Mechanical system COURSE CODE:15BAR8.6
Instructor’s name:
Shoumik Desai
Ashitha.H |NU17UAR003 |Barch sem 8 |
INDEX 1.Time problem. • Introduction • Psychometric charts • Inference table • Strategies and the mechanical systems • References
3-4 5 6-12 13
2.Five cooling systems. • Spiltairconditioner
14-17
• Vapourcompressionrefrigeration system
18-19
• Air handling unit
20-21
• Radiantcoolingsystem
22-23
• District cooling systems
24
• Reference
25-26
3.Single line diagram of radiant cooling and air handling unit.
27
4.Lifts. •Explain 5 types of lift with sketches and explain all of it's components and explain each with a short note •Identify which are the fastest lifts in the world and find the latest systems which are implemented in those lifts •Explain types of escalators and walkalators and explain all of it's components and explain each with a short note •Reference
27-29 30-32 34-40
5.questionnairs
42
Introduction: • Site -Srinagar: Largest city and the summer Capital of Jammu and Kashmir. • Climatic condition in Srinagar – In Srinagar, the summer are long, warm and clear and the winters are short, very cold and partly cloudy. • Elevation : 1585 meters • Latitude /longitude : 34° N , 74°79’ E • Average temperature in summer - Around 23°c • Average temperature in winter - Around 3°c
Different mechanical systems are used in order to provide the most suitable outcomes that works well for this particular climatic zone. 30-04-2021
mechanical systems |B.Arch sem8 |2021
3
Psychrometric charts- Jan to June
January
April 30-04-2021
February
May mechanical systems |B.Arch sem8 |2021
March
June 4
Psychrometric charts July-dec
July
October 30-04-2021
August
November mechanical systems |B.Arch sem8 |2021
September
December 5
Inference STRATERGIES
30-04-2021
mechanical systems |B.Arch sem8 |2021
ACTIVE HEATING
PASSIVE HEATING
INTERNAL GAIN
NATURAL VENTILATION
MASS COOLING
EVAPORATIVE COOLING
6
ACTIVE HEATING – SOLAR BOILERS Active solar heating strategy is required for most of the months including January, February, March, April, November and December In active heating, mechanical means are used to store, collect, and distribute solar energy in buildings in order to provide hot water or space heating.
Working • Active solar space heating systems consists of collectors that collect and absorb solar radiation combined with electric fans or pumps to transfer and distribute the solar heat. • Active system also generally have an energy storage system to provide heat when the sun is not shining.
• The two basic types of active solar space heating systems use either liquid or air as the heat transfer medium in their solar energy collectors. • Liquid based systems heat water and air based systems heat air in the collector. • Both of these systems collect and absorb solar radiation then transfer the solar heat directly to the interior space or to storage system from which the heat is distributed.
• An auxiliary or backup system provides heat when storage is discharged • Liquid system are more often used when storage is included.
30-04-2021
mechanical systems |B.Arch sem8 |2021
7
PASSIVE HEATING – EARTH BERMING • Passive heating strategy is required for the month January, February November and December • Earth berming : this technique is used both for passive cooling as well as heating building . • Earth berming is the practice of building a wall of earth around the outside of the home. The berm is about three or four feet tall and covers all but the south side. It is particularly useful for protecting homes built on flat terrain. • Earth sheltering is a more extreme version of earth berming, where the north side (and perhaps the east and west sides) of the house is buried more extensively, often right up to the roof. • Working : Here earth is acting like a massive heat sink. Summer as well as winter variations die out rapidly with increasing depth from the earths surface. This temperature at a depth of a few meter remains almost stable throughout the year . Thus the underground or partially sunken buildings would provide both cooling in the summer and heating during the winter to the living space .
