government of india ministry of railways technical...

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GOVERNMENT OF INDIA MINISTRY OF RAILWAYS

TECHNICAL SPECIFICATION FOR

DEVELOPMENT OF COMMON RAIL ELECTRONIC DIRECT INJECTION (CReDI) SYSTEM FOR 6-CYLINDER 1350 hp

ALCO ENGINES

Specification No. TS/ED/2016/80

February’ 2016

Engine Development Directorate Research Design and Standard Organisation

Manak Nagar, Lucknow- 226011

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TABLE OF CONTENTS

S.No. Content Page no.

1. Preamble 2 2. Scope of work 2 3. Scope of supply per engine 2 4. General Requirement 2-4 5. Technical data and drawing 4 6. Main design objectives 5 7. Functional requirements of CReDI fuel system 5-7 8. Software 8 9. Documentation 8

10. Performance test on engine test bed 9 11. Performance test on locomotive 9 12. Confidentiality of test results 9 13. Acceptance criteria 9 14. Pre-dispatch inspection 10 15. Intellectual Properly Right (IPR) 10 16. Training 10 17. Warranty 10 18. Annexure-I 11 19. Annexure-II 12 20. Annexure-III 13 21. Annexure-IV 14 22. Annexure-V 15-23

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1. PREAMBLE

The Common Rail Electronic Direct Injection (CReDI) fuel system will be retrofitted/ fitted on the 6 cylinder inline 1350 hp ALCO diesel engines used on diesel locomotive of Indian Railways. The CReDI fuel system shall be used on the newly built or during rebuilding.

2. SCOPE OF WORK

2.1 Design and development of CReDI fuel system for the 6 cylinder ALCo engine.

2.2 Refinement of an existing radial turbocharger to suit the upgraded ALCO 6 cylinder engine

with a turbocharger OEM.

2.3 Optimisation of the combustion chamber, injector nozzle hole geometry, spray angle and split

injection.

2.4 Selection and development of a higher effectiveness aftercooler.

2.5 Minor modifications to the cylinder head for fitment of the electronic fuel injectors of common rail system

3. SCOPE OF SUPPLY PER ENGINE

3.1 8 Common rail electronic injectors with fast response to allow split injections per cycle

3.2 1 high pressure fuel common rail with 2000 bar pressure capability

3.3 1 high pressure fuel pump for supplying high pressure fuel to the common rails

3.4 High pressure connectors from common rail to the injectors

3.5 Fuel inlet and return headers

3.6 Tertiary fuel filters to suit the injectors

3.7 Sensors

3.7.1 High pressure fuel sensors

3.7.2 Engine speed sensor

3.7.3 Engine cam phasing sensor along with toothed wheel

3.7.4 Engine cooling water temperature sensor

3.7.5 Engine oil temperature sensor

3.7.6 Engine boost pressure sensor

3.8 Engine control unit along with software and diagnostic features

3.9 Wire harnesses with all cable connectors, conduits etc.

3.10 Junction boxes for injectors and for sensors

3.11 Radial turbine state-of-the-art turbocharger

3.12 Optimised pistons – 8 nos.

3.13 Higher effectiveness aftercooler

3.14 All adaptation parts for fitment of the high pressure injectors, pumps, common rails,

turbocharger, fuel headers, sensors etc.

3.15 All required software including any diagnostics software and any data analysis/report

generation software.

4. GENERAL REQUIREMENTS

Engine data for 1350 hp ALCO engines is given at Annexure-I and performance data for ALCO engine at full power is given at Annexure-II.

The following general requirements shall also be fulfilled by the CReDI fuel system-

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4.1 Rail Traction Characteristics

The CReDI fuel system shall be suitable for Rail traction service; which is characterized by wide, fluctuating, cyclic load patterns, and extended intervals of operation at idle and full load.

4.2 Operating conditions

It shall 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 oil, vibration, extreme temperatures, Electrostatic / Electromagnetic interference, and an extremely noisy power supply.

4.3 Proven Design

The CReDI fuel system shall be of a proven design. Customization of an existing design to suit the requirements of Indian Railways (IR) is acceptable.

