cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.18462/iir.gl.2018.1264
title: Water to water heat pump minimum charge of propane.

description: This paper describes the technology for an environmentally friendly ground source heat pump for a single family home, characterized by using pure water as coolant and propane as refrigerant. The objective was to build a test system, operating under realistic conditions, using less than 150 g of propane, providing at least 5 kW heating capacity with reasonable efficiency and without freezing the coolant water. The borehole heat exchanger was of coaxial type, providing about half the thermal resistance compared to a standard U-tube collector (Acuña 2010). The evaporator and condenser where asymmetrical plate heat exchangers with small channel height (&lt; 1 mm) on the refrigerant side. They were developed and manufactured exclusively for this project with a new type of press pattern, including a special, small volume sub-cooling section at the end of the condenser. A DC-motor scroll compressor for AC in electric vehicles was used, characterized by small internal volumes, small oil charge and wide capacity range (800-9000 rpm). A PAG-type oil was used, which however seemed to cause some problems with heat transfer and pressure drop in the evaporator. The system also included a specially built mini channel liquid/suction line heat exchanger and a standard thermostatic expansion valve. The paper presents test results for a heating capacity range of 2-10 kW. The performance was reasonable in this range with a charge of 100 g of propane (-1
DOI: 10.18462/iir.gl.2018.1267
title: Performance investigation on NH3/ionic liquid absorption cycles for geothermal energy utilization.

description: Geothermal heat is a promising renewable energy resource and is becoming increasingly attractive to mitigate the global energy and environment crisis. In this study, we introduced various geothermal heat pump systems and focused on the absorption-compression heat pump (ACHP) using novel NH3/IL working pairs for cascade utilization of geothermal energy. The thermodynamic model of the ACHP cycle and the property model of four NH3/IL working pairs were established. Parameter studies showed that there was an optimal pressure ratio to achieve the highest coefficient of performance (COP). The optimal pressure ratio increased and the highest COP decreased as the allowed high-side pressure decreased. In addition, a higher pressure ratio was needed to produce a larger temperature lift. a higher absorber temperature led to a lower COP; a higher generation temperature was beneficial to a higher absorber temperature. [OMIM][BF4] (1-octyl-3-methylimidazolium tetrafluoroborate) was the best IL among the four studied ILs, yielding the highest heating COP with the lowest pressure ratio.
DOI: 10.18462/iir.gl.2018.1336
title: The commercial refrigeration sector in Mauritius: CO2 as a possible alternative solution for small tropical developing states.

description: The phase out of HCFCs in countries bound by Article 5 of the Montreal Protocol has resulted in a drastic increase in the use of high GWP HFCs in the commercial refrigeration sector. Indirect emissions which occur through high energy consumptions are important in Small Island Developing States (SIDs) like Mauritius, which rely heavily on imported fossil fuels for their electricity generation. The impact and implications of HCFC-22 phase out on the energy efficiency of refrigeration systems for Article 5 countries have to be looked into if the issue of global warming and ozone depletion is to be addressed. In this article, the energy efficiency of the commercial refrigeration sector in Mauritius is analysed with special focus on the implications of the potential use of CO2 as refrigerant. CO2 has emerged as a promising refrigerant for supermarket refrigeration systems in Europe. The shift for such alternative technologies in the commercial refrigeration sector represents a tremendous leap for SIDs. However, alternative technologies will not be an attractive option unless their energy consumption is at least equivalent to current HFC DX systems. Based on analyses carried out, the paper discusses the implications of a shift towards CO2 as a refrigerant.
DOI: 10.18462/iir.gl.2018.1368
title: Analysis of heat pump market in Russia. Prospects of application of combined system for small buildings.

