cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.18462/iir.tptpr.2017.0063
title: Investigation of the solid-liquid phase equilibria for cryogenic argon-fluorocarbon mixed refrigerant.

description: Mixed refrigerant (MR) Joule Thomson (JT) refrigerators are superior to pure refrigerant JT refrigerators in terms of their available cooling temperature range and cooling capacity. However, at cryogenic temperature below 120 K, non-flammable MRs such as argon-fluorocarbon mixtures may freeze due to their higher freezing temperatures than conventional flammable MRs. Therefore, the freezing temperature of the non-flammable MR should be investigated in advance to employ them in cryogenic MR JT refrigerators. In this paper, we investigate the solid-liquid phase equilibria (i.e. freezing temperature) of the argon-fluorocarbon mixture which consists of argon (Ar), R14 (CF4), R218 (C3F8) and R23 (CHF3). These quaternary mixtures were carefully selected to evaluate the lowest operation temperature of the MR JT refrigerator which use them. The 6 cases of molar composition of the mixtures were examined by means of the regular solution theory and the visualization apparatus to find the lowest temperature without freezing. For the experiment, the image for phase change and temperature measurement of the target MR were acquired simultaneously by camcorder and temperature sensors during the melting process. The entire experimental results were obtained between 115 K and 120 K which show significant difference with the estimated freezing temperatures by regular solution theory. These results may originate from relatively high enthalpy of fusion of R23 and the lack of binary interaction parameter. We suggest that the selected quaternary mixtures be applied to MR JT refrigerators for cooling temperature above 120 K.
DOI: 10.18462/iir.tptpr.2017.0086
title: Enhanced condensation heat transfer at a wide range of supersaturation level.

description: In this work, we fabricate superhydrophobic tube type condensers and investigate the condensation heat transfer performance. Using a well-controlled environmental chamger, a wide range of supersaturation level was achieved with minimizing non-condensable effects. We show that the supersaturation level has a significant effect on the condensate mobility and resulting heat transfer performance especially for the superhydrophobic condensers. Particularly, it is demonstrated that quality of the hydrophobic coating on the superhydrophobic surface significantly determins condensation behavior and resulting condensation heat transfer performance. This work will help optimize the surface condition of condensers operating at practical supersaturation level.
DOI: 10.18462/iir.tptpr.2017.0090
title: Entropy production minimization of a CRHP.

description: Compression resorption heat pumps (CRHP) are a promising option to upgrade waste heat from industry. One way to optimize a CRHP is by minimizing the entropy production rate of the heat pump; that is to minimize the lost work of the system. In this paper a CRHP operating with an ammonia-water mixture is analysed based on an application case from the chemical industry. First, a global approach is used to analyse the entropy production rate of each of the components in the heat pump cycle. Based on the result from the global approach the component with the maximum energy dissipation in the heat pump is identified, in this case the resorber. The resorber is therefore further analysed with a detailed thermodynamic state model and entropy production is calculated using the theory of non-equilibrium thermodynamics. Measures to reduce the non-uniformity of the entropy production are then proposed based on the theory of equipartition.
DOI: 10.18462/iir.tptpr.2017.1001
title: Refrigerant and heat pumps for efficient use of low grade thermal energy.

description: Low grade thermal energy, such as solar energy, waste heat from industries and geothermal energy, extensively exists in the environment. Heat pumps (HPs), such as vapor compression, absorption, and adsorption HPs, can upgrade the low temperature thermal energy into high temperature heat for central heating or industrial manufacturing processes. The selection of suitable cycles and refrigerants is important for getting good performance of HPs. In this paper typical refrigerants of vapor compression, absorption, and adsorption HPs, such as R152a, R1233zd (E), R1234yf, R1234ze, R134a, R245fa, R717, R718, and R744, methanol, etc., are analyzed. Various HPs and refrigerant options are compared, and different factors, which are low grade heat sources, heat sinks, and temperature lifts, are analyzed. A broad-spectrum diagram of HP applications is provided for different working modes.
DOI: 10.18462/iir.tptpr.2017.1003
title: Using hydrate slurries to increase the solar fraction of solar heating and cooling systems.

