Jaipur MetroAn Industrial Training Report

ABSTRACTFollowing is the brief description about the training at the recent establishment of Metro in Jaipur.

Puneet KumarB. Tech.(3rd Year)Roll No. 1120570NIT KurukshetraHaryana

Submitted toDelhi Metro Rail CorporationLal Kothi, Tonk RoadJaipur

AcknowledgementI’ve tried to learn a lot in this training but it would not have been possible without the kind support and help of many individuals and organization. So, I’d like to thank Mr. Rajesh Kumar (Asst. Manager, DMRC) who has supported us throughout our Training Period. He has been picking out time for training individuals in spite of having tedious and hectic work schedule.

Also I’d like to give credit to the field instructors who have tried to provide us enough exposure and understanding of the work process.

Special thanks to Mr O.P. Salwan (DGM, Electrical Dept. in DMRC) for letting us train in this prestigious Organization.

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Trainee Training In-Charge

Department Training Period Remarks

Puneet Kumar Mr. Rajesh Kumar Rolling Stock

June 02, 2014 to July 01, 2014

Summer Training Report

Verification

INTRODUCTION

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Now-a-days, rush and pollution are increasing at an alarming rate in every developing city. Due to increasing population and migration of people to cities have made it the necessity of hour to cope with traffic and pollution and to facilitate the migration of crowd within the city.

Metro is an easy and quiet solution of this as it reduces both time and effort of the people to move from one part of the city to other. It is a pollution free mode of transportation which could be used to plan the development of cities making it able to cope with increasing pace of life.

The present public transport system available for the city is not properly organized and is inadequate in terms of frequency & comfort. The fleet of about 250 buses is being operated under public transport system which connects the suburban areas to core area of the city. The private mini bus operators operate about 1800 buses mostly in city area. The private mini bus operators dominate and compete with public bus system. Their routes are in-efficiently rationalized and are not properly regulated with too many buses on some routes where as other routes have very less frequency. The other transport facility available is Rickshaws. Cycle Rickshaws operates mostly inside walled city area for short trips and Auto Rickshaws operates in whole study area. The present bus transport system is insufficient to cater the need of city due to which the share of public transport has decreased from 26% to 19% in last decade. Commuters prefer to use personalized transport. The average annual growth rate of the vehicles in Jaipur is about 12% which is causing congestion on city roads.

What is Metro?

Metro is an Electrically Motoring Locomotive very similar to the traditional Indian Railway except having its advantages over it.

Need For Metro

Public Transport System is an efficient user of space and energy, with reduced level of air and noise pollution. As the population of a city grows, share of public transport, road or rail-based, should increase.

A comprehensive Mobility Plan for the city is already prepared. Possible options for a public mass transit system are:-

i) City Buses

ii) Bus Rapid Transit Systems

iii) Tramway system

iv) A Metro System (light or medium).

The city already has a bus system operated and maintained by Rajasthan Roadways and private operators. This is totally inadequate for the needs of the city. The Government is

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also contemplating to introduce Bus Rapid Transit Systems on certain selected routes. BRT has its own limitations and constraints.

Jaipur City, with its present population of 4.45m and employment of 15.55 lakh has a travel demand of 36 lakh passenger trips every day with 3.6 lakh trips performed during peak hour. With growing population and mega development plans coming up for the Port City, the travel demand is expected to grow steeply. With the growing economy and inadequate public transport services, the passengers shall shift to private modes, which is already evident from the high vehicle ownership trends in the region. This would not only aggravate the congestion on streets but also increase the pollution. Hence, it is essential to plan and provide for a Light to medium Metro System in Jaipur.

The peak traffic demand on East-West corridors of Jaipur Metro has been assessed 11264 in 2014 and this is likely to increase to 27750 PHPDT by the year 2031. Road accidents are on the rise. Therefore, it is not possible to introduce road based transport system all along the proposed metro corridors. Moreover, traveling time on the road will be much higher. Also, bus travel is not as comfortable as that of metro. There is an urgent need to introduce a Metro system to provide fast, safe and hassle free movement of the public in the city.

