The Experts below are selected from a list of 101034 Experts worldwide ranked by ideXlab platform

Honghee Park - One of the best experts on this subject based on the ideXlab platform.

  • the cooling seasonal performance factor of a hybrid ground source heat pump with parallel and serial configurations
    Applied Energy, 2013
    Co-Authors: Honghee Park
    Abstract:

    A hybrid ground-source heat pump (HGSHP) is proposed to overcome the decrease in the performance of a ground-source heat pump (GSHP) at the degraded ground thermal condition. In this study, a performance comparison between the GSHP and the HGSHP with parallel and serial configurations was conducted by varying the leaving Fluid temperature (LFT) of the ground heat exchanger (GHEX), the Fluid Flow Rate of the supplemental loop, the mean outdoor bin temperature, and the switching temperature of the hybrid operation. At the LFT of the GHEX of 40°C, the coefficient of performances (COPs) for the HGSHP with the parallel and serial configurations were 18% and 6% higher than that of the GSHP, respectively. The cooling seasonal performance factors (CSPFs) of the HGSHPs with the parallel and the serial configurations were 6.5% and 2.0% higher, respectively, than that of the GSHP for Daegu city in South Korea.

  • performance optimization of a hybrid ground source heat pump with the parallel configuration of a ground heat exchanger and a supplemental heat rejecter in the cooling mode
    International Journal of Refrigeration-revue Internationale Du Froid, 2012
    Co-Authors: Honghee Park, Joo Seoung Lee, Wonuk Kim, Yongchan Kim
    Abstract:

    Abstract A hybrid ground source heat pump (HGSHP) combining a ground Flow loop and a supplemental heat rejecter loop in parallel is proposed to overcome the degradation of the ground thermal condition. The objective of this study is to optimize the performance of the HGSHP with the parallel configuration by varying the amount of refrigerant charge, the secondary Fluid Flow Rate of the ground loop, and the secondary Fluid Flow Rate of the supplemental loop. The coefficient of performance (COP) of the HGSHP with the parallel configuration was 21% higher than that of the conventional ground source heat pump (GSHP), and the heat rejection Rate of the ground Flow loop was 42% lower than that of the GSHP at the entering Fluid temperature (EFT) of 40 °C in the ground heat exchanger and the EFT of 28 °C in the supplemental heat exchanger.

Yongchan Kim - One of the best experts on this subject based on the ideXlab platform.

  • performance optimization of a hybrid ground source heat pump with the parallel configuration of a ground heat exchanger and a supplemental heat rejecter in the cooling mode
    International Journal of Refrigeration-revue Internationale Du Froid, 2012
    Co-Authors: Honghee Park, Joo Seoung Lee, Wonuk Kim, Yongchan Kim
    Abstract:

    Abstract A hybrid ground source heat pump (HGSHP) combining a ground Flow loop and a supplemental heat rejecter loop in parallel is proposed to overcome the degradation of the ground thermal condition. The objective of this study is to optimize the performance of the HGSHP with the parallel configuration by varying the amount of refrigerant charge, the secondary Fluid Flow Rate of the ground loop, and the secondary Fluid Flow Rate of the supplemental loop. The coefficient of performance (COP) of the HGSHP with the parallel configuration was 21% higher than that of the conventional ground source heat pump (GSHP), and the heat rejection Rate of the ground Flow loop was 42% lower than that of the GSHP at the entering Fluid temperature (EFT) of 40 °C in the ground heat exchanger and the EFT of 28 °C in the supplemental heat exchanger.

Donggen Peng - One of the best experts on this subject based on the ideXlab platform.

  • an improved evaluation method for thermal performance of borehole heat exchanger
    Renewable Energy, 2015
    Co-Authors: Changxing Zhang, Ping Chen, Donggen Peng
    Abstract:

    Thermal performance of vertical U-pipe borehole heat exchanger (BHE) is an important research subject for the design and application of ground-coupled heat pump system (GCHPs). This paper presents an improved evaluation method for thermal performance of BHE based on analytical solution model, which is validated by comparing with duct storage system (DST) model and field experiment. Using the evaluation method, impacts of inlet Fluid temperature, Fluid Flow Rate and borehole depth on thermal performance of two types of U-pipe BHEs are studied. The study provides a good alternative of the experimental method for thermal performance test (TPT) and a useful thermal performance evaluation tool for BHEs in GCHPs.

  • an improved evaluation method for thermal performance of borehole heat exchanger
    Renewable Energy, 2015
    Co-Authors: Changxing Zhang, Ping Chen, Donggen Peng
    Abstract:

    Thermal performance of vertical U-pipe borehole heat exchanger (BHE) is an important research subject for the design and application of ground-coupled heat pump system (GCHPs). This paper presents an improved evaluation method for thermal performance of BHE based on analytical solution model, which is validated by comparing with duct storage system (DST) model and field experiment. Using the evaluation method, impacts of inlet Fluid temperature, Fluid Flow Rate and borehole depth on thermal performance of two types of U-pipe BHEs are studied. The study provides a good alternative of the experimental method for thermal performance test (TPT) and a useful thermal performance evaluation tool for BHEs in GCHPs.

