High-temperature heat pumps are mainly used in high-energy-consuming heating, drying and heat treatment processes in automobile production, which can significantly improve energy efficiency and reduce carbon emissions. Automobile production involves multiple thermal processing links, such as spray paint, heat treatment after welding, mold heating, etc. High-temperature heat pumps can recover the waste heat from these processes and raise it to the required temperature to meet process needs.
Application process and temperature requirements in automobile production
- Spraying and baking:
- Process description: The car body needs to be baked after spraying to improve the adhesion and corrosion resistance of the coating. The baking process requires baking at high temperatures to allow the paint to dry quickly and cure evenly.
- Temperature requirements: The temperature for drying paint is usually 140-160°C.
- Heat pump application: High-temperature heat pumps can recycle waste heat generated during the painting process and raise it to the required drying temperature, reducing reliance on electric heaters or gas heating.
- Heat treatment after welding:
- Process description: Heat treatment is required after welding of the car body to eliminate welding stress, increase the strength of the car body and prevent material embrittlement.
- Temperature requirements: The temperature requirements for welding heat treatment are generally between 200-300°C.
- Heat pump application: High-temperature heat pumps can recover waste heat during the welding process or after welding heat treatment, raising the temperature to above 200°C for body heating or stress relief treatment, further reducing the energy consumption of heat treatment.
- Car body drying and sealing:
- Process description: After the gluing and sealing processes of the car body, it needs to be dried to ensure that the glue is completely solidified and achieves a good sealing effect.
- Temperature requirements: Drying usually requires an environment of 80-120°C.
- Heat pump application: High-temperature heat pumps can raise low-temperature waste heat to about 100°C for sealant curing and car body drying, replacing the traditional hot air circulation system and reducing the use of electricity and gas.
- Mold preheating:
- Process description: Auto parts forming molds usually need to be preheated before casting or stamping to reduce the thermal stress of the material and improve the quality of the parts.
- Temperature requirements: The temperature for mold preheating is generally between 150-250°C.
- Heat pump application: High-temperature heat pumps can provide a stable heat source for mold heating, replacing traditional electric heating and improving the energy efficiency of mold heating.
- Heating of industrial wastewater and air:
- Process description: The cleaning process in the automobile manufacturing process requires a large amount of hot water, which is usually used for degreasing, cleaning and anti-corrosion treatment of parts.
- Temperature requirements: The temperature of the cleaning water is usually 60-80°C.
- Heat pump application: High-temperature heat pumps can use waste heat to provide thermal energy for cleaning water and also be used for hot air circulation in the production environment to reduce boiler heating costs.
Advantages of high temperature heat pumps in automobile production
- Energy saving and consumption reduction: High-temperature heat pumps can make full use of waste heat, significantly reducing the demand for traditional fuels and reducing production energy consumption.
- Improve environmental protection: reducing carbon emissions in traditional heating methods helps achieve green production.
- Reduce production costs: Reduce electricity and gas consumption, making production more cost-effective.
The application of high-temperature heat pumps can help automobile manufacturing companies optimize thermal management processes, achieve more sustainable production, and contribute to the industry’s carbon neutrality goals.
A typical case is that Volkswagen of Germany successfully applied high-temperature heat pumps in its production workshop, achieving significant results in energy saving and emission reduction. Volkswagen has introduced a high-temperature heat pump system in the spray and paint shop of its Wolfsburg plant to recover and reuse waste heat from the body spray paint process.
Case overview
- Application scenario: spraying and painting workshop
- After the body is sprayed, it is usually heated to 140-160°C in a paint oven to quickly dry and solidify the coating. This process requires sustained and stable high temperatures, and has traditionally relied mainly on natural gas or electricity to maintain heating temperatures.
- Application of high temperature heat pump
- Waste heat recovery: A large amount of waste heat is generated during the spraying and baking process, which is usually directly discharged in traditional systems. The Volkswagen factory uses high-temperature heat pumps to recover this waste heat and raise it to the required temperature for drying and curing the car body.
- Energy saving and efficiency improvement: The high-temperature heat pump can increase the recovered low-grade heat to above 140°C, continuously providing the heat energy required for drying and curing. This system not only reduces reliance on natural gas, but also reduces production costs and improves the overall energy efficiency of the workshop.
- Effects and results
- Energy saving and emission reduction: After the high-temperature heat pump system of the Volkswagen Wolfsburg plant was put into operation, it has reduced thousands of tons of carbon emissions every year.
- Cost savings: By recovering and reusing waste heat from the heat pump system, Volkswagen achieves significant energy cost savings. It is estimated that the system can save millions of euros in energy bills every year.
- Environmental protection and sustainable development: The project successfully reduced the use of fossil fuels and is in line with Volkswagen’s long-term goals in sustainable development and green production.
Summarize
The high-temperature heat pump project at the Volkswagen Wolfsburg plant is a successful case of industrial heat pumps in automobile production. It demonstrates the practical feasibility of high-temperature heat pumps in high-temperature demand scenarios, and also demonstrates the potential value of high-temperature heat pumps in automobile manufacturing. Such applications can help automakers reduce operating costs and carbon footprints, in line with the global automotive industry’s trend toward low-carbon and environmentally friendly development.