Two metro corridors with a combined length of 35.666 km have been identified for the city of Jaipur.

• The E-W line starts from Manasarovar and ends at Badi Chopar with a total length of 12.067 km. (Phase 1)

• The N-S line starts from Sitapura industrial area to Ambabari via SMS hospital with a total length of 23.099 km. (Phase 2)

Main Fields covered in training at METRO:

Pneumatic Air Distribution System and Braking HVAC System Machine and Plant Suspension System

HVAC

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HVAC refers to the Heating, Venting and Air-Conditioning. It helps in maintaining the atmosphere of the Saloon very comfortable according to the weather. HVAC Systems in Jaipur Metro are provided by Sidwal Refrigeration Industries Lt.

Every Saloon has two independent systems of HVAC having separate ducts also. And the Driver’s Cab has only single HVAC system. Although they both have different configurations according to requirements.

• Saloon HVAC:- 1) Cooling capacity=48 KW

2) Heating capacity=9 KW

• Cab HVAC:- 1) Cooling capacity=5 KW

2) Heating capacity=2 KW

Necessity of effective HVAC system and its important functions:

Because human feels comfort only with some specified parameter of temperature, humidity, purity & distribution of air in the occupied area. Comfortable conditions for a normal human being are Temperature as 20-26°C & RH (Relative humidity) as 50-70%.

• To control temperature. • To control humidity.• To distribute air properly for proper inhalation.

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DETAILED PARTS OF HVAC SYSTEM

Air Conditioner Overhead

COMPRESSOR

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2 Fully hermetic scroll compressors 2 Condenser fan assemblies 1 Supply air blower assembly 2 Condenser coils 1 Evaporator coil (with 2 interlaced circuits) 2 Filter driers 2 Thermostatic Expansion valves(Tx valve) 2 Fresh air dampers 1 Return air damper (fitted in return air duct outside/under the HVAC unit) 2 Fresh air filters 2 Sight glass Set of 3 mixed air filters in mixed air compartment 1 Electrical control panel with switchgear and microprocessor RAT &FAT probe HP & LP Switches

The function of the compressor is to pump the refrigerant through the system and to compress the low pressure, low temperature refrigerant into a high pressure high temperature super-heated vapour, to allow condensing to occur.

There are 2 compressors per HVAC unit Type:- Hermetic scroll Power supply:- 3 Phase 415 V, 50 Hz Refrigerant :-R-22

CONDENSER COIL

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The function of the condenser coil is to reject the heat from refrigerant absorbed by the evaporator coil and during the compression process

The condenser coil is made of copper tubes expanded in pre-coated aluminum fins.

Frame: Stainless steel

Tube size: 9.52 mm diameter (3/8”)

Quantity: 2 Nos.

CONDENSER FAN

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Its function is to draw the atmospheric air through condenser coil , inside which hot refrigerant is flowing , thus making the heat rejection & condensing.

The condenser fans are driven by three-phase induction motors.

The air conditioner is fitted with 2 condenser fans

Type:- Axial multi-blade

Rated output :-1.5 kW

EVAPORATOR

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The prime function of the evaporator compartment is to deliver conditioned air to the main supply air duct that services the vehicle.

The evaporator coil is made of copper tubes expanded in pre-coated aluminum fins. Tube size: 9.52 mm diameter (3/8”). Quantity: 1 (with 2 interlaced refrigeration circuits).

SUPPLY FAN

There are two centrifugal fans mounted on the shaft ends of the blower motor.

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Rated output :-2.2 KW Rated Voltage:- 3 Ф, 415 V, 50 Hz

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AIR TRANSFER SYSTEM

AIR DAMPERS

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Their function is to control the fresh air & return air volume as per requirement. 2 Fresh air damper & 1 Return air damper Rated voltage :-24 V DC

Fresh Air Damper Motor

Return Air Damper

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Fresh air damper

AIR FILTERS :

FRESH AIR FILTER

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It is used to filter the fresh air There are 2 fresh air filter in a saloon HVAC unit

RETURN AIR FILTER

It is used to filter the return air There are 3 return air filter in a saloon HVAC unit

SOLENOID VALVE

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It is electrically operated magnetic valve (compressor and magnetic valve gets supply at same time).

