Theoretical and experimental studies of stratified thermocline storage of hot water

1982 ◽  
Vol 22 (3) ◽  
pp. 275-285 ◽  
Author(s):  
M.A. Abdoly ◽  
D. Rapp
Keyword(s):  
Experimental Studies ◽  
Hot Water

scholarly journals Experimental studies of energy efficiency of heat pump equipment for hot water supply and air conditioning systems in apartment buildings

2021 ◽  
Vol 937 (4) ◽  
pp. 042037
Author(s):  
Gregory Vasilyev ◽  
Victor Gornov ◽  
Marina Kolesova ◽  
Vitaliy Leskov ◽  
Victoria Silaeva ◽  
...  
Keyword(s):  
Water Supply ◽  
Heat Pump ◽  
Air Conditioning ◽  
Energy Savings ◽  
Experimental Studies ◽  
Hot Water ◽  
Apartment Buildings ◽  
Pump Equipment ◽  
Hot Water Supply ◽  
Air Conditioning Systems

Abstract Experimental studies of this article are aimed at solving the problem of reforming the housing and communal services of Russia through rational integration of non-traditional energy sources and secondary energy resources into the energy balance of buildings and structures. An important component of the work was the creation and development of industrial production of reliable competitive heat pump systems of a new generation, cogenerating heat energy and cold in an autonomous mode and providing energy savings of at least 50% due to the combined use of low-potential thermal energy of the soil, the atmospheric air and the exhaust air of ventilation systems for hot water supply and air conditioning systems of apartment buildings.

scholarly journals Experimental Studies of the Heat Exchange Between the Water Film and the Casting Roller in the Thermal Preconditioning Chamber

2021 ◽  
pp. 42-46
Author(s):  
Alexander Pereselkov ◽  
Olga Kruglyakova
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Flow Rate ◽  
Large Diameter ◽  
Experimental Studies ◽  
Water Film ◽  
Scientific Paper ◽  
Operating Conditions ◽  
Hot Water ◽  
Thermal Preparation

When the casting roller is cooled or heated in the preconditioning chamber the water is supplied to its surface by flat-jet nozzles. The visual inspection of the model of the casting roller showed that a considerable part of it can be covered with the water film spreading from sprinkling zones. It was established that the heat conductivity in the roller body is considered to be a crucial thermal preparation factor in the conjugate heat-exchange problem for the roller of a large diameter at Bio criterion values exceeding 20. Hence, it is sufficient to provide an essential level of the heat transfer that corresponds to the heat transfer coefficient of 2000 W/(m2∙K) to provide appropriate operating conditions for the thermal preparation of the roller. The conditions are also met in sprinkling zones. Due to this fact this scientific paper studies the heat exchange conditions under the water film that spreads between the adjacent sprinkling zones. A range of changes in the flow rate of the spreading water film was determined experimentally. The conditions of heat exchange between the surface of alpha-calorimeter and the water film were analyzed depending on its flow rate and the heat meter surface temperature. A generalized correlation equation was derived. It was established that the heat exchange intensity in sprinkling zones and under the spreading water film meets technological roller treatment conditions in the preconditioning chambers. The obtained research data can be used for the rational arrangement of the collectors and flat-jet nozzles in casting roller preconditioning chambers to reduce the cold and hot water consumption and cut down operating costs.

scholarly journals Experimental studies on the hybrid system of heat and cold production from solar energy

2017 ◽  
Vol 21 (6 Part B) ◽  
pp. 2827-2835
Author(s):  
Stanislaw Gil ◽  
Boguslaw Gradon ◽  
Wojciech Bialik
Keyword(s):  
Solar Energy ◽  
Large Scale ◽  
Cooling System ◽  
Renewable Energy Sources ◽  
Experimental Studies ◽  
Hot Water ◽  
Temperate Climate ◽  
Water Tank ◽  
Energy Potential ◽  
The Impact

In recent years more and more energy is consumed in the European Union countries for summer air conditioning in buildings. This consumption will probably increase even more due to the predicted climate warming and the desire to improve the quality of life. At present final energy as heat and electricity is sourced mainly from fossil fuels. However, recently alternative renewable energy sources are increasingly taken into account as a result of efforts toward environmental protection and fuels savings. This paper presents results of the analysis of a hybrid solar-assisted heating and cooling system for buildings in the temperate climate of west and central Europe. Solar energy potential was estimated. The investigation was performed using a large scale laboratory installation, which contains an evacuated solar collector, a single-stage NH3-H2O absorption chiller and a hot water tank. The impact of the main system parameters on its performance was analyzed on the basis of energy balances.