description: Paper published in poster form during the conference. Heat pump (HP) market in Russia is still in its infancy, in contrast to those of European countries, where a renewable energy becomes one of the main sources of a human life on a daily use basis. According to the European Association for HP (EHPA), in 2015, Europe has sold over 880 thousand HPs. Meanwhile, new natural refrigerants open an avenue for the use HPs even at low temperatures in winter. As a result, nowadays there is a growing interest to modern HP systems in Russia, where these systems might create a serious competition to traditional heating systems such as gas and/or petroleum. Combining HP with other equipment, operating with alternative energy sources (solar energy), and one could reduce a consumption power of HP, thereby reducing an investment cost. In fact, the use of solar thermal collectors with photovoltaic systems (PV) would significantly reduce the cost of grid electricity, providing as well the electricity for HP operation.
DOI: 10.20393/3930b6b9-c4c5-4a8e-b066-0acf31b7b76b
title: Surface water temperatures of Lough Furnace, Co. Mayo

description: The water temperature is measured at a depth of 1 metre, using a StowAway TidbiT temperature data logger from Onset (TBI32-05+37) (https://www.onsetcomp.com/products/data-loggers/tbi32-0537 ).  The logger is permanently moored over the deepest point of the lake, and records every 30 minutes. Lough Furnace is a coastal lagoon, protected under the EU Habitats Directive as an Annex I priority habitat (“in danger of disappearance”). This dataset comprises data that have been downloaded, checked and quality controlled. For more recent data, check www.marine.ie.
DOI: 10.5281/zenodo.1442616
title: Dazaga In Berlin-Brandenburg

description: Im Rahmen des sprachwissenschaftlichen Seminars "Urbane Feldforschung", das im Sommersemester 2018 an der Humboldt-Universität zu Berlin unter der Leitung von Dr. Frank Seifart stattgefunden hat, entstanden die folgenden Aufnahmen als auch der dazugehörige schriftliche Aufsatz über Dazaga, eine Sprache aus der zentralen Sahara.

Zum einen wurde eine gesamte Swadesh-Liste mit 100 Wörtern auf Dazaga aufgenommen. Zum anderen wurde eine Elizitation über das Phänomen der gespaltenen Intransitivität (split intransitivity) im Dazaga durchgeführt und nochmal aufgenommen. Außer der Tonmaterialien gibt es anbei für die jeweilige Datei eine auf Dazaga transkribierte sowie annotierte Bearbeitung.

Das ganze Projekt entand unter Mithilfe von meinem Studieteilnehmer und Dazaga-Muttersprachler Herrn Youssouf Mahamat Kerim.
DOI: 10.5281/zenodo.1442617
title: Dazaga In Berlin-Brandenburg

description: Im Rahmen des sprachwissenschaftlichen Seminars "Urbane Feldforschung", das im Sommersemester 2018 an der Humboldt-Universität zu Berlin unter der Leitung von Dr. Frank Seifart stattgefunden hat, entstanden die folgenden Aufnahmen als auch der dazugehörige schriftliche Aufsatz über Dazaga, eine Sprache aus der zentralen Sahara.

Zum einen wurde eine gesamte Swadesh-Liste mit 100 Wörtern auf Dazaga aufgenommen. Zum anderen wurde eine Elizitation über das Phänomen der gespaltenen Intransitivität (split intransitivity) im Dazaga durchgeführt und nochmal aufgenommen. Außer der Tonmaterialien gibt es anbei für die jeweilige Datei eine auf Dazaga transkribierte sowie annotierte Bearbeitung.

Das ganze Projekt entand unter Mithilfe von meinem Studieteilnehmer und Dazaga-Muttersprachler Herrn Youssouf Mahamat Kerim.
DOI: 10.17632/r7fhgwmyrv.1
title: Data for: Evaluating Different i*-based Approaches for Selecting Functional Requirements while Balancing and Optimizing Non-Functional Requirements: A Controlled Experiment

description: Controlled experiment, i*, requirements engineering, Pareto efficiency
DOI: 10.18462/iir.gl.2018.1107
title: Optimum high pressure for transcritical CO2 heat pumps considering isentropic efficiency and gliding heat extraction.

