Using sunlight to heat thermal oil used as heat transfer fluid poses challenges. From sunrise and throughout the day, the oil is subject to relatively large thermal expansion. To regulate pressure at the expansion tanks, relief valves vent ullage gas. Alfa Laval plate heat exchangers and dry coolers safely and efficiently condense and separate the oil vapor in the vent gas before releasing it to atmosphere.
On the pulse of ullage cooling
Concentrated Solar Power (CSP) plants are generally located around our planet’s solar belt, and are usualy subject to water restrictions due to limited or no availability of water. To address this issue, Alfa Laval promotes a two-stage cooling solution based primarily on air; water is only used for trim cooling to achieve the low temperature point required. For CSP plants that have sufficient water resources, a lower cost single-stage cooling process is feasible using water as the cooling medium. For both two-stage and single-stage processes, the cooling of the vent gas plus the condensation and separation of the oil fraction takes places inside a plate heat exchanger.
Broad range of efficient coolers
Alfa Laval has a broad range of proven Alfa Laval Spiral Heat Exchangers and Alfa Laval Dry Coolers, which are excellent choices for use in ullage cooling systems at power plants with concentrating solar power systems.
Compact Alfa Laval Spiral Heat Exchangers offer great installation flexibility and fast, infrequent cleaning. When cleaning is required, it typically is four to 10 times faster than conventional shell-and-tube heat exchangers. This maximizes uptime.
Alfa Laval Dry Coolers handle high capacities with ease while minimizing energy use due to their electronically commutated (EC) motors. Space-saving and cost-efficient, they are easy to operate and maintain, and typically deliver energy savings of 30% compared to comparable units with standard motors.