2. Materials and Methods
3. Results and Analysis
3.1. Thermal Performance
3.2. Economic Analysis
- highly efficient heat exchanger component for rapid heat production is proposed in view of the problem that the heat utilization of the gas water heater in the existing heater is low and the heat production speed is slow, with the use of the phase transition medium.
- The heat transfer efficiency of the new heat exchanger in gas water heater is 6% higher than that of existing one through experiment.
- The exhausted gas temperature of the new heat exchanger (81 °C~76 °C) is higher than the dew point temperature of combusted natural gas (60 °C), which avoids the low temperature corrosion of heat exchanger.
- The new heater shows low sensitivity of heat source fluctuate and provides better using experience when there is a fluctuate of gas flow production, with the help of phase transition medium.
- The new heater is more economic efficient and for individual user the cost can be recovered in about 2.5 years. For China, about 1.1 × 107 m3 of natural gas can be conserved with the use of the new heater.
- Avoidance of low temperature corrosion produces a longer service time of the new heater, and consequently contributes to a better economic efficiency, which remains to be further studied.
Conflicts of Interest
- Hoeschele, M.; Springer, D.; German, A.; Staller, J.; Zhang, Y. Strategy Guideline: Proper Water Heater Selection; Office of Scientific & Technical Information Technical Reports; U.S. Department of Energy: Washington, DC, USA, 2012.
- Tian, Y.; Liu, R.; Yang, M.; Hao, Y.; Liu, Y. Market Survey and Analysis of Gas Water Heaters in Beijing. Gas Heat 2012, 32, B11–B13. [Google Scholar]
- Lekov, A.B.; Franco, V.H.; Wong-Parodi, G.; McMahon, J.E.; Chan, P. Economics of residential gas furnaces and water heaters in US new construction market. Energy Effic. 2010, 3, 203–222. [Google Scholar] [CrossRef]
- Yi, A.X.; Wang, Y.; Cheng, F.U.Z.; Pan, S.Y.; Guo, Q. Experimental Investigation and Saving Energy Analysis on High Efficiency Gas-fired Heater. Ind. Heat. 2002, 169, 50–52. (In Chinese) [Google Scholar]
- Aguilar, C.; White, D.J.; Ryan, D.L. Domestic Water Heating and Water Heater Energy Consumption in Canada. CBEEDAC: Edmonton, AB, Canada, 2005; p. 359. [Google Scholar]
- Department of Energy (DOE), Office of Industrial Technologies, Energy Efficiency and Renewable Energy. Best Practices Program; Information on Steam; Department of Energy (DOE), Office of Industrial Technologies, Energy Efficiency and Renewable Energy: Washington, DC, USA, 2001.
- Galitsky, C.; Worrell, E. Energy Efficiency Improvement and Cost Saving Opportunities for the Vehicle Assembly Industry: An ENERGY STAR Guide for Energy and Plant Managers; Lawrence Berkeley National Laboratory: Berkeley, CA, USA, 2008; Volume 32.
- Canadian Industry Program for Energy Conservation (CIPEC). Boilers and Heaters, Improving Energy Efficiency; Natural Resources Canada, Office of Energy Efficiency: Ottawa, ON, Canada, 2001. [Google Scholar]
- Hongbin, Y.I.; Luo, C.; Liu, X.; Shang, Z.; Zou, C. Optimization of Partial Air Intake Structure of Burner in Blowing-type Gas Water Heater. Gas Heat 2014, 34, A28–A30. [Google Scholar]
- Tajwar, S.; Saleemi, A.R.; Ramzan, N.; Naveed, S. Improving thermal and combustion efficiency of gas water heater. Appl. Therm. Eng. 2011, 31, 1305–1312. [Google Scholar] [CrossRef]
- Eiamsa-Ard, S.; Promvonge, P. Enhancement of heat transfer in a tube with regularly-spaced helical tape swirl generators. Sol. Energy 2005, 78, 483–494. [Google Scholar] [CrossRef]
- Craig, S.J.; Mcmahon, J.F. The effects of draft control on combustion. ISA Trans. 1996, 35, 345–349. [Google Scholar] [CrossRef]
- Tan, S.; Luo, X.; Zheng, L. Research on condensing type gas water-heater. Nat. Gas Ind. 2002, 322, 229. [Google Scholar]
- Federal Register Part VIII: Department of Energy, Office of Energy Efficiency and Renewable Energy. Available online: www.eere.energy.gov/buildings/appliance_standards/residential/pdfs/water_heater_fr.pdf (accessed on 11 June 2018).
- Grehier, A. Condensing Heat Exchanger for Heat Recovery from Flue Gases. In Proceedings of the International Symposium on Condensing Heat Exchangers, Columbus, OH, USA, 14 April 1987. [Google Scholar]
- Pan, X.X.; Wei, D.S. Anti-corrosion of Condensing Gas Water Heater. Gas Heat 2005, 25, 11–14. [Google Scholar]
- Zhang, Y.; Huang, X.; Wang, F.; Xu, D. Corrosion Product Analysis and Corrosion Protection Measures on Heat Exchanger for Gas Water Heater. Gas Heat 2016, 36, A33–A37. (In Chinses) [Google Scholar]
- Wenjuan, L.I. Causes and Improvement of Low Temperature Corrosion of Heat Exchanger in Condensing Gas Water Heater. Gas Heat 2016, 36, A27–A29. (In Chinese) [Google Scholar]
- Hwang, K.; Song, C.H.; Saito, K.; Kawai, S. Experimental study on titanium heat exchanger used in a gas fired water heater for latent heat recovery. Appl. Therm. Eng. 2010, 30, 2730–2737. [Google Scholar] [CrossRef]
- Zheng, Y.X.; Zhao, H.Y.; Ye, Y.Z.; Zhong, J.-S.; Xia, Z.-Z.; Wu, G.-F. Experimental Study on Corrosion Prevention of Low-temperature Section of Heat Exchanger in Condensing Gas Water Heater. Gas Heat 2007, 27, 35–41. (In Chinese) [Google Scholar]
- Luo, C.-K. Heat Conducting Assembly for a Water Heater, and Method for Making the Heat Conducting Assembly. U.S. Patent 2007/0133963, 14 June 2007. [Google Scholar]
- Wang, Q.; Su, B. Enclosed and Highly-Efficient Evaporation-Condensation Instant Water Heater. C.N. Patent 201510250211, 15 May 2015. [Google Scholar]
- Wang, Q.; Wei, S. Quick-Heating Type Electric Water Heater Based on Vacuum Phase-Change Principle. C.N. Patent 201610204147, 24 May 2016. [Google Scholar]
|Geometry Parameter||Value (mm)||Geometry Parameter||Value (mm)||Geometry Parameter||Value (mm)|
|Cavity Length||200||Total Length||240||Diameter of pipe||10|
|Cavity Width||120||Total Width||160||Fin thickness||0.5|
|Cavity Height||250||Total Height||280||Fin||18 × 2|
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