PS-313-Aamir Mehmood

9th International Conference on Fracture & Strength of Solids June 9-13, 2013, Jeju, Korea

Development and Computational Flow Analysis of GSM Based Automated Solar Water Pump Aamir Mehmood1, *, Abdul Wasy2 , Adeel Waqas1, Jung Il Song2 1

Center for Energy Systems, National University of Sciences and Technology, Islamabad, Pakistan 2

Department of Mechanical Engineering, Changwon National University, Changwon, 642-773, Republic of Korea

Abstract: Environment friendly renewable energy systems are the need of time from domestic to industrial scale. Today, World is facing energy crisis due to shortage of conventional non-renewable energy which are linked with utilization of renewable resources. This research work comprise of development of solar water pump prototype for domestic and commercial purpose e.g., irrigation. The system contains the assembling of DC-motor with diaphragm pump and photovoltaic mono-crystalline solar panel. The pump is driven by solar energy solely through photovoltaic (PV) panel. The electrical energy supplied by panel can also be consumed for domestic usage during pump switched off period. Solar fraction utilization is efficiently enhanced by integrating maximum power point tracker (MPPT). The pump operation is automated by using global system for mobile (GSM) communication networking to facilitate the user. Communication operating code for micro-controller is developed using C-language and MATLAB software. Experiments are carried out for investigating the effect of pump head on flow rate with relevance of solar energy. Computational fluid dynamic analysis is performed for estimating the pressure and velocity variations as water flows through pump delivery head, especially across the bends of pipeline. The pump is modeled in GAMBIT and analysis is carried out using ANSYS-FLUENT. It is concluded that, 14W solar panel having 17% efficiency attached with 0.018hp pump gives output of 4.344 lit/h at 0.762-m head and the pump can be automated any time from any location covered by GSM network. Keywords: Renewable resources, Solar water pump, Automation, Maximum power point tracker, Fluid dynamics.

1. Introduction The whole world is going to be the victim of energy crisis because fossil fuels are at the edge of being extinct. During last two decades, a lot of focus has been given to efficient utilization of indigenous renewable energy resources like solar, wind, hydro and thermal energy along with available conventional energy resources. Renewables can’t replace fossil fuel based energy technologies but it will serve as an add-on. Vliet OPRV [1] predicted the solar energy as the most important alternative energy source among renewables in future because of its inexhaustible nature. Solar photovoltaic and thermal are specifically preferential over other renewable sources for serving over two billion people in urban and rural areas without being connected to grid electric supply as mentioned by Ottinger RL [2]. Water pump has an authoritative function in agriculture sector. Kim YB [3] suggested the photovoltaic powered solar water pump an ideal equipment for irrigation purpose in those areas where electricity is not available or is much expensive. Daud Ak [4] has revealed that the water pumping systems powered by photovoltaic panels have been practiced in many regions of world since 1977. Among several pump options for irrigation purpose, Rao DP [5] has proposed two experimented types of water pumps that were designed to be driven by solar photovoltaic energy. Yao GU [6] has introduced the modernized management of water pump operation that is achieved by a communication system consisting of public switch telephone network (PSTN) and global system for mobile communication (GSM) for monitoring and controlling the unmanned pump working. Jun-ji [7] narrated the automation process of receiving and transmitting short code message using handset that involves data line connection, transmission instructions in short message, coding embedded in program, burned on microcontroller, and AT commands analysis. Yuksekkaya B. [8] praised the automation networking system for pump operation that offers a complete, economical, powerful and user friendly way for long destination monitoring and control operation of water pump in an effective mode. Optimized output power of photovoltaic array depends upon the module temperature, solar irradiance condition, azimuth angle. For this purpose, Femia N [9] has advised the use of maximum power point tracking techniques (MPPT) that work by continuous chase of maximum solar irradiance point for *

