scholarly journals Compressor Scheduling and Pressure Control for an Alternating Aeration Activated Sludge Process—A Simulation Study Validated on Plant Data

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1037
Author(s):  
Laura Debel Hansen ◽  
Morten Veng ◽  
Petar Durdevic
Keyword(s):  
Simulation Study ◽  
Dynamic Models ◽  
Wastewater Treatment Plants ◽  
Pressure Control ◽  
Supply System ◽  
Airflow Rate ◽  
Air Supply ◽  
Plant Data ◽  
Save Energy ◽  
Aeration Performance

Aiming at reducing their emissions, wastewater treatment plants (WWTP) seek to reduce their energy consumption, where a large amount is used for the aeration. The case plant, Grindsted WWTP uses an alternating aeration strategy, with a common air supply system facilitating the process in four aeration tanks and thus making optimisation challenging. In this work, a nonlinear model of the air supply system is designed, in which multiple key parameters are estimated by data-driven optimization. Subsequently, a model-based control strategy for scheduling of compressors and desired airflow is proposed, to save energy without compromising the aeration performance. The strategy is based upon partly static- partly dynamic models of the compressors, describing their efficiency in terms of system head and volumetric airflow rate. The simulation study uses real plant data and shows great potential for improvement of energy efficiency, regardless of the aeration pattern in any of the four process tanks, and furthermore contributes to a reduction in compressor restarts per day. The proposed method is applicable to other WWTP with multiple compressors in the air supply system, as this study is conducted using first principle models validated on data from the daily operation.

The Analysis of Comfortable and Energy Saving of Ice-Storage Low Temperature Air Supply System

2014 ◽  
Vol 960-961 ◽  
pp. 635-638
Author(s):  
Li Bai ◽  
Xue Zhi Zhou ◽  
Yan Wang ◽  
Ya Wei Hua
Keyword(s):  
Low Temperature ◽  
Energy Saving ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Integrated Approach ◽  
Supply System ◽  
Energy Resources ◽  
Ice Storage ◽  
Air Supply ◽  
Save Energy

More and more attentions have been paid on ice-storage low temperature air supply system because of its notable energy saving effects and comfort. The paper expatiate on that ice-storage low temperature air supply system brings a series of especial superiority to modern air-condition cause. The results show that low temperature air supply system can exert the potential advantage of ice-storage further. The combination of ice-storage and low temperature air supply system can obtain an “integrated approach”, which can save energy resources and improve human body comfort and indoor air quality.

scholarly journals CFD simulation analysis on integrated operation of range-hood and make-up air supply for cooking-generated particulate matter

2019 ◽  
Vol 111 ◽  
pp. 04048
Author(s):  
Hyungkeun Kim ◽  
Kyungmo Kang ◽  
Yun-Gyu Lee ◽  
Taeyeon Kim
Keyword(s):  
Particulate Matter ◽  
Case Studies ◽  
Cfd Simulation ◽  
Simulation Analysis ◽  
Supply System ◽  
Airflow Rate ◽  
Cfd Simulations ◽  
Flow Angle ◽  
Air Supply ◽  
Integrated Operation

One of the most important problems of cooking-generated particulate matter (PM) is that it rapidly disperses when the range hood is in operation during cooking. To improve the performance of the range hood and prevent the dispersion of PM, a supply of make-up air equivalent to the airflow rate of the range hood should be provided. In this regard, we place an auxiliary supply system as a make-up supply to solve such problems. The objective of this study is to evaluate the performance of the make-up air supply system and the range hood. To evaluate this system, several case studies were performed involving CFD simulations. The auxiliary supply system is optimized through three types of variables (size of diffuser, distance from the source, and flow angle). An increase in the length of the diffuser causes PM dispersion to decrease. The installation of the diffuser at a certain distance from the emission source is effective in preventing dispersion of cooking-generated PM. In the building analyzed in this study, supplying the make-up air at an angle of 10° was observed to be most effective.

