A Study on the Demonstration Experiment of the Solar Hot Water Heater for Dwellings

2005 ◽  
Vol 297-300 ◽  
pp. 2320-2326
Author(s):  
Dong Jo Yang ◽  
Jae Yeol Kim ◽  
Jae Ho Han
Keyword(s):  
Hot Water ◽  
Monitoring Systems ◽  
Short Term ◽  
Water Heater ◽  
Long Period ◽  
Water Heaters ◽  
Extensive Analysis ◽  
Demonstration Experiment ◽  
Routine Procedures

The main purpose of this investigation was to evaluate the performance of the solar hot water heater for dwellings in a long period of time. In order to evaluate the performance, there were 11 solar hot water heaters located in Gwangju Chosun University examined for their performance in 30 month period as a long term. The specific monitoring systems of each heater were constructed for the demonstrational research and the data base associated to each monitoring systems were assembled for an extensive analysis for variety of data obtained. The demonstrational experiments were conducted through following the routine procedures of 4 specific tests (the replicated drainage test, the daily drain test, the daily agitation test, the short-term test). The performance evaluation was based on the performances in insulating and solar collecting and the experimental routines and the performance experiments had incorporated the consumers’ use and need of the product. The ultimate goals of this investigation were to achieve consumers’ trust on the products and to promote the extensive distributions of the solar hot water heaters. The demonstrational research of this investigation was to evaluate the performance of the solar hot water heater for the residents for a long period of time. This research will be continued extensively.

scholarly journals Assessment and Modeling of Household-Scale Solar Water Heater Application in Zambia: Technical, Environmental, and Energy Analysis

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Mehdi Jahangiri ◽  
Esther T. Akinlabi ◽  
Sam M. Sichilalu
Keyword(s):  
Fossil Fuels ◽  
Hot Water ◽  
Climate Data ◽  
Ghg Emission ◽  
Water Heater ◽  
Ghg Mitigation ◽  
Solar Water ◽  
Water Heaters ◽  
Industrial Sectors ◽  
Solar Water Heaters

Solar water heaters (SWHs) are one of the most effective plans for general and easy use of solar energy to supply hot water in domestic and industrial sectors. This paper gives the first-ever attempts to assess the optimal localization of SWHs across 22 major cities in Zambia, as well as determine the possibility of hot water generation and model the greenhouse gas (GHG) emission saving. The climate data used is extracted by using the MeteoSyn software which is modeled in TSOL™. Results show the high potential of GHG emission reduction due to nonconsumption of fossil fuels owing to the deployment of SWHs, and three cities Kabwe, Chipata, and Mbala had the highest GHG mitigation by 1552.97 kg/y, 1394.8 kg/y, and 1321.39 kg/y, respectively. On average, SWHs provide 62.47% of space heating and 96.05% of the sanitary hot water requirement of consumers. The findings have shown the potential for the deployment of SWHs in Zambia. The techno-enviro study in this paper can be used by the policymakers of Zambia and countries with similar climates.

scholarly journals Comparison of Transcritical CO2 and Conventional Refrigerant Heat Pump Water Heaters for Domestic Applications

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 479
Author(s):  
Ignacio Paniagua ◽  
Ángel Álvaro ◽  
Javier Martín ◽  
Celina Fernández ◽  
Rafael Carlier
Keyword(s):  
Heat Pump ◽  
Thermodynamic Cycle ◽  
Heat Pumps ◽  
Design Tool ◽  
Operating Conditions ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Ambient Conditions ◽  
Water Heater ◽  
Water Heaters

Although CO 2 as refrigerant is well known for having the lowest global warming potential (GWP), and commercial domestic heat pump water heater systems exist, its long expected wide spread use has not fully unfolded. Indeed, CO 2 poses some technological difficulties with respect to conventional refrigerants, but currently, these difficulties have been largely overcome. Numerous studies show that CO 2 heat pump water heaters can improve the coefficient of performance (COP) of conventional ones in the given conditions. In this study, the performances of transcritical CO 2 and R410A heat pump water heaters were compared for an integrated nearly zero-energy building (NZEB) application. The thermodynamic cycle of two commercial systems were modelled integrating experimental data, and these models were then used to analyse both heat pumps receiving and producing hot water at equal temperatures, operating at the same ambient temperature. Within the range of operation of the system, it is unclear which would achieve the better COP, as it depends critically on the conditions of operation, which in turn depend on the ambient conditions and especially on the actual use of the water. Technology changes on each side of the line of equal performance conditions of operation (EPOC), a useful design tool developed in the study. The transcritical CO 2 is more sensitive to operating conditions, and thus offers greater flexibility to the designer, as it allows improving performance by optimising the global system design.