description: The contribution of solar thermal energy to the final energy consumption has significantly increased in recent years. However the use of solar thermal energy to drive sorption heating / cooling systems is still less than 2% of the total installed solar thermal technology capacity. Reason for this low penetration are costs and complexity associated with limited solar fractions. The IEA expects that by 2050 solar thermal energy will have a major share in the CO2 emissions reduction associated with the built environment. Thermal storage can significantly increase the solar fraction of solar driven sorption heating / cooling systems. This paper discusses the aspects that should be considered when selecting the latent heat storage for a specific solar heating and cooling application. It positions latent heat storage in relation to solar heating and cooling systems helping determine the storage temperature level. It quantifies temperature losses and indicates how the major sources of irreversibilities can be quantified. It distinguishes between stationary phase change materials and pumpable slurries of phase change materials and illustrates the advantages of pumpable PCM slurries.
DOI: 10.5517/ccdc.csd.cc1pcqsk
title: CCDC 1560409: Experimental Crystal Structure Determination

description: Related Article: Xian-Rong Song|2017|CSD Communication|||
description: An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
DOI: 10.14457/kmitl.res.2016.3
title: แนวทางการปรับตัวขององค์การธุรกิจเมื่อประเทศไทยเข้าสู่ประชาคม เศรษฐกิจอาเซียน
DOI: 10.14457/kmitl.res.2016.5
title: ความสัมพันธ์ระหว่างการประยุกต์ใช้ระบบบริหารคุณภาพในองค์กร และคุณภาพชีวิตการทำงานของพนักงานออฟฟิศในเขตกรุงเทพมหานคร
DOI: 10.14457/sdu.res.2014.65
title: การเตรียมวัสดุของผสมนาโนซิงค์ออกไซด์และนาโนคอปเปอร์ออกไซด์ สำหรับวัสดุของผสมพอลิเอทิลีนบรรจุภัณฑ์อาหารยับยั้งเชื้อก่อโรค
DOI: 10.18462/iir.tptpr.2017.0017
title: 3D evaluation of thermal stresses on ceramic-metal composites used at high temperature operation.

description: Ceramic-metal composites (CMC) have been used for various high temperature applications including combustion engines, steam and gas turbines, industrial heaters and ceramic fuel cells. Reliable incorporation of the CMC at elevated temperatures, however, is very difficult in practice for the following reasons. First, meting and sublimation points of those solids are different causing undesired diffusion and mixing of elements across the material boundaries degrading functions of the materials. Secondly, maintaining temperature and pressure regimes for desired phases of the component materials is challenging during operation in many of practical cases. Lastly, thermal expansion rates of those two materials are significantly different frequently causing mechanical stresses and fractures. There have been numerous efforts to evaluate and design the CMC materials to minimize the thermo-mechanical stresses. Among various techniques, the focused ion beam-scanning electron microscope (FIB-SEM) tomography has been proved as a state-of-art technique to obtain 3D compositional and structural information of the CMC materials. In this study, we have evaluated thermal stresses applied on nickel-zirconia CMCs by using the FIB-SEM 3D tomography and finite element analysis.
DOI: 10.18462/iir.tptpr.2017.0054
title: The measurement of local temperatures under micro jet impinging using HFE-7000.

description: Experiments were conducted to understand temperature distribution and measure local heat transfer coefficients under micro scale jet impinging using a refrigerant, HFE-7000 from 3MTM. The device used in the experiment was made of a 400 μm thick silicon wafer, a 500 μm thick Pyrex substrate, and a 250 μm thick vinyl sticker. On a silicon wafer, jet orifices were etched using deep reactive ion etching (DRIE). A heater and four 100 nm thick titanium resistance temperature detector (RTD) thermistors were fabricated on the Pyrex wafer. Between the Pyrex and silicon wafers, the vinyl sticker including a 1.9 mm × 14.8 mm × 0.25 mm micro channel was located to make them together. From the experiment, local temperatures from four RTDs were measured by heat fluxes at a flow rate, and local heat transfer coefficients were estimated to understand the characteristics of the jet impinging cooling.
DOI: 10.18462/iir.tptpr.2017.0074
title: The heat transfer from the refrigerant and oil mixture in oil separator to the environment.

