Improving the effective efficiency of a spark ignition engine through the use of a fully independent valve control system

Abstract

The article presents theoretical research of the proposed system of fully independent valve control (FIVC) of the SI engine. The analysis included controlling the movement of the intake valves, which results in adjusting the mass of the fresh charge to the current engine load, as well as the movement of the exhaust valves, where the main aim is to keep the rest of the exhaust gas in the cylinder, i.e. implementation of internal EGR. The open theoretical Seiliger-Sabathe cycle with the classic throttle regulation of load is the reference cycle for assessment of benefits and study of the effectiveness of obtaining work as a result of application of the FIVC system. A comparative analysis of the effectiveness of application of the proposed system was carried out based on the selected quantities: fuel dose, cycle work, relative work of charge exchange and cycle efficiency. The use of the FIVC to regulate the SI engine load makes it possible to eliminate the throttle and thus reduce the charge exchange work, especially in the partial load range. And this then leads to an increase in internal and effective work, which in turn results in an increase in the effective energy efficiency of an engine operation.

Comparative analysis of theoretical cycles of independent valve control systems of the SI engine

“…The theoretical cycle SI engine for the EEVC is shown in Fig. 3 [20]. The load (filling) control parameter is the volume V w,z (V 7 ) of the cylinder at which the exhaust valve closes.…”

“…3. Open, theoretical cycle of the system EEVC [20] The relation between the expansion ratio ε d,o and compression ratio ε w,z of the recirculated exhaust gas is expressed by the formula: (5) where: p 0ambient pressure, Δp dpressure drop in inlet system, Δp wpressure drop in exhaust system.…”

“…The fully independent valve control system is an algorithm that combines the procedures for independent control of the inlet and exhaust valves. FIVC is achieved by combining the EIVC system [19] with the EEVC system [20]. The theoretical cycle for FIVC is presented in Fig.…”

“…4. Open, theoretical cycle for the system of fully independent valve control [20] The FIVC system is implemented using two control parameters:  ε d,z (2) relative cylinder volume when the intake valve is fully closed  ε w,z (4) compression ratio of the recirculated exhaust gas.…”

“…The objects of the study were theoretical cycles of the load control systems and charge exchange process realization of the SI engine, including: [20].…”