A brief explanation of the training received during my industrial training in Delhi Metro Rail Corporation Ltd. It was a lot but I tried to show the main portion of the HVAC system used in DMRC underground railway stations. Everyone was eager to help there. If you want to have some real experience of training then you should definitely join DMRC.

1. DELHI METRO RAIL CORPORATION LIMITED
दिल्ली मेट्रो रेल कॉरपोरेशन लललमटेड
SUMMER TRAINING IN DMRC
Presented By:
Asim Kumar Ghatak
Mechanical Engineering (7th
Sem)
1409140044
A PRESENTATION ON

2. CONTENTS
1. ECS (ENVIRONMENTAL CONTROL SYSTEM)
 AIR HANDLING UNIT (AHU)
 CHILLERS
 COOLING TOWERS
 VENTILATION SYSTEM
2. TUNNEL VENTILATION SYSTEM (TVS)
3. FIRE FIGHTING SYSTEMS
4. UNDERGROUND STATION PLATFORM LEVELS

3. Environmental control system
The environmental control system
(ECS) of Metro provides air supply,
thermal control for the crew and
passengers. Smoke detection and fire
suppression are also commonly
considered part of environmental
control system.

4. Environmental Control System consist of
1. AIR HANDLING UNITS (AHU)
2. CHILLERS
3. COOLING TOWERS
4. VENTILATION SYSTEM
AIR HANDLING UNIT (AHU)
AHU
An air handler, or air handling unit (often
abbreviated to AHU), is a device used to
regulate and circulate air as part of a heating,
ventilating, and air-conditioning (HVAC)
system. An air handler is usually a large metal
box containing a blower or centrifugal pump,
heating or cooling elements, filter racks or
chambers, sound attenuators, and dampers.
Air handlers usually connect to a ductwork
ventilation system that distributes the
conditioned air through the building and
returns it to the AHU.

5. Cross Section Of AHU
Drip Pan
Centrifugal pump
Cu tubes with fins
Air Filter

6. CHILLERS
A chiller is a machine that removes heat from a
liquid via a vapour-compression. This liquid can
then be circulated through a heat exchanger to
cool equipment, or another process stream
(such as air or process water). As a necessary
by product, refrigeration creates waste heat
that must be exhausted to ambience, or for
greater efficiency, recovered for heating
purposes.
It works on the same way as vapour
compression refrigeration cycle.

7. Hot water from AHUCold water from chiller
To AHU
Hot water from Evaporator
Cold water from Cooling Tower
Working of Chillers

8. Cooling Towers
A cooling tower is a heat rejection device that
rejects waste heat to the atmosphere through
the cooling of a water stream to a lower
temperature. Cooling towers may either use
the evaporation of water to remove process
heat and cool the working fluid to near the
wet-bulb air temperature or, in the case of
closed circuit dry cooling towers, rely solely on
air to cool the working fluid to near the dry-
bulb air temperature.
the main types of cooling towers are natural
draft and induced draft cooling towers.

9. Working of Cooling Tower (crossflow design)

10. Ventilation System
Track Way Exhaust Fan (TEF)
• Track way Exhaust Fan is required to suck the air of platform level through UPE & OTE duct and
send this air to AHU where air is cooled and filtered .
• TEF rotates in a single direction and has an axial flow of air through it .
• TEF (about 08 to 12) in numbers are located in each station.
Under Platform Exhaust (UPE) Over Track Exhaust (OTE)

11. Tunnel Ventilation System (TVS)
• This system is incorporated for the emergency
condition when there is a fire in tunnel or fire
in train inside tunnel.
• Huge size of fans are installed at each station
at both the extreme ends of station from
where tunnel starts.
• These fans are having bidirectional feature for
its rotation as per requirement i.e. the fan can
rotate in either supply mode or exhaust mode
• These fans are always at the priority level for
its operation.
• Direction of its rotation is decided as per the
location of fire and if one station TVF is in
supply mode another station where in
between fire is there will run in exhaust mode
for quick overcome on smoke and fire.

12. Piston Effect Due to Moving Train In Subway Tunnel
If tunnel length is > 1.5 Km , Boosters are used

13. FIRE SYSTEM
 It consists of
1. Fire Detectors– Located at various places of station as per layout
2. Gas Suppression– Inergen Gas (Argon 50%,Nitrogen 42% and CO2 8%) Cylinder located in ASS (Auxiliary
Service Station) rooms which operates automatically in case of fire.
Best feature – it doesn’t hamper life .
3. Hydrant Pumps—It is of different types as
--Main Hydrant Pump
--Standby Hydrant Pump
--Sprinkler Pump
--Jockey Pump
Jockey pump
A jockey pump is a small pump connected to a fire sprinkler system and is intended to maintain pressure in a
protection piping system to an artificially high level so that the operation of a single fire sprinkler will cause a pressure drop
will be sensed by the fire pump automatic controller, causing the fire pump to start.

14. • 2 tanks of 1 lakh litre each is used in Fire fighting located in ancillary building
Firefighting Equipment :

15. Underground Station
Levels
There are Four Levels In An Underground Metro Station
1. Ground Level: Parking, Lift, Escalators, Staircase to Concourse Level
2. Concourse Level:
Paid Area: Staircase down to Platform, Lift, etc.
Unpaid Area: Access to Fare Office, Ticket Window,
X-Ray Machine
AFC (Automated Fare Collection) Gates are
connecting area of paid and unpaid area
3. Platform Level: Lifts, Staircase, Escalators, FHC(Fire Hose Cabinet) etc.
4. Undercroft Level: Electric Lines, Services Of Drainage (Seepage &
Sewage), UPE Duct

17. References
 http://www.delhimetrorail.com/
 https://en.wikipedia.org/wiki/Delhi_Metro
 https://www.google.com
 Study materials provided by DMRC

18. THANK
YOU!