CESAR Overview
- For realistic pollution control
- Combustion engine in direct drive for open areas
- Auxiliary power in town
- Energy storage is the key
The CESAR Principle
At the present time, transportation of any type is almost wholly dependent upon internal combustion engines burning, usually a liquid, hydrocarbon fuel. Electric power plant offers an alternative where range and power demands are modest and fuel cells appear to offer long term prospects of substituting hydrogen for hydrocarbons as an energy source, with the costs and dramatic infrastructure changes that will be inevitably required. Thus there currently appears little prospect of avoiding combustion engines burning a hydrocarbon fuel to power any practical form of transport, with the well-established disadvantageous consequences. These result from the local and global sources of atmospheric pollution resulting from the chemical products of combustion, magnified by the inefficiency with which useful mechanical power is derived from the intrinsic energy in the fuel, about two-thirds of which is dissipated into the atmosphere. Clean Power Technologies Inc. recognises the inevitable continuing use of hydrocarbon fuels, even with their continuously increasing unit cost. With novel usage of a wide range of often well-established technologies it aims to reduce the polluting consequences of the combustion of fuel by increasing the efficiency of intrinsic energy usage by storing much of that currently dissipated and recovering this cleanly to provide power where pollution is forbidden …the CESAR principle.
Heat storage and recovery
This requires first the application of the principles of fluid flow and heat transfer to recover the normally dissipated two-thirds of the fuel energy, effectively by storing as much of this as possible, and efficiently by minimising weight and volume, important parameters in all transport systems. Heat energy can be stored in many ways in many substances, but none better that water, the liquid that, with its high latent heat and general thermal properties make it so crucial to life on earth. Saturated water can contain large amounts of energy, easily and cleanly released in vapour form as steam to produce mechanical power, as remains common in the most modern power engineering plant.
The auxiliary, vapour prime mover can take many forms that will require considerable design and development. Rotodynamic forms, like the turbine, will probably not prove suitable because of the likely small mass flow rates which require very high speed operation with resultant large fluid dynamic losses. Positive displacement engines will be more efficient and compounded reciprocation piston-cylinder designs would be effective, if heavy. Positive advantages will rest with a rotary, positive displacement design with its higher speed and smoother, vibration free capability.
Control system
Control of all such machines quickly to adapt operating speed and power output to traction requirements will present a major fundamental design challenge even with the modern availability of electronic and computer management of engine operation. Vapour conditions will also require that special attention be given to such everyday components as valves to function accurately in controlling the rate of vapour flow to the engine over a wide range of conditions of pressure and temperature. Further control of valve operation in respect of timing and duration of admission and exhaust periods will enhance the design challenge. Especially will all these modes of control be critical in the two types of operation to which the saturated liquid hybrid vehicle lends itself: first, in the anti-pollution mode, in which the combustion engine is shut down and the vehicle propelled by the vapour engine alone as the accumulator pressure is allowed to fall towards a specified pressure near to atmospheric froman initial pressure sufficiently high to give an acceptable operating range. In the second type of operation, giving the greatest fuel economy, the combustion and vapour engines would run together to minimise heat dissipation to the atmosphere. The control system will then need to optimise the power balance between the two prime movers, the combustion engine providing enough exhaust heat to maintain the accumulator pressure as the vapour engine maintains the total power required by the traction demand.
Test programme and IP
The control system concept will require major design and development of itself, but additionally a major test programme will be necessary to establish the empirical operation relationships between the parameters that quantify its operation: thus between the combustion engine exhaust conditions and the accumulator charging rate, between the latter's rate of energy output and rate of pressure change, and the interaction between the energy accumulator and all the other components of the complete power train for different operation schedules. Satisfying the requirements of the design and development work represented in this note will create a comprehensive data bank of IPR, intellectual property rights.