Experiment

We have borrowed a digital laser temperature gauge from UNITEC workshop to measure the exhaust temperature using a digital laser temperature gauge.

Car tested: BMW 520 6 cylinder engine year 2000

Test condition: after warming up the engine we drove the car on the motor way for 15 minutes at an engine speed of 3000rpm

The temperature gauge has been mounted securely in the engine bay so it can measure the exhaust manifold temperature with a webcam also mounted to read the gauge reading but was not accurate as the spot that the gauge is reading cannot be controlled from inside the car while driving.

After driving the car on the motor way we stopped on a safe place on the side way of the motor way and immediately started to change the spot that the gauge is measuring and the gauge recorded a temperature of 488 ºc  .

Using the measured temperature the wasted heat energy can be calculated.

 

CV for air fuel mixture =0.73 kj/kg

     = 488ºc

       =15ºc  

         

 

 

Using the measured temperature the wasted heat energy can be calculated

CV for air fuel mixture =0.73 kj/kg

     = 488c  761.15 k

       =15c            288.15 k

 

  

    

This is the heat out on one exhaust pipe  and as this car is 6 cylinder engine the result needs to be multiplied by 6

At engine speed of  3000RPM there is 1500 exhaust stroke multiplied by number of cylinders

1500 6 = 9000 Exhaust stroke per minute

By knowing the water heat capacity we can calculate the raise in temperature per kg of water this energy can make

Water heat capacity = 4.2 kj/kg. k

Temp raise per kg =       

If assumed that the system will run on 5liter of water we can calculate the temperature of the steam using the heat energy from the exhaust .

The temperature in the water tank is affected by the engine compartment temperature and the steam temperature as it is a close circuit, therefore it can be assumed that the water temperature in the water tank will be around 100ºC.

Water Temp = 95ºC

Water heat capacity = 4.2 kj/kg. k

latent heat of evaporation of water = 2256kj/kg

Water vapour heat capacity=1.95kj/kg.k

Q = mL(∆T)

(Q) Energy in form of heat

 (L) Latent heat

(m) Unit of mass

An experiment has been carried out to see how much fuel is injected to the engine per minute

Latent Heat & Change of State Adding or removing heat does not always result in a change of temperature. During a change of state, the heat added is called latent heat because there is no change in temperature. Latent means "hidden". Notice in the graph above that while ice is melting (change of state) the temperature stays constant at 0°C. The temperature also is constant when water boils and changes to steam or vapour. When a solid is melting the heat energy added is building up the potential energy of the molecules to break the electrical forces holding them together. Similarly, when liquids are turning to gases the heat energy increases the energy of the molecules so they get further apart and become gas molecules. Latent heat of fusion is the amount of heat required to melt 1 kg of a substance without changing its temperature. The latent heat of fusion for water is 3.3 x 105 J/kg, which means that 3.3 x 105 J of energy are needed to change 1 kg of ice at 0°C into water at 0°C. Latent heat of vaporization is the amount of heat required to vaporize 1 kg of a substance without changing its temperature. Latent Heat Formula Latent heat can be calculated using the following formula:

How do steam boilers work?

http://www.youtube.com/watch?v=a0xZPl_bwHI&feature=player_embedded

As we know in the last example how to calculate the temperature at the end of the power stroke. We can calculate heat out   of the exhaust system by this formula.

Heat out = CV × (Temperature at the end of the power stroke – Temperature in).

Example:

Heat out = cv × (Temperature at the end of the power stroke – Temperature in)

Heat out = 0,718×( 750 – 288 )

Heat out = 313 kj/kg 

How to calculate the heat out of the exhaust system

One of the most important points in our project is how to calculate the heat out of the exhaust system.

For example if we want to calculate the heat out of the exhaust system, it is important to find the next:

1- Compression Ratio

2- Pressure & temperature at B.D.C.

3- Pressure & temperature at T.D.C. Before and after ignition

4- Pressure & temperature at B.D.C. at the end of power stroke

Example:

Our project .

Hey everyone, Check this out.

Steam engine

People knew steam engine is an outdated technology for many centuries about 2,000 years, but in fact steam is once again a hot topic with vehicle manufacturers. Indeed, the next generation of hybrid cars and trucks may incorporate some form of steam power.

To build our project about steam engine we should know some main points related to the subject.

During my research in the past few weeks, I have found many important resources that can help our idea .However, I suggest to create an outline covering our project. Here some example:

 1- History

 2 -The steam cycle

 3- Components of steam engines

4- Heat source

5-Advantages

6- Safety

7- Efficiency

8- Applications

9- Stationary applications

 10-Modern applications

Important research 

- Rankine cycle.

 The Rankine cycle is a thermodynamic cycle which converts heat into work. The heat is supplied externally to a closed loop, which usually uses water as the working fluid. This cycle generates about 80% of all electric power used throughout the world, including virtually all solar thermal, biomass, coal and nuclear power plants.

The Rankine cycle is the fundamental thermodynamic underpinning of the steam engine.

-“Mitha's company aims to target the wasted heat that is currently pumped out of the exhaust and convert it into useful power. Of the energy in your petrol tank, just 27% is converted into forward motion, 33% is spent cooling the engine, 4% is lost as friction and a whopping 36% is lost as exhaust heat. "There is a lot of heat that is created and totally wasted," said Mitha. Clean Power Technologies aims to recover 40% of this exhaust heat.”

Useful links:

http://www.stanleysteamers.com/modern_steam.htm

http://www.guardian.co.uk/environment/2008/aug/27/alternativeenergy.energy#history-link-box

http://www.treehugger.com/files/2008/02/honda_rankine_c.php

http://www.guardian.co.uk/environment/2008/aug/27/alternativeenergy.energy#history-link-box

http://www.greencarcongress.com/2008/11/waste-heat-reco.html

http://www.greencarcongress.com/2011/05/cyclone-20110504.html

http://www.streetdirectory.com/travel_guide/58002/car_parts/car_giants_seek_to_increase_engine_power_from_waste_heat.html

http://www.youtube.com/watch?v=UjjQRfCl218

http://www.youtube.com/watch?v=uXLUoqzlT2k&NR=1

http://www.physicsforums.com/showthread.php?t=261719   http://www.autoweek.com/apps/pbcs.dll/article?AID=/20060217/FREE/60213002/1024/LATESTNEWS