HEAT EXCHANGER CHARACTERISTICS OF REFRIGERATION SYSTEM CONDENSERS AS HOT WATER HEATERS

Hot-water supply has high percentage of energy consumption in Japanese civilian sector. Gas water heaters are used in most cases. Therefore, improvement in thermal efficiency of a gas water heater is an important issue for energy saving. In order to improve thermal efficiency of a gas water heater, an additional heat exchanger is required for latent heat recovery from exhaust humid combustion. The purpose of this study is to develop a compact latent heat recovery heat exchanger with a simple configuration. It is necessary for compactness to reduce the gap between the heat transfer tubes. However, the narrow gap will cause stagnation of condensed water. In order to remove the condensed water from horizontal tube bank, three kinds of tubes with different surface treatments, polished tubes, unpolished tube, and smooth tube with circular micro-grooves, were examined. As the result, condensed water was easily removed by the groove with the 0.7mm depth, to avoid the formation of water bridges between tubes. The effect could lead to no deterioration in the heat transfer performance by decreasing the tube clearance to 1.0mm.

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A Study on Waste Heat Recovery in Drain Water with Water-to-Water Heat Exchanger in Barbershops

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.608-609.1231 ◽

2012 ◽

Vol 608-609 ◽

pp. 1231-1235

Author(s):

Fang Tian Sun ◽

Na Wang ◽

Xiao Gang Gong ◽

Yun Ze Fan ◽

De Ying Li

Keyword(s):

Heat Exchanger ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Waste Heat ◽

Hot Water ◽

Energy Utilization ◽

Utilization Efficiency ◽

Waste Heat Recovery System ◽

Heat Utilization ◽

Water Heaters

Heat utilization efficiency of barbershop was about 16.7% in China, because the low-temperature waste water at 30～36°C was directly discharged into sewer. And match of energy grade was not appropriate, because electric water heaters were used to producing hot water at 55～70°C in most of barbershops. A waste heat recovery system with water-to-water heat exchanger (WHR-HE) was presented, according to heat utilization characteristics of barbershop and scientific principle of energy utilization. WHR-HE was analyzed by the first Law of thermodynamics and economics. The analyzed results show that energy consumption can be reduced about 75%, and incremental payback period is less one year for WHR-HE. There is optimal cold side temperature difference of water-to-water heat exchanger.

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Residential Drain Water Heat Recovery Systems: Modeling, Analysis, and Implementation

Journal of Green Building ◽

10.3992/jgb.5.3.85 ◽

2010 ◽

Vol 5 (3) ◽

pp. 85-94 ◽

Cited By ~ 4

Author(s):

Scott Bartkowiak ◽

Ryan Fisk ◽

Andrew Funk ◽

Jonathan Hair ◽

Steven J Skerlos

Keyword(s):

Heat Exchanger ◽

Natural Gas ◽

Flat Plate ◽

Heat Exchangers ◽

Heat Recovery ◽

Cold Water ◽

Hot Water ◽

Published Data ◽

Drain Water ◽

Water Heaters

This paper describes the design and environmental improvements that can be achieved using drain water heat recovery systems (DWHR) to reduce the energy consumption associated with residential showering. DWHR systems transfer heat from hot drain water to the shower's incoming cold water stream, thus reducing the demand on the hot water heater. There are various DWHR systems available that differ in heat exchanger type, cost, and performance. This article focuses on designing a flat plate and gravity fed heat exchangers for a range of residential showering conditions. This is useful since there currently is no peer-reviewed published data on the effectiveness of DWHR, nor is there published research considering the emissions reductions that can be achieved with realistic DWHR systems. The governing equations for heat exchangers are used to model empirical data and to derive implementation recommendations for DWHR design. The model is validated using a prototype flat plate heat exchanger and test stand under varying flow rates and temperatures. A Monte Carlo simulation of the results showed that DWHR could save an average $74 a year for homes with natural gas water heaters and $160 a year for homes with electric water heaters. This corresponds to 0.3 metric tons and 1.5 metric tons of CO2offset per home per year for natural gas and electric water heaters, respectively. The results are compiled and organized into a software program that allows consumers to input their household showering habits and location to get an estimate of their CO2, energy, and cost savings to determine if they should install a DWHR system.