Corresponding author: E-mail: [email protected] ; 1

Tel: +92-300-650-7809

9th International Conference on Fracture & Strength of Solids June 9-13, 2013, Jeju, Korea photovoltaic (PV) system. Esram T [10] has stated nineteen different techniques for implementing maximum power point tracking on photovoltaic (PV) module with many variations. Enslin JHR [11] theoretically concluded that an integrated maximum power point tracker causes 25% increase in output energy as compare to power provided by standard PV panel but Koutroulis E. [12] has approved experimentally that a buck type MPPT system involving DC/DC converter and controlled by microcontroller-based unit causes only 15% increase in output power of PV module as compared to a system in which DC/DC converter duty cycle is configured in such a way that photovoltaic array produces optimum power at 1 kW/m2 and 250C climate conditions. Parametric variations in velocity and pressure are also of great interest in perspective of delivery pipeline of water pump. Zheng D. [13] suggested computational fluid dynamic (CFD) simulations to be performed for analyzing the effect of vertical pipe altitude and bends on fluid dynamic parameters like pressure and velocity variations. According to Beggs DH [14], In vertical rising delivery pipeline as fluid rises pressure at the above of fluid top surface decreases but at the bottom increases because of falling weight of above liquid. Quan S. [15] added that in a consequence of decreased pressure above the top surface and increased pressure at bottom, velocity of rising fluid also decreases because of increased viscosity ratio between fluid layers and especially of increased friction caused by boundary layer effect.

2. Modeling and Analysis 2.1 Experimental Model GSM based automated water pump model was developed that is driven by solar energy solely provided through photovoltaic panel. The basic purpose of this model is to get know how of solar water pump modeling, automation. Experimental and computational fluid dynamic analysis of delivery flow line of water pump is carried out for observing pressure and velocity variations imprinted by flow line altitude and bends. Assembled model consists of diaphragm pump, photovoltaic panel, water reservoirs, delivery pipeline, global system for mobile communication to automate the pump and maximum power point tracker. For the manufacturing, the basic pump design was based on concept of Bifzer M [16]. A 12-volt DC windscreen washer pump of 0.018hp offering 11-Ohm resistance and requires 1.091Amp current for operation, whose internal outline is shown in Fig. 1, which explained the designing and working of windscreen washer pump that operates on the principle of positive displacement reciprocating diaphragm pump having a cavity in which a flexible diaphragm is arranged with a pair of metal discs on each side of diaphragm. In general pump design, diaphragm is secured about its periphery and engaged between upper and lower casing portions in such a way that splits the cavity into two chambers, an air chamber above the top surface of diaphragm and a water chamber exists below the diaphragm lower surface.

Fig. 1 Cross-sectional View of Diaphragm Washer Pump Water pump has delivery head of 0.762-m and installed at water level for pumping water. Mono-Si photovoltaic panel of 20Watt having 17% efficiency is attached with water pump for providing operational power. Although pump requires only about 14Watt panel for operation but for the purpose of charging the battery during pump turned off period, we installed 20Watt PV panel at a slope angle of β=45o. A battery of 12Volt, 4Amp is attached with PV panel to utilize the solar energy for residential appliances powered by charged battery during non-sunny period and directly form PV panel during sunny period when pump is not in functional state. Battery charging and discharging graphs are shown in Fig. 2 [17]. Here drop caused by battery internal resistance is also taken under consideration. The maximum battery voltage variation observed is from 12.5V point to 11.6V on maximum charging and 80% discharging. 2


Fig. 2 Battery Charging and Discharging Pump operation is automated through global system for mobile communication networking that operates using SMS services. GSM SIM-900 module, shown in Fig. 3 [18], consisting of quad band GSM/GPRS 850/ 900/ 1800/ 1900 MHz, built in RS232 converter (MAX3232), built in SIM card holder, operating temperature ranges from -400C to +850C, text and PDU mode, embedded TCP/UDP protocol, implanted multi-media services, signal antenna, embedded AT and is tri-codec i.e., half rate, full rate, enhanced full rate.

