An investigation of the recent advances of the integration of solar thermal energy systems to the dairy processes

The dairy industry uses a number of energy intensive thermal processes like cooling, heating and cleaning that require thermal and electrical energy. Those processes use temperatures between 4 ◦C and 200 ◦C that could be potentially powered using solar thermal energy but one of the main challenges is the complexity of selection and integration of the components used for the solar system such as solar collectors, solar heating and cooling equipment. The heating processes with the temperature requirements between 300 ◦C and 400 ◦C are mainly powered using solar parabolic trough collectors and linear Fresnel reflectors while cooling processes with solar absorption chillers. The excesses of energy of above 200 ◦C could be stored in a thermal energy storage system. This study critically evaluates the thermal demands of the dairy processes, reviews their existing solar thermal applications and recommends a concept design for solar thermal energy integration based on the available data. The concept design includes connection of the solar collectors and thermal energy storage to the thermal energy supply line through the absorption chiller and steam drum. The benefits comprise flexibility of the heat transfer fluid selection, independency of solar energy production to conventional production and no further modification of the conventional production system or additional capacity to support the future upgrades are required