The Experts below are selected from a list of 30819 Experts worldwide ranked by ideXlab platform
Shigeru Koyama - One of the best experts on this subject based on the ideXlab platform.
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comparative assessment on Irreversible Losses in heat pumps using r744 r32 r1234yf and r744 r32 r1234ze e
Science and Technology for the Built Environment, 2016Co-Authors: Sho Fukuda, Hideki Kojima, Chieko Kondou, Nobuo Takata, Shigeru KoyamaAbstract:This article presents an experimental assessment of coefficient of performance and Irreversible Loss in the heat pump cycle using hydro-fluoro-olefin base ternary mixtures: YF300 (R744/R32/R1234yf; 4/44/52 mass%), YF200 (R744/R32/R1234yf; 5/28/67 mass%), ZE300 (R744/R32/R1234ze(E); 4/43/53 mass%), and ZE200 (R744/R32/R1234ze(E); 9/29/62 mass%). The smaller volumetric capacity of YF200 and ZE200 increases the Irreversible Loss caused by the pressure drop with increasing heat load. ZE200, which has a temperature glide of approximately 22 K, increases the Irreversible Loss in the condenser, evaporator, and expansion valve. The experimental results indicate that YF300 and ZE300 could be potential alternatives to R410A and R32.
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comparative assessment of heat pump cycle operated with r32 r1234ze e and r32 r1234yf mixtures
Proceedings of the 24th IIR International Congress of Refrigeration: Yokohama Japan August 16-22 2015., 2015Co-Authors: Hideki Kojima, Sho Fukuda, Chieko Kondou, Nobuo Takata, Shigeru KoyamaAbstract:This study measures the COPs of R32/R1234ze(E) and R32/R1234yf with GWPs of approximately 285 and 190 with a vapour compression cycle under two heating modes, where the heat sink water change temperature 10 K and 25 K. At a temperature change of 10 K, the COPs of mixtures are significantly lower than that of R410A. At a temperature change of 25 K, the COPs of mixtures are generally comparable to that of R410A. When the temperature change in heat sink fluid is large, the larger temperature glide of the combination R32/R1234e(E) is somewhat advantageous to reduce the Irreversible Loss in condenser. The smaller volumetric capacity of refrigerant mixture significantly increases the volumetric flow rate and the Irreversible Loss in the compressor at higher heating loads. The pinch point of R410A appeared in the condenser caused excess pressure rising and increased compressor Loss at a temperature change of 25 K.
Sho Fukuda - One of the best experts on this subject based on the ideXlab platform.
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comparative assessment on Irreversible Losses in heat pumps using r744 r32 r1234yf and r744 r32 r1234ze e
Science and Technology for the Built Environment, 2016Co-Authors: Sho Fukuda, Hideki Kojima, Chieko Kondou, Nobuo Takata, Shigeru KoyamaAbstract:This article presents an experimental assessment of coefficient of performance and Irreversible Loss in the heat pump cycle using hydro-fluoro-olefin base ternary mixtures: YF300 (R744/R32/R1234yf; 4/44/52 mass%), YF200 (R744/R32/R1234yf; 5/28/67 mass%), ZE300 (R744/R32/R1234ze(E); 4/43/53 mass%), and ZE200 (R744/R32/R1234ze(E); 9/29/62 mass%). The smaller volumetric capacity of YF200 and ZE200 increases the Irreversible Loss caused by the pressure drop with increasing heat load. ZE200, which has a temperature glide of approximately 22 K, increases the Irreversible Loss in the condenser, evaporator, and expansion valve. The experimental results indicate that YF300 and ZE300 could be potential alternatives to R410A and R32.