description: Paper published in poster form during the conference. The coefficient of performance COP of a transcritical CO2 heat pump system is greatly affected by the compressor discharge pressure. An internal heat exchanger is also important to improve the system performance. Simulations of the ideal transcritical heat pump cycles show maxima in the COP at optimal high pressures depending on evaporation temperature and gas cooler outlet temperature. The real compressor behavior has been incorporated by the isentropic efficiency as a function of the pressure ratio. Then slightly lower optimal high pressures and lower COP are obtained. The correlations for the optimal high pressure are given for the ideal and real heat pump. The low temperature waste heat of a large computing center is considered as heat source of a high capacity CO2 heat pump system. A gliding heat extraction has been chosen using the pinch point method to design the heat exchangers for a district heating system. Different modes of operation (room heating, domestic water heating, absorption cooling) are discussed.
DOI: 10.18462/iir.gl.2018.1142
title: Experimental evaluation of flame-free refrigerant fittings according test criteria specific to R744.

description: The successful use of CO2 as a refrigerant on a large scale and its introduction to new applications requires the development of system components, including reliable, low-cost refrigeration fittings. Press fittings are an attractive option, because this connection type does not require an open flame, is easy to establish, and is suitable for field maintenance. However, the use of R744 exposes this fitting type to challenges that are characteristic to CO2 only. This paper reports the research conducted to explore the suitability of this new fitting type for use with CO2, including new test methods to study explosive decompression characteristics of its O-ring materials and the ability of the fittings’ stainless steel body to withstand exposure to carbonic and activated acids. The results show that the sealing ability of the tested fittings is not compromised by explosive decompression or exposure to carbonic and activated acids.
DOI: 10.18462/iir.gl.2018.1248
title: Influence of compressor control strategy on energy efficiency and product temperature for professional counter cabinets.

description: EU regulations 2015/1095 and 2015/1094 of 5 May 2015 have been implemented for professional refrigerated counters along with the test standard EN 16825. These regulations rates most current counters as class C or D and consequently there is an ongoing development to construct top level counters (A or above). Apart from improving the cabinet construction and improving the condenser and evaporator design, advanced compressor control strategies could be part of the solution. This could be either variable speed drive (VSD) or adaptive energy optimization (AEO). Both control strategies may improve the energy efficiency but may also affect the temperature fluctuations of the stored goods. The influence of VSD and AEO was investigated using a validated dynamic model of a professional refrigerated counter using R290 and R600a. The influence was investigated according to the EN 16825 test conditions. Both VSD and AEO yield significant energy savings compared to ON-OFF control. A more constant product temperature was achieved by VSD control, while the product temperature fluctuates slightly more when applying AEO control.
DOI: 10.18462/iir.gl.2018.1269
title: Comparison of the compressor losses of a scroll and a reciprocating compressor working with propane.

description: This paper presents a comparison of the compressor losses of a scroll compressor and a reciprocating compressor working with propane. In order to estimate the scroll compressor losses, a semi-empirical model was implemented. The model considers the main sources of losses in the compression process and can predict the compressor and volumetric efficiencies in terms of ten empirical parameters, which have a direct physical interpretation. The model validation was performed using experimental data of a scroll compressor working with propane. The scroll compressor was tested in a calorimetric test bench in a wide range of operating conditions. Results show a correct agreement between the modeled and experimental compressor efficiencies. In addition, the mass flow rate, the compressor power input, and the discharge temperature are accurately estimated. Finally, the relative influence of the losses (mechanical, electrical, leaks, pressure drop, and heat transfer) on the compressor efficiencies is estimated in terms of the pressure ratio for the two compressors and a comparison between them is presented.
DOI: 10.18462/iir.gl.2018.1286
title: Comparison of Rankine cycle and trilateral flash cycle for power production from low temperature heat sources.

description: The performance of the Rankine Cycle (RC) and the Trilateral Flash Cycle (TFC) were compared for power production from sensible low temperature heat sources. Air was chosen as heat source fluid with a mass flow of 10 kg/s and temperatures of 100, 150, and 200°C. Water was chosen as heat sink with a temperature of 20°C. Butane, isopentane, and propane were chosen as natural working fluids and were compared to three commonly used HFO/HFCs as benchmark. The power cycles were optimized for maximum net power for a limited total heat exchanger area, and with a variable efficiency for the TFC's two-phase expander. The TFC reached higher maximum power outputs than the RC for the 100°C case. However, the required heat exchanger area and expander outlet volume flow rate were significantly higher for the TFC, indicating a larger and more expensive system. The differences in system size and performance decreased for the higher heat source inlet temperatures. The natural working fluids showed similar performance compared to the benchmark refrigerants.
DOI: 10.18462/iir.gl.2018.1301
title: Design and validation of a transcritical CO2 mobile refrigerated container system for military applications.