Fig. 3 GSM Module SIM-900 Other operational components of automation system are micro-controller PIC18F452, GSM evaluation board, octocoupler TLP521-4, voltage regulator, push button, relay, resistors and capacitors. Program for operation being automated through SMS services only is made in MATLAB using C-language in terms of AT commands. Four AT commands are used in this program for GSM automation; AT (it serves the O.K function), AT+GMGF=1 (for testing the text mode function), AT+CNMI= 1, 2,0,0,0 (sets up the SMS interrupt), AT+GMGS= “SIM card number for GSM module” (sends message to SIM-900 module and forwards response message to operator). Further, for the optimum operational efficiency of solar panel throughout the day in spite of varying ambient conditions maximum power point tracker (MPPT) technique is used. A basic idea of MPPT circuitry is shown in Fig. 4. MPPT helps the panel to be at minimum angle of incidence between solar radiations and panel surface normal and maximizes the absorbed radiations and consequently the performance of panel.

Fig. 4 Basic Idea of MPPT Circuit 3


2.2 Experimentation and Results Experimental analysis is carried out to find the effect of delivery head on flow rate of pump. Delivery pipeline has altitude of 0.762-m involving two bends as proceeds from pump, positioned at water reservoir level, to delivery tank. A positive displacement reciprocating diaphragm pump delivers a definite quantity of liquid through a specific height by displacement of its plunger. Pump discharge is given by equation 1 & 2. (1) Q = LAN/60 [For single acting pump] And Where;

Q = 2LAN/60 [For double acting pump]

(2)

L= Length of stroke/ piston A= Piston cross-sectional area N= No. of revolutions of crank/ minute Power required to drive the reciprocating diaphragm pump that sucks liquid and delivers through delivery head to some height is represented by equation 6. (kN) (3) Force on piston in forward stroke; FForward = w * H S * A Force on piston in backward stroke; Pump wok done;

FBackward = w * H d * A (kN) PumpWork = w * Q * ( H d + H S ) (kN-m)

(4) (5)

Theoretical power required to drive the pump;

PRe quired = w * Q * ( H d + H S )

(kW)

(6)

Here;

w= Specific weigh of liquid to be delivered Q= Liquid Discharge A= Piston Area Hs= Suction head of pump H d = Delivery head of pump We operated the pump by providing the solar energy through photovoltaic panel directly and determined the variations in flow rate of pump caused by delivery head. Results of repeated attempts to find out discharge of pump with and without delivery head are given in Table 1.

Sr. No

Flow Volume (Liter) 1 0.5 2 1.0 3 1.5 4 2.0 5 2.5 6 3.0 Average Flow Rate

Table 1. Experimental Results [without delivery head] Time Flow Rate (sec) (Lit/sec) (m3/sec)*10-05 5.34 0.0936 9.36 10.84 0.0922 9.22 16.68 0.0899 8.99 22.77 0.0878 8.78 28.83 0.0867 8.67 35.09 0.0855 8.55 0.0893 Lit/sec 8.93*10-05 m3/sec

[with 3.3 feet delivery head] Time Flow Rate (sec) (Lit/sec) (m3/sec)*10-05 6.80 0.0735 7.35 13.48 0.0731 7.31 20.69 0.0725 7.25 27.60 0.0722 7.22 33.71 0.0718 7.18 40.32 0.0710 7.10 0.0724 Lit/sec 7.24*10-05 m3/sec

Graph curve, shown in Fig. 5 developed using experimental results of table.1, interprets the variations of flow rate against flow volume. Resultant falling curve shows that flow rate decreases as delivery line height increases due to decrease in velocity. In same fashion, falling curve in Fig.5 showing flow volume and flow rate relation for delivery head indicates that flow rate decreases gradually with the increase in elevation and also of increased flow volume. As height increases, at any instant static pressure above the top surface of fluid decreases and in this regard velocity also decreases. Due to this decrease in velocity, weight density of upper level liquid in delivery pipeline increases over lower level fluid and consequently flow rate decreases.

