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GOVERNMENT OF INDIA MINISTRY OF RAILWAYS

Technical Specification for

‘Common Rail electronic Direct Injection (CReDI) Fuel System for DLW built 16-cylinder 3100 hp Alco Engine.’

Specification No. TS/ED/2015/79

May’2015

Engine Development Directorate Research Designs and Standards Organisation

Manaknagar, Lucknow-226011

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1.0 Introduction:

1.1 Indian Railways (IR) plans to procure 10 (Ten) loco sets of Common Rail electronic Direct Injection Fuel System (CReDI) for DLW built 16-cylinder 3100 hp Alco Engine to be used for a wider field trial.

1.2 Presently Alco engine is provided with a mechanical fuel injection system having individual mechanical fuel injection pumps actuated through camshafts to pressurise the diesel fuel. Pressurised fuel is delivered to the injectors through high pressure pipes. Start of injection is optimised at rated power and metering is controlled through governor and a control linkage mechanism.

1.3 CReDI is a two-stage fuel distribution system which offers flexibility of modulating fuel injection pressures coupled with a dynamic start of injection at each power setting, designated as engine notch. This flexibility in the system is independent of engine rpm and notch position. It is electronically controlled through an electronic engine management system integrated to the microprocessor control based traction controller.

1.4 Besides fuel savings it results in lower key engine exhaust stack emissions, over the traction duty cycle.

1.5 CReDI is envisaged to be both a retrofit and a new manufacture solution for replacement of the exiting mechanical fuel injection system on Alco diesel engine.

1.6 Tenderer, if not a past supplier to IR for a CReDI system for Alco engine, should have at least five years of experience with activities associated with design, manufacture and supply of a commercially running CReDI system and should have manufactured and supplied at least Five CReDI systems for large bore engines (>4” diameter) and other higher size engines and/or for diesel locomotive engines. It should be of a proven design. Customization of an existing design to suit the requirements of IR would be acceptable.

1.7 Specification details for future procurement would be decided based on experience gained and performance observed during wider trial.

2.0 Requirements :

2.1 General Requirements:

2.1.1 Engine data for 3100HP, 16 Cylinder Alco engine is given at Annexure 1. Indicative performance data for Alco engine at rated power with existing configuration is given at Annexure 2 for guidance. Following general requirements should be fulfilled by CreDI system:

2.1.2 It should be suitable for rail traction service characterized by a wide, fluctuating, cyclic load pattern and extended intervals of operation at idle & full load.[IR duty cycle followed is enclosed at 3].

2.1.3 It should be sturdy and reliable in operation and incorporate components that can withstand the hostile environmental conditions in the engine room such as dust, water, fuel/ lubricating

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oil, vibration, extreme temperatures, Electrostatic / Electromagnetic interference, and a noisy power supply. Common rail injectors are to be fitted inside the cylinder heads and the temperature around the injectors may reach approximately around 100-1500C.

2.2 Technical Requirements:

2.2.1 The complete system including the engine management and fuel injection components, sensors, interfaces, fuel supply system, electronics, transducers etc. would need to be mounted on the engine or in the locomotive cab. On test bed at RDSO, the system planned to be mounted in the cab can be installed in control room. This is to facilitate the testing of the power pack as one whole unit.

2.2.2 CReDI system should be designed in such a manner, that no major modification to the existing engine would be required for its fitment.

2.2.3 External dimensions of the injector shall be identical to the existing ‘Bosch’ make injector and the design offered should not require any major modification in the cylinder head for fitment. (Outline dimensioned drawing for existing injector is placed at Annexure 4 for guidance).

2.2.4 CReDI system both the electronic and the mechanical portions should be so designed that safety of the locomotive and personnel are not compromised. There should be no fire hazard from any type of electrical short circuit. Fuel supply to injectors should cut off as soon as the engine stops. Necessary tests would need to be done on the high pressure system by the tenderer before energising the locomotive and during maintenance, as required, to ensure a fail -safe and leak proof system for safe operations.

