage chamber is configured in multiple layers, with airflow between each storage layer. Each layer is equipped with multiple thermal storage balls for thermal energy storage. The thermal storage balls store heat-absorbing and heat-carrying media. Gaps are reserved between adjacent thermal storage balls. The lower end of the thermal storage chamber is connected to the self-heating / electric user end through pipeline five. Switching valve three is installed on pipeline one, switching valve one is installed on pipeline two, switching valve four is installed on pipeline three, and switching valve five is installed on pipeline five. Switching valve two is installed between the lower end of the thermal storage chamber and pipelines two and four. Switching valve six is ​​installed at the self-heating / electric user end.

2. The solar high-temperature thermal utilization system with multi-layer thermal storage balls according to claim 1, characterized in that, The heat storage balls of different storage layers can be made of different types of materials depending on the operating temperature.

3. A solar high-temperature thermal utilization system with multi-layer thermal storage balls according to claim 2, characterized in that, The thermal storage ball is made of thermal storage material with sensible heat as the main component or composite phase change material with latent heat as the main component.

4. A solar high-temperature thermal utilization system with multi-layer thermal storage balls according to claim 1, characterized in that, The heat-absorbing and heat-carrying medium is air, carbon dioxide, or nitrogen.

5. A solar high-temperature thermal utilization system with multi-layer thermal storage balls according to claim 1, characterized in that, The thermal storage chamber comprises three layers: an upper storage layer, a middle storage layer, and a lower storage layer.

6. A solar high-temperature thermal utilization system with multi-layer thermal storage balls according to claim 1, characterized in that, The thermal storage balls are arranged neatly in the storage layer.

7. A solar high-temperature thermal utilization system with multi-layer thermal storage balls according to claim 1, characterized in that, Switching valves 1, 2, 3, 4, 5, and 6 are electrically controlled valves.

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