Ammonia-Based Aeration Control of an Oxidation Ditch to Improve Effluent Quality and Reduce Operating Cost

2018 ◽  
Vol 2018 (18) ◽  
pp. 237-250
Author(s):  
Robert C Smith ◽  
Josh Holton ◽  
Jon van Dommelen
Keyword(s):  
Operating Cost ◽  
Oxidation Ditch ◽  
Effluent Quality ◽  
Reduce Operating Cost ◽  
Aeration Control

Validation of MISES Two-Dimensional Boundary Layer Code for High-Pressure Turbine Aerodynamic Design

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Philip L. Andrew ◽  
Harika S. Kahveci
Keyword(s):  
Boundary Layer ◽  
High Pressure ◽  
Operating Cost ◽  
Design Tool ◽  
Operating Conditions ◽  
Aerodynamic Design ◽  
High Pressure Turbine ◽  
Reduce Operating Cost ◽  
Wide Range ◽  
Dimensional Boundary

Avoiding aerodynamic separation and excessive shock losses in gas turbine turbomachinery components can reduce fuel usage and thus reduce operating cost. In order to achieve this, blading designs should be made robust to a wide range of operating conditions. Consequently, a design tool is needed—one that can be executed quickly for each of many operating conditions and on each of several design sections, which will accurately capture loss, turning, and loading. This paper presents the validation of a boundary layer code, MISES, versus experimental data from a 2D linear cascade approximating the performance of a moderately loaded mid-pitch section from a modern aircraft high-pressure turbine. The validation versus measured loading, turning, and total pressure loss is presented for a range of exit Mach numbers from ≈0.5 to 1.2 and across a range of incidence from −10 deg to +14.5 deg relative to design incidence.

scholarly journals Frosting Phenomenon and Frost-Free Technology of Outdoor Air Heat Exchanger for an Air-Source Heat Pump System in China: An Analysis and Review

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2642 ◽  
Author(s):  
Yi Zhang ◽  
Guanmin Zhang ◽  
Aiqun Zhang ◽  
Yinhan Jin ◽  
Ruirui Ru ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Heat Pump ◽  
Operating Cost ◽  
Heating System ◽  
Coefficient Of Performance ◽  
Outdoor Air ◽  
Pump System ◽  
Heat Pump System ◽  
Reduce Operating Cost ◽  
Air Source Heat Pump

Frost layer on the outdoor air heat exchanger surface in an air-source heat pump (ASHP) can decrease the system coefficient of performance (COP). Although the common defrosting and anti-frosting methods can improve the COP, the periodic defrosting not only reduces the system energy efficiency but also deteriorates the indoor environment. To solve these problems, it is necessary to clearly understand the frosting phenomenon and to achieve the system frost-free operation. This paper focused firstly on the analyses of frosting pathways and frosting maps. Followed by summarizing the characteristics of frost-free technologies. And then the performances of two types of frost-free ASHP (FFASHP) systems were reviewed, and the exergy and economic analysis of a FFASHP heating system were carried out. Finally, the existing problems related to the FFASHP technologies were proposed. Results show that the existing frosting maps need to be further improved. The FFASHP systems can not only achieve continuous frost-free operation but reduce operating cost. And the total COP of the FFASHP heating system is approximately 30–64% higher than that of the conventional ASHP system under the same frosting conditions. However, the investment cost of the FFASHP system increases, and its reliability also needs further field test in a wider frosting environment. In the future, combined with a new frosting map, the control strategy for the FFASHP system should be optimized.

scholarly journals MBBR+two-stage AO in upgrading and rebuilding project Of a sewage treatment plant in north China

2019 ◽  
Vol 136 ◽  
pp. 06031
Author(s):  
Shen Dongmei ◽  
Yu Cairui ◽  
Gao Yulan ◽  
Song Xinwei ◽  
Chu Jingsong
Keyword(s):  
High Efficiency ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Oxidation Ditch ◽  
Effluent Quality ◽  
Second Stage ◽  
The North ◽  
Filter Process

A sewage treatment plant is located in the middle of Inner Mongolia. There is a large amount of slaughtering wastewater in the influent with high COD, SS, low annual temperature, poor nitrogen removal effect, and the effluent quality is only grade B. In order to solve the above problems, A\A\O-MBBR + high efficiency sedimentation tank continuous sand filter process was adopted to establish a new anaerobic tank and a first stage AO-MBBR bioreactor. The selection tank and partial oxidation ditch were transformed into the second stage A pool (anoxic pool), and the remaining part of the existing oxidation ditch was transformed into the second stage O pond (aerobic pool), which further removed phosphorus and reduced the SS in the sewage, and solved the problem of low temperature biological treatment in winter in the north of China. The quality of the effluent reached level A after the upgrading.

scholarly journals Conceptual Design of Flapping Wing Using Shape Memory Alloy Actuator for Micro Unmanned Aerial Vehicle

2014 ◽  
Vol 629 ◽  
pp. 152-157
Author(s):  
Navanitha Marimuthu ◽  
Ermira Junita Abdullah ◽  
Dayang L.A. Majid ◽  
Fairuz I. Romli
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Conceptual Design ◽  
Smart Materials ◽  
Operating Cost ◽  
Flapping Wing ◽  
Complex Environments ◽  
Reduce Operating Cost ◽  
Air Vehicle ◽  
Aerial Vehicle

Micro Air Vehicle (MAV) has the capability to fly autonomously in complex environments which enables human to conduct surveillance in areas which are deemed too dangerous or in confined spaces that does not allow human entry. Research and development of MAVs aim to reduce their size further, thus novel techniques need to be explored in order to achieve this objective while still maintaining the MAVs’ current performance. In this paper, a conceptual design of an MAV with a main drive system using shape memory alloy (SMA) actuator to provide the flapping motion is proposed. SMA is considered superior to other smart materials due to its efficiency and large energy storage capacity. By incorporating SMA in the flapping wing MAV, it will provide users the flexibility to add more payloads by reducing bulky cables or reduce operating cost by using less fuel. However, there are some drawbacks in using SMAs such as nonlinear response of the strain to input current and hysteresis characteristic as a result of which their control is inaccurate and complicated.