2.2.5 100% redundancy would be desirable for sensors and devices whose failure can lead to unsafe operation of the engine.

2.2.6 Existing sensors as provided in the locomotive may be utilised by the tenderer to pick some of the reference values for the engine management system. However if it is planned to be sensed separately as part of its proposed system ,then the tenderer to provide/fit sensors suitable for shock/vibration as per IEC 60571 for lube oil pressure sensor-2 nos.(measuring range-0-12 bar), boost air pressure sensor-1 no.(measuring range 0-3 bar), fuel oil pressure sensor-1 no.(measuring range 0-9 bar), engine water temperature sensor-1 no.(measuring range- -50 to 150 oC) etc. in the respective engine systems and would form a part of tenderer’s scope of supply.

2.2.7 No maintenance including inspection would be desirable before 90 days. Care should be taken to ensure that schedules match the existing locomotive schedules, and that it has least work content.

2.3 Brief design attributes for major components:

2.3.1 Fuel Injectors-Fuel injectors are responsible for injecting fuel into the power assembly, provide correct spray characteristics and meter the fuel with the help of solenoid valves controlled through inputs from the Electronic Control Unit (ECU). Fuel injectors may have an inbuilt individual accumulator of sufficient reserve volume to meet the requirements of injected fuel per stroke satisfactorily. A wave dynamic dampening mechanism may be provided in the inlet stud of the common rail injector. The Injector should be capable of operating at the design fuel injection pressures with adequate tolerance for peaks. Some

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features of injector are-fuel injection quantity per stroke-0-1500 mm3; solenoid controlled, zero leakage at no injection; low sac type; opening pressure-400 bar; injector cooling by return fuel etc. Injector geometry should suit the operating characteristics.

2.3.2 High Pressure (HP) pump-HP pump receives delivery of fuel from low pressure system after

adequate filtration. A suction throttle, controlled through ECU, based on fuel oil pressure maintained in the common rails is provided which controls the amount of inlet fuel to the common rail. Right and Left bank of fuel system are provided with independent gear driven HP pumps mounted on fuel injection pump (FIP) supports with suitable mountings. Lubrication to the HP pumps is provided by engine lube oil. Suitable pinion and couplings may be required to couple the HP pumps with cam gear for its drive arrangement. HP pump generates constant pressure in the common rail independent of the fuel injection. The product specification should match the industry standard and/ or be the best-in-class and should have sufficient fuel delivery rate to meet engine requirements.

2.3.3 Common Rail-Common rails receive high pressure fuel from the HP pumps and act as a reservoir for the high pressure fuel. Common rails should be double walled construction with thin high pressure lines connecting the injectors, suitable to withstand the operating conditions, with a pressure rating of at-least 2000 bar.

2.3.4 Engine Control Unit (ECU)-ECU electronically controls the entire CReDI system. It monitors engine operating parameters via various sensors,interprets these parameters ,generates analog and digital signals to indicate engine’s operating states and calculates the appropriate amount of fuel to be injected ,start and duration of injection at differnt load speed combinations with help of look up tables. Combination of electronic regulation, governing and monitoring provided permits to create an engine management system which allows optimization of the system as a whole. The interface and integration of ECU with the locomotive microprocessor control system [procured by IR to specification no MP-0.17.00.01 (Rev.02 or Latest)] shall be the responsibility of the tenderer.

2.3.5 Tertiary /Fine filter-components of high pressure syetm have close tolerances therefore existing fuel filteration system may need to be enhanced by introduction of a tertiary fuel filter in series to existing primary (10-16µ) and secondary (6-10µ) fuel filters before inlet to the HP pump. Additional filtration required if any will be the part of the tenderer’s scope of supply.

2.3.6 Cam Gear Covers-Existing cam gear covers may need to be modified to accommodate a pinion housing assembly used to provide drive for HP pumps through couplings besides its basic function of covering the cam gear.

