Operational Improvements of a Large Scale Solar Thermal Plant Used for Heat Supply in the Ham Production
Abstract
The company S.O.L.I.D. and Fleischwaren Berger in Austria are operating since the end of June 2013 a solar thermal plant including a 1.067m² large flat plate field and a 60m³ storage tank. The solar plant is used to preheat the feed water of a steam boiler operated with fuel oil and also to heat service water up to 70°C (Fig.1). The solar plant has been installed in the framework of the FP7 demonstration project InSun. The objective of the InSun project is the demonstration of reliability and quality of large scale solar thermal plants for the generation of heat used in three different industrial processes working at low and medium temperature ranges. The first results of the system installed in Austria have already been published (Cotrado et al. (2013)). After the analysis of first monitoring data, some optimization potentials for the operation of the solar plant were identified. Using dynamic simulation tools, new operation parameters are set to enhance the system performance and to achieve higher solar yields (up to 2.4% more). The measures include sharing the gained heat between both processes and controlling the collector loop flow rate. Coupling the operation of both primary and secondary side pumps increases the solar gains by approximately 2.3 MWh/a. A season dependent charging of the storage tank enables energy savings of around 650 kWh/a. Furthermore, several measures to damp the originally high fluctuating supply temperature in the solar loop are shown.These are the optimization of the PI control parameters, the placement of a temperature sensor and the use of a ∆T- instead of a supply temperature set point. This also helps to increase significantly the durability of the solar pumps.
Keywords
Solar heat, Industrial process heat, Solar collectors, Solar thermal plant, Ham production, Operational