Joint Optimization Design of Insulation and Electric Heat Tracing System of Molten Salt Pipelines in Csp Plants

In view of that the molten salt pipelines and equipment of concentrating solar power (CSP) plants are equipped with electric heat tracing (EHT) system in addition to thermal insulation layer, a joint optimization design method for the insulation layer and EHT system is proposed. The design point that minimizing the total investment in insulation and EHT system is defined as optimum design point A, while the point minimizing the sum of equipment investment and whole life cycle O&M cost of ETH system is defined as optimum design point B. Taken the typical low and high temperature molten salt pipelines with large/medium/small diameter as examples, the distribution characteristics of optimal design points is analyzed and discussed. Results indicate that, for low temperature pipelines, the optimum design point A is selected with an insulation outer surface temperature of 8~9°C, and for high temperature pipelines, the optimum design point A is still recommended with the insulation outer surface temperature of 16~18°C. The corresponding insulation thickness and EHT heating capacity are the optimal design values.