نوع مقاله : مقاله پژوهشی

نویسندگان

• حسنا فتاحی ¹
• جعفر مامی زاده ²
• امیر باقی ³
• حامد عبداللهی ⁴

¹ دانشجوی کارشناسی ارشد، گروه مهندسی آب، دانشکده کشاورزی، دانشگاه ایلام، ایلام، ایران

² دانشیار، گروه مهندسی آب، دانشکده کشاورزی، دانشگاه ایلام، ایلام، ایران

³ معاونت بهره برداری و توسعه آب، آب و فاضلاب استان ایلام

⁴ دانشجوی سابق کارشناس ارشد، گروه مهندسی آب ، دانشکده کشاورزی، دانشگاه ایلام

چکیده

در این مطالعه ارزیابی میدانی و شبیه‌سازی هیدرولیکی خطوط انتقال و شبکه توزیع آب شهر چوار با هدف اطلاع از وضعیت هیدرولیکی، میزان هدررفت و بررسی علل شکستگی‌های مداوم در شبکه برای دو حالت ماکزیمم و مینیمم مصرف در شبکه، با استفاده از نرم‌افزارهای AutoCAD، WaterGEMS و GIS انجام گرفت. نتایج حاصل از شبیه‌سازی در حالت پیک مصرف نشان داد 57 درصد از گره‌های شبکه، به علت اختلاف تراز بیش از 130 متر میان مخزن و مصرف‌‌کننده و عدم وجود شیرهای فشار شکن، فشاری خارج از محدوده مجاز14 تا 45 متر آب را داشته، و 73 درصد خطوط لوله نیز به جهت قطر نامناسب خطوط لوله، فاقد سرعت بهینه 3/0 تا 5/2 متر برثانیه می‌باشند. در حالت دوم شبیه‌سازی با 7/0 حداکثر دبی، فشار در گره‌ها رو به بهبود بوده و 5/64 درصد از گره‌ها دارای فشار بهینه بوده، اما سرعت در 84 درصد خطوط لوله فاقد سرعت بهینه می‌باشند. صحت سنجی شبیه‌سازی در خطوط انتقال با مقایسه اندازه‌گیری میدانی توسط دبی سنج آلتراسونیک و مقدار محاسبه شده در نرم افزار انجام گرفت. فشارسنجی شبکه نیز در چندین نقطه از آن توسط گیج فشارسنج انجام گرفت و این مقادیر با فشارهای حاصل از شبیه‌سازی در حالت کمترین میزان مصرف مقایسه گردید. نتایج نشان دهنده تطابق بالای شبیه‌سازی با ارزیابی میدانی شبکه می‌باشد.

کلیدواژه‌ها

• ارزیابی میدانی
• شبکه‌های توزیع آب
• مدیریت فشار
• نرم‌افزار WaterGEMS

موضوعات

• توزیع آب

عنوان مقاله [English]

Field measurement and hydraulic simulation of drinking water transmission lines and distribution network (case study: Chavar city, Ilam province)

نویسندگان [English]

• hosna fatahi ¹
• jafar mamizadeh ²
• amir baqi ³
• hamed abdolahi ⁴

¹ 1. MS.c student, Department of Water Engineering, Faculty of Agriculture, Ilam University, Ilam, Iran

² Associated professor, Department of Water Engineering, Faculty of Agriculture, Ilam University, Ilam, Iran.

³ 3. Deputy of Exploitation and Development of Water, Water and Sewerage of Ilam Province, Ilam, Iran.

⁴ 4. Former MS.c, Student, Department of Water Engineering, Faculty of Agriculture, Ilam University, Ilam, Iran

چکیده [English]

Abstract

Introduction:

The set of factors of decreasing rainfall, population increase, excessive use and waste of water in water supply networks have caused the world to face a serious shortage of water resources. Preventing water loss is one of the most important indicators of preserving water resources. In any place of water consumption (agriculture, drinking water, industry, etc.), we will naturally face water loss, but in urban water distribution networks, due to their large size and multiple connections, the amount of water loss is high.

Methods:

Chavar city is one of the cities of Ilam province, located 15 kilometers to the northwest of the provincial capital. The population of this city is 10,554 people, of whom 5,831 live in the central part of Chavar city. Most of the city's distribution network pipes are made of asbestos, polyethylene pipes and even some metal pipes with small diameters. There are asbestos pipes in diameters of 50, 110, 100 and 200 mm, polyethylene pipes in diameters of 110 and 125 mm; and steel pipes in diameters of 25, 38 and 200 mm. With field surveys, the as-built water network was updated and the hydraulic analysis of the network was done by AutoCAD, GIS, WaterGEMS software. According to the location of the subscribers, their consumption was allocated to the nearest pipe. In order to measure the pressure in different points of the network, oil type (glycerin) gauges were used. An ultrasonic portable flow meter was used to measure the flow rate.



Results:

In the first step of analysis of the transmission line, the flow rate was measured from the water supply well, the transmission pipeline and the two reservoirs in the transmission system. The design of the transmission line in two sections was modeled by WaterGEMS software. The first part includes a well to a concrete reservoir of 700 cubic meters, and the second part includes a reservoir of 700 to a 1000 cubic meters. There are four pumps in this network. The PMP-1 pump belongs to the well, which has a flow rate of 56.29 liters per second and a pump head of 153.3 meters. PMP-2, PMP-3 and PMP-4 pumps belong to the 700 cubic meter tank, which operate as two active pumps and one in standby mode during the day and one active pump and two pumps in standby mode during the night. In the case of two active pumps, each pump has a flow rate of 38.44 liters per second and a head of 158.3 meters. The pipelines analyzed in the software showed that the first transmission line transfers a flow rate of 56.2 liters per second at a speed of 1.79 meters per second to the 700 cubic meter reservoir. The second transmission line transfers the flow rate of 76.8 liters per second at a speed of 1.22 meters per second for the 1000 cubic meter reservoir to the distribution network. The speed in both pipelines is acceptable according to the range of design criteria, and the flow rate is completely consistent with the design flow rate of the pumps.The results of network simulation showed that 57% of the network nodes in the peak consumption mode, due to the level difference of more than 130 meters between the reservoir and the consumer and the absence of pressure reducing valves, the pressure is outside the permissible range of 14 to 45 meters of water. Also, 73 percent of the pipelines lack the optimal speed of 0.3 to 2.5 meters per second due to the inappropriate diameter of the pipelines. In the second simulation mode with 0.7 maximum flow rate (corresponding to the lowest amount of consumption in the coldest seasons of the year), the pressure in the nodes is improving, and 64.5% of the nodes have optimal pressure, but the speed in 84% of the pipelines is still outside the standard permissible range. Validation of the simulation in the transmission lines was done by comparing the discharge field measurement using the ultrasonic flow meter and the value calculated in the software. The pressure measurement of the network was also done at several points by the pressure gauge, and these values were compared with the pressures obtained from the simulation in the lowest consumption mode. The results showed that there is a good correlation between the hydraulic simulation results and the field evaluation of the network.

کلیدواژه‌ها [English]

• field evaluation
• water distribution networks
• pressure management
• WaterGEMS software