Design of high-temperature solar receiver integrated with short-term thermal storage for Dish-Micro Gas Turbine systems

Small-scale concentrated solar power plants equipped with Micro Gas Turbines (MGTs) could be an effective way for power production in the off-grid areas. One of the most relevant concerns for such no fuel-assisted systems is the solar radiation fluctuations, which reduce system performance and, in the worst cases, can damage the MGT. To overcome this issue, the solar receiver should have sufficient thermal inertia averaging the thermal power inputted in the MGT. In the present study, the design of a novel high-temperature cavity solar receiver is presented for the application in the Dish-MGT system. The receiver has been integrated with a PCM for the short-term thermal energy storage (15-30 min). The design process was based on the main parameters of the solar dish and MGT. The thermal model enables the variation of different geometrical factors and input parameters to identify the optimum receiver design. Moreover, it can be used for the evaluation of heat losses from the cavity surface and temperature distributions in the PCM. A 1D steady-state model has been developed for the heat loss calculation from the cavity and corresponding cavity surface temperature, as well as for the evaluation of number and dimensions of the MGT working fluid tubes. Furthermore, the PCM melting and the transient temperature distribution inside the PCM domain have been determined analytically with the help of a 1D thermal model. The initial design results showed that solar receiver integrated with the high-temperature PCM is a promising option for the stable outlet temperature for MGT.