An efficient way to use medium-or-low temperature solar heat for power generation – integration into conventional power plant

This paper demonstrates that the medium-or-low temperature solar heat can be used to generate power efficiently by integrating into conventional coal-fired power plants. In so-called solar aided power generation (SAPG) technology, medium-or-low temperature solar heat is used to replace parts of bled-off steams in regenerative Rankine cycle to pre-heat feedwater. Thermal oil can be used as solar heat carrier and no solar steam needs to be generated, therefore the pressure of solar system can be much lower than that of the solar collector using water/steam as the heat carrier. A 200 MW coal-fired thermal power plant is selected as the case study to demonstrate the advantages of the SAPG technology in terms of solar to power efficiency, specific fuel and steam consumption rates, under various integration scenarios. The results indicate that there is a great potential and effect for low or medium solar heat to be used for power generation purposes through SAPG approach.

Research highlights► Solar aided power generation (SAPG) has been proposed and its merits has been demonstrated. ► SAPG is an efficient way to make use of solar heat in the medium and low temperature range for power generation. ► SAPG is to use solar heat to replace the bled-off steam in the regenerative Rankine steam cycle. ► SAPG can be operated in either power boosting or fuel saving mode.