Charge Mode

This is the normal operating mode for nighttime hours. As shown on the shematic, the chiller runs to cool the brine and to crystallize the nodules. The chiller is controlled by the leaving temperature controller. In charge mode the flow is from the bottom to the top of the tank.

Discharge Only

This condition corresponds either to peak electricity tariff where the chiller is off or to back-up. The STL meets the load without the help of the chiller. The upstream layout requires to have two set-points on the 3-way-valve controller.

Direct Production + Discharge

This is the normal operating mode for partial storage systems during daytime hours. This situation occurs when the cooling load is higher than the chiller capacity. The 3-way-valve controls the inlet temperature to the chiller.

This is the same operation as a conventional system (without STL). In this mode the entire load is met directly by the chiller. This situation occurs when the load is lower than the chiller capacity.