The Experts below are selected from a list of 12 Experts worldwide ranked by ideXlab platform
R S Mishra - One of the best experts on this subject based on the ideXlab platform.
-
methods for improving thermodynamic performance of vapour compression refrigeration systems using thirteen ecofriendly refrigerants in primary Circuit and tio2 nano particles mixed with r718 used in secondary Evaporator Circuit for reducing global wa
2014Co-Authors: R S MishraAbstract:The methods for improving first law and second law efficiency have been considered in this paper by using water as secondary coolent in Evaporator with nano particles such als Al2O3 and TiO2 mixed R718 refrigerant is investigated in this paper. Detailed energy and exergy analysis of multi-Evaporators at different temperatures in the vapour compression refrigeration systems have been done in terms of performance parameter for R507a, R125, R134a, R290, R600, R600a, R410a, R407c, R404a and R152a refrigerants. The numerical computations have been carried out for both systems. The use of nano particles improves the first law and second law performance significantly. The best performance is found using R152a and worst performance is observed using R410a. Due to flammable nature of R290, R600, R600a and R152a The results were compared by using water in secondary Circuit with nano refrigerants and without nano particles used and it was found that use of nano particles improves thermal performances. The first law performance improvement in terms of COP and second law performance in terms of exergetic efficiency (rational efficiency) using TiO2 is better than using Al2O3 with R718 refrigerant in the secondary Evaporator Circuit.
Schulze, Fabio Allan - One of the best experts on this subject based on the ideXlab platform.
-
New Solutions For Household Refrigerator Performance Improvement
'Purdue University (bepress)', 2018Co-Authors: Morriesen Andre, Thiessen, Marcio Roberto, Ronzoni, Adriano Francisco, Hense Daniel, Karnopp Jackson, Junior, João Lemos, Schulze, Fabio AllanAbstract:This paper presents some experimental results of two alternative solutions to improve household refrigerators energy consumption, the flooded Evaporator architecture and the pulse width modulation (PWM) control logic for a variable capacity compressor. The experiments were carried out in a 360-liters bottom-mounted refrigerator-freezer, with natural draft Evaporators, at two different ambient temperatures: 16°C and 32°C. The flooded Evaporator solution can imply the same performance of the parallel Circuit but with the simplicity of the serial-hybrid Circuit, demanding no check valve nor need for pump out. The flooded Evaporator Circuit has a liquid accumulator connecting the Evaporator’s outlet, which allows working with high evaporating temperatures during refrigerator compartment cooling. The liquid accumulator construction jeopardizes the compressor oil to return therefore it can be trapped in the Circuit; hence the solution requires an oiless compressor oil to operate. The PWM control solution may lead to compressor performance improvement at low cooling capacity, so it is especially applicable to compressors which have lower COP at smaller capacities. The PWM solution works through short on-off cycles – on period has high input power and high capacity, and along the off period the compressor has zero capacity at lowest power input – which overall results in higher COP with low cooling capacity. The experiments were set to modulate compressor cooling capacity according to the compressor power input, small cycle period and duty cycle. The experimental results indicate the flooded Evaporator solution lead to a reduction in energy consumption of 4.7% at 32°C and the PWM solution implied a reduction in energy consumption of 2.7% at 32°C and 7% at 16°C
Ryszard Stanislaw Michalski - One of the best experts on this subject based on the ideXlab platform.
-
An Optimized Design of Finned-Tube Evaporators Using the Learnable Evolution Model
Hvac&r Research, 2004Co-Authors: Piotr A. Domanski, Kenneth A. Kaufman, David A. Yashar, Ryszard Stanislaw MichalskiAbstract:Optimizing the refrigerant Circuitry for a finned-tube Evaporator is a daunting task for traditional exhaustive search techniques due to the extremely large number of Circuitry possibilities. For this reason, more intelligent search techniques are needed. This paper presents and evaluates a novel optimization system called ISHED1 (intelligent system for heat exchanger design). This system uses a recently developed non-Darwinian evolutionary computation method to seek Evaporator Circuit designs that maximize the capacity of the Evaporator under given technical and environmental constraints. Circuitries were developed for an Evaporator with three depth rows of 12 tubes each, based on optimizing the performance with uniform and nonuniform airflow profiles. ISHED1 demonstrated the capability to generate designs with capacity equal or superior to that of best human designs, particularly in cases with non-uniform airflow.
Morriesen Andre - One of the best experts on this subject based on the ideXlab platform.
-
New Solutions For Household Refrigerator Performance Improvement
'Purdue University (bepress)', 2018Co-Authors: Morriesen Andre, Thiessen, Marcio Roberto, Ronzoni, Adriano Francisco, Hense Daniel, Karnopp Jackson, Junior, João Lemos, Schulze, Fabio AllanAbstract:This paper presents some experimental results of two alternative solutions to improve household refrigerators energy consumption, the flooded Evaporator architecture and the pulse width modulation (PWM) control logic for a variable capacity compressor. The experiments were carried out in a 360-liters bottom-mounted refrigerator-freezer, with natural draft Evaporators, at two different ambient temperatures: 16°C and 32°C. The flooded Evaporator solution can imply the same performance of the parallel Circuit but with the simplicity of the serial-hybrid Circuit, demanding no check valve nor need for pump out. The flooded Evaporator Circuit has a liquid accumulator connecting the Evaporator’s outlet, which allows working with high evaporating temperatures during refrigerator compartment cooling. The liquid accumulator construction jeopardizes the compressor oil to return therefore it can be trapped in the Circuit; hence the solution requires an oiless compressor oil to operate. The PWM control solution may lead to compressor performance improvement at low cooling capacity, so it is especially applicable to compressors which have lower COP at smaller capacities. The PWM solution works through short on-off cycles – on period has high input power and high capacity, and along the off period the compressor has zero capacity at lowest power input – which overall results in higher COP with low cooling capacity. The experiments were set to modulate compressor cooling capacity according to the compressor power input, small cycle period and duty cycle. The experimental results indicate the flooded Evaporator solution lead to a reduction in energy consumption of 4.7% at 32°C and the PWM solution implied a reduction in energy consumption of 2.7% at 32°C and 7% at 16°C
Piotr A. Domanski - One of the best experts on this subject based on the ideXlab platform.
-
An Optimized Design of Finned-Tube Evaporators Using the Learnable Evolution Model
Hvac&r Research, 2004Co-Authors: Piotr A. Domanski, Kenneth A. Kaufman, David A. Yashar, Ryszard Stanislaw MichalskiAbstract:Optimizing the refrigerant Circuitry for a finned-tube Evaporator is a daunting task for traditional exhaustive search techniques due to the extremely large number of Circuitry possibilities. For this reason, more intelligent search techniques are needed. This paper presents and evaluates a novel optimization system called ISHED1 (intelligent system for heat exchanger design). This system uses a recently developed non-Darwinian evolutionary computation method to seek Evaporator Circuit designs that maximize the capacity of the Evaporator under given technical and environmental constraints. Circuitries were developed for an Evaporator with three depth rows of 12 tubes each, based on optimizing the performance with uniform and nonuniform airflow profiles. ISHED1 demonstrated the capability to generate designs with capacity equal or superior to that of best human designs, particularly in cases with non-uniform airflow.