Analytical modelling of food storage cooling with solar ammonia-water absorption system, powered by parabolic trough collectors. Method.

The study presents a new analytical model capable to reveal the thermal behaviour of all the components of the solar ammonia-water absorption system, powered by parabolic trough collectors, serving different types of food storages: refrigeration chamber, refrigerated food storage, freezing chamber and frozen food storage. The heat inputs, that determine the total cooling load, for each food storage spaces consist of: heat gains through walls, heat gains through ventilation (fresh air), heat that must be dissipated from the stored products (technological cooling load required to cool down the products) and heat gains through operation. The influence of the number of solar parabolic trough collectors and of the storage tank size on different parameters of the refrigeration plant are investigated under low and high storage temperatures.

Assessment of Strains Produced by Thermal Expansion in Printed Circuit Boards.

The paper proposed an alternative optical metrology to classical methods (strain gauge measurements and numerical simulation) for strain determination on printed circuit board (PCBs) due to thermal loads. The digital image correlation (DIC) technique was employed to record the strain distribution in some particular areas of the PCB. A thermal load was applied using a heating chamber, and the measurements were performed at four different temperature steps (25 °C, 50 °C, 85 °C and 120 °C).

Preliminary sizing of solar district heating systems with seasonal water thermal storage.

The study proposes a method for preliminary and estimative sizing of the main components of solar district heating systems, with seasonal thermal storage. The main parameters determined by this method, are the aperture area of the solar thermal collectors and the volume of the seasonal thermal storage. The proposed method is only estimative, but it provides the necessary input data for the investigation ofthe dynamic thermal behavior of such systems.