2.3.7 Adaptation kit consisting of common rail holding clamps, connection hose pipes for fuel circuit continuity, dummies gaskets and closing plates for FIP supports, HP pump mounting plates, injector mounting clamps, HP pumps guard assembly, modified cylinder head gaskets, modification components for over speed trip (OST) housing, pressure sensor boxes, connection cables, etc. as needed for working of the system would need to be supplied and will form part of the tenderer’s scope of supply.

2.3.8 Following major components/subassemblies are likely to be removed /modified from the existing mechanical fuel injection system as provided on the Alco engine with use of CReDI system-Fuel injection pump assemblies, injector assemblies, fuel header assembly, FIP

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operating assembly, OST assembly, control shaft assembly, cam gear covers and governor assembly etc.

2.3.9 Following restrictions would apply for the CReDI system:

2.3.9.1 Peak cylinder firing pressure shall not exceed 1850 psi.

2.3.9.2 No major modifications would be made to the existing engine.

2.4 Functional Requirements: CReDI system would take over existing functions of the engine governor and the over-speed trip mechanism. Some broad functions of the offered CReDI for ALCO engine would be as under:

2.4.1 Precise control on diesel fuel injection timing, fuel quantity and injection pressures at each notch position.

2.4.2 It would be desirable to have capability for independent forming of opening and closing flank of the diesel fuel injection rate.

2.4.3 It should have multi injection capability in a cycle.

2.4.4 It should have the capability to vary injection pressure and timing over a broad range, independent of engine speed and capability for injection pressures of at-least +1600 bar.

2.4.5 It should be able to map injection timings with respect to load, speed, boost air pressure etc., as applicable, to achieve the lowest fuel consumption.

2.4.6 It should be able to enter low idle mode of the engine operation without driver's intervention and should have superior engine speed control capability to hold the engine speed within +/- 5 rpm (or less) of the required speed at all speeds and loads under steady state conditions without any signs of hunting or overshooting.

2.4.7 It should allow full flexibility for development and tuning in a test bed by a simple change in the software or its base data. Parameters like notch vise engine speed, minimum lube oil pressure for locomotive shutdown, fuel injection quantity, engine speed response time, electronic over speed limit etc. should be user settable parameters and should allow the same calibration to be duplicated on engines fitted with similar CReDI systems.

2.4.8 It should have built-in diagnostics and should run a full self-diagnostic on every power-on and at regular intervals while the engine is in operation. This operation should be transparent, and not affect the normal working of the system. All faults should be logged for later downloading to a PC by the maintenance staff and major fault conditions be indicated by suitable indicators mounted on the controller itself.

2.4.9 The Tenderer can offer other features that may be useful to IR. Technical aspects and price impact of these additional features should be clearly brought out in the offer.

2.4.10 Tenderer would be responsible for the overall system integration, testing / optimization and validation of the system on the engine test bed at RDSO and on locomotives in coordination with IR.

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3.0 Scope of supply:

Broadly the scope of supply per engine set for CReDI would consist of following items ,but not limited to:

3.1 Injectors with injector holder:16 nos 3.2 High pressure pump with guard assembly , pump supports with adequate number of mounting

bolts-2 nos. 3.3 FIP support closing plate with gasket and dummies-16 nos. 3.4 Common rail (double walled) left and right bank with relief valve and adequate number of

mounting clamps and rubber mounts. 3.5 Modified cam gear cover assembly left and right bank with pinion for cam gear, coupling and

coupling bolts. 3.6 Tertiary/Fine filter assembly (if required )-1 no. 3.7 Double walled S pipe between common rail to injectors and fuel inlet stud with WDD-16 nos. 3.8 Fuel inlet header with adequate number of clamps-2 nos. 3.9 Fuel return header with adequate number of clamps-2 nos. 3.10 Injector fuel return pipe with clamps-16 nos. 3.11 Governor mounting closing plate -1 no. 3.12 OST gear with spacer-1 no. 3.13 Engine control unit including power supply-1 no. 3.14 Sensor junction box -1 no. 3.15 Injector junction box-2 nos. 3.16 Pressure Sensor Box (PRS box)-1 no. 3.17 Modified Cylinder head gasket-16 nos. 3.18 Sensors as required including engine speed/position sensor-2 nos. (Hall sensor, measuring

