The Experts below are selected from a list of 7560 Experts worldwide ranked by ideXlab platform

Predrag Stojan Hrnjak - One of the best experts on this subject based on the ideXlab platform.

  • characteristics of oil annular mist flow in the Compressor discharge pipe
    International Journal of Refrigeration-revue Internationale Du Froid, 2019
    Co-Authors: Jiu Xu, Predrag Stojan Hrnjak
    Abstract:

    Abstract Oil is essential to the Compressor, but oil brings side effects on the heat exchanger performance. It is preferred to reduce the amount of oil circulating in the system and retain the oil in the Compressor for both reliability and efficiency reasons. Oil leaves the compression chamber in the form of mist. Oil droplets are propelled by refrigerant vapor flow and form a developing annular-mist flow in the discharge pipe, as droplets gradually attach to the inner wall. In this paper, a video-based method to quantify the oil flow in the Compressor discharge pipe is presented. Oil droplet size, oil droplet velocity, oil film thickness, and oil film wave velocity are measured at different mass flow rates and Compressor speed. The measurements show a variety of oil flow parameters as functions of distance along the discharge pipe. The impact of system flow rate, Compressor Type, and oil properties are also discussed. The characteristics of oil discharged by the Compressor provide essential information for oil separator design and optimization. The research approach also has the potential to be applied in other multiphase studies.

Arpagaus Cordin - One of the best experts on this subject based on the ideXlab platform.

  • High Temperature Heat Pumps: Market Overview, Stateof the Art, Research Status, Refrigerants, and Application Potentials
    2018
    Co-Authors: Arpagaus Cordin, Bless Frédéric, Uhlmann Michael, Schiffmann, Jürg Alexander, Bertsch, Stefan S.
    Abstract:

    This study reviews the current state of the art of high temperature heat pumps (HTHPs) with heat sink temperatures of 90 to 160°C. The focus is on the analysis of heat pump cycles, suitable refrigerants, and the operating ranges of commercially available HTHPs and heat pumps at the research status. More than 20 HTHP models from 13 manufacturers havebeen identified on the market that are able to provide heat sink temperatures of at least 90°C. Only a few heatpump suppliers have already managed to exceed 120°C. Large application potentials have been recognized particularly in the food, paper, metal, and chemical industries, especially in drying, pasteurizing, sterilizing, evaporation, and distillation processes. The heating capacities range from about 20 kW to 20MW. The refrigerants used are mainly R245fa, R717,R744, R134a, and R1234ze(E). Most circuits are single-stage and differ primarily in the applied refrigerant and Compressor Type. Internal heat exchangers (IHX) are used to ensure sufficient superheating. Process optimization is achieved with economizer cycles or two-stage turbo Compressors with intermediate vapor injection. Two-stage cascade cycles or open flash economizers are also used in commercial HTHPs. The COP values range from about 1.6 to 5.8 at temperature lifts of 130 to 40 K, respectively. Several research projects push the limits of the achievable COPs and heat sink temperatures to higher levels. Groups in Austria, Germany, France, Norway, the Netherlands, Switzerland, Japan, Korea, and China are active in the experimental research of HTHPs. Several laboratory scale HTHPs have been built to demonstrate the technical feasibility of sink temperatures above 120°C. The heat pump cycles examined are mainly single-stage and in some cases contain an IHX for superheating or an economizer for vapor injection into the Compressor. The investigated refrigerants are R1336mzz(Z), R718, R245fa, R1234ze(Z), R600, and R601. R1336mzz(Z) enables exceptionally high heat sink temperatures of up to 160°C. The experimentally obtained COPs at 120°C heat sink temperature vary between about 5.7 and 6.5 at 30 K temperature lift and 2.2 and 2.8 at 70 K lift. New environmental friendly refrigerants with low GWP and improved components lead to a need for research on optimized cycles. The high level of research activity and the large number of demonstration R&D projects indicate that HTHPs with a heat sink temperature of 160°C will reach market maturity in the next few years. However, despite the great application potential, other competing heating technologies and most importantly low prices for fossilfuels are still hindering the wider spread of HTHPs in industry