Vendor should have at least five years of experience with the activities associated with the design, manufacture and supply of commercially running CReDI fuel system. Vendor should also take the responsibility of the overall System Integration, testing / optimization and Validation of the Common Rail Fuel Injection System on the test engine of ALCO as well as the locomotives in coordination with Indian Railways.

4.4 Mounting Arrangement

The complete system including the Engine Management and high pressure fuel injection

components, sensors and set point generators, interfaces, fuel supply system (low pressure

stage), electronic components and transducers, turbocharger adaptation kit, higher

effectiveness aftercooler shall be mounted on the engine or in the locomotive cab.

4.5 Other Design Requirements

To ensure easy fitting, the following restrictions in the design shall apply:

4.5.1 The CReDI fuel system shall be designed in such a manner, that no major modification to the existing engine shall be required for its fitting. However any modification which the vendor feels is for the improvement in performance and reliability of the engine and the locomotive should be offered by the vendor preferably with quantification of benefits.

4.5.2 The external dimensions of the injector shall be identical to the existing ‘BOSCH’ make injector for ALCO Engine. Injector design offered should not require any major modification in the cylinder head.

4.5.3 The vendor should endeavour to design and offer a system, which avoids major modifications in the existing locomotive fuel oil circuit. Any special requirements such as additional/ improved filters etc. shall form part of the CReDI fuel system. The present fuel oil circuit incorporates a primary and a secondary fuel oil filter. The inclusion of any new component shall become part of adaptation kit to be supplied with the system by vendor.

4.5.4 Vendor should provide design support for any design changes needed on the engine parts to use the CReDI fuel system. Fitting of camshaft/crankshaft speed and position sensors etc. shall not require any major design modifications. Sensors for pressure and

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temperature measurements shall be mounted on the existing lube oil/ water/ air circuits at suitable locations.

4.5.5 In case the vendor offers a high pressure fuel oil pump which is to be lubricated by engine lubricating oil, they may specify the filtration requirement and also supply the additional filter for lube oil to be used for filtering the engine lube oil before supply into the high pressure fuel oil pump. The engine lubricating oil pressure varies from 2 to 6 bar in ALCO engine, in case the high pressure fuel pump offered by the vendor is designed for higher lubricating oil pressures, the vendor should also supply any additional pump required for the purpose. The additional pump should be electrically driven with a fractional horsepower d.c. motor capable of running at 72 V d.c.

4.6 Safety Requirements

The CReDI fuel system, both, the electronic and the mechanical portions shall be so designed

that safety of the locomotive and personnel are not compromised. The following points shall be

specifically ensured-

4.6.1 There shall be no fire hazard from any type of electrical short circuit.

4.6.2 Fuel supply to injectors shall be cut off as soon as the engine stops. This is necessary to prevent fuel oil from dribbling into the cylinder due to faulty injector operation. Suitable arrangement in the CReDI fuel system may be used to ensure this.

4.7 Redundancy

100% redundancy is desired for the sensors and devices whose failure can lead to unsafe

operation of the engine. For those sensors, where 100% redundancy has not been provided, a

fail-safe, fall-back strategy shall be adopted for all likely failures. Failure of any single

component/ sensor/ sub-system shall not lead to an avoidable complete shut down of the

engine. Limp home capability shall be built-in.

4.8 Preventive Maintenance

No maintenance including inspection of any type shall be required before 120 days. The

manufacturer shall specify the preventive maintenance schedule required. Care shall be taken

by the manufacturer to ensure that these schedules match the existing locomotive schedules,

and the least work content in these schedules shall be preferred.

5. TECHNICAL DATA AND DRAWINGS

Vendor should specify the details of the specifications, data and drawings to be provided by

RDSO. RDSO will share all relevant data with the Vendor after signing of a Non Disclosure

Agreement with Engine Development Directorate. Format for the same is enclosed as Annexure V.

After the development of the CReDI fuel system, the supplier shall provide the following technical

data and drawings:-

5.1 Detailed specification of the CReDI fuel system including detailed dimensioned drawings of the interfacing dimensions except the proprietary design details.