Modelling of aeration systems at wastewater treatment plants

2006 ◽  
Vol 53 (4-5) ◽  
pp. 439-447 ◽  
Author(s):  
L. Rieger ◽  
J. Alex ◽  
W. Gujer ◽  
H. Siegrist
Keyword(s):  
Response Time ◽  
Response Times ◽  
Wastewater Treatment Plants ◽  
Step Change ◽  
Process Conditions ◽  
Airflow Rate ◽  
Control Loops ◽  
Air Supply ◽  
Aeration System ◽  
Different Types

A model for the response time of aeration systems at WWTPs is proposed. It includes the delays caused by the air supply system (consisting of blowers, throttles and pipes), the rise time of the air bubbles and all control loops except the master DO controller. Beside a description of the required step-change experiments, different approaches for model calibration are given depending on the available data. Moreover, the parameters for the oxygen transfer and the response time of the aeration system model are not clearly identifiable. The model can be used for simulation studies which compare different types of controllers under changing loading and process conditions. The results from full-scale experiments at three different plants show that the response times of the aeration systems are in the range of 4–5 min. Taking all processes and time constants into account, some 30 min are needed to reach a new steady state after a step change of the airflow rate.

scholarly journals Cathode Pressure Control of Air Supply System for PEMFC⋆

2021 ◽  
Vol 54 (10) ◽  
pp. 247-252
Author(s):  
Huayang Liu ◽  
Hai Yin ◽  
Tianwei Ding ◽  
Xiaoliang Huang ◽  
Jinwu Gao
Keyword(s):  
Pressure Control ◽  
Supply System ◽  
Air Supply

Concept development for the optimisation of the Hamburg Wastewater Treatment Plants

2000 ◽  
Vol 41 (9) ◽  
pp. 89-95 ◽  
Author(s):  
G. Ladiges ◽  
N-P. Bertram ◽  
R. Otterpohl
Keyword(s):  
Computer Simulation ◽  
Wastewater Treatment ◽  
Simulation Study ◽  
Storage Capacity ◽  
Wastewater Treatment Plants ◽  
Concept Development ◽  
Final Solution ◽  
Effluent Standards ◽  
Dynamic Computer Simulation ◽  
Traditional Manner

The Hamburger Stadtentwässerung (HSE) is planning to take on a further approximately 250,000 PE in addition to the 1.85 m PE already served by its combined wastewater treatment plants at Köhlbrandhöft/Dradenau. To cope with the increased load, a concept for the extension of the plants had to be developed. Various concepts were compared and evaluated using a dynamic computer simulation. The very wide-ranging simulation study showed that the required effluent standards can still be achieved after the volume of the sludge liquor storage capacity has been increased. As many concepts had been assessed in detail, the final solution chosen was considerably less expensive than if the wastewater treatment plants had been extended in a traditional manner.

scholarly journals Dimensionless Analysis on the Characteristics of Pneumatic Booster Valve with Energy Recovery

2016 ◽  
Vol 2016 ◽  
pp. 1-13
Author(s):  
Fan Yang ◽  
Kotaro Tadano ◽  
Gangyan Li ◽  
Toshiharu Kagawa
Keyword(s):  
Mathematical Model ◽  
Energy Efficiency ◽  
Energy Recovery ◽  
Operational Parameters ◽  
Local Pressure ◽  
Air Power ◽  
Improve Energy Efficiency ◽  
Dimensionless Analysis ◽  
Air Supply ◽  
Save Energy

Factories are increasingly reducing their air supply pressures in order to save energy. Hence, there is a growing demand for pneumatic booster valves to overcome the local pressure deficits in modern pneumatic systems. To further improve energy efficiency, a new type of booster valve with energy recovery (BVER) is proposed. The BVER principle is presented in detail, and a dimensionless mathematical model is established based on flow rate, gas state, and energy conservation. The mathematics model was transformed into a dimensionless model by accurately selecting the reference values. Subsequently the dimensionless characteristics of BVER were found. BVER energy efficiency is calculated based on air power. The boost ratio is found to be mainly affected by the operational parameters. Among the structural ones, the recovery/boost chamber area ratio and the sonic conductance of the chambers are the most influential. The boost ratio improves by 15%–25% compared to that of a booster valve without an energy recovery chamber. The efficiency increases by 5%–10% depending on the supply pressure. A mathematical model is validated by experiment, and this research provides a reference for booster valve optimisation and energy saving.