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comparative assessment of heat pump cycle operated with r32 r1234ze e and r32 r1234yf mixtures
Proceedings of the 24th IIR International Congress of Refrigeration: Yokohama Japan August 16-22 2015., 2015Co-Authors: Hideki Kojima, Sho Fukuda, Chieko Kondou, Nobuo Takata, Shigeru KoyamaAbstract:This study measures the COPs of R32/R1234ze(E) and R32/R1234yf with GWPs of approximately 285 and 190 with a vapour compression cycle under two heating modes, where the heat sink water change temperature 10 K and 25 K. At a temperature change of 10 K, the COPs of mixtures are significantly lower than that of R410A. At a temperature change of 25 K, the COPs of mixtures are generally comparable to that of R410A. When the temperature change in heat sink fluid is large, the larger temperature glide of the combination R32/R1234e(E) is somewhat advantageous to reduce the Irreversible Loss in condenser. The smaller volumetric capacity of refrigerant mixture significantly increases the volumetric flow rate and the Irreversible Loss in the compressor at higher heating loads. The pinch point of R410A appeared in the condenser caused excess pressure rising and increased compressor Loss at a temperature change of 25 K.
Prashant N. Kumta - One of the best experts on this subject based on the ideXlab platform.
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Silicon-Carbon Core-Shell Hollow Nanotubular Configuration High-Performance Lithium-Ion Anodes
Journal of Physical Chemistry C, 2017Co-Authors: Bharat Gattu, Ramalinga Kuruba, Prashanth H. Jampani, Rigved Epur, Moni Kanchan Datta, Prashant N. KumtaAbstract:Silicon anode systems, due to their intrinsic high theoretical specific capacity, show tremendous potential in lithium ion batteries (LIBs). Unfortunately, commercial application still remains elusive due to the cycling-related coLossal volume expansion issues following Li alloying and dealloying. Herein, core–shell C@Si@C hollow nanotubes with optimal Si thickness (∼60 nm) showing no microstructural damage during lithiation and delithiation processes, have been developed as a stable anode for LIBs with low first-cycle Irreversible Loss (FIR) of ∼13% and high areal capacity (∼3 mAhcm–2) for the first time. The hollow Si nanotubes (h-SiNTs) have been generated via our previously reported high-throughput and recyclable, sacrificial MgO wire template fabrication approach. Generation of Si films of varying thickness by low-pressure thermal chemical vapor deposition (LPCVD) with subsequent etching yields h-SiNTs. Modification/optimization of the h-SiNT physical characteristics exhibit improved performance in L...
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tin and graphite based nanocomposites potential anode for sodium ion batteries
Journal of Power Sources, 2013Co-Authors: Moni Kanchan Datta, Rigved Epur, Partha Saha, Karan Kadakia, Sungkyoo Park, Prashant N. KumtaAbstract:Abstract Pure tin (Sn) and a homogeneous nanocomposite of tin and graphite (C), denoted as Sn/C, have been studied as a suitable anode for sodium ion batteries. The Sn/C nanocomposites have been synthesized by high energy mechanical milling (HEMM) of pure Sn and graphite of nominal composition C-70 wt.% Sn. Pure microcrystalline Sn (≤44 μm) exhibits a 1st discharge capacity ∼856 mAh g −1 which is close to the expected theoretical capacity, however, it shows a large 1st cycle Irreversible Loss (∼67%) and the anticipated inevitable rapid fade in capacity expectedly due to structural failure of the electrode. On the other hand, the resultant Sn/C based nanocomposite, synthesized by HEMM after 1h of milling, exhibits a 1st cycle discharge capacity ∼584 mAh g −1 with a 1st cycle Irreversible Loss ∼30%. The Sn/C nanocomposite shows a 1st cycle charge capacity of ∼410 mAh g −1 with improved capacity retention in comparison to pure Sn displaying 0.7% fade in capacity per cycle up to 20 cycles when cycled at a rate of ∼C/8. Scanning electron microscopy (SEM) analysis indicates that the structural integrity and microstructural stability of the Sn/C nanocomposite during the alloying/dealloying processes appear to be the primary factors contributing to the good cyclability observed in the above HEMM derived nanocomposite suggesting its promise as a potential anode for Na-ion systems.
Hideki Kojima - One of the best experts on this subject based on the ideXlab platform.
