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This document covers the first step of the exergy analysis as it was planned in the GA for the task T8.5. The objective of this analysis is to identify the irreversibility of the different components and to assess the inefficiencies of the system to propose different alternatives of optimization. To attain this objective, some simulations of the integrated ASTEP systems for MAN and AMTP cases were performed in some representative days and for a whole year. The formulation used allows the identification of the inefficiencies of each component. The results of these simulations show that, as expected, the main contributor to the irreversibility of the system is the Sundial. Other important contributors are the heat exchangers, the chiller and the boiler and, when the storage system is almost full, the mixture that controls the temperature at the inlet of the demand side. In addition, further mixing and splitting processes were analysed and comparisons between the two systems were established. This task runs in parallel to those of WP5 aimed to the optimization of the system, so it has influenced in the decision of the final layout of each system, as it was highly conditioned by some constraints exposed in [1]. This task will continue once the data collected from WP6 and WP7 will be available, to propose additional improvements to the system.

This deliverable presents the final design of the ASTEP system specifically tailored for both end-users, including the requirements of the different components integrated in the system. This includes the final system design and the requirements of the piping, heat transfer fluid and ancillary systems, sensors, pumps, heat exchangers and cooling lines. The accumulator will be installed in series with solar concentrator for both end-users. This configuration has been selected due to its easier control and lower actuation and measuring costs. Therminol 59 is selected as the HTF. First, synthetic oils have been selected instead of pressurized water or direct steam generation due to its application flexibility. Then, Therminol 59 was selected thanks to its higher pumpability at low temperatures, especially important for AMTP case. Regarding the piping, DN20 tubes are selected for most lines (except those within the SunDial concentrator affected by the HTF recirculation, which should be DN50) in order to limit pressure drop. This design would limit total line pressure drop to 2 bar. In what refers to the piping insulation, 101.6 mm fiberglass insulation is selected to limit heat losses. Heat losses might still be relatively high (2 kW) due to the small size of the prototype, but cost limitations led to this choice both in terms of material and thickness. The components to fill and drain the system are designed together with the expansion vessel. A pump with a manifold is used to initially fill the system or to drain it completely. The expansion vessel is sized to ensure pressure limitations in the system. The cooling circuit for MAN is also designed. This cooling is based on two absorption chillers (Purix A25 units), 3.1 kW each. The inertia tank sizing, the pumps and the sensors required for its control are detailed in the deliverable. The temperatures, pressures, and mass flows of the different sensors, valves, pumps and heat exchangers have been considered in order to select these systems. This selection has always been done with cost perspective since these elements might be relatively expensive for the system size. Finally, the requirements of the chiller-water line are given in terms of the required elements, including the absorption and compressor chillers to be used. This configuration with absorption chiller and compression chiller in series has been selected since no absorption chillers have been found for the system size. Nevertheless, a large application of ASTEP system would lead to larger absorption chillers directly fed by synthetic oil with lower cooling temperatures. Therefore, no compression chiller in series would be necessary and higher COP would be achieved.

One of the solutions for the decarbonization of productive processes is the use of solar thermal technologies to supply the demanded thermal energy required to run such industrial process. The European Project ASTEP (Application of Solar Thermal Energy to Processes) proposed a concept to demonstrate the viability of using solar thermal energy to cover heating and cooling demands on two different relevant industrial sites located on two different climate regions. The objective of this work is the design and simulation of the integration of the ASTEP concept in one of the industrial sites, a dairy industry with heating and cooling demand. Results of the steady-state simulations showed that the defined integrated system (Sundial, thermal storage system in series and control strategy) was able to supply 27.4 MWh along the year to the end-user. It was also demonstrated that the ASTEP concept is suitable for different working temperatures and end user sites, offering a reliable and versatile alternative to fossil fuels.

The ASTEP concept was proposed within the European Project with the same name (Application of Solar Thermal Energy to Processes). It consists in the integration of a rotary Fresnel collector and a Phase Change Material (PCM) Thermal Energy Storage (TES) connected in series with the collector, to demonstrate the viability to cover the energy demands of industry processes with solar thermal technologies. The concept will be tested in two industrial sites with different demands and meteorology. The maximum working temperature will be 240ºC, and the heat thermal fluid is Therminol 55®. The demand studied in the first case (Mandrekas, Greece) is a boiler producing steam at 175ºC and two chillers to cool water at -5ºC.This work aims to assess the exergy analysis of the concept. Majority exergy losses are located in the solar receiver, followed a long way behind by the salt heat exchanger, and in the same order of magnitude, boiler and pumps/valves losses.

