Optimum Use of Water Heating Systems - New Control Concept in the Heating Systems of Liquid-Cooled Commercial Vehicle Engines, for Optimum Use of the Installed Heating Capacity of Engine-Independent Water Heaters

1992 ◽  
Author(s):  
D. Schmalenbach ◽  
M. Humburg
Keyword(s):  
Commercial Vehicle ◽  
Water Heating ◽  
Heating Systems ◽  
Water Heaters ◽  
Heating Capacity ◽  
Control Concept

Transient and Rate-Dependent Performance of Conventional Electric Storage Water Heating Systems

2005 ◽  
Vol 128 (1) ◽  
pp. 90-97 ◽  
Author(s):  
J. W. McMenamy ◽  
K. O. Homan
Keyword(s):  
Electrical Power ◽  
Performance Limits ◽  
Water Heating ◽  
Water Heater ◽  
Storage Element ◽  
Heating Systems ◽  
Water Heaters ◽  
Rate Dependent ◽  
Power Draw ◽  
Storage Volume

Electric resistance water heaters are relatively simple and are therefore one of the most common water heating configurations. Due to constraints on the allowable instantaneous electrical power draw, most electric water heating systems incorporate a sizable thermal storage component. The inherently unsteady storage component therefore has an overwhelming impact on the system behavior. In this investigation, a residential-scale electric storage water heater was tested across a range of flow rates for both powered and nonpowered discharge processes as well as for charge processes with no throughflow. The flow dynamics internal to the storage volume is shown to be strongly multidimensional and transient, especially when the internal heating elements are energized. Comparison of the measured data to the performance limits of a system with a fully mixed or a perfectly stratified storage element reveals that the conventional system operates relatively near to the fully mixed limit. As a result, there appears to be significant potential for improvements in system performance through reductions in the level of thermal mixing internal to the storage volume.

scholarly journals Towards Strategic Plan for Wide Spreading of Solar Water Heaters in Libya

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
M.J.R Abdunnabi ◽  
M. A Musa
Keyword(s):  
Solar Energy ◽  
Public Awareness ◽  
Strategic Plan ◽  
Water Heating ◽  
Heating Systems ◽  
Solar Water Heating ◽  
Solar Water ◽  
Water Heaters ◽  
Excellent Research ◽  
Solar Water Heaters

Solar water heaters have been in use for decades in many countries in the world that have less favorable climatic conditions for solar energy as compared with Libya. However, still there is no usage of such technologies in the country. This could be attributed to many factors including, among others, lack of clear policy and/or serious plans to establish such technology, cheap prices of conventional energy, and lack of environmental awareness.The Center for Solar Energy Research and Studies (CSERS) of Libya has developed an excellent research and development program on national scale for domestic solar water heating systems. The national program started in the early 1990’s aiming at increasing public awareness. The program utilizes different ways such as pilot projects, studies, workshops, and reports to convince people and decision- makers of Libya about this subject and its benefits.This paper attempts to suggest a strategic plan (win-win situation between government and people) for encouraging and helping wide spread (replacement) of solar water heaters nationwide based on economic and environmental pointers in favour of the replacement.The suggested strategic plan is to provide 25% of existing houses in 2013 with solar water heating systems by 2022, with governmental subsidy of up to 65% of the system cost. The study has shown that every L.D. paid by the government will return with at least 2 L.D. after 10 years of investment without considering the money saved from the fuel savings, power plant installations to fulfill the demand, and the environmental benefits.

Field Performance of Photovoltaic Solar Water Heating Systems

1997 ◽  
Vol 119 (4) ◽  
pp. 265-272 ◽  
Author(s):  
A. H. Fanney ◽  
B. P. Dougherty ◽  
K. P. Kramp
Keyword(s):  
The United States ◽  
Hot Water ◽  
Operating Characteristics ◽  
Water Heating ◽  
Heating Systems ◽  
Solar Water Heating ◽  
Solar Water ◽  
Photovoltaic Modules ◽  
Water Heaters ◽  
Solar Water Heaters

Energy consumed for water heating accounts for approximately 17.9 EJ of the energy consumed by residential and commercial buildings. Although there are over 90 million water heaters currently in use within the United States (Zogg and Barbour, 1996), durability and installation issues as well as initial cost have limited the sales of solar water heaters to less than 1 million units. Durability issues have included freeze and fluid leakage problems, failure of pumps and their associated controllers, the loss of heat transfer fluids under stagnation conditions, and heat exchanger fouling. The installation of solar water heating systems has often proved difficult, requiring roof penetrations for the piping that transports fluid to and from the solar collectors. Fanney and Dougherty have recently proposed and patented a solar water heating system that eliminates the durability and installation problems associated with current solar water heating systems. The system employs photovoltaic modules to generate electrical energy which is dissipated in multiple electric heating elements. A microprocessor controller is used to match the electrical resistance of the load to the operating characteristics of the photovoltaic modules. Although currently more expensive than existing solar hot water systems, photovoltaic solar water heaters offer the promise of being less expensive than solar thermal systems within the next decade. To date, photovoltaic solar water heating systems have been installed at the National Institute of Standards and Technology in Gaithersburg, MD and the Florida Solar Energy Center in Cocoa, FL. This paper will review the technology employed, describe the two photovoltaic solar water heating systems, and present measured performance data.

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