range 0-2000 rpm), common rail pressure sensor-2 nos.(measuring range 0-2000 bar) etc. 3.19 Connection Cables: High temperature resistant (minimum 150 °C), covered with Teflon or

other suitable high temperature resistant covering material with as required conduits, coupler, shields, clamps etc.

3.19.1 Cable (ECU to injector junction box left & right)-2 nos 3.19.2 Cable (Injector junction box to injectors)-16 nos 3.19.3 Cable (ECU to PRS box)-1 no. 3.19.4 Cable (ECU power supply)-1 no 3.19.5 Input and output cable-1 no 3.19.6 Cable (ECU to sensor box) for Engine speed sensor and Common Rail Pressure sensor-2

nos. 3.19.7 Cable engine speed sensors to sensor junction box-2 nos 3.19.8 Cable (sensor junction box to common rail pressure sensor left & right)-2 nos 3.20 Copper /MS pipes/hoses with couplers ,in running length to be cut to suit size on locomotive- 3.20.1 16mm OD copper pipe- secondary filter to tertiary filter, tertiary filter to fuel inlet header right,

fuel inlet header right to fuel inlet header left, fuel inlet to pressure regulator in, pump fuel return to tank, common rail relief valve to tank,

3.20.2 16mm OD MS seamless pipe for right bank and left bank junction 3.20.3 1/2" OD copper pipe fuel return header to tank

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3.20.4 1/2" hose pipe -fuel inlet header to high pressure pump, lube oil header to high pressure pump 3.20.5 1/4" hose pipe -high pressure pump to FP support 3.21 System configuration and fault analysis software installed in the ECU. 3.22 Adequate number of ferrules, tees, elbow, coupling, adapters, dummies etc. as required. 3.23 Tenderer may add components as required in its offer to supply a self-supporting complete set

to meet the requirement of successful operation of the system on test bed and on the locomotive.

Note : Overall responsibility for fitment and successful demonstration of the CReDI system on the test bed/ locomotive in a diesel shed in coordination with IR would be of the tenderer. Requisite assistance to be provided by the tenderer during maintenance activities on the CReDI system in a diesel shed initially.

4.0 Acceptance criteria: This would be applicable to a tenderer who shall be supplying CReDI for Alco engine IR for

the first time: 4.1 Fuel saving of minimum 4% over the IR duty cycle. 4.2 Reduction in key engine exhaust stack emissions by a minimum of 15% over the IR duty

cycle.

5.0 Process of prototype development : This would be applicable to a tenderer who would be supplying CReDI for Alco engine to IR

for the first time: 5.1 The Tenderer is required to have suitable CAD software, suitable hydraulic simulation

software like AME-Sim for fuel system simulation, high pressure hydraulic pump test bench, injector test bench and other necessary simulation arrangement or test benches, etc.

5.2 The Tenderer is expected to follow the following path for prototype design and development- 5.2.1 Design layout of injectors, HP pump, common rails, all piping from pump to injectors and other

system components for Alco engine. 5.2.2 1-D simulation (and if required 3-D simulation) for entire system of Alco engine with simulation

software like AME-Sim and optimisation of major functional parameters. 5.2.3 Detailed design of all system components for Alco engine. 5.2.4 Supply to RDSO of the following Assembly drawings and documentation prior to beginning of

hardware manufacturing or prior to beginning of CReDI assembly on the Alco engine for engine test bed testing:

5.2.4.1 Dimensional outline drawing of injector, high pressure pump, CreDI installation, etc. 5.2.4.2 Technical specifications needed for assembly of the CReDI on RDSO engine test bed. 5.2.4.3 Detailed report indicating simulation results indicating basis of optimisation of major functional

parameters. 5.2.4.4 Literature, Maintenance and operating instructions, spare part catalogues (including drawing's

reference parts) and tools catalogues appropriate for a prototype system. 5.3 RDSO shall share all information as available with successful tenderer on signing of a non

disclosure agreement after placement of purchase order. 5.4 All data that is generated as result of testing on engine and/or the test rigs by IR shall

automatically become the sole property of IR. No part of such information shall be disclosed to

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any third party without proper written consent to IR.

6.0 Inspection: 6.1 For a tenderer who has supplied CReDI system for Alco engine to IR in the past: 6.1.1 Inspection on receipt of material supported with WTC-first set by RDSO; balance –consignee 6.1.2 First set to be supplied to Engine Development Directorate, RDSO and balance to consignee 6.1.3 The system would be fitted on diesel locomotives for a field trial for reliability verification for a

minimum duration of six months .During this period, all failure modes experienced during the operation of the diesel locomotives would need to be documented and the tenderer would need to carry out the necessary trouble shooting jointly with IR. Tenderer may need to carry out necessary design/ manufacturing modifications and introduce modified components on the locomotives, if required, so as to ensure that the reliability of the CReDI system is proven.

6.2 For a tenderer who would be supplying CReDI for Alco engine to IR for the first time: 6.2.1 Inspection of components: Components (wet and electric/electronic) would be inspected by

RDSO before dispatch at manufacturer’s facility 6.2.2 Performance tests on RDSO Engine Test Bed: 6.2.2.1 CReDI system would need to be qualified for system optimization/tuning/performance testing

on the Engine Test Bed in Engine Development Directorate at RDSO. During the engine validation tests on the Engine Test beds at RDSO, the supplier needs to be associated and will carry out necessary design modifications and replacement of parts / systems with the modified ones as may be required.

6.2.2.2 Performance of the CReDI system would be validated on the test bed by first generating baseline data on the Alco engine fitted with a mechanical fuel injection system and then with the fitment of the CReDI system and its accessories. All other engine components shall be kept identical. Performance of final output will be compared with the base line results, for meeting the acceptance criteria.

6.2.2.3 The Alco engine on test bed will be run close to predetermined speed and load points during the tests as indicated in Annexure-5.Optimization will be done under, as far as possible, identical conditions and combination of components. Engine will be loaded by hydraulic dynamometer controlled by AVL test commander. For calculation of corrected horsepower and brake specific fuel consumption, Alco formula will be used. Performance parameters will be recorded in direction of descending order of load and speed.

6.2.2.4 Tenderer may like to visit the RDSO test bed to assess the facilities available with RDSO and its capabilities. Details of data acquisition system of the test bed are at Annexure-6

6.2.2.5 Tenderer in consultation with RDSO will draw up the optimization programme. 6.2.3 Performance test on a locomotive: 6.2.3.1 After successful completion of the validation testing on the engine test bed at Engine

Development Directorate, RDSO the system would be fitted on diesel locomotives for a field trial for reliability verification testing. This test will be for a minimum duration of six months and may stand extended based on performance observed. During this period, all failure modes experienced during the operation of the diesel locomotives would need to be documented and the tenderer would need to carry out the necessary trouble shooting jointly with IR. Tenderer may need to carry out necessary design/ manufacturing modifications and introduce modified

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components on the locomotives, if required, so as to ensure that the reliability of the CReDI system is proven.