scholarly journals Analysis of the possibility of applications for a two-phase reverse thermosyphon in passive heat transport systems

2018 ◽  
Vol 49 ◽  
pp. 00020 ◽  
Author(s):  
Michal Duda ◽  
Jurij Dobrianski ◽  
Daniel Chludzinski
Keyword(s):  
Heat Transfer ◽  
Heat Source ◽  
Heat Transport ◽  
Heat Load ◽  
Experimental Studies ◽  
Hot Water ◽  
Transport Systems ◽  
Working Fluid ◽  
Two Phase

Devices called reverse thermosyphon enable passive heat transfer when the heat source is above the place of its receipt. This is often the case in solar installations for the preparation of hot water. The article concerns the determination of the possibility of using a two-phase inverted thermosyphon with two working factors in a passive downwards heat transport installation. The analysis was carried out on the basis of previous experimental studies. The height of the tested installation in one case was 1.5 m, in the second 18 m, at a heat load of 300, 600 and 900 W. Water and pentane was used as a working fluid inside the loop. Initial conclusions from the analysis confirm the possibility of using reverse thermosyphon with two working factors in the construction of a passive heat transport system.

scholarly journals Heliosystem of Auxiliary Heat Supply for a Mining Enterprise

2020 ◽  
Vol 7 (1) ◽  
pp. G9-G14
Author(s):  
S. Shkrylova ◽  
V. Kostenko ◽  
I. Skrynetska
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Electric Power ◽  
Thermal Energy ◽  
Solar Collector ◽  
Alternative Energy ◽  
Experimental Studies ◽  
Hot Water ◽  
Ecological Crisis ◽  
Stable Operation

In the conditions of the global ecological crisis in the world and Ukraine, the issue of finding alternative energy sources becomes relevant. One of the most common types of renewable energy is solar energy. In Ukraine today, the most promising direction of using solar energy is its direct transformation into low-potential thermal energy. To get electric power, solar radiation is the mere alternative to electric power generated from mined fuel, and without the pollution of air and water, or adverse consequences manifested in global warming. The disadvantage of this type of installation is the limitation of the duration of light time, as well as the effect of cloudiness. During the day, the number of solar radiation changes, to stabilize it is necessary to accumulate and accumulate it for further use, the technical implementation of stable operation of solar installation due to the use of terrestrial radiation and the accumulator of a specific part of solar energy is proposed. The purpose of the work is experimental studies to ensure the stable operation of the solar collector under cloudy conditions. The paper is aimed at the stabilization of the operation of the solar installation and to obtain additional heat after the Sun’s cloud cover. The use of a solar thermal collector is advisable in solar heating and hot water systems in conditions of alternating solar radiation. The results of physical modeling have proved the efficiency of the method of combining types of thermal radiation, due to the accumulation of energy it is possible to increase the quantitative index of solar energy in the conditions of cloudiness by 3 times Keywords: alternative energy, solar energy, solar collector, thermal energy, clouds, terrestrial radiation, ecology.

scholarly journals Coverage of energy for the preparation of hot tap water by installing solar collectors in a singlefamily building

2018 ◽  
Vol 49 ◽  
pp. 00106
Author(s):  
Aleksander Starakiewicz
Keyword(s):  
Thermal Energy ◽  
Tap Water ◽  
Experimental Studies ◽  
Hot Water ◽  
Solar Collectors ◽  
Solar Panels ◽  
Final Energy ◽  
Outlet Valve ◽  
Higher Temperature ◽  
Measurement Period

The paper presents the results of experimental studies on the consumption of hot water, energy obtained from the solar installation in the production process and the degree of coverage of usable and final energy with solar collectors. Thermal energy measurements from solar collectors cover the measurement period from 2011 to 2017. During this period, the annual final energy obtained from solar collectors ranged from 1033-1576 kWh. Monthly and annual demand for usable and final energy for the demand for hot water is presented depending on the amount of hot water used. Monthly actual consumption of hot water in the measurement period ranged from 3.57-9.16 m3. During this period, the number of residents has changed from 3 to 5 people. Annual coverage of energy useful for heat and energy by solar panels in the years 2011-2017 fluctuated from 38.0%-63.9% and 25.2%-42.3% for final energy. Monthly energy coverage ranged from 5.5% to over 100%. Covering energy above 100% in practice means getting a higher temperature of hot water in the outlet valve than expected.

scholarly journals A Rapid Systematic Review and Meta-Analysis of the Efficacy of Slaughter and Processing Interventions To Control Nontyphoidal Salmonella in Beef and Pork