Ahmad Fauzi Ismail - One of the best experts on this subject based on the ideXlab platform.

  • morphology and property study of green ceramic hollow fiber membrane derived from waste sugarcane bagasse ash wsba
    Ceramics International, 2018
    Co-Authors: Siti Khadijah Hubadillah, Mohd Hafiz Dzarfan Othman, Mohd Riduan Jamalludin, Zawati Harun, Muhamad Zaini Yunos, Ahmad Fauzi Ismail
    Abstract:

    Abstract This work describes the preparation of green ceramic hollow fiber membranes derived from waste sugarcane bagasse ash (WSBA) using phase inversion and sintering techniques as membrane support for water filtration. The first step consisted in the production of WSBA is by the calcination process of sugarcane bagasse at 800 °C and followed characterizing of the microstructure, phases present, and thermal behavior using transmission electron microscopy (TEM), X-ray fluorescence (XRF), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and Fourier-transform infrared spectroscopy (FTIR). This process was followed by the preparation of ceramic dope suspension consisting of WSBA powder as the main material, NMP as the solvent, PESf as the binder, and Arlacel P135 as the dispersant. In this work, various spinning parameters (effect of SWBA contents, bore Fluid Flow Rate, air gap, and sintering temperature) were evaluated. By varying these parameters, significant effects on the membrane structure and mechanical strength were observed. The different sintering temperatures resulted in wormlike pores in the membrane structure due to neck growth and melting mechanism. The preliminary performance tests show that the green ceramic hollow fiber membrane prepared with a WSBA content of 60 wt%, bore Fluid Flow Rate of 10 mL/min, air gap of 10 cm, and sintering temperature of 1000 °C induced a stable permeate water flux (PWF) of ~ 466.2 L/m2 h at the beginning of the filtration process.

  • fabrication and characterization of polysulfone membranes coated with polydimethysiloxane for oxygen enrichment
    Aerosol and Air Quality Research, 2017
    Co-Authors: Kok Chung Chong, Ahmad Fauzi Ismail, Hui San Thiam, A K Zulhairun
    Abstract:

    ABSTRACTThis paper presented the application of polymeric membranes for oxygen/nitrogen (O2/N2) gas separation. Polysulfone (PSF) hollow fiber membranes were fabricated by phase inversion process using N,N-dimethylacetamide (DMAc) and tetrahydrofuran (THF) as co-solvent and ethanol as additive. The effects of bore Fluid Flow Rate and polydimethysiloxane (PDMS) coating concentration on the separation characteristics of hollow fiber membranes were studied. Prior to gas permeation study, characterizations were performed to study the membrane morphology, its thickness and quality of PDMS coating layer on the membrane surface. It was found that the bore Fluid Flow Rate played an important role for the O2/N2 separation as it could alter the membrane structure and dimension. The membrane fabricated with lower bore Fluid FlowRate exhibited better gas permeance and selectivity, owing to better structural integrity that favored the PDMS coating. The results indicated that the PSF hollow fiber membrane coated with optimum PDMS concentration could show greater O2/N2 gas permeability and selectivity relative to the PSF membrane without PDMS coating.

Mohd Riduan Jamalludin - One of the best experts on this subject based on the ideXlab platform.

  • morphology and property study of green ceramic hollow fiber membrane derived from waste sugarcane bagasse ash wsba
    Ceramics International, 2018
    Co-Authors: Siti Khadijah Hubadillah, Mohd Hafiz Dzarfan Othman, Mohd Riduan Jamalludin, Zawati Harun, Muhamad Zaini Yunos, Ahmad Fauzi Ismail
    Abstract:

    Abstract This work describes the preparation of green ceramic hollow fiber membranes derived from waste sugarcane bagasse ash (WSBA) using phase inversion and sintering techniques as membrane support for water filtration. The first step consisted in the production of WSBA is by the calcination process of sugarcane bagasse at 800 °C and followed characterizing of the microstructure, phases present, and thermal behavior using transmission electron microscopy (TEM), X-ray fluorescence (XRF), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and Fourier-transform infrared spectroscopy (FTIR). This process was followed by the preparation of ceramic dope suspension consisting of WSBA powder as the main material, NMP as the solvent, PESf as the binder, and Arlacel P135 as the dispersant. In this work, various spinning parameters (effect of SWBA contents, bore Fluid Flow Rate, air gap, and sintering temperature) were evaluated. By varying these parameters, significant effects on the membrane structure and mechanical strength were observed. The different sintering temperatures resulted in wormlike pores in the membrane structure due to neck growth and melting mechanism. The preliminary performance tests show that the green ceramic hollow fiber membrane prepared with a WSBA content of 60 wt%, bore Fluid Flow Rate of 10 mL/min, air gap of 10 cm, and sintering temperature of 1000 °C induced a stable permeate water flux (PWF) of ~ 466.2 L/m2 h at the beginning of the filtration process.