Unit-3.pptx Describes about IC engines and future mobility

IC engines

1. UNIT-3 Fundamentals of IC Engines:

2. Different components of IC engine

3. Working principle of two stoke engine

4. Working principle of four stoke engine

5. Application of IC Engines

6. Electric and Hybrid Vehicles

7. Hybrid electric vehicles are powered by an internal combustion engine and one or more electric motors, which uses energy stored in batteries. A hybrid electric vehicle cannot be plugged in to charge the battery. Instead, the battery is charged through regenerative braking and by the internal combustion engine. The extra power provided by the electric motor can potentially allow for a smaller engine. The battery can also power auxiliary loads and reduce engine idling when stopped. Together, these features result in better fuel economy without sacrificing performance How Do Hybrid Electric Cars Work?

8. Key Components of a Hybrid Electric Car Battery (auxiliary):  In an electric drive vehicle, the low-voltage auxiliary battery provides electricity to start the car before the traction battery is engaged; it also powers vehicle accessories. DC/DC converter:  This device converts higher-voltage DC power from the traction battery pack to the lower-voltage DC power needed to run vehicle accessories and recharge the auxiliary battery. Electric generator:  Generates electricity from the rotating wheels while braking, transferring that energy back to the traction battery pack. Some vehicles use motor generators that perform both the drive and regeneration functions. Electric traction motor:  Using power from the traction battery pack, this motor drives the vehicle's wheels. Some vehicles use motor generators that perform both the drive and regeneration functions. Exhaust system:  The exhaust system channels the exhaust gases from the engine out through the tailpipe. A three-way catalyst is designed to reduce engine-out emissions within the exhaust system. Fuel filler:  A nozzle from a fuel dispenser attaches to the receptacle on the vehicle to fill the tank. Fuel tank (gasoline):  This tank stores gasoline on board the vehicle until it's needed by the engine. Internal combustion engine (spark-ignited):  In this configuration, fuel is injected into either the intake manifold or the combustion chamber, where it is combined with air, and the air/fuel mixture is ignited by the spark from a spark plug. Power electronics controller:  This unit manages the flow of electrical energy delivered by the traction battery, controlling the speed of the electric traction motor and the torque it produces. Thermal system (cooling):  This system maintains a proper operating temperature range of the engine, electric motor, power electronics, and other components. Traction battery pack:  Stores electricity for use by the electric traction motor. Transmission:  The transmission transfers mechanical power from the engine and/or electric traction motor to drive the wheels.

9. Advantages and disadvantages of Evs and Hybrid vehicles Advantages of Hybrid Cars 1. Fuel Economy Hybrid cars are proven to be more fuel efficient than conventional petrol/diesel vehicles due to improvements in weight reduction, aerodynamics and a smaller engine. Hybrid cars will also run purely on the electric motor whenever possible, which makes a large impact on the car’s fuel economy. 2. Require Less Maintenance Hybrid cars require less maintenance than traditional gas-powered cars, as hybrids are designed to last longer and run better than gas-powered cars. They have fewer parts, which means they require less maintenance than a traditional car. 3. Light Materials Hybrid cars are made up of lighter materials and the engine is significantly smaller and lighter so that less energy is required to run the vehicle. The petrol engine used in hybrid cars is smaller and lighter as they aren’t solely responsible for powering the car because there’s an electric motor to support powering the car. Disadvantages of Hybrid Cars 1. Higher Insurance Hybrid cars usually have a higher insurance cost than petrol or diesel cars because the technology used inside them is much more expensive to repair or replace. Some insurance companies offer discounts on insuring hybrid vehicles as an incentive to drive one because hybrid cars are much better for the environment than regular petrol or diesel cars. 2. Higher Upfront Cost Electric and hybrid cars are more expensive than traditional petrol/diesel cars, and with this will come a higher upfront cost. Once you start driving your hybrid car, the running costs will be considerably lower, so the savings on this will make the higher upfront cost worth it in the long run. 3. Performance Hybrid cars are often manufactured with the goal of improving fuel efficiency and being better for the environment. This means the car is often designed with this in mind, fuel efficiency is improved at the sacrifice of performance. A fully hybrid car will be slower in speed compared to its counterparts. 4. Poorer Handling Hybrids are built with two engines into one car, and this weight affects the handling of the car. This is important to keep in mind when looking to either purchase or lease a hybrid car. 5. Battery Replacement Can Be Expensive A lot of hybrid cars and electric vehicles use a battery that uses specific rare-earth materials that can only be mined in certain areas of the world. Due to the rarity of these materials, the batteries in hybrid cars are quite expensive when it comes to replacing them.