scholarly journals Learning from past mistakes: improving automatic speech recognition output via noisy-clean phrase context modeling

2019 ◽  
Vol 8 ◽  
Author(s):  
Prashanth Gurunath Shivakumar ◽  
Haoqi Li ◽  
Kevin Knight ◽  
Panayiotis Georgiou
Keyword(s):  
Neural Network ◽  
Speech Recognition ◽  
Automatic Speech Recognition ◽  
Language Model ◽  
Context Modeling ◽  
Short Term ◽  
Extensive Analysis ◽  
Network Language ◽  
Correction System

AbstractAutomatic speech recognition (ASR) systems often make unrecoverable errors due to subsystem pruning (acoustic, language and pronunciation models); for example, pruning words due to acoustics using short-term context, prior to rescoring with long-term context based on linguistics. In this work, we model ASR as a phrase-based noisy transformation channel and propose an error correction system that can learn from the aggregate errors of all the independent modules constituting the ASR and attempt to invert those. The proposed system can exploit long-term context using a neural network language model and can better choose between existing ASR output possibilities as well as re-introduce previously pruned or unseen (Out-Of-Vocabulary) phrases. It provides corrections under poorly performing ASR conditions without degrading any accurate transcriptions; such corrections are greater on top of out-of-domain and mismatched data ASR. Our system consistently provides improvements over the baseline ASR, even when baseline is further optimized through Recurrent Neural Network (RNN) language model rescoring. This demonstrates that any ASR improvements can be exploited independently and that our proposed system can potentially still provide benefits on highly optimized ASR. Finally, we present an extensive analysis of the type of errors corrected by our system.

scholarly journals The use of borehole inclinometry in determining basal sliding and internal deformation at Haut Glacier d’Arolla, Switzerland

1997 ◽  
Vol 24 ◽  
pp. 331-337 ◽  
Author(s):  
Luke Copland ◽  
Jon Harbor ◽  
Marie Minner ◽  
Martin Sharp
Keyword(s):  
Hot Water ◽  
Short Term ◽  
Digital Inclinometer ◽  
Basal Sliding ◽  
Internal Deformation ◽  
One Year ◽  
Annual Scale ◽  
Insight Into ◽  
Displacement Measurements

A series of boreholes were drilled with high-pressure hot water across a section of Haut Glacier d’Arolla, Switzerland, in summer 1995. Twenty-three of the boreholes were profiled with a digital inclinometer soon aller drilling, and 14 were re-profiled up to 6 weeks later to determine changes in the longitudinal shape of boreholes with time. In addition to the main surveys, three boreholes were surveyed 14 times each to assess the accuracy and reproducibility of inclinometry measurements. These repeat surveys suggest that caution is needed in the interpretation of short-term borehole displacement measurements, and that the reoccupation of boreholes from one year to the next may be a better way to determine patterns of internal deformation and basal sliding. The annual scale may also have advantages in providing more long-term insight into glaciological processes than short term (single season) measurements.

A New Performance Estimate Method for Design of Storage-Type Domestic Electrical Water-Heaters Based on the CFD Simulation

2010 ◽  
Vol 129-131 ◽  
pp. 463-466
Author(s):  
Li Li Zhao ◽  
Zhi Jun Zhang ◽  
Shi Wei Zhang
Keyword(s):  
Water Temperature ◽  
Cfd Simulation ◽  
Cold Water ◽  
Discharge Rate ◽  
Water Discharge ◽  
Hot Water ◽  
New Method ◽  
Dynamics Simulation ◽  
Water Heater ◽  
Water Heaters

The 3D physical model of the electrical water heater was built. The water-heater performance was resolved by computer fluid dynamics simulation (CFD). The heater performance is characterized by a new method rather than that the discharge efficiency, extraction efficiency and fraction of heat recoverable. The new method is based on the constant discharge water temperature and rate for end user, 5L/min and 43°C that include the hot water from EWH and cold water from outside EWH. But the water discharge rate from EWH was variable as the water temperature discharge from EWH was variable. Compared with the traditional method, it is more close to the user using reality condition.

Solar Water Heaters: A Review of Systems Research and Design Innovation

Green ◽  
2011 ◽  
Vol 1 (2) ◽  
Author(s):  
Brian Norton
Keyword(s):  
System Development ◽  
Unit Cost ◽  
Hot Water ◽  
Water Heating ◽  
Water Heater ◽  
Solar Water Heating ◽  
Solar Water ◽  
Water Heaters ◽  
Systems Research ◽  
And Performance

AbstractSolar water heating can be considered to be an established mature technology. The achievement of this status is the outcome of over a century of system development that culminated with a flourish of innovation in the last thirty years. Drivers for research and development have been achieving economic viability by devising systems that, for specific applications in particular climate contexts produced more hot water per unit cost. Reductions in both initial capital and installation costs have been achieved as well as in those associated with subsequent operation and maintenance. Research on solar water heating is discussed with the emphasis on overall systems though some key aspects of component development are also outlined. A comprehensive taxonomy is presented of the generic types of solar water heater that have emerged and their features, characteristics and performance are discussed.

Reliability and reproducibility of a clinical application of a simple technique for repeated circumferential leg measurements

2010 ◽  
Vol 26 (1) ◽  
pp. 14-19 ◽  
Author(s):  
A te Slaa ◽  
P Mulder ◽  
D Dolmans ◽  
P Castenmiller ◽  
G Ho ◽  
...  
Keyword(s):  
Simple Technique ◽  
Correlation Coefficients ◽  
Repeated Measurements ◽  
Medium Term ◽  
Short Term ◽  
Intra Class Correlation ◽  
Long Period ◽  
Simple Instrument ◽  
Reproducible Method

Objective The aim of this study is to determine the reliability and reproducibility of repeated tape measurements to assess the leg circumference during a long period. Methods A tape measure is a simple instrument that is applicable in the presence of oedema. Measurements were performed by four observers on 11 volunteers. Four measurements were done in the first week (short term), a fifth measurement at two weeks (medium term) and a sixth measurement was done at 12 weeks (long term). Results The short-, medium- and long-term intra-class correlation coefficients for repeated measurements were 0.90, 0.89 and 0.78, respectively. The short-term and long-term reproducibility indices equalled 4.4% and 6.5%. If only a single observer would be involved, the short-term intra-class correlation coefficients would improve to 0.94 (reproducibility index 3.3%). Conclusion Tape measurements have been proved to be a reliable and reproducible method to asses the lower limb circumference.

scholarly journals Techno-Economic Assessment of a Hybrid Gas Tank Hot Water Combined Heat and Power System

2021 ◽  
Vol 13 (23) ◽  
pp. 13040
Author(s):  
Brent B. Skabelund ◽  
Joseph Elio ◽  
Ryan J. Milcarek
Keyword(s):  
Economic Analysis ◽  
Economic Assessment ◽  
The United States ◽  
Combined Heat And Power ◽  
Gas Production ◽  
Hot Water ◽  
Operating Voltage ◽  
Water Heater ◽  
Water Heaters ◽  
Potential System

Combined heat and power (CHP) systems with an integrated solid oxide fuel cell (SOFC) is a promising technology to increase overall efficiency of traditional residential combustion systems. One potential system is gas tank hot water heaters where partial oxidation of the fuel serves as a means of fuel reforming for SOFCs while producing thermal energy for heating water. In this study, a residential hybrid gas tank hot water heater with an integrated SOFC model was developed and a thorough techno-economic analysis was performed. Fuel-rich combustion characterization was performed at equivalence ratios 1.1 to 1.6 to assess synthesis gas production for the SOFC. The effect of fuel utilization and operating voltage of the model SOFC stack were analyzed to provide an in-depth characterization of the potential of the system. CHP and electrical efficiencies over >90% and >16% were achieved, respectively. The techno-economic analysis considers the four major census regions of the United States to evaluate regional savings based on respective utility costs and hot water demand. The results show the hybrid system is economically feasible for replacement of an electrical water heater with the longest payback period being approximately six years.

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