description: Gaseous refrigerant and liquid lubricant oil mixture circulates inside an oil separator of refrigeration or heat pump systems. Lubricant oil in this mixture sometimes hits the wall, thus oil is separated from the refrigerant flow in the oil separator. Because of the high temperature of the mixture, heat is transferred to the environment, and this heat loss affects separation phenomena and the total system efficiency. In this study, the circulation phenomenon of oil separator and the heat transfer rate from vertical and horizontal pipes to the environment are analyzed numerically through CFD, and through these data, the relation of charge level of lubricant oil in compressor and heat loss are investigated. R410A and polyvinylether (PVE) are used as refrigerant and lubricant oil, respectively. The key components of cyclone are body diameter, body height, circulation speed, and other dimensions of the cyclone. The circulation speed of cyclone is affected by mass flow rate (MFR) and inlet diameter. The performance of the cyclone is affected by liquid circulation ratio (LCR). In this study, therefore, we analyzed heat transfer of vertical and horizontal pipes with various MFR and LCR to apply to real phenomena of oil separators. These analyzing is very fundamental to measure heat loss of oil separator with respect to the ratio of refrigerant and oil. As the body diameter and height become greater, the heat transfer amount grows bigger. As LCR increases, the same phenomena are expected. These results are useful to design an optimal oil separator and improve the heat transfer performance of refrigeration or heat pump systems.
DOI: 10.18462/iir.tptpr.2017.0075
title: A generalized analytic method for predicting refrigerant charge amount in a variable refrigerant flow (VRF) system.

description: The search for alternatives to high GWP refrigerants primarily focuses on the use of natural fluids (hydrocarbons, ammonia, carbon dioxide) and new synthetic refrigerants having low GWP. Unfortunately, single-component low-GWP refrigerants so far cannot cover all the applications unless some drawbacks, such as flammability, are accepted. A solution may be found using blends of refrigerants, to satisfy the demand for a wide range of working conditions. In this paper, the boiling heat transfer performance of a non-azeotropic mixture of R1234ze(E) and R32 (0.26/0.74 by mass) is investigated. This blend exploits the good characteristics of R32 reducing at the same time its GWP value. Local flow boiling heat transfer coefficients have been measured in 1 mm internal diameter microchannel. The heat transfer coefficients of the present mixture are compared against predicting models available in the literature. The new experimental data are also compared to the boiling heat transfer of the pure components R1234ze(E) and R32, to analyze the heat transfer penalization due to the mass transfer resistance.
DOI: 10.18462/iir.tptpr.2017.0077
title: Performance characteristics of a CO2 water heater at various gas-cooler designs and operating conditions.

description: This work presents a numerical model of a CO2 water heater. By using the numerical model, the design of a water -CO2 double tube gas-cooler and operating conditions by evaporation pressure were suggested. The double tube gas-cooler in the numerical model was developed using a finite volume method and the compressor efficiency and discharge temperature were calculated by an artificial neural network based on the experimental data. The numerical model was validated by experimental data and the maximum difference of the water temperature at the gas-cooler outlet was 2.62°C. To apply various gas-cooler designs to the numerical model, three gas-coolers having different inner-tube numbers (2, 4, 8) were used in the experiments. For the comparison of the performance according to the inner-tube number, a dimensionless quantity ‘GCAR’ was suggested and was defined as the ratio between the inner-tube cross-sectional area and the outer tube cross-sectional area of the gas-cooler. With the decrease of GCAR at same heat transfer area water-CO2, the heating capacity and gas-cooler thermal effectiveness increased by approximately 5% and 9%, respectively. The optimized pressure ratio of the CO2 water heater cycle to obtain the maximum heating capacity was shown at 2.65.
DOI: 10.18462/iir.tptpr.2017.0120
title: Supercritical heat transfer characteristics in vertically upward flow.