30-04-2021
mechanical systems |B.Arch sem8 |2021
8
INTERNAL HEAT GAIN – TROMBE WALL Internal heat gain techniques are required for the month of March, April, May and September
Trombe wall : A Trombe wall is a wall that warms trapped air, and then circulates it to help heat a house. Trombe walls are ideally made out of a material with a fairly high thermal mass materials (like bricks or concrete), and are often painted black to improve heat conduction. Trombe walls feature a pane of glass or plastic glazing installed a short distance in front of the wall. This creates an air compartment where air is heated, then allowed in and out of the house through vents at the top and bottom of the Trombe wall Working : During the day the sun heats first the air in this space , then the solid wall behind .once the air is heated it rises and enters into the room, giving it additional heat. Also the rising air pulls in cooler air from the room below to then be heated . but for sometime after the sun goes down the hot wall will keep heating the wall will still keep heating and exchanging that heat into the room. Details : The space between the thermal mass wall and the glass should be a minimum of 4 inches Vents must be closed at nights Wall thickness must be atleast 10-14 inches for brick and 8 -12 inches adobe 30-04-2021
mechanical systems |B.Arch sem8 |2021
9
NATURAL VENTILATION– WINDOW SHEETS
• Natural ventilation is required mainly during the months of May, June, September and October • Window sheets are used to stop strong chilly winds entering through window openings but still allowing the sunlight and to enter for the cold climatic regions • Working: south side of the building are provided with more openings for more solar radiation. • These windows have a huge thick plastic sheet attached at an angle. This stops the cold harsh winds from entering the indoor spaces and hence keeping it warm but also providing minimal flow of air with sunlight and heat during winters • During summer, this sheet is rolled up to let in the fresh air
30-04-2021
mechanical systems |B.Arch sem8 |2021
10
MASS COOLING – THERMAL MASS Mass cooling is required for the months of June, July, August and October Thermal Mass : 'Thermal mass' describes a material's capacity to absorb, store and release heat. For example water and concrete have a high capacity to store heat and are referred to as 'high thermal mass' materials. Insulation foam, by contrast, has very little heat storage capacity and is referred to as having 'low thermal mass'. Working: Thermal mass is used in a passive cooling design to absorbs heat and moderate internal temperature increases on hot days. During the night, thermal mass can be cooled using ventilation, allowing it to be ready the next day to absorb heat again. It is possible to use the same thermal mass for cooling during the hot season and heating during the cold season. Material detail
30-04-2021
mechanical systems |B.Arch sem8 |2021
11
EVAPORATIVE COOLING- EVAPORATIVE COOLERS • Evaporative cooling is only required for the month of July and August • An evaporative cooler (also evaporative air conditioner, swamp cooler, swamp box, desert cooler and wet air cooler) is a device that cools air through the evaporation of water.
• Evaporative air conditioning uses evaporation to cool the air. In an evaporative cooler, a pump circulates water from the reservoir onto a cooling pad, which in turn becomes very wet. A fan draws air from outside the unit through the moistened pad. As it passes through the pad, the air is cooled by evaporation. • The key to effective evaporative cooling is ensuring that each of the cooling pads are completely saturated at all times during operation and that the system’s fan and motor are sized and designed to deliver the appropriate airflow.
An earlier form of evaporative cooling, the windcatcher, was first used in ancient Egypt and Persia thousands of years ago in the form of wind shafts on the roof. They caught the wind, passed it over subterranean water in a qanat and discharged the cooled air into the building. Modern Iranians have widely adopted powered evaporative coolers
30-04-2021
mechanical systems |B.Arch sem8 |2021
12
References •
https://www.researchgate.net/figure/Working-principle-of-a-traditional-Trombe-wall-and-energy-gain_fig1_228678835
•
https://www.thethirdpole.net/en/energy/indian-army-looks-to-passive-solar-heating-inladakh/#:~:text=The%20school%20buildings%20are%20heated,powered%20heating%20or%20firewood%20burning
•
https://www.new-learn.info/packages/clear/thermal/buildings/passive_system/earth_berming.html
•
https://refrigerationandaircon.co.za/index.php/features/contributor/77-grant-laidlaw/137-evaporative-coolers
•
https://acarchitects.biz/thermal-mass/
•
https://indiaclimatedialogue.net/2018/02/26/passive-solar-housing-keeps-people-warm-icy-ladakh/
30-04-2021
mechanical systems |B.Arch sem8 |2021
13
Spilt air conditioningsystems • These are kits of 2 units ,one internal and another external . • The indoor unit installed inside a room intakes warm air and throws in cold air
• The outdoor unit on the other hand is installed out of the house.it contains the compressor and is linked to the internal unit via drain pipes and electric cable. This external unit throw out the warmair.
• Spilt air conditioners are suitable for hot and dryclimate • Type of space :housing ,restaurants/cafes, office etc
Specifications for air conditioner Room size and capacity tonnage needed
30-04-2021
mechanical systems |B.Arch sem8 |2021
Reference :trane technologies
14
Mechanism/principle of working of each system • In a split system, the compressor condenses and circulates the refrigerant through the outdoorunit. • changing it from a gas to aliquid.
