SOLAR ROOFING SYSTEM FOR LOW-COST DOMESTIC WATER HEATING AT THE ENERGY EFFICIENT RESEARCH FACILITY

Author(s):  
A. M. Boies ◽  
K. O. Homan

Solar integral collector storage (ICS) devices are a potentially low cost means of displacing a portion of the energy required for domestic water heating. However, since ICS systems are rarely used as a stand-alone system and are more typically utilized as a preheater for conventional water heaters, it is imperative to analyze the overall water heating system in order to determine the advantage of any improvements in the thermal performance of the ICS component. In particular, this paper analyzes the performance of a solar ICS heater, in divided and undivided storage configurations, in series with a conventional electric resistance water heater (ERWH) for a range of ICS storage volumes, heat exchanger NTU, initial ICS temperature, and ERWH storage volumes. The undivided storage configuration corresponds to the typical UPICS system whereas the divided storage configuration corresponds to a recently proposed concept for improving the thermal performance of the ICS device. The results show that the ICS preheater does provide significant increases in solar fraction when adequately sized. Although comparison of the divided to undivided storage concept, with the same total ICS storage volume, shows only modest gains of 5–10% in solar fraction, the ICS storage volume necessary to attain the same solar fraction is much less for the divided storage concept. The smaller required storage volume would, in turn, enable faster charging times and potentially higher initial temperatures thereby leading to even further improvements in overall system performance.


Nanoscale ◽  
2021 ◽  
Author(s):  
Xianyun Peng ◽  
Junrong Hou ◽  
Yuying Mi ◽  
Jiaqiang Sun ◽  
Gaocan Qi ◽  
...  

Electrocatalytic hydrogen evolution reaction (HER) for H2 production is essential for future renewable and clean energy technology. Screening energy-saving, low-cost, and highly active catalysts efficiently, however, is still a grand...


2021 ◽  
Author(s):  
Yingle Tao ◽  
Qiangqiang Li ◽  
Qiannan Wu ◽  
Haiqing Li

Localized eddy current heating delivered by metal foam embedded in a MOF monolith provides a novel, low-cost, and energy efficient way to overcome the thermal insulation nature of MOF monoliths and realize their highly efficient regenerations.


2021 ◽  
Vol 14 (2) ◽  
pp. 124-131
Author(s):  
K. A. Ignatiev ◽  
E. R. Giniyatullin ◽  
M. G. Ziganshin

Combined air and water heating schemes have been actively used recently for heating public and residential premises. They have certain advantages in countries with a warm climate, whereas in a temperate climate, their use may be unfeasible. The most effective regulation of the heating system in the building can be expected, if all the technology specifics are taken into account, in terms of both the purpose of the room and the methods of regulation. A system focused only on weather-based regulation falls short of meeting to energy-efficient control classes: a heat carrier with the same temperature is distributed among rooms with different requirements for temperature and humidity characteristics. The issues of ensuring the energy efficiency of the combined air and water heating system in public buildings for the temperate continental climate of Russia — the academic building (AB) and laboratory building (LB) of the Kazan State Energy University (KSEU) have been considered. Heating devices of the KSEU heating system have manual control valves installed in the premises, or radiator valves with thermostatic heads, but without room controllers, which does not meet the energy-efficient control classes. An experimental survey of the functioning of the heating system of the KSEU buildings during the 2019 – 2020 and 2020 – 2021 heating seasons was conducted. The optical pyrometry method was used to measure the temperature of the surfaces of windows, walls and elements of the heating system, as well as the temperature and humidity of the air in lecture rooms and corridors of the AB and LB of the KSEU. The parameters of heating devices and indoor air in rooms of various purposes were found compliant with the current sanitary and hygienic requirements. At the same time, the need to switch to a higher class of regulation has been revealed, since, under the current situation, the parameters of the indoor air depend on the outdoor temperature: in the abnormally warm winter of 2020, the indoor air temperature was at the edge of the maximum permissible value, while in the normal climate of winter of 2021, it was at the edge of the minimum permissible value.


2010 ◽  
Vol 67 (6) ◽  
pp. 727-730 ◽  
Author(s):  
Leonardo Oliveira Medici ◽  
Hermes Soares da Rocha ◽  
Daniel Fonseca de Carvalho ◽  
Carlos Pimentel ◽  
Ricardo Antunes Azevedo

Despite the massive demand of water for plant irrigation, there are few devices being used in the automation of this process in agriculture. This work evaluates a simple controller to water plants automatically that can be set up with low cost commercial materials, which are large-scale produced. This controller is composed by a ceramic capsule used in common domestic water filters; a plastic tube around 1.5 m long, and a pressostate used in domestic washing machines. The capsule and the pressostate are connected through the tube so that all parts are filled with water. The ceramic capsule is the sensor of the controller and has to be placed into the plant substrate. The pressostate has to be placed below the sensor and the lower it is, the higher is the water tension to start the irrigation, since the lower is the pressostate the higher is the water column above it and, therefore, the higher is the tension inside the ceramic cup to pull up the water column. The controller was evaluated in the control of drip irrigation for small containers filled with commercial organic substrate or soil. Linear regressions explained the relationship between the position of pressostate and the maximum water tension in the commercial substrate (p < 0.0054) and soil (p < 0.0001). Among the positions of the pressostate from 0.30 to 0.90 m below the sensor, the water tension changed from 1 to 8 kPa for commercial substrate and 4 to 13 kPa for the soil. This simple controller can be useful to grow plants, applying water automatically in function of the water tension of the plant substrate.


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