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Cummins ISX turbine then turns a generator which converts waste heat into electricity. In the Cummins ISX engine the electricity is used to power a small electric motor built into the crankshaft. After the superheated dry steam’s energy is transferred into the turbine it later is sent to a recuperator then to a condenser where it is condensed and routed back into the boiler
producing a closed loop system. This is quite a revolutionary concept for the Cummins ISX having both the internal and external combustion in one engine. The extra energy that is recovered comes from four different sources: 6 percent increase in energy will come from the EGR, 2 percent will come from exhaust energy, and 2 percent will
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come from other accessories that used to drain additional power. All of this additional energy adds up to about 10 percent increase in overall fuel efficiency for the Cummins ISX 15. The basic premise of the Cummins ISX engine’s fuel efficiency is recovering waste energy. Waste energy can be described as energy that is not used for any practical purposes. Energy can be neither created nor destroyed. It is stored in the form of kinetic energy (in motion) or potential energy (stored energy). When studying energy within the Cummins ISX engine we can ascertain that most of the energy is stored in the diesel fuel as potential energy. When that diesel fuel is burned in the combustion engine it changes form to kinetic energy, which then drives the pistons. However, most of the diesel fuel’s energy is lost as heat. One gallon of diesel fuel contains about 139,000 Btu (British Thermal Unit) of potential energy. One Btu is defined as the amount of heat required to increase one pound of water one degree Fahrenheit. The goal with any engine is to achieve peak thermal efficiency where as peak thermal efficiency is described as the work you get divided by the energy you put in. For example, a gas powered car engine is roughly 25 percent efficient and a heavy-duty diesel powered Cummins ISX engine is roughly 40 percent efficient. What that means is that if a vehicle used 10 gallons of gas only 4 gallons would go to towards propelling the tires forward; the other 6 gallons are wasted. The Organic Rankine Cycle technology in the Cummins ISX 15 aims to recovery as much energy as possible through heat recovery. Across the board, only roughly 33 percent of energy is used towards moving the motor. An example of waste energy in relation to trucks is when heat escapes from the engine to the outdoors. The heat sources on a Cummins