Its function is to circulate the refrigerant in the system. There are 2 solenoid valves in a saloon HVAC unit. There are 2 bypass valve(solenoid valve) in a saloon HVAC unit

SOLENOID VALVE

SIGHT GLASS: It used to check the refrigerant (Presence of air or moisture).

SIGHT REFRIGERANT MOISTURE

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GLASS STATUS

CONDITION CONTENT

GREEN NO REFRIGERANT IN SYSTEM

DRY SYSTEM

GREEN YELLOW

GOOD REFRIGERANT CHARGE IN SYSTEM

SOME MOISTURE PRESENT

YELLOW REFRIGERANT CHARGE IS LOW

WET/HIGH MISTURE CONTENT

Vapor Compression Refrigeration System – Construction

Condenser: It is a coil of tubes made of copper.Receiver tank: It is the reservoir of liquid refrigerant.

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Expansion Valve: This is a throttle valve. High pressure refrigerant is made to flow at a controlled rate through this valve.

Evaporator: It is the actual cooler and kept in the space to be cooled. The evaporator is a coil of tubes made of copper

Basic Principle of Air Conditioning

Working of the Refrigeration System

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1. The low pressure refrigerant vapor coming out of the evaporator flows into the compressor.

2. The compressor is driven by a prime mover.

3. In the compressor the refrigerant vapor is compressed.

4. The high pressure refrigerant vapor from the compressor is then passed through the condenser.

5. The refrigerant gives out the heat it had taken in the evaporator (N)

6. The heat equivalent of work done on it (w) on the compressor.

7. This heat is carried by condenser medium which may be air or water.

8. The high pressure liquid refrigerant then enters the expansion valve.

9. This valve allows the high pressure liquid refrigerant to flow at a controlled rate into the evaporator. While passing though this valve the liquid partially evaporates.

10. Most of the refrigerant is vaporized only in the evaporator, at a low pressure.

11. In the evaporator the liquid refrigerant absorbs its latent heat of vaporization from the material which is to be cooled.

12. .Thus the refrigerating effect (N) is obtained.

13. Then the low pressure refrigerant enters the compressor and the cycle is repeated.

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Generation of Air Pressure in Brake Pipe :The pantograph rises at a pressure of 3.8 bar with the help of pneumatic system .It supplies electrical energy to the whole train system and also runs the pneumatic systems.

So initially a primary pneumatic circuit is required to generate a pressure of 308 bar to raise the pantograph and get further electric supply.

1) Air is compressed by the compressor driven by the DC supply.2) Hose pipe is used to make the flow continuous even during vibration.3) ACMG controls the air pressure between 6.0 to 7.0 bar.4) During the malfunctioning of ACMG it may generate a pressure of air upto 12 bar and

get worn out. So, a safety valve is used to control the maximum pressure generated by ACMG and draining out the excessive pressure and maintaining the topmost pressure of ACMG up to 9.0 bar and prevents it from damaging.

5) Filter is used to filter the compressed air6) A cylinder [25 ltr] is used to store compressed air7) A cock is used to regulate or control the pressure between the cylinder and pantograph.

Initially the circuit is broken and then the pantograph touches the 25 KV supply so no spark is produced and no damaging or burning of pantograph takes place.

Later on as the pressure in circuit rises up to 4.9 bar the vacuum circuit breaker actuates and connection with 25 KV supply is made.

Now as the primary circuit is on the main pneumatic circuit comes in action. After receiving air from the hose pipe some of the oil impurities are separated and is stored in the drainer. After this the air is passed to the air drier at a particular period of time only one half of it operates (2 min) while other half dries the moisture separated from air.

It then passes through a filter and get stored in a 200 ltr at a pressure of 10 bar. In the cylinder some more oil is collected in drainer. Air at a pressure of 10 bar is used by the magnetic valve which is controlled by a pulse to open the drain valve to eject out the oil impurities from the cylinder.

A safety valve of 12 bar is used to regulate the pressure limit of ACMG. A safety valve of 10.5 bar is used to drain excess pressure from the main pipe (10 bar) during summer due to increase in pressure due to high temperature.

