This concept focuses on the utilization of engine waste heat energy and it is done by the ORC (Organic Rankine Cycle), which uses the refrigerant as a working fluid by replacing coolant (Ethylene Glycol) from engine jacket. The ORC generates high pressure to run the turbine of turbocharger. The turbocharger increases the pressure at the time of combustion due to which efficiency and the performance of the engine get increased. With this idea we can develop the I.C. engine having one more additional turbocharger with the existing triple turbo charged engine, having Record HP per liter capacity. Hence, it will be called as TETRA TURBOCHARGED ENGINE.
Almost all engines are cooled by the coolant (ethylene glycol), which take large amount of heat and keep the engine at desired temperature.
The working of ORC by utilizing the heat energy from engine (low temperature reservoir) by working fluid, which is previously taken by the coolant. This working fluid gets converted into vapour phase to do work and then condense to initial stage to complete the cycle.
Now the working fluid in this cycle should fulfill the basic cooling condition of the engine and should also have desirable property to attain high pressure, hence for this the appropriate refrigerant is selected i.e. Refrigerant R141-b as working fluid although it has some negative impact to atmosphere so replacement of this refrigerant can be done or need to blend it to meet the requirements
Efficiency with ORC Turbocharger
P1V 1???? = P2V2????
(V1/V2)???? = P2/P1
P2 = P1 (r)
P1= 4 bar Approx. (after turbocharged)
P2 = 4 (18.5)1.3
= 88.78 bar
Compression ratio = (88.78/1)1/????
? =1 – 1 (e???? - 1)
r????-1 [???? (e - 1)]
= 1 – 1 (1.8751.3 - 1)
? = 0.605 or 60.5%
Increase in thermal efficiency = 60.5-53.6
= 6.9 ? 7%
TETRA TURBOCHARGED ENGINE:
The development of engine with the above discussed concept of ORC with existing triple turbocharger combining make the system with four turbocharger which can drastically reduce the size of the engine which makes vehicle lighter with high power output.
This schematic diagram of engine gives the idea of installation (fig b).
For sake of study 5 cylinder engine is taken, one with high compression ratio cylinder will solve the problem of starting. After starting the engine it will get stop or disengage (or in heavy vehicle with some modification can be used as air compressor), the system will now run on the four small cylinder equipped with tetra turbocharger and will able to utilize the maximum fuel energy with high power.
- The thermal efficiency of ORC is calculated as 13.33%.
- The thermal efficiency of engine without ORC Turbocharger is 53.6%.
- The thermal efficiency of engine alone with ORC Turbocharger is 60.9%.
- ORC Turbocharger combining with existing triple turbocharger makes TETRA TURBOCHARGER.
- TETRA TURBOCHARGER increases power to cylinder capacity ratio as well as fuel efficiency.