工业过程用太阳能技术简介（英文版）_40页-5mb

Summary of Solar Heat for Industrial Processes

Core Content

This document provides an overview of solar thermal technologies for industrial process heat, highlighting their potential, current status, and challenges in deployment. It outlines the different types of solar thermal systems, their applications, and the economic and technical considerations for their use in various industries.

Main Points

1. Solar Thermal Technologies for Industrial Use

• Three main categories of solar thermal technologies are identified for industrial process heat:
  • Solar air collectors: Used primarily in the food processing industry for drying and to reduce food spoilage. They can be locally built and are cost-effective in certain regions.
  • Solar water systems: Include flat-plate collectors (FPC) and evacuated tube collectors (ETC), which are suitable for heating up to 125°C. They are commonly used in residential but can be adapted for industrial use.
  • Solar concentrators: Such as parabolic dish, linear parabolic trough, and Linear Fresnel collectors, capable of generating up to 400°C. They are more advanced and costly than conventional systems.

2. Deployment and Economic Considerations

• Deployment levels are largely influenced by the economic competitiveness of solar thermal systems.
• Key challenges include short payback periods (<3 years), low fossil fuel prices, and the difficulty of integrating solar heat into existing industrial processes.
• Opportunities include integrating solar thermal systems during the construction of new industrial plants and reducing dependence on volatile fossil fuel prices for small- and medium-sized enterprises (SMEs).

3. Technical Potential and Applications

• Solar process heat can fulfill up to 50% of industrial heat demand in developed economies and has significant potential in developing countries, especially in agriculture, textiles, and food processing.
• Industrial process heat accounts for more than two-thirds of total energy consumption in industry, with about 40% covered by natural gas and 41% by petroleum.
• Potential for solar thermal heat could reach 10% of industrial energy demand by 2030, with a possible 33% deployment share in the industrial sector.

4. Solar Thermal Systems and Their Capabilities

• Solar air heating is used to dry food products, prevent spoilage, and preheat air for boilers. It includes both passive and active systems, with active systems being more efficient but requiring electricity.
• Solar water heating systems are mature and widely used, especially in regions like India, China, and Brazil, where costs are significantly lower.
• Solar concentrators are used for higher temperature applications and are more suitable for industrial processes that require continuous heat supply.

5. Solar Cooling Applications

• Solar thermal systems can also be used for cooling through absorption/adsorption chillers or desiccant systems.
• These systems can replace traditional gas- or electricity-driven cooling systems, especially in industries requiring cooling capacities above 100 kW.
• The use of higher temperature solar thermal systems enables integration with more efficient double- and triple-effect chillers.

6. Integration into Industrial Processes

• Solar thermal systems can be integrated into industrial processes in three main ways:
  1. As a direct heat source for fluid heating.
  2. For low-temperature processes.
  3. As an additional heat source for preheating supply water or integrating into fossil-fuelled boilers.
• Integration requires storage systems and control strategies to manage the intermittent nature of solar energy.

Key Information

• Solar thermal systems can provide heat up to 400°C, with many applications in industries such as food, textiles, and agriculture.
• Costs vary based on temperature levels, project size, and location. For example, FPC and ETC systems in India cost EUR 200-300/kW, while CSP systems are much more expensive.
• Policy support is crucial for increasing deployment, including awareness creation, financing mechanisms, and potentially replacing fossil fuel subsidies.
• Local manufacturing plays a key role in reducing costs and promoting adoption, as seen in countries like India.
• Technological advancements are ongoing, including better insulation materials, concentrator designs, and heat transfer fluids, which are essential for improving efficiency and reducing costs.

Conclusion

Solar thermal energy has significant potential to meet industrial heat and cooling demands, particularly in regions with high solar irradiance. While challenges like high upfront costs and integration complexities exist, technological improvements and supportive policies can enhance its adoption and sustainability in the industrial sector.