• The liquid is then forced through the indoor evaporator coil or cooling compartment.
• The indoor unit’s fan circulates the inside air to pass across the evaporator fins. • The evaporator’s metal fins exchange the thermal energy with the air around it. There, the refrigerant turns from liquid into vapor, removing any heat from the surroundingair.
• As the heat is removed from the air, the air is cooled and blown back into the house. • From that point, the condenser or outdoor unit then turns the refrigerant vapor back into a liquid, removingany heat.
• By the time the fluid leaves the evaporator again, it is a cool, low-
pressure gas, eventually returning to the condenser to begin its trip all over again.
• This process continues again and again until your home reaches the cooling temperature you want, as programmed and sensed by your thermostat setting.
30-04-2021
mechanical systems |B.Arch sem8 |2021
15
Cooling and Dehumidification Process
Cooling anddehumidification
The process in which the air is cooled sensibly and at the same time the moisture is removed from it is called ascooling and dehumidification process. Cooling and dehumidificationprocess is obtained whenthe air at the givendry bulb anddew point (DP) temperature is cooledbelow the dew point temperature. Whenthe air comesin contact with the coolingcoil that is maintainedat the temperature below its dew point temperature, its DBtemperature starts reducing. The process of cooling continuesandat some point it reaches the value of dew point temperature of the air. At this point the water vapor within the air starts getting converted into the dew particles due to which the dew is formed on the surface of the cooling and the moisture contentof the air reducesthereby reducing its humidity level. Thuswhenthe air is cooled below its dew point temperature, there is cooling aswell asdehumidificationof air. in split air conditioners the evaporator coil or cooling coil is maintained at temperature lower than the dew point temperature of the room air or the atmospheric air by the cool refrigerant passing through it. When the room air passesover this coil its DBtemperature reducesandat the sametime moisture is alsoremovedsince the air is cooledbelow its DP temperature. The dew formed on the cooling coil is removed out by small tubing. In the central air conditioning systems the cooling coil is cooled by the refrigerant or the chilled water. Whenthe room air passesover this coil, it gets cooledanddehumidified. In the generalthe cooling and dehumidificationprocessis obtained by passingthe air over coil through whichthe cool refrigerant, chilled water or cooledgasis passed. During the cooling anddehumidification processthe dry bulb,wet bulb and the dew point temperature of air reduces. Similarly, the sensible heat and the latent heat of the air also reduce leading to overall reduction in the enthalpy of the air. The cooling and dehumidification process is represented by a straight angular line on the psychrometric chart. The line starts from the given value of the DBtemperature and extends downwards towards left. 30-04-2021
mechanical systems |B.Arch sem8 |2021
16
An air conditioner has 5 main parts: • 1.Refrigerant • Refrigerant(alsoknownascoolantor by its brand name Freon®)is aspecialfluid that is vital to cooling and freezingtechnology.It operates on a closedloop and carries heat from the inside of your building to the outside. Youcan think of the refrigerant asthe messenger/traveler. We use refrigerant because it changes states from liquid to vapor at convenienttemperatures for the refrigeration cycle. 2. Compressor The job of the compressor is to pressurize the refrigerant, thus raising its temperature. Due to the combined gaslaw (a combination of Boyle’s Law,Charles’ Law,andGay-Lussac’s Law), which states that if pressure increases so does its temperature, when you compress the refrigerant, it will heat up. It does this by squeezing the gasvery tightly together. Weheat up the refrigerant in order to get its temperature higher than the outdoor temperature. Sinceheat naturally flows from ahotter to colder bodies, in order to dispense heat outdoors, the refrigerant must be hotter than the air outdoors. This is why we need the compressorto increase its pressure and thus its temperature. 3. CondenserCoil Thecondensercoil is in the outdoor air conditioning unit. It receives the high pressure,high temperature refrigerant from the compressor.the condensercoils contain hot refrigerant. The condenser coils are designed to facilitate heat transfer to the outdoorair. 4.ExpansionValve When the refrigerant leaves the condenserin its liquid state, it has dispersed heat, but it is still too hot to enter the evaporatorcoils. Beforethe refrigerant passesto the evaporator coils, it must be cooled down. This is where the expansion valve (also known asa metering device) comes in, normally a thermostatic expansionvalve. 5. EvaporatorCoil Evaporatorcoils are very important to an air conditioner. It’s where the air conditioner actually picksup the heat from inside your home. Thecopper tubes receive the depressurized,liquid refrigerant from the expansion valve.When your indoor air blows over the cold coils, the heat from inside the home gets absorbed. Thisis becauseof the 2nd law of thermodynamics which states that heat flows naturally from hot to cold. Just like the condensercoils need the help of the condenserfan to facilitate heat transfer, the evaporator coils rely on the indoor air handler’s fan (aka the blower) to blow air over the coils. Asthe refrigerant absorbsheat from the indoor air, it starts to evaporate to form avapor.