10. Principle of refrigeration The main principles of refrigeration are:  Evaporation: Absorbs heat to change a liquid into a vapor Condensation: Releases heat to change a vapor back into a liquid Refrigeration is a process that transfers heat from one area to another.   The working principle of refrigeration is based on a cycle movement system. The system uses a refrigerant that is hermetically sealed and moved from the evaporator to the condenser in different forms. The purpose of this system is to cool down temperatures in the storage section

11. Refrigeration effect The refrigeration effect is the amount of heat that a refrigeration system removes from a space or substance. It's also the amount of cooling that a refrigeration system achieves.  The refrigeration effect is equal to the difference between the enthalpy of the vapor leaving the evaporator and the enthalpy of the liquid at the flow control.  The refrigeration duty, or refrigeration capacity, is the total amount of heat absorbed in the chiller by the process. It's usually expressed in kW.  The coefficient of performance is the rate of refrigerating effect to the heat equal to the supplied work.  Factors that affect the efficiency of a refrigeration system include:  Evaporating temperature Condensing temperature Type of refrigerant Type of equipment System controls Correct maintenance

12. High latent heat of vaporization Large conductivity Low specific volume of vapor Low freezing point Low boiling point High critical temperature Low specific heat of liquid Non-corrosive to metal Non-flammable Non-explosive Non-toxic Desirable properties of refrigerants include: 

13. Evaporation The evaporator absorbs heat from the surrounding environment and turns the refrigerant liquid into a gas. Compression The compressor draws wet vapor refrigerant from the evaporator and compresses it to high pressure and temperature. Condensation The high-pressure vapor refrigeration cools in the condenser at constant pressure. Expansion The refrigerant changes state from a liquid to a vapor. The vapor compression cycle uses refrigerants like ammonia (NH3) or carbon dioxide gas (CO2). The refrigerant is a working fluid that extracts heat absorbed in the system. As the refrigerant changes state, the system absorbs and expels heat, lowering the temperature of the conditioned space The vapor compression cycle involves the following processes: 

14. A Vapour Absorption Refrigeration System consists of four main components: an evaporator, absorber, generator, and condenser. Heat from an external source, such as a gas burner or waste heat, drives the absorption process, allowing it to create cooling effects. Here's how a VARS works:  Evaporator Low-pressure refrigerant vapor (NH3) is absorbed in the absorber by a weak solution of refrigerant. This lowers the pressure in the absorber to draw more NH3 vapor from the evaporator. Absorber The weak solution of ammonia and water in the absorber absorbs the low-pressure ammonia vapor. This converts the weak solution into a strong ammonia water solution. Generator The ammonia-rich solution is pumped to the generator where it is heated and the ammonia vapor separates. Rectifier The rectifier removes water vapor from the ammonia vapor. The components of a VARS are: Absorber, Pump, Generator, Condensor , Expander Vapour Absorption Refrigeration System

15. Air Conditioning An air conditioning (AC) system is a machine or device that cools the air in a defined area. It works by removing warm air and replacing it with cooler air. AC systems can also control the humidity and purity of the air. Split-systems These systems have an outdoor unit (condenser) and an indoor unit (evaporator). Central AC These systems are designed for multiple rooms or large rooms. They cool the air at a central location and distribute it to rooms through ducts. Centralized ducted “All – Air” Systems These systems move heat around a building using heated and cooled air. They are commonly used in large spaces like office buildings, airports, and hotel lobbies. Some other types of AC systems include:  Window air conditioners Portable air conditioners Wall hung split or multi head split systems Ducted air conditioners Here are some types of AC systems: