Calculation method for determining the capacity of intermediate storage tanks in storm sewer networks (for discussion)

Author(s):  
А.Г. Гудков

Целью работы является дополнение и уточнение методик, приведенных в действующей нормативно-методической базе, для инженерного расчета схем регулирования расходов в сетях дождевого водоотведения. Методом математического моделирования с применением системы компьютерной алгебры проанализированы три схемы регулирования, включающие емкости, насосы и разделительные камеры. Предложена универсальная расчетная формула определения объема регулирующего резервуара в схеме регулирования с опорожнением емкости насосами для всех типов разделительных камер. Установлены зависимости и приведены графики, показывающие влияние на величину объема резервуара коэффициента, который учитывает непостоянство расхода, отводимого разделительной камерой в коллектор. Для схемы регулирования без насоса и разделительной камеры подобрана степенная аппроксимирующая функция, позволяющая проводить расчет величины объема с приемлемой точностью, без численного интегрирования. Для двух схем регулирования с опорожнением самотеком предложены новые формулы определения объема регулирующего резервуара в широких диапазонах коэффициентов регулирования и параметров дождей. Приведены уточненные таблицы, упрощающие инженерные расчеты регулирующих резервуаров. Предложенные в работе формулы и таблицы позволяют рассчитывать емкость резервуаров для всех рекомендуемых схем регулирования расходов. The work aims at supplementing and clarifying the methods given in the current regulatory and methodological framework for the engineering calculation of flow control schemes in storm sewer networks. By the method of mathematical modeling using a computerized algebra system, three control schemes are analyzed, including tanks, pumps and separation chambers. A universal calculation formula for determining the capacity of an intermediate storage tank in a control scheme with emptying the tanks by pumps is proposed for all types of separation chambers. Dependencies are established and graphs are presented that show the effect on the tank capacity of a coefficient that takes into account the variations of the flow discharged by the separation chamber into the sewer. For the control scheme without a pump and a separation chamber, an exponential approximating function has been selected that allows calculating the capacity value with acceptable accuracy, without numerical integration. For two control schemes with gravity emptying, new formulas are proposed for determining the capacity of an intermediate storage tank in wide ranges of control coefficients and rain parameters. Amended tables are given that simplify the engineering calculations of intermediate storage tanks. The formulas and tables proposed in the paper allow calculating the capacity of tanks for all the recommended flow control schemes.

2012 ◽  
Vol E95.B (9) ◽  
pp. 2751-2758
Author(s):  
Atsushi TAKAHASHI ◽  
Nobuyoshi KOMURO ◽  
Shiro SAKATA ◽  
Shigeo SHIODA ◽  
Tutomu MURASE
Keyword(s):  

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 55
Author(s):  
Nicholas Hawkins ◽  
Bhagyashri Bhagwat ◽  
Michael L. McIntyre

In this paper, a nonlinear controller is proposed to manage the rotational speed of a full-variable Squirrel Cage Induction Generator wind turbine. This control scheme improves upon tractional vector controllers by removing the need for a rotor flux observer. Additionally, the proposed controller manages the performance through turbulent wind conditions by accounting for unmeasurable wind torque dynamics. This model-based approach utilizes a current-based control in place of traditional voltage-mode control and is validated using a Lyapunov-based stability analysis. The proposed scheme is compared to a linear vector controller through simulation results. These results demonstrate that the proposed controller is far more robust to wind turbulence than traditional control schemes.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Musa Manga ◽  
Timothy G. Ngobi ◽  
Lawrence Okeny ◽  
Pamela Acheng ◽  
Hidaya Namakula ◽  
...  

Abstract Background Household water storage remains a necessity in many communities worldwide, especially in the developing countries. Water storage often using tanks/vessels is envisaged to be a source of water contamination, along with related user practices. Several studies have investigated this phenomenon, albeit in isolation. This study aimed at developing a systematic review, focusing on the impacts of water storage tank/vessel features and user practices on water quality. Methods Database searches for relevant peer-reviewed papers and grey literature were done. A systematic criterion was set for the selection of publications and after scrutinizing 1106 records, 24 were selected. These were further subjected to a quality appraisal, and data was extracted from them to complete the review. Results and discussion Microbiological and physicochemical parameters were the basis for measuring water quality in storage tanks or vessels. Water storage tank/vessel material and retention time had the highest effect on stored water quality along with age, colour, design, and location. Water storage tank/vessel cleaning and hygiene practices like tank/vessel covering were the user practices most investigated by researchers in the literature reviewed and they were seen to have an impact on stored water quality. Conclusions There is evidence in the literature that storage tanks/vessels, and user practices affect water quality. Little is known about the optimal tank/vessel cleaning frequency to ensure safe drinking water quality. More research is required to conclusively determine the best matrix of tank/vessel features and user practices to ensure good water quality.


Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 573
Author(s):  
Sameer Shadeed ◽  
Sandy Alawna

In highly water-poor areas, rooftop rainwater harvesting (RRWH) can be used for a self-sustaining and self-reliant domestic water supply. The designing of an optimal RRWH storage tank is a key parameter to implement a reliable RRWH system. In this study, the optimal size of RRWH storage tanks in the different West Bank governorates was estimated based on monthly (all governorates) and daily (i.e., Nablus) inflow (RRWH) and outflow (domestic water demand, DWD) data. In the estimation of RRWH, five rooftop areas varying between 100 m2 and 300 m2 were selected. Moreover, the reliability of the adopting RRWH system in the different West Bank governorates was tested. Two-time series scenarios were assumed: Scenario 1, S1 (12 months, annual) and scenario 2, S2 (8 months, rainy). As a result, reliable curves for preliminary estimation of optimal RRWH storage tanks for the different West Bank governorates were obtained. Results show that the required storage tank for S1 (annual) is more than that of the S2 (rainy) one. The required storage tank to fulfill DWD is based on the average rooftop area of 150 m2, the average family members of 4.8, and the average DWD of 90 L per capita per day (L/c/d) varies between (75 m3 to 136 m3) and (24 m3 to 84 m3) for S2 for the different West Bank governorates. Further, it is found that the optimal RRWH tank size for the 150 m2 rooftop ranges between 20 m3 (in Jericho) to 75 m3 (in Salfit and Nablus) and between 20 m3 (in Jericho) to 51 m3 (in Jerusalem) for S1 and S2 scenarios, respectively. Finally, results show that the implementation of an RRWH system for a rooftop area of 150 m2 and family members of 4.8 is reliable for all of the West Bank governorates except Jericho. Whereas, the reliability doesn’t exceed 19% for the two scenarios. However, the reduction of DWDv is highly affecting the reliability of adopting RRWH systems in Jericho (the least rainfall governorate). For instance, a family DWDv of 3.2 m3/month (25% of the average family DWDv in the West Bank) will increase the reliability at a rooftop area of 150 m2 to 51% and 76% for S1 and S2, respectively.


Photonics ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 7
Author(s):  
Jia-Ning Guo ◽  
Jian Zhang ◽  
Gang Xin ◽  
Lin Li

As a novel mode of indoor wireless communication, visible light communication (VLC) should consider the illumination functions besides the primary communication function. Dimming control is one of the most crucial illumination functions for VLC systems. However, the transmission efficiency of most proposed dimming control schemes changes as the dimming factor changes. A block coding-based dimming control scheme has been proposed for constant transmission efficiency VLC systems, but there is still room for improvement in dimming range and error performance. In this paper, we propose a dimming control scheme based on extensional constant weight codeword sets to achieve constant transmission efficiency. Meanwhile, we also provide a low implementation complexity decoding algorithm for the scheme. Finally, comparisons show that the proposed scheme can provide a wider dimming range and better error performance.


Author(s):  
Nasim Ullah ◽  
Irfan Sami ◽  
Wang Shaoping ◽  
Hamid Mukhtar ◽  
Xingjian Wang ◽  
...  

This article proposes a computationally efficient adaptive robust control scheme for a quad-rotor with cable-suspended payloads. Motion of payload introduces unknown disturbances that affect the performance of the quad-rotor controlled with conventional schemes, thus novel adaptive robust controllers with both integer- and fractional-order dynamics are proposed for the trajectory tracking of quad-rotor with cable-suspended payload. The disturbances acting on quad-rotor due to the payload motion are estimated by utilizing adaptive laws derived from integer- and fractional-order Lyapunov functions. The stability of the proposed control systems is guaranteed using integer- and fractional-order Lyapunov theorems. Overall, three variants of the control schemes, namely adaptive fractional-order sliding mode (AFSMC), adaptive sliding mode (ASMC), and classical Sliding mode controllers (SMC)s) are tested using processor in the loop experiments, and based on the two performance indicators, namely robustness and computational resource utilization, the best control scheme is evaluated. From the results presented, it is verified that ASMC scheme exhibits comparable robustness as of SMC and AFSMC, while it utilizes less sources as compared to AFSMC.


2013 ◽  
Vol 671-674 ◽  
pp. 1399-1402
Author(s):  
Ying Sun ◽  
Jian Gang Sun ◽  
Li Fu Cui

To study the impact of floating roof on seismic response of vertical storage tank structure system subjected to seismic excitation, select 150000m3 storage tanks as research object, and the finite element analysis model of storage tanks with and without floating roof were established respectively. The seismic response of these two types of structure in different site conditions and seismic intensity were calculated and the numerical solutions were compared. The results show that floating roof has little impact on base shear and base moment in different site conditions and seismic intensity. Floating roof can effectively reduce the sloshing wave height. The influence of floating roof on dynamic fluid pressure decreases with the increase of seismic intensity, which is less affected by ground conditions.


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