"Heat Engine" Heat and Energy PPT Courseware

Description

"Heat Engine" Heat and Energy PPT Courseware

1. Acquisition of internal energy:

Through the combustion of fuel, the chemical energy inside the fuel is converted into internal energy.

2. Utilization of internal energy:

1. Directly heat objects

2. Use internal energy to do work

Internal energy converted into mechanical energy

Fuel combustion converts chemical energy into internal energy, and then converts internal energy into mechanical energy through work

3. Heat engine

A machine that converts internal energy into mechanical energy

3. Types of internal combustion engines

When the internal combustion engine is working, the piston reciprocates up and down in the cylinder. When the piston moves from one end of the cylinder to the other, it is called a stroke.

Most internal combustion engines ensure continuous operation by a continuous cycle of four strokes: suction, compression, power, and exhaust.

1. Structure and working principle of gasoline engine:

(1) Structure of gasoline engine

(2) Structure of diesel engine

suction stroke

_____Open close. The piston moves from _____ to _____, and a fuel mixture consisting of gasoline and air is sucked into the cylinder through the intake valve.

Compression stroke

Both the intake valve and the exhaust valve _____, the piston moves toward _____, the fuel mixture is compressed, _____ increases, and _____ increases the mechanical energy and converts it into _____.

power stroke

At the end of the compression stroke, _____ generates an electric spark, causing the fuel to burn violently, producing high-temperature and high-pressure gas, pushing the piston to _____ movement, and driving the crankshaft to rotate through the connecting rod. Internal energy is converted into _____.

exhaust stroke

_____ closes, _____ opens, the piston _____ moves, and the exhaust gas is discharged from the cylinder.

3. Calorific value of fuel:

1. There are many types of fuels, which can be divided into solid fuels, liquid fuels and gaseous fuels.

2. Burning different fuels of the same mass releases different amounts of heat.

3. Calorific value of fuel: The heat released by the complete combustion of 1kg of a certain fuel is called the calorific value of the fuel.

4. Unit of calorific value: J/kg

5. The symbol of calorific value: q

6. Calculation of fuel combustion heat release: Q=mq

When Xiao Ming used a stove to boil water, he consumed a total of 1.5kg of bituminous coal. How much heat is released when the bituminous coal is completely burned (the calorific value of bituminous coal q=2.7×107J/kg)?

Solution: Q=mq=1.5kg×2.7×107J/kg=4.05×107J

Answer: The heat released by complete combustion of these coals is 4.05×107J

4. Fuel utilization:

Thinking: In the above example, Xiaoming used 1.5kg of bituminous coal to boil water. The heat released by complete combustion of these coals is 4.05×107J. Is the actual heat released 4.05×107J? Why? What about the actual amount of heat absorbed by the water?

The heat actually absorbed by water is called effectively utilized heat.

1. The efficiency of the furnace: the ratio of the heat effectively utilized (the heat absorbed by the water) to the heat released by the complete combustion of the fuel.

Formula: η=Q suction/Q release=cm△t/mq

2. Improve fuel utilization and save energy

1) Make coal fully burn: Grind the coal into coal particles and increase the air supply volume.

2) Increase the heating area and reduce the heat taken away by the flue gas:

3. Efficiency of a heat engine: The ratio of the part of energy used to do useful work to the heat released when the fuel is completely burned is called the efficiency of the heat engine.

Incomplete combustion of fuel, heat loss after cylinder components absorb heat, heat taken away by exhaust gas, and energy consumed to overcome friction and perform work are all causes of energy loss. Therefore, improving the efficiency of heat engines can improve fuel utilization.

Ways to improve the efficiency of thermal engines and energy-saving methods: (1) Reduce various heat losses as much as possible, such as ensuring good lubrication and reducing the energy consumed by overcoming friction;

(2) Make full use of the energy of waste gas and improve fuel utilization, such as using waste gas from thermal power stations to provide heat. This kind of thermal power station that provides both power and heat has much higher fuel utilization than ordinary thermal power stations.

Keywords: Heat and Energy teaching courseware, Heat engine teaching courseware, Shandong Education Edition ninth grade physics PPT courseware download, Volume 2 physics PPT courseware download, Ninth grade physics slide courseware download, Heat and energy PPT courseware download, Heat engine PPT courseware download, .PPT format;

For more information about the PPT courseware "Heat and Energy Thermal Engine", please click the Heat and Energy ppt Heat Engine ppt tab.

"Heat Engine and Social Development" Internal Energy and Heat Engine PPT Courseware 3:

"Heat Engines and Social Development" Internal Energy and Heat Engines PPT Courseware 3 Teaching Objectives 1. Know the working principle of heat engines and energy conversion. 2. Understand the working principle and working process of gasoline engines. 3. The difference between gasoline engine and diesel engine. 4. Improve thermal engine efficiency. Test Preview 1 Understand...

"Heat Engine and Social Development" Internal Energy and Heat Engine PPT Courseware 2:

"Thermal Engine and Social Development" Internal Energy and Thermal Engine PPT Courseware 2 1. Heat engine Steam engine Diesel engine Gas turbine Gasoline engine Jet engine Rocket engine. 2: Working process (1) When the internal combustion engine is working, the four strokes start over and over again. In a working cycle of the internal combustion engine...

"Heat Engines and Social Development" Internal Energy and Heat Engines PPT Courseware:

"Thermal Engine and Social Development" Internal Energy and Heat Engine PPT Courseware Learning Objectives 1. Understand the energy conversion process during the operation of heat engines. 2. Understand the working principle and working process of gasoline engines and improve your ability to read pictures. 3. Through the study of issues such as heat engine efficiency and heat engines and the environment...

File Info

Update Time: 2024-10-03

This template belongs to Physics courseware Lu Jiao Edition Ninth Grade Physics Volume 2 industry PPT template

Preview