Design and supply of air/water heat exchangers for the automotive industry

AITESA has carried out a solution for heat recovery in an automotive plant in Spain. This initiative seeks to optimize the energy use of the lacquer drying process, reducing gas consumption and improving operational efficiency.

The proposed solution is based on a heat recovery system using a superheated water circuit and the integration of air/water exchangers. The main elements of the installation include:

• Waste heat capture: The thermal energy contained in the exhaust gases of the two lacquer kiln lines is used to avoid waste.
• Efficient energy exchange: Installation of two air/water exchangers to transfer the recovered energy to the superheated water circuit.
• Optimization of intermediate furnace consumption: Incorporation of a heating coil in the recirculation group of the intermediate furnace, reducing the need to activate the burner and, therefore, gas consumption.
• System automation: Implementation of a temperature and pressure control system that regulates heat flow, ensuring efficient and safe operation.

The system design ensures that the stack temperature does not drop below 160 °C, allowing maximum heat recovery without affecting the performance of industrial processes.

Thanks to this solution, significant energy recovery is estimated:

• Recovered power on lacquer kiln line 1: 452 kW
• Recovered power on lacquer kiln line 2: 318 kW
• Total power recovered: 770 kW

These values cover the net power required for the intermediate furnace (590 kW), with a surplus of 180 kW that could be used for other purposes within the plant.