Energy savings potential of new aeration system: Full scale trials

2012 ◽  
Vol 7 (4) ◽  
Author(s):  
A. Lazić ◽  
V. Larsson ◽  
Å. Nordenborg

The objective of this work is to decrease energy consumption of the aeration system at a mid-size conventional wastewater treatment plant in the south of Sweden where aeration consumes 44% of the total energy consumption of the plant. By designing an energy optimised aeration system (with aeration grids, blowers, controlling valves) and then operating it with a new aeration control system (dissolved oxygen cascade control and most open valve logic) one can save energy. The concept has been tested in full scale by comparing two treatment lines: a reference line (consisting of old fine bubble tube diffusers, old lobe blowers, simple DO control) with a test line (consisting of new Sanitaire Silver Series Low Pressure fine bubble diffusers, a new screw blower and the Flygt aeration control system). Energy savings with the new aeration system measured as Aeration Efficiency was 65%. Furthermore, 13% of the total energy consumption of the whole plant, or 21 000 €/year, could be saved when the tested line was operated with the new aeration system.

Water ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 945 ◽  
Author(s):  
Yong Qiu ◽  
Chi Zhang ◽  
Bing Li ◽  
Ji Li ◽  
Xiaoyuan Zhang ◽  
...  

Oxidation ditches are popularly used in rural areas and decentralized treatment facilities where energy deficiency is of concern. Aeration control technologies are well established for diffusion systems in order to improve energy efficiency, but there are still challenges in their application in oxidation ditches because surface aerators have unique characteristics with respect to oxygen transfer and energy consumption. In this paper, an integral energy model was proposed to include the energy, aeration, and fluidic effects of surface aerators, by which the energy for aeration of each aerator can be estimated using online data. Two types of rotating disks with different diameters (1800 mm and 1400 mm) were monitored in situ to estimate the model parameters. Furthermore, a feedforward–feedback loop control strategy was proposed using the concept of energy analysis and optimization. The simplified control system was implemented in a full-scale Orbal oxidation ditch, achieving an approximately 10% saving in full-process energy consumption. The cost–benefit analysis and carbon emission assessment confirmed the economic feasibility and environmental contribution of the control system. The energy model can help process designers and operators to better understand and optimally control the aeration process in oxidation ditches.


2021 ◽  
Vol 6 (2) ◽  
pp. 03-17
Author(s):  
Gazal Dandia ◽  
◽  
Pratheek Sudhakaran ◽  
Chaitali Basu ◽  
◽  
...  

Introduction: High energy consumption by buildings is a great threat to the environment and one of the major causes of climate change. With a population of 1.4 billion people and one of the fastest-growing economies in the world, India is extremely vital for the future of global energy markets. The energy demand for construction activities continues to rise and it is responsible for over one-third of global final energy consumption. Currently, buildings in India account for 35% of total energy consumption and the value is growing by 8% annually. Around 11% of total energy consumption are attributed to the commercial sector. Energy-efficient retrofitting of the built environments created in recent decades is a pressing urban challenge. Presently, most energy-efficient retrofit projects focus mainly on the engineering aspects. In this paper, we evaluate various retrofitting options, such as passive architectural interventions, active technological interventions, or a combination of both, to create the optimum result for the selected building. Methods: Based on a literature study and case examples, we identified various energy-efficient retrofit measures, and then examined and evaluated those as applied to the case study of Awas Bhawan (Rajasthan Housing Board Headquarters), Jaipur, India. For the evaluation, we developed a simulation model using EQuest for each energy measure and calculated the resultant energy savings. Then, based on the cost of implementation and the cost of energy saved, we calculated the payback period. Finally, an optimum retrofit solution was formulated with account for the payback period and ease of installation. Results and discussion: The detailed analysis of various energy-efficient retrofit measures as applied to the case study indicates that the most feasible options for retrofit resulting in optimum energy savings with short payback periods include passive architecture measures and equipment upgrades.


2021 ◽  
Author(s):  
A.M.C.K. Polgolla ◽  
◽  
H.M.D.P. Herath ◽  
M.D.A. Wickramasinghe ◽  
M.A. Wijewardane ◽  
...  

Inside buildings, heating, ventilation, and air conditioning systems are utilized to provide a comfortable environment. However, they account for a significant percentage of overall total energy consumption: in the United States, they account for about 50% of building final energy consumption and 20% of total energy consumption. [1]. The installation of a heat exchanger between the exhaust and fresh air streams is critical, owing to the significant energy savings. [2], [3]. Thermal wheels have recently gotten a lot of attention because of their high efficiency and low-pressure loss when compared to other energy recovery solutions [4]. The goal of this research is to give a comprehensive study and optimization of Thermal wheel design, with the goal of enhancing sensible effectiveness while reducing pressure loss based on channel shape.


2021 ◽  
Vol 65 (1) ◽  
pp. 113-118
Author(s):  
Hamdi Sunnetci ◽  
Deniz Yilmaz

In these days, people spend 87% of their time indoors. Therefore, buildings are responsible for 36% of the total energy consumption and 40% of the CO2 emissions in the world. Besides, energy expenditures can be reduced, especially through improvements in public buildings used by many people. In this study, an annual energy consumption was conducted for an Olympic ice-skating rink and sports complex in Istanbul with a capacity of 900 spectators, was analyzed. Annual energy consumption of the building was 2 915 032 kWh electrical energy and 157 944 m3 natural gas. It was foreseen that 40 000kWh energy savings can be achieved annually with the evaporative pre-cooling system.


2020 ◽  
Vol 2020 (3) ◽  
pp. 25-39
Author(s):  
Vladimir Zolotarev

Red fescue (Festuca rubra L.) it is one of the most popular crops for creating lawns of various types and as a component of meadow and pasture poly-species mixtures of long-term use. The volume of domestic production of seeds of this crop is less than 2% of the total sales of seed material on the Russian market. The wide expansion of imported seeds of foreign-selected varieties to the domestic market sharply raises the question of the need to develop seed production of this crop in Russia. To do this, it is necessary to intensify breeding for the development of new varieties of red fescue, the development of zonal technologies for cultivating them for seeds. Analysis and generalization of research results shows that when using a set of optimal agricultural techniques, it is possible to consistently receive seed collections of more than 0.4 t/ha. This level of seed yield ensures high profitability of production and recoupment of energy costs. Assessment of the energy efficiency of technologies for cultivation of red fescue pasture-lawn ecotype shows that the total energy consumption per 1 ha of seed was 17.7 GJ, per 1 kg of seeds – 68.2 MJ. Due to the increase in yield by 44.4% and the use of energy-saving techniques, energy savings per 100 kg of seeds amounted to 25.6%. The energy assessment showed that as a result of harvesting seed crops by direct threshing in the optimal time frame, total energy costs decreased by 19%, and energy consumption for fuel – by 29%.


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