5.2 Detailed purchase specifications should include the High pressure pumps, Fuel injectors, pipes/tubes, filters, ECU, sensors to enable procurement for maintenance etc.

5.3 Any other supporting literature, documents etc. needed.

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5.4 For the entire major bought out items / components, the essential detail should be given in the offer. In addition, the vendor must give para-wise remarks to all the clause of draft specification. without these, the offer is likely to be rejected.

6. MAIN DESIGN OBJECTIVES

Environmental Objectives

● Reduced exhaust emissions ● Reduced black smoke emissions ● Reduced noise emissions

Economy Objectives

● Reduced fuel consumption ● Increase in specific power output ● Reduced Life Cycle costs ● Prolonged Maintenance and Time Between Overhaul intervals ● Prolonged Service life ● Reduced overhaul of main parts (Re-manufacturing, where needed)

Reliability Objectives

● Improvement in reliability of diesel engine by having restriction on the peak firing pressures by proper rate shaping, multiple injections of the fuel injection pulses

● FIE system reliability enhancement ● On-board diagnosis potential

7. FUNCTIONAL REQUIREMENT OF CReDI FUEL INJECTION SYSTEM

Since the CReDI fuel system uses electrical signals to control the start and end of fuel injection, the

existing fuel rack mechanism in the locomotive diesel engine becomes redundant. Consequently,

the engine governor and the over-speed trip mechanism also become redundant. The CReDI fuel

system has to therefore, take over the following existing functions of the engine governor and the

over-speed trip mechanism:

Isochronous governing of engine speed

Engine load shedding as and when required

Low lube oil pressure protection

Hot engine protection

Engine over-speed protection

Acceleration control to reduce exhaust smoke

Engine shut down, wherever necessary

Engine idling, wherever necessary

Limp home capability

Main functions of the offered CReDI fuel system for ALCO engine shall be as under:

7.1 The basic functions involve the precise control of diesel-fuel injection timing and fuel quantity at the reference pressure. In this way, the CReDI fuel system should be able to ensure that the diesel engine has low fuel consumption and smooth running characteristics.

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7.2 Independent forming of opening and closing flank of the fuel injection rate – It is desirable that the CReDI fuel system offered should be able to independently shape the fuel injection rate of the opening and closing flanks of the fuel injection rate curve, as also to maintain the required fuel injection rates throughout the cycle of fuel injection. This should help in varying the rate of heat release inside the combustion chamber so that the peak firing pressures do not cross the threshold limit of 1850 psi for ALCO engine. At the same time this should help in reducing the brake specific fuel consumption, noise and emissions from the engine. In case the vendor can demonstrate the same advantages through multi-injection capability, details shall be provided by the vendor.

7.3 Multi-Injection capability- CReDI fuel injection system should be able to have multi-injections in a cycle, i.e. pre, main and post injections. This should help in varying the rate of heat release inside the combustion chamber so that the peak firing pressures do not cross the threshold limit of 1850 psi for ALCO engine. At the same time this should help in reducing the brake specific fuel consumption, noise and emissions from the engines.

7.4 The offered CReDI fuel system should have the capability for High Injection pressures even at low engine speeds and almost free pressure modulation capability.

7.5 Variable Injection Timing – The offered CReDI should have the capability to vary injection pressure and timing over a broad scale. This will be achieved by separating pressure generation (in the high pressure pump) from the fuel-injection system (injectors). Use of the CReDI fuel system or the self contained volumes in injectors as accumulators or combination of the two are permitted provided major modifications to the engine design are not required and the overall dimensions of the engine and power pack are not increased. The common-rail system offered should be highly flexible system for adapting fuel injection to the engine. This shall be achieved by: ● High injection pressure up to approximately 2000 bar ● Injection pressure adapted to the operating status ● Proper rate shaping of the fuel injection curve ● Variable start of injection ● Possibility of several pre-injection events and secondary injection events (even highly retarded secondary injection events)

7.6 CReDI fuel system shall have the ability to provide Higher Injection Pressures, Faster Switching times and a variable-rate-of-discharge curve modified to the engine operating state, change the injection timing while the engine is running, and take feedback from the Manifold air temperatures. In case the inlet manifold air temperature rises due to either higher ambient temperature or due to cooling system degradation, the ECU should be able to retard the injection timing to control NOx emissions. This is also required for optimisation of fuel injection timings for each operating point of the engine.