30-04-2021
mechanical systems |B.Arch sem8 |2021
17
Vapour compression refrigeration system(VCRS) Applicationsof VCRCin warmandhumidclimaticregions•It is used in domestic refrigeration for keeping the food. •It is helpful in food processing and coldstorages. •It is useful in Industrial refrigeration for chemical processing, heating andcooling. •It is useful in Cryogenic refrigeration, Medical refrigeration, Transport refrigeration and Electronic cooling. Working ofVapor Compression Refrigeration System:
The working of Vapor Compression Refrigeration System can be completed under 4 processes and are as follows. • CompressionProcessThe vapour at low temperature and low pressure enter the compressor where it is compressed isentropically and subsequently, its temperature and pressure considerably increase. • CondensationProcess-
This vapour after leaving the compressor enters into the condenser, where it is condensed into highpressure liquid and is collected in a receiver tank. • ExpansionProcessFrom the receiver tank, it passes through the expansion valve, where it is throttled down to low pressure and temperature. • VaporizationProcess-
After finding its way through an expansion valve, it finally passes onto the evaporator, where it extracts heat from the surroundings or circulating fluid and vaporizes to lower pressure vapour.
30-04-2021
mechanical systems |B.Arch sem8 |2021
18
Components of Vapour Compression Refrigeration System: 1. Compressor: The vapour at low pressure and low temperature enters the compressor from the evaporator where it is compressed to high pressure and high temperature. This high pressure and temperature vapour refrigerant are discharged into the condenser through the discharge valve. 2. Condenser: The condenser or cooler consists of coils of pipe in which the high pressure and temperature vapour refrigerant are cooled and condensed. The refrigerant while passing through the condenser gives up its latent heat to the surroundings condensing medium which is normally air or water. 3. Receiver: The condensed liquid refrigerant from the condenser is stored in a vessel known as a receiver from where it is supplied to the evaporator through the expansion valve. 4. Expansion Valve: It is also called a throttle valve. Its function is to allow the liquid refrigerant under high pressure and temperature to pass through it where it reduces its temperature and pressure. 5. Evaporator: It also consists of coils of pipe in which liquid-vapour refrigerant at low pressure and temperature is evaporated and converted into vapour refrigerant at low pressure and temperature.
Advantages: •The temperature at the evaporator section can be controlled employing regulation of expansion valve. • It exhibits high Coefficient of Performance. Disadvantages: • Make sure that there should be no leakage of refrigerant from the pipes/hose. • Refrigerant can affect the atmosphere. • The cost of the system is high. 30-04-2021
mechanical systems |B.Arch sem8 |2021
19
Air handling unit Principle of working
Psychrometric processes
An Air Handling Unit (AHU) is used to re-condition and circulate air as part of a heating, ventilating and air-conditioning system. The basic function of theAHUis to take in outsideair, re-conditionit andsupplyit asfresh air to abuilding. All exhaust air is removed, which creates an acceptable indoor air quality. Depending on the required temperature of the reconditioned air, the fresh air is either heated by a recoveryunit or heating coil or cooledby a cooling coil.