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Fig. 5 Experimental Results Analysis Delivery pipeline inlet velocity and pressure values would be equal to corresponding pump exit values as pump is installed at water level. Parametric variations in their values that cause decrease in flow rate of operating pump as fluid rises through 0.762-m height is calculated as by using Equ. 7 & 10. (7) v =Q/ A Here;

A = (π / 4) * d 2 [cross-sectional area of pipe] [d = 0.2 in] A = (π / A) * (0.2) 2 = 0.0314 in2 = 2.026* 10-05 m2 Q= 8.93*10-05 m3/sec

From Equ.7;

v =Q/ A

v = 8.93* 10-05 / 2.026* 10-05 [(m3/sec)/m2] v = 4.408 m/sec [=Pump exit velocity] Fluid flow inlet velocity = v in = 4.408 m/sec And at the altitude of 0.762-m, velocity of fluid flowing out of delivery pipeline is; From Equ.7; v =Q/ A v= 7.24*10-05 / 2.026* 10-05 [Q= 7.24*10-05 m3/sec] Fluid flow exit velocity = v exit = 3.574 m/sec So, there is about 18.92% decrease in velocity as fluid rises through a uniform area delivery pipeline having 0.762-m height. For calculating fluid flow pressure at delivery pipe inlet; Torricelli’s Theorem;

v = 2gh 0.5 H = P/w

(8) [from P = w * H ]

And Putting (Equ.9) in (Equ.8) and by taking square; Thus;

v 2 = 2 gP / w Pin = v 2 * w / 2 g

(9)

(10)

For ρ = 1000 kg/m3;

w = 9.807 kN/m3 (considered flowing liquid is pure water) [(m2/sec2)*(kN/m3)/ (m/sec2)] P in = (4.408)2* (9.807)/ 2*(9.98) 2 [=Pump exit pressure] Fluid flow inlet Pressure = P in = 9.547 kN/m And fluid flow exit pressure at 0.762-m height of delivery pipeline; From Equ.10;

PExit = v 2 * w / 2 g

= (3.574)2* (9.807)/ 2*(9.98) Fluid flow exit Pressure = P Exit = 6.276 kN/m2 Delivery pipeline inlet and exit pressure values shows that there is about 34.262% decrease in pressure value as fluid rises through altitude of 0.762-m. 2.3 Computational Fluid Dynamic Analysis Computational fluid dynamic (CFD) analysis is carried out to interpret the impression of delivery head and bends present in flow line on pressure and velocity of liquid flow through pump supply line. Delivery pipeline is designed using GAMBIT having 0.762-m elevation and two bends from pump 5

9th International Conference on Fracture & Strength of Solids June 9-13, 2013, Jeju, Korea installed level to receiving reservoir, as shown in Fig. 6. Oltra R [19] has suggested the micro-stresses that influence the pressure and velocity gradient during flow through a specific elevation can be described by using numerical simulation based finite element method. In consequence of this method, quadratic meshing, shown in Fig. 7, of modeled pipeline having about 9300 quadrilateral cells is performed for interpreting unambiguous analysis results.

Fig. 6 GAMBIT Modeled Delivery Pipeline

Fig. 7 Meshed Pipeline

For performing analysis and interpreting results, meshed modeled pipeline is imported in FLUENT. By using above calculated fluid flow inlet velocity and pressure values, analysis is carried out in FLUENT. Results interpreting pressure and velocity variations are shown in Fig. 8 & 9 respectively. Pressure results shows that as height of pipeline increases, absolute value of pressure exists above the top surface of rising fluid decreases. Same trend is observed for static pressure variations that is corresponds to pressure above the top surface at any instant. As pressure values at top surface of fluid decreases, pressure value at bottom of pipeline increases due to above rising fluid weight density and decreased velocity. From Bernoulli’s relation, velocity magnitude of fluid flow also decreases, as shown in Fig. 9, with the decrease in absolute and static pressures. Boundary layer effect also causes the velocity to be decreased. Across the bend there would be an intense decrease in velocity values because of additional increased friction between fluid layers, increased boundary layer effect and decreased pressure.