7.7 The CReDI fuel system shall be able to map injection timings with respect to load, speed, boost air pressure, boost air temperature and engine jacket temperature to achieve the lowest fuel consumption (both under static and dynamic conditions), and shall have improved cold start ability.

7.8 Automatic Low Idle: The CReDI fuel system shall be able to enter the low idle mode of the engine operation without the driver's intervention. When the driver brings the throttle handle to IDLE, the engine speed shall drop to the specified rpm. After a small time delay, CReDI fuel system shall reduce the engine speed at a predetermined rate. While it is reducing the engine speed, it will keep a watch on the engine lube oil pressure and the loco main reservoir pressure. When either of these two pressures reaches a predetermined minimum level, the CReDI fuel system will stop reducing the engine speed further. From this point onwards it will keep adjusting the engine speed in a manner that will ensure that the above-mentioned two pressures never touch their minimum levels. Whenever the driver moves the throttle handle to

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first notch, the engine speed shall be raised to the first notch speed rapidly by the CReDI fuel system.

7.9 Closed Loop Hot Engine Load Shedding: During the summer months the diesel locomotives are subjected to high ambient temperatures, which bring down the efficiency and heat dissipating capacity of the radiator panels and a hot engine alarm results. The CReDI fuel system shall monitor the engine water temperature and whenever it starts approaching the upper limit it shall gradually reduce the power output of the engine without reducing the engine speed. This will result in decreased heat production by the engine. On the other hand the cooling capacity of the radiator shall remain at its maximum, as the radiator fan and the water pump (which are engine driven) shall continue to run at their maximal rated speed. The engine water temperature shall not be allowed to exceed its maximum limit. The power from the engine shall be restored back to its normal value gradually, as it cools down.

7.10 Improved Engine Control: The CReDI fuel system shall have superior engine speed control capability. It shall be able to hold the engine speed with +/- 5 rpm (or less) of the required speed at all speeds and loads under steady state conditions. Under a step input, this control shall be achieved without any signs of hunting or overshooting.

7.11 Limp Home Capability: The system shall be designed in such a way that if there is failure of any component or subsystem of the CReDI fuel system, it shall be possible to run the locomotive at a reduced level of efficiency or power or functional capability.

7.12 Design Flexibility: The CReDI fuel system shall allow complete freedom and flexibility to program any engine speed at any notch, by a simple change in the software or its base data. All system parameters such as engine acceleration, maximum fuel quantity, etc. shall be freely programmable. The system shall be designed in such a way, as to allow it to be adapted to different engine/ loco requirements in a variety of ways.

7.13 Diagnostics: The CReDI fuel system shall have built-in diagnostics. It shall run a full self-diagnostic on every power-on. In addition, it shall also run diagnostics at regular intervals, even while the engine is in operation. This operation shall be transparent, and should not affect the normal working of the system. All faults shall be logged for later downloading to a PC by the maintenance staff. Major fault conditions shall be indicated by a suitable indicator mounted on the controller itself. This is to help the driver in the field where a PC is not available. At a specified and alterable frequency, even in no fault condition, the data should be logged and recoverable for analysis or other use later.

7.14 The CReDI offered should have the capability of additional open- and closed-loop control functions. The Engine Control Unit offered along with the CReDI should have the capability for integration with the overall locomotive propulsion control system.

7.15 Depending on the output stages of the engine control unit, adequate number of engine control units should be planned in the design. These can be coupled within the “master/slave” network via an internal, high speed interface. This should lead to a higher microcontroller processing capacity available. Some functions can be permanently allocated to a specific control unit (e.g. fuel balancing control). Others can be dynamically allocated to one or other of the control units as situations demand (e.g. to detect sensor signals).

