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Cooling - Compressor - Arena - hockey & skating / United States of America
Case study assignment
An ice arena's refrigeration system operates on a control strategy that maintains a constant high compressor discharge pressure. Due to this, the cooling system COP is relatively low.
Base Case
Solution
The worked-out solution is the data file selected from within the RETScreen Project Database. The user automatically downloads the Project Database file while downloading the RETScreen software.
Similar project
In 1999 an ice arena, in Madison, Wisconsin switched from a constant high compressor discharge pressure to a floating head pressure control strategy to boost their system efficiency. Maintaining a high fixed compressor discharge pressure assures safe, reliable operation over a range of outdoor temperatures. High discharge pressure maintains adequate refrigerant flow, freeze protection for the evaporative condenser, and sufficient pressure difference across the expansion valve. However, it is more energy efficient to allow head pressure to "float" with ambient wet-bulb temperature, down to a pre-set safe level for a given system. With floating head pressure, the system works only as hard as it needs to under all weather conditions, yet safety and reliability are maintained.
Real project (301 KB)
Case study assignment
An ice arena's refrigeration system operates on a control strategy that maintains a constant high compressor discharge pressure. Due to this, the cooling system COP is relatively low.
Base Case
- Ice rink operates about 5,500 h annually
- Operation starts in mid-September and ends in May
- Peak cooling load is 80 kW
- Using constant high compressor discharge pressure, effective COP of cooling system is 1.75
- Electricity rate is $0.10/kWh
- Change to floating head pressure control strategy to increase effective COP of cooling system to 2.83
- Cost for monitoring and control equipment to maintain control strategy is $840
Solution
The worked-out solution is the data file selected from within the RETScreen Project Database. The user automatically downloads the Project Database file while downloading the RETScreen software.
Similar project
In 1999 an ice arena, in Madison, Wisconsin switched from a constant high compressor discharge pressure to a floating head pressure control strategy to boost their system efficiency. Maintaining a high fixed compressor discharge pressure assures safe, reliable operation over a range of outdoor temperatures. High discharge pressure maintains adequate refrigerant flow, freeze protection for the evaporative condenser, and sufficient pressure difference across the expansion valve. However, it is more energy efficient to allow head pressure to "float" with ambient wet-bulb temperature, down to a pre-set safe level for a given system. With floating head pressure, the system works only as hard as it needs to under all weather conditions, yet safety and reliability are maintained.
Real project (301 KB)