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Annexure-1

Engine Data – 16 cylinders DLW built 251-B ALCo engine

1. Application Rail traction diesel (Indian Railways, broad gauge)

2. Engine type DLW built 251-B engine 3. No. of cylinders 16 4. Configuration ‘V’ 5. Cycle 4 stroke 6. Bore 9”(228.6 mm) 7. Stroke 10.5”(266.7mm) 8. Compression ratio 11.75:1 9. Ratio of con rod length to crank radius 4 10. Fuel injection (at full load) Spill port closing 22.0 degree CA BTDC Duration of injection Approx. 34 degree CA Pumps 17 mm plunger dia, 20 mm stroke Nozzles 0.35 mm dia. 9 holes, 157-degree spray angle,

90-degree tip angle. 11. Firing order 1R 1L, 4R 4L, 7R 7L ,6R 6L, 8R 8L, 5R 5L, 2R

2L, 3R 3L 12. Valves (4 valve head) Air inlet open 80.1 degrees CA before TDC Air inlet close 35.4 degrees CA after BDC Exhaust open 57.7 degrees CA before BDC Exhaust close 57.7 degrees CA after TDC Valve dia 7.62 cm Max. valve lift 2.04 cm Port diameter 7.40 cm 13. Turbocharger One per engine 14. After cooler Single, water-cooled.

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Annexure-2

Engine Performance Data at full load- 16 cylinder DLW built ALCo 251-B engine

1. Brake horse power 3100 hp 2. Engine speed 1050 rpm 3. BMEP 14.25 bar approx. 4. Turbo inlet temperature 485ºC (approx.) 5. Average cylinder head exhaust temperature 350ºC (approx.) 6. Max. ambient temp. expected 55º C 7. Specific air consumption 4.5 kg/s approx 8. Vacuum at compressor air intake 300 mm H2O approx. 9. Compressor outlet pressure 1.60 bar approx 10. Pressure drop across after cooler 0.1 bar approx. 11. Inlet manifold pressure (engine air gallery) 1.55 bar approx. 12. Exhaust pressure before turbine 1000 mm of Hg approx.

13. Turbine outlet pressure (exhaust) 440 mm H2O approx. on engine test bed.

14. Maximum cylinder pressure 1850 psi

NOTE: These figures are indicative and can be used only for approximate guidance

Annexure-3

Typical Indian Railways Operating duty cycle for Diesel Locomotives

Notch Freight service (%) Passenger service (%) Idle 60 49 1st 3 6 2nd 5 7 3rd 3 5 4th 4 4 5th 4 7 6th 5 5 7th 6 5 8th 10 12

Extracted from RDSO report no.-MP-Misc. – 204, Feb. - 2008

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Annexure-4

Outline indicative drawing of Injector of Alco engine

Annexure-5

Operating points - Alco 251 B engine

Notch RPM Load (N) Power (hp) 8 th 1050±3 21600±50 3100 7th 950±3 19082±50 2500 6th 850±3 16018±50 1870 5th 750±3 13826±50 1430 4th 650±3 10616±50 950 3rd 550±3 8138±50 615 2nd 450±3 5361±50 330 1st 350±3 2984±50 145

Idle 350±3 2131±50 105

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Annexure-6

Data Acquisition System The data acquisition system of engine test bed consists of the following components:

AVL test commander capable of real time on-line measurement system consisting of 180 channels controls the engine. The test commander also controls Dynamometer coupled to the Diesel engine. Different performance parameters like speed, load, torque, power, temperature and pressure of engine are recorded. This test commander operates on Windows NT operating system with PUMA 5.6 engine monitoring and testing software.

High Speed Data Acquisition system (HSDA) system supplied by M/s AVL is used to measure on-line high speed parameters of engine viz. Cylinder pressure, an instrumented injector was used to measure Start of Injection, End of Injection and needle lift for baseline test. HSDA also plot graph of various parameters with respect to crank angle.

AVL fuel balance measures online brake specific fuel consumption and rate of fuel flow gravimetrically.

Firing pressure in one cylinder head at cylinder no. 16 was measured with the help of P-θ diagram (Firing pressure vs. Crank angle) using High Speed Data Acquisition system. This data has been used in this report.

Smoke opacity at the various engine speed and load combinations was measured with help of smoke meter of M/s AVL.