xdxadmin
08-31-2004, 11:15 AM
Evaluation of Data Collected During Equipment Manufacturer’s Test of Performance Enhancement of XDX® Valve - October 23, 2002 – David Eslinger, Research Engineer and Dr. William Worek, Energy Resources Center, University of Illinois at Chicago
Objective
The purpose of this test was to determine the impact of the XDX® XSTREAM® Valve on the performance of a conventional, split system refrigeration system. In order to ensure verifiable and accurate test results, a major manufacturer tested the valve in their laboratory facilities. After first monitoring both steady state and transient characteristics of the standard unit, test administrators inserted the XDX® device downstream of the refrigerant expansion valve and repeated the procedure. Temperature and humidity controlled rooms isolated both the evaporator and condensing units thus providing comparable testing conditions.
Conclusions
The XDX® valve quantitatively improved system performance in all evaluation criteria:
• Product temperature consistency
• Evaporator performance
• Product temperature pull down
• Cycle time
• Energy reduction.
From an initial ambient temperature of 77˚F the XDX® unit achieved box set point temperatures 13% faster than the conventional unit. The XDX® unit showed increased latent cooling effects, achieving product surface water temperatures 12% lower before the first door opening event. Once reaching set-point temperature, both systems were evaluated for cooling performance between defrost cycles. As the equipment cycled, product surface temperature fluctuated. The range of surface temperatures allowed by the conventional unit was 5˚F. More rapid cycling by the XDX® system restricted this variation to 2.5˚F.
Also observed during the period between defrost events, cycle times for the conventional unit increased by 23%. This pattern implies degradation in evaporator performance. While not confirmed by observation, frost buildup could be to blame. Conversely, the XDX® unit was able to operate twice as long between defrost cycles and shown no increase in cycle times.
Key: Restaurants, Food Service, Freezer Cases, Refrigerated Cases
Objective
The purpose of this test was to determine the impact of the XDX® XSTREAM® Valve on the performance of a conventional, split system refrigeration system. In order to ensure verifiable and accurate test results, a major manufacturer tested the valve in their laboratory facilities. After first monitoring both steady state and transient characteristics of the standard unit, test administrators inserted the XDX® device downstream of the refrigerant expansion valve and repeated the procedure. Temperature and humidity controlled rooms isolated both the evaporator and condensing units thus providing comparable testing conditions.
Conclusions
The XDX® valve quantitatively improved system performance in all evaluation criteria:
• Product temperature consistency
• Evaporator performance
• Product temperature pull down
• Cycle time
• Energy reduction.
From an initial ambient temperature of 77˚F the XDX® unit achieved box set point temperatures 13% faster than the conventional unit. The XDX® unit showed increased latent cooling effects, achieving product surface water temperatures 12% lower before the first door opening event. Once reaching set-point temperature, both systems were evaluated for cooling performance between defrost cycles. As the equipment cycled, product surface temperature fluctuated. The range of surface temperatures allowed by the conventional unit was 5˚F. More rapid cycling by the XDX® system restricted this variation to 2.5˚F.
Also observed during the period between defrost events, cycle times for the conventional unit increased by 23%. This pattern implies degradation in evaporator performance. While not confirmed by observation, frost buildup could be to blame. Conversely, the XDX® unit was able to operate twice as long between defrost cycles and shown no increase in cycle times.
Key: Restaurants, Food Service, Freezer Cases, Refrigerated Cases