Copyright © 2010 Jindal Steel & Power Ltd. · 27 Copyright © 2010 Jindal Steel & Power Ltd. Analysis : Impeller of the Pump proposed to be ‘trimmed-down’ up to acceptable level,

Copyright © 2010 Jindal Steel & Power Ltd. 1


These Pumps supply DM water in close circuit cooling system of ‘bed ash cooler’ and bearing oil cooler of HT motors (BFP, PA/SA/ID Fans etc).

Power Plant (6x135 MW): Motor: 110 kW, 196 Amp; Pump: 430 m3/hr, 60 m-H. Quantity – 3 (2W + 1S) for each two Units

Process Boiler (3x180TPH): Motor: 30 kW, 52.4 Amp; Pump: 200 m3/hr, 36 m-H. Quantity – 4 (3W + 1S) One pump for each Boiler



Observation:

Earlier pumps were running in throttled valve condition and whenever we try to open discharge valve beyond 20%, the motor was getting over loaded and unable to increase the flow rate.


Analysis:

As DMCW Tank is placed on de-aerator floor (+20m), so NPSHA =20m against of 6m required head. Due to this, discharge head is reaching up to 90m, against of rated

discharge head 60m.

Pump Suction Head = 20/22M Discharge Head = 90M


Proposal: Impeller of the pump proposed to trim-down, which will reduce discharge head and at the same time input power of the motor will be decreased. Thus discharge valve can be opened fully.


Analysis: Designed diameter of Impeller = 450 mm As per calculation for desired pressure and flow, proposed diameter = 415 mm, which is approved and has been implemented.


Pump assembled after modification of Impeller


Analysis:

After implementation of the proposal, Pumps are running on full valve position, thus flow has increased significantly and power has reduced up to 90 kW as shown in picture.


Savings Calculation: Power Plant – Power Saving = 3000 Units/day = 9.45 Lac Units/year Process Boiler – Power Saving = 912 Units/day = 3.10 Lac Units/year Total Power Saving = 12.55 Lac Units/year Money Saving = 12.55 x 3.25 = 40.78 Lac Rupees/year. Investments = NIL (In-house)


These Pumps supply water from Reservoir to Power Plant – WTP (Water Treatment Plant) for CT make-up and for DM Water Generation. Design Capacity: Pump: Q – 2700 m3/hr, H – 30 m, NPSHR – 6 m Motor: 315 kW, 34.5 Amp, 6.6 kV. Quantity – 3 (2W + 1S)


Raw Water Pump House (Power Plant)


Observation: Existing positive suction head available (25m) is much higher than required (6m) due to huge storage in reservoir. Due to advantage of higher head, Pump flow can be increased significantly which was not taken into

consideration during operation.

The same Raw Water Pump house is also catering water to WTP of Steel Plant with separate Pumps (180 KW each).


Observation: Earlier, Valve Position of supply line = 5 to 8% open only, and Pressure before Valve = 4.2 Kg/cm2.


Proposal:

From the Power Plant Raw Water pumps, part of water can be supplied to Steel Plant WTP for the maximum utilization of PP Pumps.

With the below minor modifications, supply of water from PP Pumps to Steel Plant WTP can be made possible –

1. One valve needs to be installed in branch line after Steel Plant branch line.

2. Another valve needs to be installed in Steel Plant line to isolate Raw Water intake from Steel Plant Pumps.



Implementation of Proposal: By installing valve in each line as per below picture, the proposal made successfully implemented

Recently Installed Valves


Observation: Flow available in Utility branch line = 1500 m3/hr after valve

installation, at 50% valve position.


Observation: Flow available in Power Plant line = 3000 m3/hr, at around 50% valve position and pressure get reduced to 1.4 kg/cm2


Observation: Earlier flow was in by-pass line, as some issue in pneumatic flow control valve, which has rectified and now taking flow in main straight line.


Observation: Earlier Input Power of RW Pump was 285 kW, which has reduced to 230 kW now by the modification implemented.


Parameters Before

Modification

After Modification

(10th –August)

Raw Water Flow 2500 m3/hr to

Power- Plant

3000 m3/hr to Power Plant

1500 m3/hr to Steel Plant

Raw Water Pump

(315kW) 285 KW 230 KW

Steel Plant Pump (180kW) 170 KW NIL (Stopped)

Pump Vibration 6.64 mm/sec 3.86 mm/sec

Observation: The modification has implemented just within two days, after getting approval and following data's are noted:


Savings Calculation: Power Saving by –

1. Raw Water Pump = (285 – 230) = 55 kW

2. Steel Plant Pump = 170 kW (The Pump is now stopped) Power Saving = 2590 Units/day or 9.45 Lac Units/year Money Saving = 9.45 x 3.25 = 30.72 Lac Rupees/year Investment = 20,000 Rupees (one time cost)


These Pumps supply clarified water for Cooling Tower make-up from Central Utility to Coal Gasification Plant, DRI, SMS, Plate Mill, Oxygen Plant etc. Design Capacity: Pump: Q – 2000 m3/hr, H – 60 m, N – 1491 rpm. Motor: 450 kW, 49 Amp, 6.6 kV. Quantity – 5 (4W + 1S)


Make-up Water Pump House Central Utility


Observation: We found that this Pump was running on 1000-1100 m3/hr of average flow since long , as compared of rated 2000 m3/hr. Because of less consumption in Plant at present situation, major part of flow was being re-circulated as ‘un-useful work’ and Motor was operating on full load. So there was an opportunity observed for Efficiency Improvement.


Analysis : Impeller of the Pump proposed to be ‘trimmed-down’ up to acceptable level, which can meet existing required flow with head and to save power consumption. By the study of pump curve it was proposed that, Impeller can be trimmed up to 425 mm against of 465 mm existing. As the result of such trimming, motor will consume around 270 - 275KW power with providing 1300 to 1400 m3/hr flow and 45 meters head as the pump curve confirm. The proposal is approved and has been implemented. Now Pump is running Smoothly & Efficiently since June-15.


Savings Calculation: Running load of Motor before modification = 425 kW Running load of Motor after modification = 285 kW Power Saving = (425 – 285) = 140 KW or 3360 Units/Day Total Power = 3360 Units/day or 12.26 Lac Units/year Money Saving = 12.26 x 3.25 = 39.85 Lac Rupees/Year Special Note: As the system is working fine, so the same modification has been implemented on Pump No-1 also, which is running efficiently since July’ 15.


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Copyright © 2010 Jindal Steel & Power Ltd. · 27 Copyright © 2010 Jindal Steel & Power Ltd. Analysis : Impeller of the Pump proposed to be ‘trimmed-down’ up to acceptable level,