• In buildings where the hygienic requirements for air quality are lower. A mixing chamber has dampers for controlling the ratio between the return, outside and exhaust air. • The AHU is a large metal box containing separate ventilators for supply and exhaust, heating coil, cooling coil, heating/cooling recovery system, mixing chamber, and dampers. Air conditioning involves control of the air temperature, humidity, cleanliness, and distribution, Processes Heating and cooling , Cooling and dehumidification Mixing Humidification Zone 1) Ideal Mixing 2) Ideal Gas Air 3) Ideal Gas Water Vapor 4) Adiabatic Saturation 5) Four Psychrometric Processes
Single Line diagram 06-04-2021 30-04-2021
mechanical systems |B.Arch sem8 |2021
20
The major types ofcomponents Filters •
Filtration is typically placed first in the AHU in order to keep all the downstream components clean. Depending upon the grade of filtration required, typically filters will be arranged in two (or more) successive banks with a coarse-grade panel filter provided in front of afine-grade bagfilter, or other "final" filtration medium. Thepanel filter is cheaper to replace
and maintain, and thus protects themore expensive bag filters
Heating and/or coolingelements •
Air handlers may need to provide heating, cooling, or both to change the supply air temperature, and humidity level depending on the location and the application. Such conditioning is provided by heat exchanger coils within the air handling unit air stream, such coils may be direct or indirect in relation to the medium providing the heating or cooling effect
Humidifier •
Humidification is often necessary in colder climates where continuous heating will make the air drier, resulting in uncomfortable air quality and increased static electricity. Various types of humidification may be used:
Blower •
Air handlers typically employ a large squirrel cage blower driven by an ACinduction electric motor to move the air. The blower may operate at a single speed, offer a variety of set speeds, or be driven by a variable-frequency drive to allow a wide range of air flow rates
Controls
ADVANTAGES
•
•A Swift Solution, due to having a fixed set of features, standard
Controls are necessary to regulate every aspect of an air handler, such as: flow rate of air, supply air temperature, mixed air temperature, humidity, air quality. They may be as simple as an off/on thermostat or as complex asa building automation system.
Vibration isolators •
The blowers in an air handler can create substantial vibration and the large area of the duct system would transmit this noise and vibration to the occupants of the building. To avoid this, vibration isolators (flexible sections) are normally inserted into the duct immediately before and after the air handler and often also between the fan compartment and the rest of the AHU.
30-04-2021
mechanical systems |B.Arch sem8 |2021
AHUs can be produced for significantly shorter lead times for customers. • Speed Buildup • Simple Specification • Stay in Control.
Mainly used in warm and Humid climate
21
District cooling systems A district cooling system (DCS) distributes cooling capacity in the form of chilled water or other medium from a central source to multiple buildings through a network of underground pipes for use in space and process cooling. Individual user purchases chilled water for their building from the district cooling system operator and do not need to install their own chiller plants The DCS is an energy-efficient air-conditioning system as it consumes 35% and 20% less electricity as compared with traditional air-cooled air-conditioning systems and individual water-cooled air-conditioning systems using cooling towers respectively. In some countries that have substantial heating demand, the plant can also be designed to supply hot water to form a District Heating and Cooling System (DHCS).
30-04-2021
For this system, a central chiller plant, a distribution pipeline network and consumer substation are required. Central Chiller Plant Chilled water is typically generated at the central chiller plant by compressor driven chillers, absorption chillers or other sources like ambient cooling or “free cooling” from deep lakes, rivers, aquifers or oceans. Groups of large and energy-efficient water-cooled chillers are usually installed in a central chiller plant to take advantage of the economy of scale and the cooling demand diversity between different buildings within a district. Sea water condensers or fresh water cooling towers can be utilized to reject waste heat from the central chillers. Distribution Network District chilled water is distributed from the cooling source(s) to the user stations through supply pipes and is returned after extracting heat from the building’s secondary chilled water systems. Pumps distribute the chilled water by creating a pressure differential between the supply and return lines. Consumer Substation The interface between the district cooling system and the building cooling system is commonly referred to as consumer substation. The consumer substation would usually comprise of air handling units, heat exchanger and chilled water piping in the building. A consumer substation is required in each user's building to connect the DCS distributed chilled water pipe to the building. Inside the consumer substation, devices called heat exchangers are installed to transfer heat between the chilled water supply of DCS and the air-conditioning system of the user building. The consumer substation could be designed for direct or indirect connection to the district cooling distribution system. With direct connection, the district cooling water is distributed within the building directly to terminal equipment such as air handling and fan coil units, induction units, etc. An indirect connection utilizes one or multiple heat exchangers in between the district system and the building system.
mechanical systems |B.Arch sem8 |2021
22
Application
The Cooling Process
Climatic : Best suited for hot and dry climate Space : Industrial areas, Large housing setup or townships They have been around since ancient Rome and are prevalent in the Middle East, across Europe, and in Scandinavian countries. Particularly the implementation of District Cooling systems has become a popular choice in the Middle East as it significantly reduces CO2 emissions, uses less harmful chemicals, and lowers energy use.
