Showing papers by "Savvas A. Tassou published in 2023"
TL;DR: In this article , a concept design of the solar collectors and thermal energy storage is presented for solar thermal energy integration in dairy processes, which is based on the available data, including connection of solar collectors to the thermal energy supply line through the absorption chiller and steam drum.
Abstract: 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 powdered 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, review 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. • The dairy processes have a great potencial to use solar energy for their processes. • The most suitable solar collectors proved to be Parabolic trough and Fresnel reflector. • They can be integrated through the energy supply lines of the processes. • The cooling processes could be additionally powered using absorption chiller. • The new concept design of the solar collectors and thermal energy storage is presented in this study.
9 citations
TL;DR: In this article , the authors present recent developments in supercritical CO2 heat exchangers in terms of material selection, design, manufacture, and operation, and identify technology gaps and research needs to accelerate the development of effective designs.
Abstract: Heat exchangers for supercritical CO2 power generation and waste heat to power conversion systems have a significant impact on the overall cycle efficiency and system footprint. Key challenges for supercritical CO2 heat exchangers include ability to withstand high temperature and high pressure (typical temperature range of heat source 350 to 800 °C and typical required operating pressure range 150 to 300 bars), and large pressure differential between fluid streams. Other requirements are low pressure drop, high effectiveness and high reliability under thermal cycling. This paper presents recent developments in supercritical CO2 heat exchangers in terms of material selection, design, manufacture, and operation. Since heat exchangers represent a significant portion of the total system cost, another key challenge is to find a compromise between the heat exchanger type, cost, durability, and performance. This paper explores heat exchanger technologies, manufacturing techniques and materials for high temperature and high pressure heat exchangers for supercritical CO2 applications. It also identifies technology gaps and research needs to accelerate the development of effective designs to facilitate the commercialization of both supercritical CO2 heat exchanger technologies and power cycles.
1 citations