12-10-2016, 02:16 PM
AUTOMATION IN URBAN DRINKING WATER FILTRATION, WATER THEFT AND LEAKAGE IDENTIFICATION USING PLC AND SCADA
1458796804-AUTOMATIONINURBANDRINKINGWATERFILTRATION.docx (Size: 2.21 MB / Downloads: 6)
ABSTRACT:
Drinking water supply is one of the prime services to be provided by government in any nation. our survey shows that in Mysore and Ramanahalli, Karnataka, India the water reservoir near filtration has capacity to intake raw water and delivers 50MLD(Million Litres per Day) of filtered water. And also there is frequent problem of tapping water illegally by making use of suction pumps. Hence an efficient water distribution system is prime necessary to meet every demand for water supply. In this paper an improved method of water distribution system by automization using PLC (Programmable Logic Controller) and SCADA (Supervisory Control and Data Acquisition) is explained. And also water theft theft monitoring is implemented using flow variation sensed by flow sensors mounted on the water pipes. The above process is implemented in a prototype model and tested. Water tax calculation is also made based on the usage of water by an individual house.
. INTRODUCTION
The present drinking water supply control system is facing many problems related to testing of water filtration, pumping of water, storage and distribution of water. Conventional water supply department comprises five different sections for water supply. First is the pumping station, which does the sucking of water from water source (aerator) [2]. The second section is water testing laboratory in which turbidity and pH value is measured and find out the content of alum, chlorine and lime should be dosed [2]. Third section is the filtration department contains clariflacculator and sedimentation for clarifying of alum and lime dosage, granular media filter for further filtering of water. Fourth section is storage section which will store the filtered water for distribution. Fifth section is the distribution section through which water is distributed in all the municipal wards Currently these sections are working independently and manually. The major problems in water supply system are leakage or wastage of water and the majority public is using suction motors to suck water from main supply connection, which results decrease in water pressure and considered as theft.
To overcome above said problems an automated system has been proposed which enhances the water filtration, storage, distribution and reduces wastage of water as well as identify the theft of water. The water supply system is a part of the urban infrastructure which must assure the continuity of the water distribution, water quality control and the monitoring. The use of water diversity increases because of restriction imposed by the water availability, hydrological conditions, storage capability of tank, control and process parameters [1]. The entire SCADA system structure includes one or more main-station (PC based) that communicates with more PLC’s implemented into the pumping, control stations located in control panels throughout the network. The PLC’s handle the direct control of the technological process whereas the central dispatching unit user interfaces SCADA [2]. The treatment of data is implemented by the central station. The reduction of the operating cost as well as reduction in the water losses is now possible by the implementation of an intelligent control system. This offers the support for the optimization of the functional exploitation strategy and the optimization of equipment +use. The global online supervision of the water distribution network is realized by the central dispatching operator as well as the remote control of the actuators installed into the most important points of the system [2]. According to the requirements of the water flow condition, the flow sensors are installed in Wall Street stations or measuring points throughout the network. These electronic devices are connected to the PLC’s which transmit the data to the central dispatching station in order to offer dynamic behavior [2]. The PLC’s provide the data acquisition facility for different sensors (specific for water pressure, flow, level or chemical component concentration) using digital and analog modules; which insure the preliminary signal treatment and wireless data communication to the dispatching unit [2]. The SCADA system implemented to the central dispatching unit manages the data communication with all the PLC’s and which store the received data from measuring points and the pumping station. It offers advanced analysis functions as well as the remote control of the major technological parameters [2].
II. LITERATURE SURVEY
Conventional water supply department In Mysore and Ramanahalli (Karnataka), there is a capacity to intake raw water and deliver 50 MLD of filtered water in the pure water reservoirs near filtration house. The filtration process is divided into three main processes
• Aerator (intake water from water source),
• Water filtration (clariflacculator and sedimentation, granular media filter),
• Pure water storage and pump house.
The raw water from aerator is mixed with alum and chlorine in flash mixture. The oxidized water is passed to clariflacculator for sedimentation of dust particles as sludge and gets pure water for filtration unit for further Purification. The rotating fans in flocculation tank are switched on for few minutes so that the fine dust particles get coagulated & become heavy & get settled at bottom which can be guided to sludge pit. The water is filtered over rock sand bed in filtration unit. The filtration (rock sand) bed consists of 5-6 layers formed by jelly stones & sand particles of varying size. The bottom 3 layers consist of jelly stones of different sizes the top layers are filled with fine sand material. The filtered water from the sand bed is collected in the pipe with pores on the top. The backwash process is done to remove accumulated dust particles in the spaces between jelly stones in rock sand bed due to continuous filtration. When the backwash process is to be done to remove accumulated dust particles on rock sand bed, the output valve from granular filter to storage is closed. Conventional water distribution system comprises mechanical valves to distribute water. Since process is controlled manually, it requires more time and man power, with significant amount of wastage of water. Solenoid controlled valves will be incorporated to avoid wastage of water. Selection of solenoid valve depends upon size of water supply pipe and pressure of the water. The purified water is chlorinated to required amount and stored in storage tank.
III. PROPOSED SYSTEM
In this paper, it is proposed that the usage of atomization in water supply control and anti-theft control system for drinking water supply. It also includes self power generation and control’s the drinking water theft in the domestic areas. The Fig.1 shows the proposed system. The working process is as follows, the raw water from the aerator is mixed with alum and chlorine. The opening and closing of valve from alum tank is done manually in existing system which results in less or more release of alum into raw water channel. This is overcome by automatic open and close of valves by using PLC. A fan is situated in the faculator tank, in the existing system, this fan is turned on by manually by walking on small pavement, left and right hand side of the pavement is filled with water which is 30ft under the ground, there is risk in life of an operator. Therefore to overcome this problem, the operation of fan is atomized using PLC. The main purpose of using this fan in flocculator is when the fan is turned on, the minute dust particles in the raw water get coagulated and get become heavy so that it is settled at the bottom which can be guided to the sludge pit later The filtration process is controlled by PLC. When the backwash process is to be done, the valve between granular filter and storage is closed and the opening of valve to sludge pit is automatically controlled. The water theft and leakage are identified using flow sensors. Each flow sensor records the incoming and outgoing flow rates. The PLC calculates the difference in the flow rates of sensors, if the difference exceeds the limiting value it is recorded as leakage or theft, and the valve behind the first flow sensor and distribution motor are turned off automatically. As leakage or theft occurs a message is delivered to responsible officers in control room and wall men .A red alarm pops up on the SCADA screen when the leakage or
theft occurs. According to the usage of water by an individual house, water tax be calculated automatically using smart meters which has the ability to store and transmit consumption date frequently. Sometimes it used as “time of use” meters because in addition to measuring the volume consumed, they also record the data and time the consumption occurs. Smart meters can read remotely and more frequently, providing instant access to water consumption information of both customers and water utilities. It is a two way meter communications, allowing information and commands to be sent towards end users for multiple purpose including real time usage and pricing information, leak and abnormal usage detection ,targeted water efficiency messaging, measuring changes in water use and even remote service disconnects. Here using flow sensor pulses itself the water tax is calculated and displayed on scada screen. In real time implementation due to technology upgrades smart meters will be more economical.