So how does District Cooling actually work? Let’s break it down. The chilled water is pumped through a network of insulated distribution piping to the various buildings served. Each building has an Energy Transfer Station, which can vary by district or even from building to building, but generally consists of an interface with meters, valves, and pumps. Many buildings have a simple plate heat exchanger that allows the building system to reject heat to the chilled water being circulated by the district. The water returns to the chiller plant at significantly warmer temperatures, about 1315⁰C, having absorbed the heat from the individual building systems. Return water is filtered, treated, and passed through the chiller where it is again cooled and recirculated to the buildings.
Interior of a cooling plant
30-04-2021
mechanical systems |B.Arch sem8 |2021
23
Radiant cooling system • Radiant Cooling is based on the physical principle, that bodies with varying temperatures exchange thermal radiation until an equilibrium is achieved. The principle of radiant cooling has been around in nature, and human beings have been using this principle knowingly or unknowingly for ages.
Working: •
A radiant cooling system coupled with a chiller to feed chilled water to the system through polymer pipes installed in floors, ceilings or walls. This network of pipes can turn the floors ,ceilings and walls of a conditioned space into cooled surface that evenly absorbs the heat energy
• Chilled water was produced in a radiant chiller and supplied to the radiant panels • A conventional chiller was used to feed chilled water to a cooling coil for dehumidification of air in the DOAS. In the DOAS, supply air first enters the energy recovery wheel, where it exchanges heat with return air and then enters the cooling coil. Radiant cooling system operated with chiller
30-04-2021
mechanical systems |B.Arch sem8 |2021
24
• Radiant cooling system is used in climates in cold and dry to very hot and humid • It is used in residential area, commercial area , industries , hospitals and laboratories.
Components: • Radiant cooling panels: These are the panels with integrated pipes and they are fixed to the building construction by hangers. While both ceiling and walls can be used to attach radiant panel. • Chiller: This is used to cool the fluid medium to the required temperature, Exchange heat takes place in the condenser where the hot refrigerant in the chiller transfers heat to the cold water. • Pipes: Loops of cross linked polythene pikpes are embedded in walls, or floors or ceiling ans chilled water is passed through.
Advantages: • It increases thermal comfort
•
Low maintenance cost and energy saving
Radiant cooling panels 30-04-2021
mechanical systems |B.Arch sem8 |2021
Polythene pipes 25
References • Ref:www.slideshare.net/NooruleInieOsman/air-conditioning-system slide no 8
• Ref :https://www.brighthubengineering.com/hvac/41436-psychrometric-processes-sensible-cooling-andsensible-heating-of-air/ • https://www.allweatherheatingandairconditioning.com/blog/five-basic-components-of-an-effective-airconditioning-system/ • https://www.globalspec.com/reference/64935/203279/chapter-11- equipment-part-3-air-handling-systems • http://www.ibpsa.org/proceedings/BS2017/BS2017_737.pdf • https://fairconditioning.org/knowledge/sustainable-cooling-technologies/radiant- cooling/ • https://www.araner.com/blog/district-cooling-energy-system-cooling-process
• https://www.emsd.gov.hk/energyland/en/building/district_cooling_sys/dcs.html#:~:text=What%20is%20 District%20Cooling%3F,in%20space%20and%20process%20cooling.
30-04-2021
mechanical systems |B.Arch sem8 |2021
26
Single line drawing on cooling system
30-04-2021
mechanical systems |B.Arch sem8 |2021
27
Types of Lifts Introduction An elevator is a platform that could either be open or closed and is used for lifting or lowering both people and goods to upper and lower floors. In the past, it was not mandatory for story buildings to have elevators. As a result, some real estate investors avoided installing elevators because they were expensive to install and maintain.
30-04-2021
mechanical systems |B.Arch sem8 |2021
28
Traction Elevator: The Traction Elevator has a electrical motor that is attached to ropes that passes over a wheel. The ropes are used to both raise and lower the elevator car. These uses a counterweight, which eliminates the weight of the occupants and the car. These can be used for both mid and high rise applications.
Hydraulic Elevator: The hydraulic elevator are used for low risers and has 2 to 8 stories with a maximum speed of 200 feet per minute. These has a piston located at the bottom of the elevator that pushes the elevator up. The elevator descents as a the valve releases the fluid from the piston.
Traction elevator 30-04-2021
mechanical systems |B.Arch sem8 |2021
Hydraulic elevator 29
Machine room Elevator: The machine room less elevator has the machine in the over ride spaces and is accessed from the top of the elevator cab when repairs or maintenance is required.The control room is adjacent to the elevator shaft on the highest landing. These have a maximum travel distance of upto 250 feet with a speed of 500 feet per minute. These are low energy consumption compared to geared elevator.
