Hybrid Thermosolar-Lpg Dehydrating Plant Installed in Xochitepec, México. Case Study: Pineapple

A hybrid thermosolar plant for the dehydration of food products was designed and installed in Xochitepec, Morelos, Mexico. The plant is integrated by a semi-continuous drying chamber with a drying area of 56.3 m2. The required energy is provided by two solar thermal systems: an air heating system and solar water heating system, both with 16 solar collectors (40 m2), a thermotank (2500 l), and an air/water heat exchanger. The plant has a fossil energy backup system of Liquefied Petroleum Gas (LPG) to heat air with hot water and the air/water heat exchanger. The monitoring system measures and records different process variables (temperature, relative hu-midity, solar irradiance, air velocity, and water mass flow rate). The average thermal efficiency of the field of solar water heaters and air heaters was 38.80 % and 50.40 %, respectively. Both thermosolar systems are able to deliver air temperature above 40 degrees C required during the process. The return of investment analysis is developed according to life cycle analysis and payback period methods. According to the results, different kinds of food products can be dried on the thermosolar plant, resulting in attractive payback periods and environmental benefits.