2016 ◽  
Vol 79 (12) ◽  
pp. 2196-2210 ◽  
Author(s):  
IAN YOUNG ◽  
BARBARA J. WILHELM ◽  
SARAH CAHILL ◽  
REI NAKAGAWA ◽  
PATRICIA DESMARCHELIER ◽  
...  
Keyword(s):  
Systematic Review ◽  
Data Extraction ◽  
Meta Analysis ◽  
Experimental Studies ◽  
Hot Water ◽  
Food Sources ◽  
Weight Of Evidence ◽  
Meat Industry ◽  
Local Conditions ◽  
Quasi Experimental

ABSTRACT Pork is one of the major food sources of human salmonellosis worldwide, and beef products have been implicated in numerous foodborne outbreaks. Thus, effective interventions to reduce Salmonella contamination during beef and pork processing are of interest to both regulators and the meat industry. We conducted a rapid systematic review and meta-analysis of literature investigating the efficacy of slaughter and processing interventions to control Salmonella in beef and pork. Review steps included a comprehensive search strategy, relevance screening of abstracts, relevance confirmation of articles, data extraction, risk-of-bias assessment, meta-analysis (where appropriate), and a weight-of-evidence assessment. A total of 191 relevant experimental studies were identified. The results of two controlled trials indicated that hot water and steam treatments were effective for reducing the prevalence of Salmonella on beef carcasses (relative risk [RR] = 0.11; 95% confidence interval [CI]: 0.02, 0.58), whereas in four trials, prechill organic acid washes were effective for reducing Salmonella on pork carcasses (RR = 0.32; 95% CI: 0.13, 0.78), with high confidence in the estimates of effect. In four quasi-experimental studies, postexsanguination chemical washes were effective for reducing the prevalence of Salmonella on cattle hides, with low confidence in the specific estimate of effect; however, moderate confidence was found for the effect estimates of scalding (RR =0.20; 95% CI: 0.14, 0.29) and singeing (RR = 0.34; 95% CI: 0.22, 0.52) of pork carcasses. The overall evidence supports enhanced reductions of Salmonella through a multihurdle approach. Various slaughter and processing interventions can contribute to reduction of Salmonella on beef and pork carcasses, depending on the context of application, and an appropriate combination should be selected, validated, and verified by establishment operators under their local conditions.

Slow waves of boiling under hot water depressurization

2000 ◽  
Vol 413 ◽  
pp. 149-180 ◽  
Author(s):  
OLEG E. IVASHNYOV ◽  
MARINA N. IVASHNEVA ◽  
NICKOLAI N. SMIRNOV
Keyword(s):  
Numerical Experiment ◽  
Slow Wave ◽  
Experimental Studies ◽  
Physical Experiment ◽  
Hot Water ◽  
Slow Waves ◽  
Phase Velocities ◽  
Bubble Breakup ◽  
The Difference ◽  
Good Agreement

Experimental studies of hot water depressurization show that the pressure in a vessel, just after it is opened, drops much lower than the pressure of saturation but the liquid does not boil uniformly throughout the vessel. Essentially, liquid boiling begins only on the arrival of a ‘slow wave’ of rarefaction which moves at a low speed of approximately 10 m s−1 from the open end deep into the vessel.To explain this phenomenon we suggest a model that takes into account the difference in phase velocities. Although this difference in bubble flows is only about 1 m s−1 it proves to be sufficient to cause bubble breakup. Using this model we obtained the ‘slow wave of boiling’ in a numerical experiment that was in good agreement with the physical experiment.

scholarly journals Autonomous Energy-Efficient Complexes Based on Crude Oil for Working in Arctic Conditions

2021 ◽  
Vol 2096 (1) ◽  
pp. 012142
Author(s):  
P V Roslyakov ◽  
Yu V Proskurin ◽  
B G Grisha ◽  
I L Ionkin
Keyword(s):  
Crude Oil ◽  
Experimental Studies ◽  
Hot Water ◽  
Load Range ◽  
Technical Problems ◽  
Exchange Processes ◽  
Operating Load ◽  
Arctic Conditions ◽  
Ignition And Combustion ◽  
New Generation

Abstract The work is devoted to solving scientific and technical problems on the development of new generation Russian power equipment. Comprehensive theoretical and experimental studies of the effect of aerodynamic and heat-mass exchange processes on the ignition and combustion of crude oil in the straitened conditions of fire-tube boilers are reviewed and described. Based on the results of the research, design developments were carried out, prototypes of a fire-tube hot-water boiler with a remoted economizer and an automated low-emission burner device were manufactured and successfully tested. The efficiency of the boiler more than 94% and the reduced level of pollutants emissions in the operating load range are confirmed.

Sign in / Sign up

Export Citation Format

Share Document