description: This paper describes the design and analysis of a transcritical CO2 (R744), multi-temperature, mobile refrigerated container system. The use of CO2 as a refrigerant has been widely applied to supermarket refrigeration systems in recent years and shown to be promising for other applications as well. However, the extreme operating conditions of this application (up to 57°C ambient temperature and frozen temperature of -20°C) make using CO2 as a refrigerant a unique challenge here. In order to achieve reasonable efficiency at the extreme conditions of this application, several improvements have been implemented: Multi-stage compression with intercooling, improved gas cooler performance with a microchannel heat exchanger, internal heat exchange, and expansion work recovery with an ejector. The results presented in this paper show that the very high ambient temperature of this system allows for very significant COP improvement using each of the above improvements methods (over 50 % combined improvement).
DOI: 10.18462/iir.gl.2018.1334
title: Thermodynamic assessment of nanofluids as secondary coolants in refrigeration applications: design guidelines for nanofluids developers.

description: In a previous work, the suitability of nanofluids as secondary coolants in refrigeration systems was assessed aiming at the external irreversibilities of the heat exchangers of the refrigeration cycle. The results suggested that, in the case where the heat exchangers are optimized to minimize the rate of entropy generation, water-based nanofluids do not perform as well as pure water. Nanofluids enthusiasts, however, might advocate that nanosuspensions would allow the refrigerator to operate with lower condensing and higher evaporating temperatures, thus increasing the system COP. The present paper is therefore aimed at assessing both the internal and external irreversibilities of the refrigeration cycle when nanofluids are used as secondary coolants. The analyses pointed out that although most of the nanofluid research and development has been focused on the transport properties (viscosity, conductivity), the thermodynamic properties related with the thermal capacity (specific heat, density) showed to be the most influential factors on the total system COP. In the case of most water-based nanofluids, the nanoparticles have twice the density but only a quarter of the specific heat of the base fluid, reason why it is unlikely that such nanosuspensions will perform better than pure water.
DOI: 10.18462/iir.gl.2018.1398
title: Energy recovering using greywater as cold body in a CO2 heat pump water heater.

description: Paper published in poster form during the conference. The use of heat pumps for the production of domestic water is a fact nowadays. Our research group is involved in a project for the characterization of different configurations of CO2 heat pumps for the production of hot water by recovering the energy contained in the greywater, used this as secondary fluid in the evaporator. This will be done numerically by means of a dynamic study of the different options. As a first step, we have constructed an installation to experimentally analyses these systems and to validate the models we aim to use in the process. So, in this paper, a description of the experimental facility developed is presented. This allows testing four different configurations for the refrigeration circuit which let us to compare their energy efficiency, control capabilities and initial cost and determine what the best solution is. The system is modeled dynamically by using TRNSYS® 17. The data reduction process followed to determine the main operating parameters of the system, as well as a brief description of the uncertainty analysis is presented. The paper finishes presenting a comparison between some preliminary experimental results and the results obtained by using the numerical model developed in TRNSYS® 17.
DOI: 10.18462/iir.gl.2018.1405
title: Evaluation of different evaporator designs and concepts for sorption processes using water as refrigerant.

description: Evaporation characteristics of water at low temperatures and pressures (5-30 °C, 870 – 4200 Pa) are of great interest for sorption processes. The work presents the experimental characterization of the evaporation performance measured on different market available and newly developed heat exchanger designs. Designs, experimental data, and performance evaluation criteria are described. As a central evaluation values the heat transfer coefficient and the volumetric UA-value are discussed for the different scales of samples. The focus is led on an alternating operation mode, where the same heat exchanger is used as condenser first and then changed to evaporation. Additionally the influence of a flooded operation is analyzed. The results illustrate that different designs and operation modes result into different time dependent performances. High UA-values are reached with the open, unflooded operation mode. Nevertheless the mass of refrigerant kept in the heat exchanger can be increased strongly by flooded operation.
DOI: 10.18462/iir.gl.2018.1239
title: Optimizing lubricants for hydrocarbon refrigerant applications.