30-04-2021
Pneumatic Elevator: Pneumatic lift uses alighting mechanism which has a hollow cylinder and piston. An external motor or pump moves the piston within the cylinder. The cylinder motions along the axis creates linear force which is used to extend the lift component, raising or lowering the object
mechanical systems |B.Arch sem8 |2021
Paternoster lift: A Paternoster lift is a elevator consisting of a chain with open compartment which moves slowly in a loop inside the building without stopping. These have a smaller belt which consists of an endless belt with no compartments. These were intended for only transporting people, the construction for the same is no longer available in many countries due to high risk accidents
30
Top 5 fastest lifts in the world
1. Shanghai World Finance Centre • location – Shanghai, china Systems implemented • Two special lifts were originally designed to serve the observation deck at the top of the tower but were modified to support evacuation from each of the refuge floors in an emergency • Occupants with disabilities and other occupants who cannot use the stairs to reach a refuge floor are required to wait adjacent to one of the fire-fighting lifts for evacuation by building management or the fire service
2. CTF Finance Centre Tower • Located -Guangzhou, China • the new CTF Finance Centre Tower not only is the world’s seventh tallest building, but is contains the world’s fastest elevator. Systems implemented • Ultra-high-speed Elevator with World Record Speed of 1,260 m/min • Brand- Hitachi
3. Taipei 101 •
4.Yokohama Landmark Tower •Location-Japan
Located -Taiwan.
Systems implemented
•Systems implemented
•
The two lifts in the Taipei whizz up from ground to roof in 30 seconds at a speed of 37.7mph.
•has a total of seventy-nine lifts.
•
Features -Aerodynamic pressure and controlled cans
•
The evacuation using lifts and stairs took 57 minutes as opposed to 2 hours using the stairs alone
•
Types of lifts used - emergency/service lifts and to firefighting lifts 30-04-2021
mechanical systems |B.Arch sem8 |2021
•4 Mitsubishi ACCEL (mod. Emotion+) Traction Lifts •The 296.3 meter (2,460ft) building also boasts a Mitsubishi lift which can travel 28mph; this is the fastest lift in Japan. 32
5. Burj Khalifa Tower • Location -Dubai. Systems implemented • At a staggering 828 meters (2,717ft), this mega-skyscraper is currently the tallest building in the world and it’s lifts move at 22mph. • In addition, the speedy, double decker lifts in the Burj Khalifa have capacity of twelve to fourteen people per cabin. • The building was constructed to IBC: 2003 and to NFPA101 fire and life safety code and was designed for the use of some lifts to assist the evacuation process. A full building evacuation uses 10 of the 58 lifts installed in the building.
30-04-2021
mechanical systems |B.Arch sem8 |2021
33
walkalators and its components Introduction •Walkalator is a slow conveyor mechanism that transports people across a horizontal or inclined plane over a short to medium distance . •moving walkways can be used by standing or walking on them .they are often installed in pairs ,one of teach direction
Type of moving walkways
Inclination angle
Flat moving surface
Speed
Types of moving walkways Inclination angle
According to inclination angle ➢ Horizontal and inclined walkways ▪ Zero degrees inclination “horizontal “moving walkways. ▪ Up to 15 degree inclination inclined moving walkways . 30-04-2021
mechanical systems |B.Arch sem8 |2021
Horizontal
Inclined 34
According to the flat moving surface ➢ Moving belt These are generally built with mesh metal belts or rubber walking surfaces over metal rollers . The walking surface may have a solid feel or a bouncy feel
➢ Pallet type A continuous series of flat metal plates mesh together to form a walkway. Most have a metal surface, though some models have a rubber surface for extra traction
According to the speed ➢ Slow – speed standard type The speed for these walkways is determine by the need for safety upon entry and exit which is generally limits it to approximately half normal walking speed or 30-40m/min. 30-04-2021
➢ High –speed walkways The idea is to accelerate the riders so that they be traveling fast enough to step onto the moving walkway belts.