Braking System :20

1) Service braking- Used speed down the train (Pure service upto 14kmph).2) Holding braking- used when train is running on inclined or during reaching platform.

Only 70% braking is used to slow down the train.3) Emergency brakes- Used to stop train the train when there’s a malfunction or

irregularity in the general plan. 4) Driver braking valve

(i) Used in Indian Railways(ii) Secondary braking system used in metro

5) Parking braking system- Used when metro is to be parked in depot.Spring mechanism is added in addition to the general Pneumatic mechanism for service braking and is used to move the piston and air pressure of 10 bar is used to oppose the spring and restrict it to expand.During braking air at a pressure of bar is drained out and the spring expands which moves the piston and actuates the braking.

Service Brake :

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Priority of braking effort:I. Electric Regenerative brake controlled by C/I of Motor car

II. EP friction brake controlled by BECU of Driving trailer carIII. EP friction brake controlled by BECU of Motor car (In the beginning and end of

service braking)IV. EP friction brake of Driving Trailer car & Motor car (In case of failure of electric

brake)

Brake Blending : The Electric brake of each Motor car is used in preference to the Pneumatic Brake, as it works without wearing either brake blocks and is therefore more economical. The electric brake is controlled by the C/I (Converter/ Inverter), in case that the Electric Regenerative brake cannot provide the braking effort as demanded by the master controller of the driver, the missing brake effort will be supplied by the pneumatic brake. This feature is called Bending.

The M car BECU on a two-car basis controls the brake blending. Blending is carried out between Motorcar and Driving trailer car of a unit.Emergency Brake – The train set is equipped with an emergency brake loop wire. The emergency brake loop is connected to the emergency brake magnet valve, which is opened when de-energized and closed when energized (Fail-safe system).So, in case the emergency brake magnet valve is de-energized by interrupting emergency brake loop, the emergency brake will be applied automatically.Holding brake – The holding brake is provided to prevent the train from rolling backwards on a rising gradient and the train from moving at the station.The holding brake is released when C/I sends the signal “Reset Holding Brake” to the BECU. The tractive effort, which is applied when the signal Reset “Holding Brake Request” is initiated, shall ensure that the train will not roll backwards at a slope. The holding ones are 70% of full service brakes.Parking Brake –Parking brake is used for parking the train in depot and these are installed at Driving-Trailer car and Motor cars (1 set per axle and diagonally placed in a bogie).Parking brake can be applied manually or these may apply automatically also when the MR pressure is low. To apply parking brake put Mode Selector at Standby position and press “Parking Brake On Push Button”. To release press “Parking Brake OFF Push Button”.Parking brakes are automatically applied in the event of loss of the main reservoir pipe pressure.

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Brake Calliper

Parking Brake Manual Release - When MR pressure is low, it is possible to release individual parking brake manually from track level by; pulling out the manual release device installed at the parking brake cylinder. Operation of parking brake is monitored through the parking brake lamp installed at driver’s desk and TIMS screen. When the parking brake is applied the parking brake lamp will be illuminated and the application can be read through TIMS screen also.

Driver Brake Valve (DBV) -BPIC-brake pipe insulation cokeBPCON-brake pipe cone(mechanically controlled)BPMV-brake pipe magnetic valve(electrically controlled)BPCON-used to cut-off DBV from supplyBPMV- used to move the train even if some other signals are received to apply the brakes.Pressure valve is used to reduce the pressure from 10 bar to 5 barDBV works at 5 bar.

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Load Weighing: The load dependent pressure limiting valve (B3.C) is used to limit the supply reservoir air pressure according to the actual car load.

At the same time the average load signal is electrically fed to the BECU from the T pressure transducer on the EP-BCU. This signal is used for load compensation of the propulsion and air-conditioning system.