description: Hydrocarbon refrigerants, though not new to the industry of cooling and refrigeration, are finding increased value due to environmental and performance benefits as a refrigerant. From small domestic appliances to large industrial systems and applications in between, refrigerants like R-600a, R-290, R-1270 and others are increasing in use. Like any refrigerant used in a system there will be an interaction with the lubricant that is designed to work within the system. Compressor/System performance and reliability are tied to this lubricant-refrigerant interaction which needs to be optimized. Lubricant optimization with various hydrocarbon refrigerants and compressor/system designs can benefit in energy efficiency gains, charge optimization and compressor bearing durability. This paper will investigate various hydrocarbon refrigerant applications detailing specific needs and challenges that exist when developing a lubricant formulation based on refrigerant lubricant chemistry and additive response, focusing on lubricants that provide overall performance benefits.
DOI: 10.18462/iir.gl.2018.1290
title: Comparison of a CO2 refrigeration and heat pump test system with and without ejector.

description: This experimental study investigates the performance and some questions related to controllability of a smallscale CO2 ejector test system. The test system is operated in both refrigeration and heat pump operation with and without the ejector. Different inlet temperatures on the secondary side of the gas cooler are investigated for both operations as well as a variation of compressor speed. Additionally, the possibility to flood the evaporator in ejector mode is studied including the use of a prototype “quality sensorTM” (capacitive void fraction sensor). The results showed that the ejector performed well in refrigeration operation, considering the pressure drop caused by the undersized piping from the diffuser to the suction of the compressor. The COP improved by around 0.2 (12 % to 17 %) and if the superheat (10 K) was eliminated by flooding the evaporator, a further 0.3 improvement was possible (33 % compared with standard cycle mode). In heat pump operation, the COP became similar or lower because the ejector was slightly oversized for that operation (gas cooler pressure became lower than optimal). The quality sensor showed a significant change in the electrical capacitance as the evaporator was increasingly flooded. Furthermore, the measured capacitances were converted into reasonable void fractions by using both a linear calibration function and an annular flow void fraction calibration function from the literature. The gas cooler pressure was possible to control with the speed of the compressor within a range of around 10 bar in refrigeration mode, but had insignificant effect on the gas cooler pressure in heat pump mode.
DOI: 10.17632/nnfmh6fdhc.1
title: Data for: Automatic endmember bundle unmixing methodology for lunar regional area mineral mapping with ChangE-1 data

description: The dataset is collected by ChangE-1, which can be downloaded from Ground application system (http://moon.bao.ac.cn/) for lunar exploration project. The data ID of the research area is CE1_BMYK_IIM_SCI_N_20081204081022_20081204101804_4458, and the image concludes 2843 rows with 128 lines. The dataset includes 32 bands from 0.48 μm to 0.96 μm, the spectral resolution is 15nm.
DOI: 10.17632/y4z7t5p54k.1
title: Data for: Automatic endmember bundle unmixing methodology for lunar regional area mineral mapping with ChangE-1 data

description: The dataset is 2 Level collected by Chandrayaan-1 includes 85 contiguous bands from 460 nm to 2970 nm with 140-280 m spatial resolution for global observations. The data ID of the research area is M3G20090118T022705-V01-RFL, which can be downloaded from (http://pds-imaging.jpl.nasa.gov/data/m3).
DOI: 10.5281/zenodo.1442825
title: A Compendium Of Extinction Curves For Simple Galactic Geometries

description: This is a tabulation of dust extinction curves for simple galactic geometries computed using the Hyperion radiative transfer package. Full details of the calculations and the file structure can be found here.
DOI: 10.5281/zenodo.1442826
title: A Compendium Of Extinction Curves For Simple Galactic Geometries

description: This is a tabulation of dust extinction curves for simple galactic geometries computed using the Hyperion radiative transfer package. Full details of the calculations and the file structure can be found here.
DOI: 10.18112/openneuro.ds001514.v1.2.0
title: Addimex CONN