  • High Temperature Heat Pumps: Market Overview, State of the Art, Research Status, Refrigerants, and Application Potentials
    'Purdue University (bepress)', 2018
    Co-Authors: Arpagaus Cordin, Bless Frédéric, Uhlmann Michael, Schiffmann Jürg, Bertsch Stefan
    Abstract:

    This study reviews the current state of the art of high temperature heat pumps (HTHPs) with heat sink temperatures of 90 to 160°C. The focus is on the analysis of heat pump cycles, suitable refrigerants, and the operating ranges of commercially available HTHPs and heat pumps at the research status. More than 20 HTHP models from 13 manufacturers have been identified on the market that are able to provide heat sink temperatures of at least 90°C. Only a few heat pump suppliers have already managed to exceed 120°C. Large application potentials have been recognized particularly in the food, paper, metal, and chemical industries, especially in drying, pasteurizing, sterilizing, evaporation, and distillation processes. The heating capacities range from about 20 kW to 20 MW. The refrigerants used are mainly R245fa, R717, R744, R134a, and R1234ze(E). Most circuits are single-stage and differ primarily in the applied refrigerant and Compressor Type. Internal heat exchangers (IHX) are used to ensure sufficient superheating. Process optimization is achieved with economizer cycles or two-stage turbo Compressors with intermediate vapor injection. Two-stage cascade cycles or open flash economizers are also used in commercial HTHPs. The COP values range from about 1.6 to 5.8 at temperature lifts of 130 to 40 K, respectively. Several research projects push the limits of the achievable COPs and heat sink temperatures to higher levels. Groups in Austria, Germany, France, Norway, the Netherlands, Switzerland, Japan, Korea, and China are active in the experimental research of HTHPs. Several laboratory scale HTHPs have been built to demonstrate the technical feasibility of sink temperatures above 120°C. The heat pump cycles examined are mainly single-stage and in some cases contain an IHX for superheating or an economizer for vapor injection into the Compressor. The investigated refrigerants are R1336mzz(Z), R718, R245fa, R1234ze(Z), R600, and R601. R1336mzz(Z) enables exceptionally high heat sink temperatures of up to 160°C. The experimentally obtained COPs at 120°C heat sink temperature vary between about 5.7 and 6.5 at 30 K temperature lift and 2.2 and 2.8 at 70 K lift. New environmental friendly refrigerants with low GWP and improved components lead to a need for research on optimized cycles. The high level of research activity and the large number of demonstration R&D projects indicate that HTHPs with a heat sink temperature of 160°C will reach market maturity in the next few years. However, despite the great application potential, other competing heating technologies and most importantly low prices for fossil fuels are still hindering the wider spread of HTHPs in industry

Stefan S Bertsch - One of the best experts on this subject based on the ideXlab platform.

  • high temperature heat pumps market overview state of the art research status refrigerants and application potentials
    Energy, 2018
    Co-Authors: Cordin Arpagaus, Frederic Bless, Michael Uhlmann, Jurg Schiffmann, Stefan S Bertsch
    Abstract:

    Abstract This study reviews the current state of the art and the current research activities of high temperature heat pumps (HTHPs) with heat sink temperatures in the range of 90 to 160 °C. The focus is on the analysis of the heat pump cycles and the suitable refrigerants. More than 20 HTHPs from 13 manufacturers have been identified on the market that are able to provide heat sink temperatures of at least 90 °C. Large application potentials have been recognized particularly in the food, paper, metal and chemical industries. The heating capacities range from about 20 kW to 20 MW. Most cycles are single-stage and differ primarily in the refrigerant (e.g. R245fa, R717, R744, R134a or R1234ze(E)) and Compressor Type used. The COPs range from 2.4 to 5.8 at a temperature lift of 95 to 40 K. Several research projects push the limits of the achievable COPs and heat sink temperatures to higher levels. COPs of about 5.7 to 6.5 (at 30 K lift) and 2.2 and 2.8 (70 K) are achieved at a sink temperature of 120 °C. The refrigerants investigated are mainly R1336mzz(Z), R718, R245fa, R1234ze(Z), R600, and R601. R1336mzz(Z) enables to achieve exceptionally high heat sink temperatures of up to 160 °C.