mechanical systems |B.Arch sem8 |2021
35
Basic components of walkways • • • • • • • •
Handrail Pallets Decks Balustrade panel Newelends Controller Pallets chain Tracks
30-04-2021
• • • • • • • •
Truss Comb plates Gear box Access cover Front plates Service track Handrail drive wheels Lower reversing stations
mechanical systems |B.Arch sem8 |2021
36
Components in inclined and horizontal walklators • • • • • • • •
• • • • •
Floor opening enclosures Wring inlet Working point Intermediate support Tension station Drive stations Head room decks
Tension station Drive stations Working point Intermediate support beam Wring inlet
30-04-2021
mechanical systems |B.Arch sem8 |2021
37
Components in high speed walkways
• • • • •
30-04-2021
mechanical systems |B.Arch sem8 |2021
Motor Brake Gears High speed zone drive chains Low speed zone drive chain
38
Escalator and Types An escalator is a moving staircase- a conveyer transport device for carrying people between floors of a building, places such as moving malls, airports. Types of escalator parallel
Crisscross
Multiple parallel
Curved escalator
Parallel escalator:
Parallel up and down escalator side by side or separated by a distance seen often in metro station. These type of escalator go up and down simultaneously. 1.Speed 0.5m/s 2.Inclination.30.35 3. Step width 800/1000 4.Power 50Hz/3p 30-04-2021 30-04-2021
mechanical systems |B.Arch sem8 |2021
39
Crisscross Escalator
Multiple escalator:
• Crisscross minimizes structural spaces requirements by stacking escalators that go in one direction, frequently used in department stores or shopping centers.
Multiple parallel two or more escalators together that travel in one direction next to one or two escalators in the same bank that travel in the other direction. Escalators are required to have moving handrails that keep pace with the movement of the steps. The direction of movement (up and down) can be permantly the same, or be controlled by personnel according to the time of the day or automatically.
• These stacks the escalator that go in single direction and reduces structural space requirement. • Step width 600/800/1000 • Power 300V/50Hz/3p • 3. Handrails,Rubber/Stainless steel
Spiral escalator: A spiral escalator is a special design type of escalator in the form of a spiral/helical with curved steps. This escalator can curves to the left or right
30-04-2021
mechanical systems |B.Arch sem8 |2021
40
Reference: • https://www.northernarchitecture.us/interior-designers/arrangement-of-escalators.html • https://www.eroselevators.com/elevators-type.php • https://www.archtoolbox.com/materials-systems/verticalcirculation/elevatortypes.htmlhttps://www.vacuumelevators.com/a-guide-for-choosing-the-type-ofelevator-you-need/
30-04-2021
mechanical systems |B.Arch sem8 |2021
41
Questionnaire 1.
What is a heat engine?
2.
What is refrigerators and heat pump? explain their function?
3.
what is the difference between refrigerator, heat pump and heat engine?
4.
what is passive cooling systems?
5.
What is the principle behind evaporative cooler?
6.
explain function of split ac with drawing
7.
explain Carnot cycle
8.
heat pump diagram
9.
what is psychrometric chart?
10.
explain Isothermal Expansion.
11.
How does the evaporator work?
12.
How does the radiant cooling system work?
13.
How Does A Condensing Unit Work?
14.
Why is a Compressor used?
15.
What is Constant Volume System (CAV)?
16.
What is the function of AHU?
17.
What Is Sensible Heat Ratio (SHR)?
18.
What is desiccant cooling?
19.
How does a Dehumidifier work?
20.
What are HVAC filters used for?
30-04-2021
21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40.
How do we measure the efficiency of room air conditioners? What is EER? What is a refrigerant? Explain the working of a typical Air conditioner with a single line drawing? Name the four stages of Carnot cycle What factors are to be considered to estimate the air conditioning load? What is cooling load? What is space heat extraction rate? What are some methods to calculate cooling load? On what basis do we select the air conditioning apparatus? What is COP and formula? What are the properties of air included in psychrometric chart? What is SEER and it formula? What are the indoor and outdoor unit in air conditioner? What are the main factors to be considered while choosing coolant for the cooling? Explain any 3 types of the dehumidifiers. What is BTU? What is the meaning of 1ton of AC? What are the components of chiller? Do coolers and ACs use same working principles?
41. 42. 43. 44. 45. 46. 47. 48. 49. 50.
What is a lift/elevator? What is the importance of lift? What are the types of lifts? What are the components of lifts? What are the factors considered for the selection of lift for a building? What is escalator? What are the type of escalators? What are the components of an escalator? What are the advantages of escalator over elevators? What is the angle of inclination for escalator?
mechanical systems |B.Arch sem8 |2021
42
30-04-2021
mechanical systems |B.Arch sem8 |2021
43
30-04-2021
mechanical systems |B.Arch sem8 |2021
44
30-04-2021
mechanical systems |B.Arch sem8 |2021
45