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comparative assessment on Irreversible Losses in heat pumps using r744 r32 r1234yf and r744 r32 r1234ze e
Science and Technology for the Built Environment, 2016Co-Authors: Sho Fukuda, Hideki Kojima, Chieko Kondou, Nobuo Takata, Shigeru KoyamaAbstract:This article presents an experimental assessment of coefficient of performance and Irreversible Loss in the heat pump cycle using hydro-fluoro-olefin base ternary mixtures: YF300 (R744/R32/R1234yf; 4/44/52 mass%), YF200 (R744/R32/R1234yf; 5/28/67 mass%), ZE300 (R744/R32/R1234ze(E); 4/43/53 mass%), and ZE200 (R744/R32/R1234ze(E); 9/29/62 mass%). The smaller volumetric capacity of YF200 and ZE200 increases the Irreversible Loss caused by the pressure drop with increasing heat load. ZE200, which has a temperature glide of approximately 22 K, increases the Irreversible Loss in the condenser, evaporator, and expansion valve. The experimental results indicate that YF300 and ZE300 could be potential alternatives to R410A and R32.
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comparative assessment of heat pump cycle operated with r32 r1234ze e and r32 r1234yf mixtures
Proceedings of the 24th IIR International Congress of Refrigeration: Yokohama Japan August 16-22 2015., 2015Co-Authors: Hideki Kojima, Sho Fukuda, Chieko Kondou, Nobuo Takata, Shigeru KoyamaAbstract:This study measures the COPs of R32/R1234ze(E) and R32/R1234yf with GWPs of approximately 285 and 190 with a vapour compression cycle under two heating modes, where the heat sink water change temperature 10 K and 25 K. At a temperature change of 10 K, the COPs of mixtures are significantly lower than that of R410A. At a temperature change of 25 K, the COPs of mixtures are generally comparable to that of R410A. When the temperature change in heat sink fluid is large, the larger temperature glide of the combination R32/R1234e(E) is somewhat advantageous to reduce the Irreversible Loss in condenser. The smaller volumetric capacity of refrigerant mixture significantly increases the volumetric flow rate and the Irreversible Loss in the compressor at higher heating loads. The pinch point of R410A appeared in the condenser caused excess pressure rising and increased compressor Loss at a temperature change of 25 K.
Chieko Kondou - One of the best experts on this subject based on the ideXlab platform.
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comparative assessment on Irreversible Losses in heat pumps using r744 r32 r1234yf and r744 r32 r1234ze e
Science and Technology for the Built Environment, 2016Co-Authors: Sho Fukuda, Hideki Kojima, Chieko Kondou, Nobuo Takata, Shigeru KoyamaAbstract:This article presents an experimental assessment of coefficient of performance and Irreversible Loss in the heat pump cycle using hydro-fluoro-olefin base ternary mixtures: YF300 (R744/R32/R1234yf; 4/44/52 mass%), YF200 (R744/R32/R1234yf; 5/28/67 mass%), ZE300 (R744/R32/R1234ze(E); 4/43/53 mass%), and ZE200 (R744/R32/R1234ze(E); 9/29/62 mass%). The smaller volumetric capacity of YF200 and ZE200 increases the Irreversible Loss caused by the pressure drop with increasing heat load. ZE200, which has a temperature glide of approximately 22 K, increases the Irreversible Loss in the condenser, evaporator, and expansion valve. The experimental results indicate that YF300 and ZE300 could be potential alternatives to R410A and R32.
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comparative assessment of heat pump cycle operated with r32 r1234ze e and r32 r1234yf mixtures
Proceedings of the 24th IIR International Congress of Refrigeration: Yokohama Japan August 16-22 2015., 2015Co-Authors: Hideki Kojima, Sho Fukuda, Chieko Kondou, Nobuo Takata, Shigeru KoyamaAbstract:This study measures the COPs of R32/R1234ze(E) and R32/R1234yf with GWPs of approximately 285 and 190 with a vapour compression cycle under two heating modes, where the heat sink water change temperature 10 K and 25 K. At a temperature change of 10 K, the COPs of mixtures are significantly lower than that of R410A. At a temperature change of 25 K, the COPs of mixtures are generally comparable to that of R410A. When the temperature change in heat sink fluid is large, the larger temperature glide of the combination R32/R1234e(E) is somewhat advantageous to reduce the Irreversible Loss in condenser. The smaller volumetric capacity of refrigerant mixture significantly increases the volumetric flow rate and the Irreversible Loss in the compressor at higher heating loads. The pinch point of R410A appeared in the condenser caused excess pressure rising and increased compressor Loss at a temperature change of 25 K.