description: The characteristics of supercritical heat transfer of refrigerant R245fa in heating condition were investigated experimentally in a vertical bare tube with a diameter of 4 mm and a length of 840 mm at an constant pressure of 4 MPa, the local heat transfer coefficient for heat flux ranging from 20 to 100 kW/m2 and mass flux stabilizing at 400 kg/m2s. By changing the inlet temperature of test section, the refrigerant state changed to across pseudo-critical point. The experiment data were also compared with existing empirical correlations.
DOI: 10.18462/iir.tptpr.2017.0009
title: Extention of the predictive E-PPR78 equation of state to freon-containing systems.

description: Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) have a high ozone depletion potential (ODP) and hydrofluorocarbons (HFCs) are high global warming potential (GWP) refrigerants. Consequently, refrigeration and air conditioning industries carry out extensive researches to find highly efficient alternative refrigerants with zero ODP and GWP lower than 150. The search for next-generation refrigerants requires the preselection of good candidate likely to exhibit low environmental impact and leading to high thermodynamic cycle efficiency. To do so, disposing of powerful predictive thermodynamic models is a necessary prerequisite. In this work, the well-established E-PPR78 predictive equation of state was extended to systems containing freons. Therefore, 6 different groups were added to the 21 already-existing groups: group 22: CF3-CF3 (R116), group 23: -CF3, group 24: -CF2, group 25: =CF2 / =CF-, group 26: CHF2-CH3 (R152a), group 27: CF3-CH2F (R134a). All the experimental data available in the open literature were then selected to estimate the various group interaction parameters between the 6 new groups and the 21 previously defined.
DOI: 10.18462/iir.tptpr.2017.0020
title: Performance of an adsorption bed using fam-Z01.

description: This study investigates the characteristics of ferroaluminophosphate (FAM-Z01) compared to silica gel in the performance of an adsorption bed. FAM-Z01 has high potential to replace silica gel due to some key advantages, including a low heating temperature and high adsorption rate resulting from its S-shaped isotherm. The performance of the FAM-Z01/water system is expected to be enhanced due to the increased adsorption capacity due to the nature of S-shaped isotherm. However, the result shows that the COP and SCP of the FAM-Z01/water systems turn out to be 14.4 % lower and 3.87 % higher than the Type-RD silica gel, respectively.
DOI: 10.18462/iir.tptpr.2017.0021
title: The existence of non-equilibrium two-phase flow of R600a at subcooled temperature in a vapor compression refrigeration system.

description: Most of vapor compression refrigeration systems are designed such that the refrigerant is a subcooled liquid state at the condenser outlet. In this study, experiments were conducted to investigate the refrigerant state between at the condenser outlet and capillary tube inlet. The experimental apparatus equipped with thermocouples, pressure measurements, and visualization device was installed and operated with R600a as a refrigerant. The visual observation shows that the refrigerant flows in a two-phase state at the condenser outlet although the temperature of the refrigerant is much lower than the saturation temperature corresponding to its pressure. A method to calculate the specific enthalpy of the two-phase mixture at subcooled temperature was proposed. Experiments were conducted to verify the proposed method in various test conditions. The calculated enthalpy using proposed method in this study well agreed with the measured values.
DOI: 10.18462/iir.tptpr.2017.0048
title: Enhanced condensation via surface modification: flow visualization.

description: The effectiveness of condensation heat transfer to a surface is affected by the type of condensation that occurs. Condensation heat transfer is shown to improve in dropwise condensation (DWC) compared to filmwise condensation (FWC). This is mainly because condensate more readily departs the condensing surface as droplets in DWC than as a film in FWC, making room for further condensation. Steam-based DWC can also be promoted by making the surface more hydrophobic or other surface modifications.  

Two external condensation experiments have been developed to explore heat transfer and visualize condensation on hydrophobic surfaces. One is a tube condensing heat exchanger (TC-HEX) with carefully monitored coolant conditions inside the tube sample and ambient conditions in the surrounding chamber. The second is a plate condensing heat exchanger (PC-HEX) with a large viewport to the condensing surface of the plate sample. 