Simple control strategies of methanol dosing for post-denitrification

1998 ◽  
Vol 38 (3) ◽  
pp. 291-297 ◽  
Author(s):  
N. Puznava ◽  
S. Zeghal ◽  
E. Reddet
Keyword(s):  
Control Strategies ◽  
Operating Cost ◽  
Feed Water ◽  
Effluent Quality ◽  
Second Stage ◽  
Point Tracking ◽  
Regulatory Constraints ◽  
Operation Costs ◽  
Line Measurement ◽  
On Line

The objective of this work is to propose a simple but efficient way of controlling the carbon addition for the post-denitrification process in order to comply with regulatory constraints and optimize operating cost. A Biostyr® pilot column filled with polystyrene beads was used for the experiments. In order to simulate a secondary treated water from a nitrifying stage with a carbon source addition, the feed water was composed of river water dosed with nitrates, phosphates and methanol. Methanol was added initially with no control (at different constant rates) and in a second stage with different control strategies based on the on-line measurement of inlet and/or outlet nitrate concentrations. This simple dosing mode proved to be very efficient in set-point tracking to ensure the effluent quality and in minimizing the methanol addition (up to 20% less methanol consumption), thus optimizing operation costs.

An aeration control strategy for oxidation ditch processes based on online oxygen requirement estimation

2013 ◽  
Vol 68 (1) ◽  
pp. 76-82 ◽  
Author(s):  
J. X. Zhan ◽  
M. Ikehata ◽  
M. Mayuzumi ◽  
E. Koizumi ◽  
Y. Kawaguchi ◽  
...  
Keyword(s):  
Control Strategy ◽  
Suspended Solids ◽  
Nitrogen Concentration ◽  
Treatment Plant ◽  
Electricity Consumption ◽  
Oxygen Demand ◽  
Endogenous Respiration ◽  
Oxidation Ditch ◽  
Oxygen Requirements ◽  
Aeration Control

A feedforward-feedback aeration control strategy based on online oxygen requirements (OR) estimation is proposed for oxidation ditch (OD) processes, and it is further developed for intermittent aeration OD processes, which are the most popular type in Japan. For calculating OR, concentrations of influent biochemical oxygen demand (BOD) and total Kjeldahl nitrogen (TKN) are estimated online by the measurement of suspended solids (SS) and sometimes TKN is estimated by NH4-N. Mixed liquor suspended solids (MLSS) and temperature are used to estimate the required oxygen for endogenous respiration. A straightforward parameter named aeration coefficient, Ka, is introduced as the only parameter that can be tuned automatically by feedback control or manually by the operators. Simulation with an activated sludge model was performed in comparison to fixed-interval aeration and satisfying result of OR control strategy was obtained. The OR control strategy has been implemented at seven full-scale OD plants and improvements in nitrogen removal are obtained in all these plants. Among them, the results obtained in Yumoto wastewater treatment plant were presented, in which continuous aeration was applied previously. After implementing intermittent OR control, the total nitrogen concentration was reduced from more than 5 mg/L to under 2 mg/L, and the electricity consumption was reduced by 61.2% for aeration or 21.5% for the whole plant.

scholarly journals Reducing Operating Cost With Anammox In Wastewater Treatment -- A Simulation Study

2021 ◽  
Author(s):  
Eliav J. Eini
Keyword(s):  
Total Nitrogen ◽  
Simulation Study ◽  
Operating Cost ◽  
Operational Strategies ◽  
Reduce Operating Cost ◽  
Start Up ◽  
Whole Plant ◽  
Plant Simulation ◽  
Biological Nitrogen ◽  
Anammox Process

A simulation study is presented to investigate the use of the Anammox process for removing nitrogen compounds from wastewater to reduce operating cost. The literature review of technologies for removal of Total Nitrogen includes an overview of the biological nitrogen cycle, the discovery of Anammox, bioreactor design, operational strategies, and start-up of full-scale processes. A facility of 656 MLD with influent loading of 35 mg/L as NH3-N and 250 mg/L as BOD is used as a basis of the simulation study. Preliminary bioreactor sizing calculations are developed for six configurations. Subsequently, eight whole-plant simulation cases are compared to demonstrate operational savings for removal of Total Nitrogen. For the sample facility, this is shown to be on the order of $460 to $680K/year while attaining 66-70% Total Nitrogen removal and reduced greenhouse gas emissions by 2 kt CO2/year. The project concludes with ideas about future development of the Anammox process.

scholarly journals Aeration Control for Nitrogen Removal in a Small-Scale Oxidation Ditch.

2000 ◽  
Vol 36 (3) ◽  
pp. 107-117
Author(s):  
TERUHISA YOSHIDA ◽  
HIDEAKI HAMADA ◽  
MASANORI FUJITA
Keyword(s):  
Nitrogen Removal ◽  
Small Scale ◽  
Oxidation Ditch ◽  
Aeration Control
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