Safety and performance of gas-fired hot water boilers (60kW to 2 MW input)

1983 ◽  
Keyword(s):  
Hot Water ◽  
And Performance

scholarly journals Numerical Study of Nanofluid Irreversibilities in a Heat Exchanger Used with an Aqueous Medium

Entropy ◽  
2020 ◽  
Vol 22 (1) ◽  
pp. 86
Author(s):  
Guillermo Efren Ovando-Chacon ◽  
Sandy Luz Ovando-Chacon ◽  
Abelardo Rodriguez-Leon ◽  
Mario Diaz-Gonzalez ◽  
Jorge Arturo Hernandez-Zarate ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Aqueous Medium ◽  
Entropy Generation ◽  
Numerical Study ◽  
Oil Extraction ◽  
Hot Water ◽  
Bejan Number ◽  
Extraction Properties ◽  
And Performance

Heat exchangers play an important role in different industrial processes; therefore, it is important to characterize these devices to improve their efficiency by guaranteeing the efficient use of energy. In this study, we carry out a numerical analysis of flow dynamics, heat transfer, and entropy generation inside a heat exchanger; an aqueous medium used for oil extraction flows through the exchanger. Hot water flows on the shell side; nanoparticles have been added to the water in order to improve heat transfer toward the cold aqueous medium flowing on the tube side. The aqueous medium must reach a certain temperature in order to obtain its oil extraction properties. The analysis is performed for different Richardson numbers (Ri = 0.1–10), nanofluid volume fractions (φ = 0.00–0.06), and heat exchanger heights (H = 0.6–1.0). Results are presented in terms of Nusselt number, total entropy generation, Bejan number, and performance evaluation criterion. Results showed that heat exchanger performance increases with the increase in Ri when Ri > 1 and when reducing H.

Design and Performance Analysis on CO2 Combined System in Supermarket

2012 ◽  
Vol 433-440 ◽  
pp. 1219-1225
Author(s):  
Jing Hong Ning ◽  
Sheng Chun Liu
Keyword(s):  
Energy Consumption ◽  
Waste Heat ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Working Fluid ◽  
Space Heating ◽  
Combined System ◽  
Space Cooling ◽  
Gas Cooling ◽  
And Performance

This paper reports a combined space cooling, space heating, water heating and food refrigeration system (named CO2 combined system) in supermarket. This system using CO2 as the working fluid consists of a two-stage CO2 transcritical cycle used for food refrigeration, a single-stage CO2 transcritical cycle for space cooling in summer and space heating in winter. The waste heat emitted from the CO2 gas cooling in food refrigeration cycle and space cooling and space heating cycles is recovered by heat recover exchanger and is used to provide hot water for space heating and for general usage, such as the catering, the washing and the toilet facilities in the supermarket. So this CO2 combined system improves the coefficient of performance, decreases the energy consumption as well as reduces the heat pollution. Moreover, this CO2 combined system is compared with typical conventional supermarket technology, the results show that the energy consumption of CO2 combined system is reduced largely and energy efficiency is increased obviously. It can be concluded that the CO2 combined system has a good future for protecting environment and saving energy.

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.

Design of a Solar Tunnel Dryer Combined Heat with a Parabolic Trough for Paddy Drying

2016 ◽  
Vol 851 ◽  
pp. 239-243 ◽  
Author(s):  
Krissadang Sookramoon
Keyword(s):  
Heat Exchanger ◽  
Performance Test ◽  
Focal Point ◽  
Tracking System ◽  
Cross Flow ◽  
Hot Water ◽  
Parabolic Trough ◽  
Tunnel Dryer ◽  
And Performance ◽  
Flat Plate Collector

This paper presents the design, build and performance test of a solar tunnel dryer combined heat with a parabolic trough for paddy drying. A 2.27 m² parabolic trough stainless steel made with a single-axis solar tracking system produced hot water and delivered to the cross flow heat exchanger equipped with a solar tunnel dryer with the size of flat plate collector of 2.112 m2. The system received solar radiation and reflected sunlight to the receiver at the focal point of a parabolic trough. At this point, a copper heat pipe with the inside diameter of 25.4 mm for water heating is placed. A parabolic trough is covered with plastic sheets for protecting the wind in order to prevent the heat loss by convection. The produced hot water is used to warm the air and is sent to the heat exchanger and the blower passes hot air through the drying chamber of solar tunnel to dry paddy. The average drying temperature was 57.73 °C. The paddy moisture content was assessed in a reduction from 49.96 to 15.61 MC (% d.b.) in 6 hours. The heated air was around 245.87 W, with the incoming heat in the solar tunnel dryer of 1271.84 W. The thermal efficiency of a solar tunnel dryer, a parabolic trough, and the overall efficiency were on the average of 28.31%, 8.73%, and 3.80%, respectively.

Thermal analysis and performance optimization of a solar hot water plant with economic evaluation

Solar Energy ◽  
2012 ◽  
Vol 86 (5) ◽  
pp. 1378-1395 ◽  
Author(s):  
Young-Deuk Kim ◽  
Kyaw Thu ◽  
Hitasha Kaur Bhatia ◽  
Charanjit Singh Bhatia ◽  
Kim Choon Ng
Keyword(s):  
Thermal Analysis ◽  
Economic Evaluation ◽  
Performance Optimization ◽  
Hot Water ◽  
Water Plant ◽  
And Performance

Development and Performance Validation of a Heat Pump Water Heater

2006 ◽  
Author(s):  
H. I. Abu-Mulaweh
Keyword(s):  
Heat Pump ◽  
Testing Procedure ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Experimental Measurements ◽  
Water Heater ◽  
Flow Rates ◽  
Heat Pump Water Heater ◽  
And Performance ◽  
Performance Validation

Heat pump water heater was designed and a prototype was developed and constructed. The performance of the heat pump water heater prototype is described by presenting some experimental test data. The experimental measurements include temperature, flow rates, and power consumption. The testing procedure consisted of evaluating the recovery rate and the coefficient of performance (COP) of the system. The results strongly indicate that heat pump water heater system design is very practical and it provides the consumer with a more efficient hot water heater alternative.

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