The TC-HEX is used to obtain the condensation heat transfer coefficient enhancement for a treated tube compared to an untreated tube. A high-speed camera is used in the PC-HEX to visualize the condensation phenomenon on the surface of a plate sample. Image analysis of the high-speed footage allows for further characterization of hydrophobic treated surfaces, including droplet radii, droplet population densities, and condensate sweep rate, all of which are relevant in heat flux models of dropwise condensation.
DOI: 10.18462/iir.tptpr.2017.0049
title: Diffuser shaped fuel channel design study in solid oxide fuel cell stacks.

description: Solid oxide fuel cell (SOFC) stacks were operating with metallic interconnects that separate each cells. Metallic interconnects play an important role in gas flow system and heat transfer mechanism, because its geometry makes gas flow channel and it has a high thermal conductivity. Many researcher design the flow channel for optimizing the cell performance like a ratio of height and width, channel to channel distance, or new type channels. For high conversion efficiency, most solid oxide fuel cell in power generation application operate at high fuel utilization and low current condition. However, high fuel utilization condition makes a large gradient of chemical potential by fuel depletion and it induces a low cell performance and a large chemical stress in flow direction. This phenomena can be observed at high performance cell or high operating temperature condition, because almost fuel is consumed at upstream of fuel channel by high electrochemical reaction kinetics and most cell area has a low chemical potential environment. Therefore, even distribution of electrochemical reaction rate is important. In this study we reduce the gradient of chemical potential by using diffuser-shape fuel channel, and optimize the diffuser-shape by design study. In chemical species conservation law, higher flow velocity at upstream makes higher convective flux in flow direction compared to diffusive flux in cell-thickness direction, and it can reduce the electrochemical reaction rate at reacting electrode. Optimized diffuser-shape fuel flow channel from this study may enhance the performance and the durability of solid oxide fuel cell stacks.
DOI: 10.18462/iir.tptpr.2017.0052
title: Boiling heat transfer of a R32/R1234ze(E) mixture inside a microchannel.

description: The search for alternatives to high GWP refrigerants primarily focuses on the use of natural fluids (hydrocarbons, ammonia, carbon dioxide) and new synthetic refrigerants having low GWP. Unfortunately, single-component low-GWP refrigerants so far cannot cover all the applications unless some drawbacks, such as flammability, are accepted. A solution may be found using blends of refrigerants, to satisfy the demand for a wide range of working conditions. In this paper, the boiling heat transfer performance of a non-azeotropic mixture of R1234ze(E) and R32 (0.26/0.74 by mass) is investigated. This blend exploits the good characteristics of R32 reducing at the same time its GWP value. Local flow boiling heat transfer coefficients have been measured in 1 mm internal diameter microchannel. The heat transfer coefficients of the present mixture are compared against predicting models available in the literature. The new experimental data are also compared to the boiling heat transfer of the pure components R1234ze(E) and R32, to analyze the heat transfer penalization due to the mass transfer resistance.
DOI: 10.18462/iir.tptpr.2017.0079
title: Evaporation heat transfer and pressure drop of R32 in a horizontal multiport tube with microfins.

description: This study investigated the evaporation heat transfer and pressure drop characteristics of refrigerant R32 in a horizontal multiport tube consisting of rectangular minichannels with straight microfins. The heat transfer coefficient and pressure drop were measured for a range of mass velocities from 100–400 kg*m-2*s-1 and range of heat fluxes from 5–20 kW*m-2 at a saturation temperature of 15°C. The frictional pressure drop during adiabatic two-phase flow was also measured for a range of qualities from 0.1–0.9 at the same saturation temperature. The heat transfer coefficient increased with increasing mass velocity in the high quality region. The effects of heat flux on the heat transfer coefficient were small except in the high quality region. The heat transfer coefficient values for the multiport tube with straight microfins were higher than the values for the multiport tube without microfins at lower mass velocity. The effects of mass velocity and microfins on the frictional pressure drop were clarified.