Two layout configurations for the ASTEP concept (Application of Solar Thermal Energy to Processes) were analyzed with the goal of maximized production and operation simplicity with less cost. The ASTEP system includes the SunDial, which was previously analyzed [1], phase change thermal storage (TES), and two heat exchangers. The first one considers a parallel connection with TES, which is a common layout used in SHIP systems; the second one is an innovative series connection with a simplified control system. The ASTEP system will be installed in Romania and will preheat a steel tube oven. The working fluid is a thermal oil, that will be heated to 220ºC. The main objective of this study was to design the control strategy and simulate the two systems in Dymola to finally choose the one that best fits the project goals.

Solar heat for industrial processes (SHIP) is becoming one of the most attractive solutions for industry decarbonisation. Solar plants require a complex control system to manage the fluctuation of their source, solar radiation. One of the problems of this system is the possibility of overheating when solar production is greater than consumption. The main objective of this study was to design a defocus controller for the SunDial, the rotatory Fresnel collector. A dynamic simulation was carried out for a SHIP system with the defocus controller. Finally, a solution to satisfy the accuracy needed for the SunDial was presented.

This document covers the contents of the ASTEP deliverables ‘D3.3 - Design of the daily and yearly operation for AMTP and MAND’ and ‘D5.1 - Report on the integrated ASTEP model development and Conceptual Designs’. First, the ASTEP concept design is described for the two end-users of the project, the dairy industry Mandrekas in Corinth (Greece) and the ArcelorMittal Tubular Products factory of Iasi (Romania). In a first stage, two different layouts are proposed, one with the Sundial and the thermal energy storage system in series and the other with the Sundial and the thermal energy storage in parallel. Then, a control strategy is outlined with the objective of maximising the solar energy integration into the processes and minimising the hysteresis in the thermal energy storage system. The different operation modes of the system and the sensors and actuators are selected for that. Once the layout, the operation modes and the control strategy are defined, two simulation models are developed, namely a steady-state one and a dynamic one. Afterwards, the steady-state simulation model is used to assess the whole system making different analyses. First, the daily and yearly behaviour of the two proposed designs (one for each end-user) is analysed. To complete these reference cases, some sensitivity analyses and a comparison of the selected configuration to the alternative one (storage in parallel) is performed, showing that the selected design is feasible. After that, the concept is analysed considering different thermal loads at the industry side, both for the heating and cooling demands, and also varying the number of accumulators inside the thermal energy storage system. Finally, the steady-state simulator is used to analyse the ASTEP concept at different working temperatures and in different sites to provide information about its possible performance within industries different from the end-user cases. The dynamic model finally is used to analyse the response of the control system in the different transients conditions during some representative days, and also to assess the defined operation modes. The analysis is done for the designs selected for the two end-user.

This study evaluates the dynamic performance of rotatory Fresnel collector, called SunDial. The SunDial is built on an 8 meters’ diameter platform with an azimuthal sun tracking system. It has a two-tube receiver connected in series, oil as a heat transfer fluid, and 8 mirrors with a 20-25 m2 aperture area. We developed a dynamic model of the SunDial receiver with a control system to test its abilityto maintain a constant temperature in different operation modes and variable weather conditions.

The use of solar thermal technologies to provide thermal energy required by an industrial process, also known as Solar Heat for Industrial Processes (SHIP), is one of the solutions proposed to promote the decarbonization of productive industries. The European Project ASTEP (Application of Solar Thermal Energy to Processes) has the main objective of demonstrating the viability of applying solar thermal energy to partially cover heating and cooling demands on two different relevant industrial demo sites located on two different climate regions. The main focus in this project is the decrease of cost, modularity of systems and thermal supply manageability for industrial heat above 150 ºC. The ASTEP concept is based on the modular and flexible integration of two innovative designs for the solar collector (SunDial) and the Thermal Energy Storage (TES), based on Phase Change Materials (PCM). This concept will be tested and validated in two industrial sites. The objective of this work is the design and feasibility study of the integration of the ASTEP concept in two industrial processes, including parameter definition of both the solar collector and the whole system.