Wet compression versus dry compression in heat pumps working with pure refrigerants or non-azeotropic mixtures

Itard, Laure

doi:10.1016/0140-7007(95)93788-l

Cited by 23 publications

(9 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Itard [1,2], Hultén and Berntsson [3] and more recently Zaytsev [4] investigated this potential. For high temperature industrial heat pumps, a gain of about 20% in comparison with 'conventional' vapor compressor heat pumps can be attained.…”

Section: Introductionmentioning

confidence: 99%

“…Two different ways of implementing compressorabsorption heat pump cycles have been investigated in the past: the wet compression and the dry compression types. The differences between the two solutions have extensively been discussed by Itard [1,2]. The dry compression implementation raises two problems: (i) the irreversibility losses associated with vapor superheating play a major role in degrading the overall performance of the cycle; (ii) dry compressors require oil lubrication, with the implication of oil contamination of the liquid refrigerant [5] and additional degradation of the performance.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Twin screw oil-free wet compressor for compression–absorption cycle

Ferreira

Zamfirescu

Zaytsev

2006

International Journal of Refrigeration

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Twin screw oil-free wet compressor for compression–absorption cycle

Ferreira

Zamfirescu

Zaytsev

2006

International Journal of Refrigeration

View full text Add to dashboard Cite

“…This section covers studies performed on heat pump cycles, working fluids and their equations of state, thermodynamic analyses, and the development of high‐temperature heat pumps. A few notable studies of heat pumps based on Stirling and reversed Brayton cycles …”

Section: Introductionmentioning

confidence: 99%

“…A few notable studies of heat pumps based on Stirling 10,11 and reversed Brayton cycles. 12,13 Another type of heat pump used in high-temperature applications is the chemical heat pump. Such a device adjusts operating pressures at which some exothermic or endothermic reactions take place to shift the reaction equilibrium in the desired direction.…”

Section: Introductionmentioning

confidence: 99%

Investigation of new mechanical heat pump systems for heat upgrading applications

2018

View full text Add to dashboard Cite

Summary In this study, two novel high‐temperature heat pump systems based on vapor compression cycles are introduced and examined. Three fluids (water, cyclohexane, and biphenyl) are selected and analyzed thermodynamically as prospective working fluids for the high‐temperature heat pumps. These working fluids are used in cascaded cycles to upgrade the heat to a temperature of 600°C. The equations of state used in performance analysis are Peng‐Robinson, non‐random two‐liquid model, and International Association for the Properties of Water and Steam 95. A parametric analysis is carried out to study the effects of isentropic efficiency, sink temperature, source temperature, and ambient temperature on the system performance. Both energetic and exergetic coefficients of performance (COPs) of the overall and individual cycles are determined. The COP values obtained are found to range from 2.3 to 3.8, depending upon the cycle and temperature levels. The high COP values in some instances make these systems promising alternatives to fossil fuel and electrical heating. As a possible sustainable scenario, these pumps can utilize low‐grade heat from geothermal, nuclear, or thermal power plants and derive work from clean energy sources (solar, wind, nuclear) to deliver high‐grade heat. The high delivery temperatures make these heat pumps suitable for processes with corresponding needs, like high‐temperature endothermic reactions, metallurgical processes, distillation, and thermochemical water splitting.

show abstract

“…The vapor-liquid compression in a heat pump system is called wet compression, which brings it closer to the Ideal Carnot Cycle for a pure refrigerant and closer to the Lorenz Cycle for non-azeotropic refrigerants, because the irreversibilities caused by vapor superheating during compression are prevented. It was shown that the advantage of a wet compression cycle offers the highest possible efficiency for thermodynamic cycles operating between two temperatures with a heat sink and heat source [2,3]. While some earlier works [4,5] showed improvements in the isentropic and volumetric efficiency of the compressor, they did not recommend using wet compression due to the following possible dangers.…”

Section: Introductionmentioning

confidence: 99%

The Effects of Wet Compression by the Electronic Expansion Valve Opening on the Performance of a Heat Pump System

Seong

Lee

2017

Applied Sciences

View full text Add to dashboard Cite

Abstract:In this study, by controlling the Electronic Expansion Valve opening, the influence of wet compression on a heat pump system was experimentally investigated in different heating conditions. The results demonstrate that the discharge temperature decreased and the mass flow rate increased, due to quality of the rising liquid droplets. It was also found that the heating capacity and power input of wet compression increased more than that of dry compression, with a superheat of 10 • C. The maximum COP (Coefficient of Performance) exists at a specific quality of ca. 0.94 to 0.90, as the power input in the region of wet compression is proportionally larger than the increase in the heating capacity, according to the decreasing quality. When the Entering Water Temperature of the Outdoor Heat Exchanger was 10 • C, 5 • C, and 0 • C, the COP increased by a maximum of ca. 12.4%, 10.6%, and 10.2%, respectively, in comparison to the superheat of 10 • C. In addition, the superheat at the discharge line is proposed as a proper controlling parameter to adjust the quality at the suction line, by varying the opening of the expansion valve during wet compression.

show abstract

Wet compression versus dry compression in heat pumps working with pure refrigerants or non-azeotropic mixtures

Cited by 23 publications

References 5 publications

Twin screw oil-free wet compressor for compression–absorption cycle

Twin screw oil-free wet compressor for compression–absorption cycle

Investigation of new mechanical heat pump systems for heat upgrading applications

The Effects of Wet Compression by the Electronic Expansion Valve Opening on the Performance of a Heat Pump System

Contact Info

Product

Resources

About