7.16 Turbocharger 7.17 Higher-effectiveness aftercooler 7.18 Optimised Piston

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8. CReDI FUEL SYSTEM FOR ALCO DLW 6 Inline configuration Layout and Performance data

are as given below:

Maximum Rail Pressure 1600-2000 bar

Injection quantity 0-1500 mm3/stroke

Maximum speed 1100 rpm

No. of cylinders in engine 6

Cylinder arrangement Inline configuration

Injector type Solenoid controlled, zero leakage at no injection

Injector outline Must fit without modification into cylinder head, same as ‘Bosch’

make injectors for ALCO

Nozzle of injector Low sac type for DI combustion

Injector electric connector Axial from top of cylinder head cover

Individual injector micron filter Placed at the entrance or within the body of each injector

No. of pumps One pump per engine

Drive ratio Pump / Engine To be determined

Pump drive Suitable pump drive shall be provided

System configuration With individual accumulator and with Dynamic Wave control

High pressure control Inlet metering at the pump

Piping configuration Mainly placed outside of the engine covers

Piping type Double walled, pressure rating 2000 bar for prototype only. The

pipes should be more sturdy in construction than the present Popp

and Pothoffe single walled pipes being used for the PLN system on

the ALCO engines

Pressure relief valve One relief valve for over pressure safety

Injector LP fuel return Separate return fuel header

Fuel filtering One fine filter with 3 micron mesh or better to suit the CReDI system

Low pressure stage Use of the fuel supply system components of the existing Low

Pressure system

Sensors and Pickups One rail pressure sensor, one engine rpm and TDC pickup, lube oil

and boost air pressure sensor

Cabling As required to interconnect ECU, injectors, High pressure Pump

delivery control, Pressure sensor as well as Engine rpm and TDC

pick-ups

Electronic Control Unit Common microprocessor controlled unit for Engine Test Bed

operation and Locomotive fitting

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9. SOFTWARE

All required software including any diagnostics software and any data analysis/report generation software.

10. DOCUMENTATION

After the design of the prototype system and before fitting on the engines on the engine test bed,

the supplier shall need to provide the following documentation-

Dimensional outline drawing of injector for engine.

Dimensional CReDI installation drawing for engine.

Technical specifications needed for assembly of the CReDI on the ALCO DLW 6 inline

configuration engine on the engine test bed.

Dimensional drawing for fitment of radial turbocharger on the 6 cylinder ALCO engine

11. SERVICE

Assistance during test bed trials.

Assistance during Locomotive fitting and field trials locomotives.

After sales service for two years. The vendor can offer other features that may be useful to the Indian Railways. The technical

aspects and price impact of these additional features shall be clearly brought out in the offer.

12. PERFORMANCE TESTS ON ENGINE TEST BED

The performance of the CReDI fuel system in respect of BSFC (Brake Specific Fuel

Consumption), noise and emissions is most important. The minimum saving in fuel consumption

(over the duty cycle of the locomotive as specified in Annexure-III) over the existing BOSCH make

mechanical fuel injection equipment for ALCO engine that can be expected in percentage terms

shall be specified by the vendor. For the consideration of an offer, the vendor must have indicated

a performance that will give a maximum fuel saving over the duty cycle specified in this

specification as compared to the existing BOSCH make fuel injection system for ALCO engine.

The specified performance shall be validated on a test bed of ALCO engine by first generating

baseline data with the existing FIE and then with the fitting of the CReDI equipment and its

accessories. All other engine components shall be kept identical.

The engine will be run at the predetermined speed and load points during the test as per

Annexure-IV. The optimisation shall be done under the identical conditions and combination of

components. For calculation of corrected horsepower and brake specific fuel consumption, ALCO

correction factor will be used. The performance parameters will be recorded in direction of

descending order of load and speed.

The vendor in consultation with RDSO shall draw up the optimisation programme. The

specifications and details of performance tests may be suitably altered by EDD, RDSO and their

judgement and decision shall be final.

