Wednesday, May 6, 2009

NP Stroke engine and Active Stroke cycle management

Was thinking on how to increase the efficiency of an ICE engine. 

Searched on different engines  and got one idea.

We are not even using any heat energy generated by the internal combustion engine. Lets first explain a four stroke engine 

Four stoke engine consists of 
  Intake stroke
  Compression stroke
  Power stroke
  Exhaust stroke

In intake stroke, the air is taking in then compress the air ,fuel gets injected to the compressed air and then ignited results in the power stroke and after the compression stroke the exhaust gases will be removed in the exhaust stroke. Its all fine and give 35-37% efficiency.

One of the problem is the heat is never utilized for any purpose.  So the idea of six stroke engine came in.
The six-stroke engine is a type of internal combustion engine based on the four-stroke engine, but with additional complexity to make it more efficient and reduce emissions. 

Two different types of six-stroke engine have been developed since the 1990s:

In the first approach, the engine captures the heat lost from the four-stroke Otto cycle or Diesel cycle and uses it to power an additional power and exhaust stroke of the piston in the same cylinder. Designs use either steam or air as the working fluid for the additional power stroke. As well as extracting power, the additional  stroke cools the engine and removes the need for a cooling system, making the engine lighter and giving an estimated efficiency of 40%. The pistons in this type of six-stroke engine go up and down six times for each injection of fuel.

 There are two power strokes: one with fuel, the other with steam or air.

The second approach to the six-stroke engine uses a second opposed piston in each cylinder that moves at half the cyclical rate of the  main piston, thus giving six piston movements per cycle. Functionally, the second piston replaces the valve mechanism of a conventional  engine but also increases the compression ratio. 

I started thinking more in this direction and found another way called NP Stroke engine and Active Stroke cycle management for a better solution.. 

The theory i propose always gives variable  efficiency optimal according the  circumstance of operation.  

Lets go to the first proposal of NP  stroke engine. 

N is a number where this can be 1 to any number. P denotes Power stroke, Lets explain how NP stroke engine works when N is equal to 3.

The additional requirements/changes in the design is an additional  closed hot air chamber, Air injector , Heat transfer agent and injector ( ex water).

Once the 4 strokes of 4 stroke engine is over , the exhaust stroke will push the air to the air chamber. Once the exhaust stroke is over, instead of another intake stroke,  1/3rd of the hot exhaust air stored in the air chamber is released to the intake .After this a  compression stroke of this air occurs. Once its compressed, a heat transfer agent is injected (ex: water ). This agent will utilize the heat in the exhaust gas and convert to a vapour form results in a power stroke. Once the power stroke is over another exhaust stroke occurs and the exhaust is send out. Again in another intake stroke the air injector injects another 1/3 of the exhaust gas and same 4 strokes occurs. Lets call these strokes as thermal energy transfer strokes. Once the 4 strokes are over, the last 1/3 is utilized t make another 4 strokes. which results in total of 12 strokes.

Which means the engine gets 3 times efficient than the normal 4 stroke engine. 

Here a number of  questions arises : 

Is 3 an optimal number ? 
What happens in a cold place
What happens when i drive a lot
What happens when i start the car where engine is cool.

Here the second theory comes in effect. Active Stroke cycle management:

This consists of a temperature sensor, a decision making logic and a control to the air injector attached to the hot air chamber

The temperature sensor senses the temperature and decides the optimal number of heat exchange cycles which can be performed on the current temperature.

ex: In a cold condition starting , the engine can work as normal 4 stroke, while its running heat increases and it can increase the number of thermal cycles based on the   temperature and other deciding parameters.

So in a long ride, according to the temperature readings, it can control and decide N of the NP cycle engine.This will result in high efficiency engine which is according to the operating conditions

By the implementation its possible to have 120mpg engines using attaching proper thermal conversion cycles to a 40 mpg capable engine. Once its tuned to run ,  the efficiency will be increased heavily according to the operating conditions.

tail piece: This is to make sure this idea is fresh and intellectual property rights of this idea is for me as i didn't find anybody have the idea published. The intellectual property rights includes,idea,rights of implementations , decisions of different control parameters, heat transfer agent, agent recovery methods  etc and  the trade marks of  Active Stroke cycle management/ Active cycle management.

Thanks Wikepedia to understand the prior art for this idea.

© yankandpaste®

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