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The “Florida” Steam and Hot Water Heaters

Scientific American ◽

10.1038/scientificamerican10011891-64hbuild ◽

1891 ◽

Vol 12 (4build) ◽

pp. 64-64

Keyword(s):

Hot Water ◽

Water Heaters

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Experimental Investigation of Heat Transfer Enhancement by Using Different Number of Fins in Circular Tube

Wasit Journal of Engineering Sciences ◽

10.31185/ejuow.vol6.iss3.99 ◽

2018 ◽

Vol 6 (3) ◽

pp. 1-12

Author(s):

Kamil Abdul Hussien

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Cold Water ◽

Finned Tube ◽

Hot Water ◽

Copper Tube ◽

Smooth Tube ◽

Tube Heat Exchanger ◽

Mass Flow Rates ◽

Flow Heat

Abstract-The present work investigates the enhancement of heat transfer by using different number of circular fins (8, 10, 12, 16, and 20) in double tube counter flow heat exchanger experimentally. The fins are made of copper with dimensions 66 mm OD, 22 mm ID and 1 mm thickness. Each fin has three of 14 mm diameter perforations located at 120o from each to another. The fins are fixed on a straight smooth copper tube of 1 m length, 19.9 mm ID and 22.2 mm OD. The tube is inserted inside the insulated PVC tube of 100 mm ID. The cold water is pumped around the finned copper tube, inside the PVC, at mass flow rates range (0.01019 - 0.0219) kg/s. The Reynold's number of hot water ranges (640 - 1921). The experiment results are obtained using six double tube heat exchanger (1 smooth tube and the other 5 are finned one). The results, illustrated that the heat transfer coefficient proportionally with the number of fin. The results also showed that the enhancement ratio of heat transfer for finned tube is higher than for smooth tube with (9.2, 10.2, 11.1, 12.1 13.1) times for number of fins (8, 10, 12, 16 and 20) respectively.

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CUPRO NICKEL 30%-716

Alloy Digest ◽

10.31399/asm.ad.cu0200 ◽

1969 ◽

Vol 18 (6) ◽

Keyword(s):

Corrosion Resistance ◽

Heat Exchanger ◽

Power Plant ◽

Iron Alloy ◽

High Strength ◽

Oil Refinery ◽

Feed Water ◽

Nickel Iron ◽

Water Heaters ◽

Nickel Iron Alloy

Abstract Cupro Nickel, 30%-716 is a high strength copper-nickel-iron alloy for heat exchanger tubes in power plant feed water heaters, and also for oil refinery service. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, joining, and surface treatment. Filing Code: Cu-200. Producer or source: Anaconda American Brass Company.

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Gas-fired storage water heaters for the production of domestic hot water

10.3403/02328026 ◽

2000 ◽

Keyword(s):

Hot Water ◽

Domestic Hot Water ◽

Water Heaters

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Effect of Twisted Fin Array in a Triple-Tube Latent Heat Storage System during the Charging Mode

Sustainability ◽

10.3390/su13052685 ◽

2021 ◽

Vol 13 (5) ◽

pp. 2685

Author(s):

Mohammad Ghalambaz ◽

Jasim M. Mahdi ◽

Amirhossein Shafaghat ◽

Amir Hossein Eisapour ◽

Obai Younis ◽

...

Keyword(s):

Energy Storage ◽

Heat Exchanger ◽

Latent Heat ◽

Thermal Energy ◽

Heat Storage ◽

Hot Water ◽

Melting Time ◽

Latent Heat Storage ◽

Tube Heat Exchanger ◽

Storage Rate

This study aims to assess the effect of adding twisted fins in a triple-tube heat exchanger used for latent heat storage compared with using straight fins and no fins. In the proposed heat exchanger, phase change material (PCM) is placed between the middle annulus while hot water is passed in the inner tube and outer annulus in a counter-current direction, as a superior method to melt the PCM and store the thermal energy. The behavior of the system was assessed regarding the liquid fraction and temperature distributions as well as charging time and energy storage rate. The results indicate the advantages of adding twisted fins compared with those of using straight fins. The effect of several twisted fins was also studied to discover its effectiveness on the melting rate. The results demonstrate that deployment of four twisted fins reduced the melting time by 18% compared with using the same number of straight fins, and 25% compared with the no-fins case considering a similar PCM mass. Moreover, the melting time for the case of using four straight fins was 8.3% lower than that compared with the no-fins case. By raising the fins’ number from two to four and six, the heat storage rate rose 14.2% and 25.4%, respectively. This study presents the effects of novel configurations of fins in PCM-based thermal energy storage to deliver innovative products toward commercialization, which can be manufactured with additive manufacturing.

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