Chilled Water Thermal Storage

Chillers plays the key role in Heating Ventilation and Air Conditioning (HVAC) for the centralized air conditioning system. The chilled water from chillers are utilized at air handling units and fan coil units for cooling air. The electrical energy used at chillers can be minimized so that the power consumption gets reduced.
Thermal energy storage systems use the electrical energy to chill water or freeze water thereby storing the thermal energy. This action is done at off peak hours so that power consumption at peak hours get reduced.HeatingVentilationAirConditioningTrainingCenterKerala
Governments try to reduce the consumption of electrical power at peak hours for the reason the total consumption at peak hours actually exceeds the desired capacity of the distribution system. Government have introduced measures such as reduced tariff rates at off peak hours to encourage the consumption at off peak hours.
Thermal energy storage systems use the energy at off peak hours to chill water and thermal energy is stored. This stored energy is then used at peak hours to produce cooling effect. The total operation cost is thus reduced and also reduces the peak consumption of designed building load.
The thermal energy storage system can be mainly classified into Ice Thermal Storage and Chilled Water Thermal Storage. During off peak hour’s ice is made and stored inside ice bank energy storage tanks. The stored ice is then used to cool building ,occupants later as we make ice ahead of time and store it in our freezer and uses when guests arrives at our home.HeatingVentilationAirConditioningTrainingCenterKerala
In chilled water thermal storage the tank will always be filled with water. During discharge c old water is pumped from bottom of tank. While an equal amount of warm return water is supplied to top of the tank. The density difference of water at different temperature helps to obtain stable stratification of layer of water. The incoming water mixes with water in tank. The interfacial zone between the warm water and the chilled water called thermocline in the storage tank with large temperature gradient prevents further moving of water above it with that below it. The thermocline that gets formed will move from bottom to the top slowly as the charging is continued. The charging of chilled water is at the same rate at which the warm water is displaced from the top of the storage tank.HeatingVentilationAirConditioningTrainingCenterKerala
The chilled water TES have higher efficiency than low temperature chiller and also the initial investment is also low. It uses only lesser equipment’s no additional heat exchangers are used. The storage tank for the chilled water makes difference from the conventional chillers. This storage tank can also be utilized at the time of fire fighting. Heating Ventilation Air Conditioning Training Center Kerala