Thermal and mechanical improvement of the air supply system of a turbocharged piston engine

2021 ◽  
Vol 14 (2) ◽  
pp. 108-114
Author(s):  
Y. M. Brodov ◽  
L. V. Plotnikov ◽  
K. O. Desyatov
Keyword(s):  
Heat Transfer ◽  
Experimental Studies ◽  
Local Heat Transfer ◽  
Supply System ◽  
Scale Model ◽  
Piston Engine ◽  
Intake System ◽  
Gas Dynamic ◽  
Air Supply ◽  
Air Flows

A method of thermomechanical improvement of pulsating air flows in the intake system of a turbocharged piston engine is described. The main objective of this study is to develop a method for suppressing the rate of heat transfer to improve the reliability of a piston turbocharged engine. A brief review of the literature on improving the reliability of piston engines is given. Scientific and technical results were obtained on the basis of experimental studies on a full-scale model of a piston engine. The hot-wire anemometer method was used to obtain gas-dynamic and heatexchange characteristics of gas flows. Laboratory stands and instrumentation facilities are described in the article. The data on gas dynamics and heat exchange of stationary and pulsating air flows in gas-dynamic systems of various configurations as applied to the air supply system of a turbocharged piston engine are presented. A method of thermomechanical improvement of flows in the intake system of an engine based on a honeycomb is proposed in order to stabilize the pulsating flow and suppress the intensity of heat transfer. Data were obtained on the air flow rate and the local heat transfer coefficient both in the exhaust duct of the turbocharger compressor (i.e., without a piston engine) and in the intake system of a supercharged engine. A comparative analysis of the data has been carried out. It was found that the installation of a leveling grid in the exhaust channel of a turbocharger leads to an intensification of heat transfer by an average of 9%. It was found that the presence of a leveling grid in the intake system of a piston engine causes the suppression of heat transfer within 15% in comparison with the baseline values. It is shown that the use of a modernized intake system in a diesel engine increases its probability of failure-free operation by 0.8%. The data obtained can be extended to other types and designs of air supply systems for heat engines.

scholarly journals Methodology for Energy Optimization in Wastewater Treatment Plants. Phase II: Reduction of Air Requirements and Redesign of the Biological Aeration Installation

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1143
Author(s):  
Ana Belén Lozano Avilés ◽  
Francisco Del Cerro Velázquez ◽  
Mercedes Llorens Pascual Del Riquelme
Keyword(s):  
Wastewater Treatment ◽  
Energy Consumption ◽  
Phase Ii ◽  
Wastewater Treatment Plants ◽  
Energy Optimization ◽  
Treatment Plant ◽  
Pressure Losses ◽  
San Pedro ◽  
Air Supply ◽  
Optimization Methodology

Phase I of the proposed energy optimization methodology showed how the selection of best management criteria for the biological aeration process, and the guarantee of its control at the wastewater treatment plant (WWTP) in San Pedro del Pinatar (Murcia, Spain) produced reductions of around 20% in energy consumption by considerably reducing the oxygen needs of the microorganisms in the biological system. This manuscript focused on phase II of this methodology, which describes the tools that can be used to detect and correct deviations in the optimal operating points of the aeration equipment and the intrinsic deficiencies in the installation, in order to achieve optimization of the oxygen needs by the microorganisms and improve the efficiency of their transfer from the gas phase to the liquid phase. The objectives pursued were: (i) to minimize the need for aeration, (ii) to reduce the pressure losses in the installation, (iii) to optimize the air supply pressures to avoid excessive energy consumption for the same airflow, and (iv) to optimize the control strategy for the actual working conditions. The use of flow modeling and simulation techniques, the measurement and calculation of air transfer efficiency through the use of off-gas hoods, and the redesign of the aeration facility at the San Pedro del Pinatar WWTP were crucial, and allowed for reductions in energy consumption in Phase II of more than 20%.

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