Wheel Slide Protection (Anti-skid control): Wheel slide protection is used to optimize the stopping distance and to avoid the wheel flats under wheel sliding conditions. Wheel slide protection is active in service brake and emergency brake. The wheel slide protection acts per bogie on each car by the dump valves (G2). Wheel-slide protection is operational at all speeds down to 3 km/h.Speed sensor mounted on the cover of each axle box, detects the speed of the associated wheel. When a potential wheel-slide event is detected, the BECU will release/apply the brakes through energizing/ de-energizing the magnets of the dump valves.Wheel slip/slide is also controlled by CI during electric regenerative braking and powering.

BP-Back up Brake - Additional BP (Brake pipe) controlled back-up brake system is provided in order to take over the

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Brake control function in case of failure of individual electronic or electrical control elements. The driver can continue to control the pneumatic friction brake by using the driver’s brake valve. The driver is able to apply or release the pneumatic brake by operating the driver’s brake valve installed at the driver’s cab. By the brake valve the brake pipe (BP) pressure can be reduced or increased depending on the time the brake lever is maintained at “braking” or “driving”. During the normal service brake operation, the drivers brake valve lever shall be maintained at “driving”.

Electrically Controlling Unit: LLB: Load Limiting Valve (Calculates total load on car)DG: Digital Convertor (takes input from pressure transducer and Controlled by BECU)SBL: Service Brake Line (pressure is controlled in this line by BECU through controlling the valves)EBL: Emergency Brake Line (nearly 10 bar), during service braking MV holds the EBL and passes compressed air from SBL. During EB it allows air at 10 bar to flow through the circuit.DCV: Double Check Valve (receives and compare two inputs and passes the higher one to flow)During DBV (5 bar>SBP) hence actuating DBV.During SB service brake force is greater than DBV force allowing the SBP (2-4 bar) to operate through the circuit.KR6: It also receives two inputs and then increases the flow rate by keeping the pressure constant in the pipe.Dump Valve: Sometimes the wheel slides during the Braking so the dump valve (1 per car) is used to regulate the pressure on each axel.

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Machine and Plant:Includes the process of levelling, aligning and installing machinery and is called Millwright. In this aspect of training, we were introduced with the following machinery:

RRM-1 (Rail Road Mover) Pit Jack Mobile Jack Electric Fork Lifter (EFL) Aerial Work-lift Platform Battery Operated Platform Mobile Compressor High Pressure Wash Pump Rescue Equipment Rail-Rescue Vehicle (RRV) Pit Wheel Lathe Auto Wash Plant (AWP) Electrical Overhead Trailer Crane (EOT) Air Con Lifter (AC lifter) Bogie Turn Table (BTT)

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Pit Wheel Lathe

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Suspension System: Suspension is the mechanism to absorb sudden jerks applied by the rail on the Metro.

Suspension System is a necessity when it comes to the comfort and most importantly safety of the passenger. Basically Metro system has adopted two suspension mechanisms:

Primary Suspension: Between Bogie and Wheels (Conventional Spring Mechanism is used)

Secondary Suspension- Between Bogie and Car Body (Pneumatically Controlled).

Bellows- It’s a balloon type tube used as Secondary Suspension maintaining an adequate height of the Metro under different pressure.

Levelling Rod- It is a main component of the system as it maintains sufficient air pressure in the bellows to align it horizontally with the rails as the load is varied on the lateral sides of the Metro.

Differential Valve: It is a one-way valve between the two bellows allowing the passage of pneumatic pressure from one bellow to the other. It generally comes in action when one of the bellow experience leakage and hence the pressure loses, the Differential Valve is made such that it only allows the movement of the air pressure when the pressure difference is up to 1.5 bar. When the difference reaches 1.5 bar it stops the flow from either of them and hence avoiding the chance of collapse.

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Primary Spring Suspension

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ConclusionAfter studying different parts and technology used in metro in a very effective short period of time, it is clear that metro is technically very advanced than other means of transportation for people within the city without creating pollution providing a good solution to plan a Metropolitan City.

It is a very sophisticated system controlled manually and automatically with safety precautions heavily taken care of. Each and every component used in its each car is managed by TIMS (Train Integrated Management System). So, error detection and failure is easily controlled and managed through the driver’s cabin only.

In the end I’d say that it was worth a Training Period and an incredible experience spending two weeks in Metro.

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