Fig. 8 Pressure vs Position Results (a) Absolute pressure variations (b) Static pressure variations

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Fig. 9 Contours of Velocity Magnitude Suggestions This research work includes the demonstrative prototype of GSM based automated solar water pump. This prototype can be prolonged into commercial scale applications that would be very beneficial for formers especially in those regions facing energy problems or do not have grid connected electricity access. Graphical results show that there is more intense decrease in pressure and velocity of flowing fluid due to bends relative to height. Although longer the delivery head, greater will be decrease in flow rate. But this flow rate can be increased by reducing number of bends present in delivery head rather than compromising on delivery head. The efficiency of system can further be improved by producing good quality pyramids at the top surface of mono-crystalline solar cells that increases the solar array’s absorption of solar radiations up to 98%. The application of anti-reflection coating (ARC) on the surface of pyramids further reduces the deflection of solar radiations and enhances solar radiations absorption up to 99%. This work will prove to be a significant contribution in alternative energy, especially solar systems and can easily be adopted at industrial scale manufacturing. References [1] Vliet OPRV, Kruithof T, Turkenburg WC, Faaij APC. Techno-economic comparison of series hybrid, plug-in hybrid, fuel cell and regular cars. Journal of Power Sources 2010;195 (19):65706585. [2] Ottinger RL, Williams R. Renewable energy sources for development. Pace Law Faculty Publications 2002; Paper 254. [3] Kim YB, Lee SK, Kim ST, La WJ, Son JG, Lee YK. Experimental analysis on the performance of a solar powered water pump. Journal of Biosystems Engineering 2004; 29(6):521-530. [4] Daud AK, Mahmoud MM. Solar powered induction motor-driven water pump operating on a desert well, simulation and field tests. Renewable Energy 2005; 30(5):701-714. [5] Rao DP, Rao KS. Soalr water pump for lift irrigation. Solar Energy 1976;18(5):405-411. [6] Yao GU, Xing HE, Wei-dong Z. Remote monitoring and control system for urban unmanned pump station. China Water and Wastewater 2004. [7] Jun-ji WU, Wen-bin W, Peng Z. Remote metering system based on GSM. Electric Power Automation Equipment 2006. [8] Yuksekkaya B, Kayalar AA, Tosun MB, Ozcan MK, Alkar AZ. A GSM, internet and speech controlled wireless interactive home automation system. Consumer Electronics, IEEE Transactions 2006;52 (3):837-843. [9] Femia N, Petrone G, Spagnuolo G, Vitelli M. Optimization of perturb and observe maximum power point tracking method. Power Electronics, IEEE Transactions 2005; 20(4):963-973. [10] Esram T, Chapman PL. Comparison of photovoltaic array maximum power point tracking techniques. Energy Conversions, IEEE Transactions 2007;22 (2):439-449. [11] Enslin JHR, Wolf MS, Snyman DB, Swiegers W. Integrated photovoltaic maximum power point

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9th International Conference on Fracture & Strength of Solids June 9-13, 2013, Jeju, Korea tracking converter. Industrial Electronics, IEEE Transactions 1997; 44(6):769-773. [12] Koutroulis E, Kalaitzakis KC, Voulgaris NC. Development of a microcontroller-based photovoltaic maximum power point tracking control system. Power Electronics, IEEE Transactions 2001; 16(1):46-54. [13] Zheng D, He X, Che D. CFD simulations of hydrodynamic characteristics in a gas–liquid vertical upward slug flow. International Journal of Mass and Heat Transfer 2007; 50(21-22):4151-4165. [14] Beggs DH, Brill JP. A study of two-phase flow in inclined pipes. Journal of Petroleum Technology 1973;25: 607-617. [15] Quan S, Lou J. Viscosity-ratio-based scaling for the rise velocity of a Taylor drop in a vertical tube. Physical Review E- Statistical, Nonlinear and Soft Matter Physics 2011; 84(3 Pt2):036320. [16] Bifzer M. Windshield washer. US Patent 2,881,959, 1959 – Google Patents; Serial No. 618,893. [17] Ghaffar H, Ali SM, Waleed A, Gellani HE. Economic and environmental viability of hybrid solar vehicle in Pakistan. In conference program guide of International Conference on Engineering Sciences (ICES) 2012; SEED-1:28-29 Feb, 2012, Lahore. [18] Hardware Design SIM_HD_V1.01. A company of SIM Tech; 2009. [19] Oltra R, Vignal V. Recent advances in local probe techniques in corrosion research – Analysis of the role of stress on pitting sensitivity. Corrosion Science 2007; 49(1):158-165.

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