Presentation on Pumps By G.MURALIKRISHNA EE(E) BSNL ED-1
Transcription
Presentation on Pumps By G.MURALIKRISHNA EE(E) BSNL ED-1
Presentation on Pumps By G.MURALIKRISHNA EE(E) BSNL ED-1 An Overview Types of Pumps Features of various Pumps Selection of pumps Performance Calculation Flow control strategies Energy saving measures in Pumps Types of Pumps Dynamic Pumps • Centrifugal • Special effect pumps Displacement Pumps • Rotary • Reciprocating Order of Preference Centrifugal Rotary Reciprocating Pumps Used in Building Services Sump Pumps • Monobloc Bore well Pumps • Submersible Pumps • Jet Pumps Centrifugal Pumps Very simple design Two main parts are the impeller and the diffuser Impellers • Bronze • poly carbonate • cast iron stainless steel Pressure developed by the Pump depends upon • • • • Impeller dia No.of impellers size of the impeller eye shaft speed Size of the pump Depends on • Head • Capacity Advantages of centrifugal Pump Very efficient Produce smooth and even flow Reliable with good service life Disadvantages Loss of priming easily Efficiency depends upon operating design head & speed. Submersible Pumps Centrifugal pump closely coupled with motor Does not require long drive shaft Motor operates at a cooler temperature. Noiseless operation. High efficiency Smooth and even flow In case of repair full pump to be removed. Jet Pumps Combination of a surface centrifugal pump, nozzle and venturi arrangement. Used in small dia bore wells. Simple design Low purchase and maintenance cost. Easy accessibility to all moving parts. Low efficiency. DSM measures to reduce consumption in pumps Demand side management measures Use of friction less foot valve. Use of HDPE pipes Use of appropriate capacitor. Use of higher size suction pipe compared to delivery pipe. Pump Performance calculation Overall Efficiency = Hydraulic power ( P2) X 100/ Power input ( P1) Pump efficiency. = Hydraulic power ( P2) X 100/ Power input to pump shaft ( P3) Hydraulic Power ( P2) = Q X Total Head ( hd hs ) X p X g / 1000 Q = discharge in m³/s p = density of fluid in kg/ m³ g = acceleration due to gravity ( m/s²) P1 = 1.732 X V X I X pf P3 = P1 X eff.of motor. Key Parameter for determining efficiency Flow Head Power Flow Measurement Techniques Tracer Method Ultrasonic flow measurement Tank filling method Installation of online flow meter Determination of total head Suction head • measured from pump inlet pressure gauge reading Discharge head • This is taken from the pump discharge side Pr. gauge Typical name plate details of pump Pumps: (Monoblock Pumps used for Drinking water) • • • • • Sl.No ITEM 1 Make 2 Capa hp/kW 3 Pipe sizes S/D 4 Head Pump1 Pump2 Beacon Beacon 5 (3.7) 5 (3.7) 65/50 mm 65/50 mm 25 m 25 m Typical name plate details of pump • 5 Discharge • 6 Amps • 7Overall Efficiency 8 L/s 8 47% 8 L/s 8 47 % Typical performance calculations PUMP EFFICIENCY CALCULATION SHEET SL.NO. ITEM Pump1 Pump2 Units 1 Voltage 406 407 volts 2 Current 6.0 6.6 amps 3 P.F 0.83 4 Power input 3.5 0.82 3.48 KW Typical performance calculations 5 6 7 8 9 Dis. Head 22.2 Suc.Head 2.2 discharge 8 Hyd.Power 1.57 Pump Effi. 44.85 22.2 m 2.2 m 8 L/s 1.57 KW 45.10 Typical observations/ Recommendations 1. Replace the existing discharge line with the 50 mm dia pipes to reduce the friction losses. 2. Provide water level switch to switch off the pump sets as soon as the Tank is filled. 3. Replace the existing pump sets with high efficiency pump sets. Factors to be considered from user side Size pump correctly Operate close to the best efficiency point. Size all piping and valves correctly Avoid all leakages. Flow control Strategies Varying speed Pumps in parallel stop/start control Flow control valve By pass control valve Trimming impeller Use of VFDS Energy conservation opportunities in pumping Operate pump near best efficiency point. Replace old pumps by energy efficient pumps Reduce system resistance by pressure drop assessment and pipe size optimization. Provide booster pump for few areas of higher head. Energy conservation opportunities in pumping Conduct water balance to minimize water consumption. Ensure availability of instruments like pressure gauges, flow meters. Repair seals and packing to minimize water loss. Avoid valves in discharge side as far as possible. Operate pumpset during non-peak hours. Thank You