13. PERFORMANCE TESTS ON LOCOMOTIVE

After the validation of the system performance on test bed, the system would be fitted on ALCO-

DLW diesel locomotive. After proving out the functional requirement on the locomotive, its

performance regarding maintainability and reliability under field conditions would be jointly

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monitored by RDSO/Indian Railways and the manufacturer for six months. All problems noticed

during this period shall be logged and a satisfactory solution acceptable to RDSO/Indian Railways

shall be found jointly.

14. CONFIDENTIALITY OF TEST RESULTS All data that is generated as a result of testing of the CReDI fuel system on the engine and/or the

test rigs by Indian Railways shall automatically become the sole property of RDSO/Indian

Railways.

15. ACCEPTANCE CRITERIA

15.1 Bsfc, emissions and noise with CReDI fuel system should be better than the existing 6-cylinder ALCo engine

15.2 Should have cleared million cycle test on test rig at bidders premises in non-firing high temperature condition.

16. PRE-DISPATCH INSPECTION Inspection of the scoped supply would be carried out by representative of Engine Development Directorate at firm’s manufacturing facility without any additional cost before dispatch of the same. Expense for travel to and fro to the firm’s premises, boarding and lodging of the IR personnel shall be borne by IR. The firm should indicate for each equipment the relevant specification to which the equipment would be type tested. Type test program should be drawn up by the firm in consultation with RDSO, ED Dte.

17. INTELLECTUAL PRPERTY RIGHT (IPR) Vendor should give the undertaking for non-infringement of IPR as per Annexure ‘A2’ of RDSO ISO Document QO-F-7.1-7 dated 07/05/15.

18. TRAINNING The Vendor shall be willing to train five IR personnel for two weeks in the new technology at the time of prove-out on engine test bed.

19. WARRANTY 19.1 All the scoped material should be warranted for minimum 24 months from the date of

acceptance of the completed work by RDSO/Indian Railways.

19.2 The Vendor shall provide a Work Test Certificate (WTC) that all the equipment shall be free from all defects and faults in material, design, workmanship and manufacture and shall be of acceptable standards for the contracted work and in full conformity with the technical specifications and other purchase order stipulations.

19.3 During the warranty period any fault in the system shall be replaced /repaired by the vendor

free of cost within 90 days of the failure and the warranty shall stand extended, by the period that is taken to effect replacement.

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Annexure-I

ENGINE DATA – 6 CYLINDERS DLW BUILT 251 ALCO ENGINE

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

2. Engine type DLW built 251 engine

3. No. of cylinders 6

4. Configuration Inline

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 1-4-2-6-3-5

12. Valves (4 valve head)

Air inlet open 63.8 degrees CA before TDC

Air inlet close 29.6 degrees CA after BDC

Exhaust open 41.5 degrees CA before BDC

Exhaust close 60 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, air-cooled.

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Annexure-II

ENGINE PERFORMANCE DATA AT FULL LOAD- 6 CYLINDERS DLW BUILT 251 ALCO ENGINE

1. Brake horse power 1350 hp

2. Engine speed 1100 rpm

3. BMEP 15.86 bar

4. BSFC (Corrected 60ºF/15.55ºC) 155 gm/bhp-hr

5. Average cylinder head exhaust temperature 400 0C

6. Max. ambient temp. expected 50 0C

7. Specific air consumption 1.7 kg/sec (approx)

8. Vacuum at compressor air intake -4.01 mbar

9. Compressor outlet pressure 1.6 bar

10. Pressure drop across after cooler 0.06 bar

11. Inlet manifold pressure (engine air gallery) 1.5 bar

12. Exhaust pressure before turbine 1.25 bar

13. Turbine outlet pressure (exhaust) 37 mbar

14. Maximum cylinder pressure 125 bar

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

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Annexure-III

TYPICAL INDIAN RAILWAY 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

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Annexure-IV

OPERATING POINT AT VARIOUS NOTCHES FOR ALCO 251 ENGINE

NOTCH RPM hp

LOAD (N) POWER (hp)

8 th

1100 8700 1350

7th

1000 8100 1121

6th

900 7200 900

5th

800 6000 668

4th

700 4800 469

3rd

600 2300 194

2nd

500 2300 162

1st

400 1200 69.1

Idle 400 600 35.8

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Annexure-V

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