Bertsch Stefan - One of the best experts on this subject based on the ideXlab platform.

  • High Temperature Heat Pumps: Market Overview, State of the Art, Research Status, Refrigerants, and Application Potentials
    'Purdue University (bepress)', 2018
    Co-Authors: Arpagaus Cordin, Bless Frédéric, Uhlmann Michael, Schiffmann Jürg, Bertsch Stefan
    Abstract:

    This study reviews the current state of the art of high temperature heat pumps (HTHPs) with heat sink temperatures of 90 to 160°C. The focus is on the analysis of heat pump cycles, suitable refrigerants, and the operating ranges of commercially available HTHPs and heat pumps at the research status. More than 20 HTHP models from 13 manufacturers have been identified on the market that are able to provide heat sink temperatures of at least 90°C. Only a few heat pump suppliers have already managed to exceed 120°C. Large application potentials have been recognized particularly in the food, paper, metal, and chemical industries, especially in drying, pasteurizing, sterilizing, evaporation, and distillation processes. The heating capacities range from about 20 kW to 20 MW. The refrigerants used are mainly R245fa, R717, R744, R134a, and R1234ze(E). Most circuits are single-stage and differ primarily in the applied refrigerant and Compressor Type. Internal heat exchangers (IHX) are used to ensure sufficient superheating. Process optimization is achieved with economizer cycles or two-stage turbo Compressors with intermediate vapor injection. Two-stage cascade cycles or open flash economizers are also used in commercial HTHPs. The COP values range from about 1.6 to 5.8 at temperature lifts of 130 to 40 K, respectively. Several research projects push the limits of the achievable COPs and heat sink temperatures to higher levels. Groups in Austria, Germany, France, Norway, the Netherlands, Switzerland, Japan, Korea, and China are active in the experimental research of HTHPs. Several laboratory scale HTHPs have been built to demonstrate the technical feasibility of sink temperatures above 120°C. The heat pump cycles examined are mainly single-stage and in some cases contain an IHX for superheating or an economizer for vapor injection into the Compressor. The investigated refrigerants are R1336mzz(Z), R718, R245fa, R1234ze(Z), R600, and R601. R1336mzz(Z) enables exceptionally high heat sink temperatures of up to 160°C. The experimentally obtained COPs at 120°C heat sink temperature vary between about 5.7 and 6.5 at 30 K temperature lift and 2.2 and 2.8 at 70 K lift. New environmental friendly refrigerants with low GWP and improved components lead to a need for research on optimized cycles. The high level of research activity and the large number of demonstration R&D projects indicate that HTHPs with a heat sink temperature of 160°C will reach market maturity in the next few years. However, despite the great application potential, other competing heating technologies and most importantly low prices for fossil fuels are still hindering the wider spread of HTHPs in industry

Uhlmann Michael - One of the best experts on this subject based on the ideXlab platform.

  • High Temperature Heat Pumps: Market Overview, Stateof the Art, Research Status, Refrigerants, and Application Potentials
    2018
    Co-Authors: Arpagaus Cordin, Bless Frédéric, Uhlmann Michael, Schiffmann, Jürg Alexander, Bertsch, Stefan S.
    Abstract:

