Some aspects of thermal load and operating indexes after downsizing for internal combustion engine

Abstract

The twenty-first century started with many downsizing applications. This important trend in the engine technology has been constantly developed. There are questions about limits and on the other hand new solutions in the face of new materials, tribological discovery, lubrication oils, turbo-or supercharging, new control electronic system of the engine run, higher accuracy in designing, etc. Some of parameters of thermodynamics of working cycle and thermal load according to the downsizing engine parameters were considered in this article. The downsizing impacts on fuel economy and emission were analysed, too. The investigations were carried out with own measured data (i.e. pressure inside inlet manifold, temperature of engine wall) as well as data from references (for example material properties) and at the end the simulations were done. The essential achievements of the work are (a) downsizing factor (DSF) was defined first time in this article (nobody before), (b) because of possibility of exceeding thermal load in piston (as an example engine part) the changes of DSF has to be restricted to almost 0.95 giving changes of 0.85 for base cylinder diameter and 0.90 ratio of base volume for stroke, (c) the main goal of downsizing to reduce CO 2 emission was results of all tests but it show only 10% benefit, and (d) it is possible to optimise the downsizing technology. So, the next research work will be focused on changes of super-and turbocharging as well as lean mixture combustion for better optimisation of downsizing.

Impact of supercharging and compression ratio on performance characteristics in a single cylinder DICI engine

“…Supercha-rger BP Type of engine [10] Roots blower-type super-charger 100,120,140 kPa (abs) 1 cylinder, CR: 18, 5.1 kW /2400rpm, IP:21.7 MPa [11] Two stage reciprocating air compressor 20,30, 40 kPa (g)) 1 cylinder, 3.7 kW at 1500 rpm, CR: 16.5 [12] two-stage reciprocating compressor 50 kPa(g) 1 cylinder, 3.7 kW at 1500 rpm, CR: 16.5, IP: 18, 21, and 24 MPa [13] two-stage reciprocating compressor 2,2.5, 3 bar (abs) 1 cylinder, 6 HP at 660 rpm, CR: 16.1,…”

“…The researchers have studied the influence of both supercharging as well as the variable compression ratio separately on performance characteristics of a diesel engine. The supercharging and charge cooling have improved the peak pressure, charging ratio, and brake mean effective pressure by 18 %, 5 %, and 53 % respectively [11]. It is reported that for all tested fuels, the emission of CO and smoke has scaled down considerably and brake thermal efficiency improved notably [12].…”

Analysis of the tribological behaviour of an automotive engine exhaust valve and a valve seat using a newly developed high temperature workbench

“…There are many considerations, however, for the valve seat and valve to have good performance as a pair, the following characteristics must be considered: high temperature resistance; wear resistance; corrosion resistance; tenacity; impact resistance and thermal conductivity [7].…”

Experiments on subcooled flow boiling in I.C. engine-like conditions at low flow velocities

“…While different possibilities may allow to achieve these goals [2], manufacturers are specially interested in engine downsizing. However, among other problems a serious issue associated with this technical solution is heat transfer, since the implied increase in the relative heat losses, together with the observed changes in their spatial distribution [3] actually pose intrinsic limitations to the engine size limits [4]. