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Evaluation The Effect Of Washing On The Heat Transfer Capacity And Air-Side Flow Resistance Of Air Cooled Condensers, Mehdi Mehrabi, David Yuill
Evaluation The Effect Of Washing On The Heat Transfer Capacity And Air-Side Flow Resistance Of Air Cooled Condensers, Mehdi Mehrabi, David Yuill
David Yuill
Air cooled condensers are commonly used in rooftop units and residential air-conditioners to reject heat outdoors. Airborne particles in the environment, such as dust, grass, leaves, seeds, and anthropogenic agents, can foul the air side of the condensers. Therefore, it is common practice to regularly clean the air side of condensers. Seven fouled wavy fin, and two fouled spine fin condensers from residential condensing units were collected at the end of their service lives, and examined in the laboratory to study the effect of the fouling on heat transfer capacity and air-side flow resistance. A test apparatus was designed and …
Numerical Simulation Of Fault Impacts For Commercial Walk-In Freezers, Alireza Behfar, David Yuill
Numerical Simulation Of Fault Impacts For Commercial Walk-In Freezers, Alireza Behfar, David Yuill
David Yuill
Refrigeration systems can undergo many faults that could negatively affect their operation and performance. This paper describes a modeling process to simulate the fault impacts on the operation of a commercial walk-in freezer using semi-empirical models. These models often require less modeling effort than full forward models and could be used in scenarios where detailed information is missing, such as in field-measured systems. An important characteristic of a typical walk-in refrigeration system is the existence of a liquid-line receiver after the condenser, which significantly changes the behavior of the cycle, in comparison to a receiver-less system. Component models described in …
Generalized Effects Of Faults On Normalized Performance Variables Of Air Conditioners And Heat Pumps, Mehdi Mehrabi, David Yuill
Generalized Effects Of Faults On Normalized Performance Variables Of Air Conditioners And Heat Pumps, Mehdi Mehrabi, David Yuill
David Yuill
The effects of several types of faults on air conditioners and heat pumps have been studied in many laboratory experiments. All available data have been gathered, and the independent
variable (fault intensity) and each of the dependent variables (fault impacts) are normalized to show the trends in a generalized fashion. Relationships are provided wherever there are sufficient results. Most of the significant fault types are included (except refrigerant charge variation, which was discussed in Mehrabi and Yuill (2017)): condenser heat transfer (CA), evaporator heat transfer (EA), liquid line restriction (LL), compressor leakage (VL), and noncondensables in the refrigerant (NC). Relationships …