    This study reviews the current state of the art of high temperature heat pumps (HTHPs) with heat sink temperatures of 90 to 160°C. The focus is on the analysis of heat pump cycles, suitable refrigerants, and the operating ranges of commercially available HTHPs and heat pumps at the research status. More than 20 HTHP models from 13 manufacturers havebeen identified on the market that are able to provide heat sink temperatures of at least 90°C. Only a few heatpump suppliers have already managed to exceed 120°C. Large application potentials have been recognized particularly in the food, paper, metal, and chemical industries, especially in drying, pasteurizing, sterilizing, evaporation, and distillation processes. The heating capacities range from about 20 kW to 20MW. The refrigerants used are mainly R245fa, R717,R744, R134a, and R1234ze(E). Most circuits are single-stage and differ primarily in the applied refrigerant and Compressor Type. Internal heat exchangers (IHX) are used to ensure sufficient superheating. Process optimization is achieved with economizer cycles or two-stage turbo Compressors with intermediate vapor injection. Two-stage cascade cycles or open flash economizers are also used in commercial HTHPs. The COP values range from about 1.6 to 5.8 at temperature lifts of 130 to 40 K, respectively. Several research projects push the limits of the achievable COPs and heat sink temperatures to higher levels. Groups in Austria, Germany, France, Norway, the Netherlands, Switzerland, Japan, Korea, and China are active in the experimental research of HTHPs. Several laboratory scale HTHPs have been built to demonstrate the technical feasibility of sink temperatures above 120°C. The heat pump cycles examined are mainly single-stage and in some cases contain an IHX for superheating or an economizer for vapor injection into the Compressor. The investigated refrigerants are R1336mzz(Z), R718, R245fa, R1234ze(Z), R600, and R601. R1336mzz(Z) enables exceptionally high heat sink temperatures of up to 160°C. The experimentally obtained COPs at 120°C heat sink temperature vary between about 5.7 and 6.5 at 30 K temperature lift and 2.2 and 2.8 at 70 K lift. New environmental friendly refrigerants with low GWP and improved components lead to a need for research on optimized cycles. The high level of research activity and the large number of demonstration R&D projects indicate that HTHPs with a heat sink temperature of 160°C will reach market maturity in the next few years. However, despite the great application potential, other competing heating technologies and most importantly low prices for fossilfuels are still hindering the wider spread of HTHPs in industry

  • High Temperature Heat Pumps: Market Overview, State of the Art, Research Status, Refrigerants, and Application Potentials
    'Purdue University (bepress)', 2018
    Co-Authors: Arpagaus Cordin, Bless Frédéric, Uhlmann Michael, Schiffmann Jürg, Bertsch Stefan
    Abstract:

    This study reviews the current state of the art of high temperature heat pumps (HTHPs) with heat sink temperatures of 90 to 160°C. The focus is on the analysis of heat pump cycles, suitable refrigerants, and the operating ranges of commercially available HTHPs and heat pumps at the research status. More than 20 HTHP models from 13 manufacturers have been identified on the market that are able to provide heat sink temperatures of at least 90°C. Only a few heat pump suppliers have already managed to exceed 120°C. Large application potentials have been recognized particularly in the food, paper, metal, and chemical industries, especially in drying, pasteurizing, sterilizing, evaporation, and distillation processes. The heating capacities range from about 20 kW to 20 MW. The refrigerants used are mainly R245fa, R717, R744, R134a, and R1234ze(E). Most circuits are single-stage and differ primarily in the applied refrigerant and Compressor Type. Internal heat exchangers (IHX) are used to ensure sufficient superheating. Process optimization is achieved with economizer cycles or two-stage turbo Compressors with intermediate vapor injection. Two-stage cascade cycles or open flash economizers are also used in commercial HTHPs. The COP values range from about 1.6 to 5.8 at temperature lifts of 130 to 40 K, respectively. Several research projects push the limits of the achievable COPs and heat sink temperatures to higher levels. Groups in Austria, Germany, France, Norway, the Netherlands, Switzerland, Japan, Korea, and China are active in the experimental research of HTHPs. Several laboratory scale HTHPs have been built to demonstrate the technical feasibility of sink temperatures above 120°C. The heat pump cycles examined are mainly single-stage and in some cases contain an IHX for superheating or an economizer for vapor injection into the Compressor. The investigated refrigerants are R1336mzz(Z), R718, R245fa, R1234ze(Z), R600, and R601. R1336mzz(Z) enables exceptionally high heat sink temperatures of up to 160°C. The experimentally obtained COPs at 120°C heat sink temperature vary between about 5.7 and 6.5 at 30 K temperature lift and 2.2 and 2.8 at 70 K lift. New environmental friendly refrigerants with low GWP and improved components lead to a need for research on optimized cycles. The high level of research activity and the large number of demonstration R&D projects indicate that HTHPs with a heat sink temperature of 160°C will reach market maturity in the next few years. However, despite the great application potential, other competing heating technologies and most importantly low prices for fossil fuels are still hindering the wider spread of HTHPs in industry