Ice stores are used in refrigeration to cover an increased additional cooling requirement (peak load). The ice stores are usually charged over night when general energy requirements and energy costs are low.
To charge and discharge the ice store a circuit with glycolwater mixture is used between the ice store and the compression refrigeration system. When charging the ice store the glycol-water mixture is cooled via a compression refrigeration system to below 0°C and thereby withdraws heat from the water in the ice store, causing the water to freeze. During discharging the melting ice withdraws heat from the glycol-water mixture causing the mixture to cool down. During this cooling process the ice store replaces or supports the compression refrigeration system. consists of an ice store, a refrigeration system, a circuit with glycol-water mixture, a dry and a wet cooling tower. During the evaporation of the refrigerant in the refrigeration circuit and during discharging of the ice store, heat is withdrawn from the mixture, whereas during the condensing of the refrigerant heat is added. As required the cooling towers add heat to or withdraw heat from the mixture.
The record of all required variables enables an energy balance for the individual processes. The measured values are read from digital displays and can be transmitted simultaneously via USB directly to a PC where they can be analysed using the software included.
The unit shall perform the following experiments and investigations:
Learning Objectives / Experiments
Design and operation of an energy-efficient
Refrigeration system
Function and operation of an ice store
Charge
Discharge
Energy flow balance
Energy transport via different media
Compression refrigeration cycle in the log p-h
Diagram
Function and operation of a wet cooling tower
Function and operation of a dry cooling tower
Specification
Investigation of the charging and discharging of an ice store
System with ice store, compression refrigeration system, dry and wet cooling towers
Refrigeration circuit for R134a with compressor, condenser, evaporator and expansion valve
Glycol-water circuits with pumps: cooling of the refrigerant condenser, heating of the refrigerant evaporator, charging/discharging of the ice store, operation of the dry cooling tower
Water circuit with pump to operate the wet cooling tower
Measurement of all relevant temperatures, pressures, flow rates and power consumption to balance the processes
Software for data acquisition via USB under Windows Vista or Windows 7