Waste heat recovery

The interest in energy consumption reduction, together with its aftermaths, is evolving continuously; among the available options, the recovery of waste heat from production processes is an interesting possibility. It is quite common that industrial activities have to dispose some process heat, operation that could even lead to a further consumption of energy and material. The recovery of this heat allows to cover a fraction of the energy required for the process itself or other uses such as offices heating and domestic hot water.

In order to exploit effectively the recovered heat two condition must be fulfilled: it has to be present a thermal user and the recovery’s temperature must match (i.e. be higher) with the requirements. The PCM thermal storage ensure a great flexibility in heat recovery because is able to store thermal energy at a specified temperature close to the source one, and to release it whenever necessary; the physical concept of phase change with the release of energy at a constant temperature, allows to keep high the useful heat content (exergy) supplied to the user.

The first step for the realization of a heat recovery system is the calculation of available energy: it becomes necessary to evaluate thermal fluxes and their availability over time. Then is carried out a quantification of the fraction of heat that can actually be recovered out from the total and which depends on the thermal level, the process features and the recovery activity. The heat recovery process is outlined once the end use of energy is defined.

When all the previous operation have been completed is possible to move towards the energy storage design, the material which is going to be used and the operation timing.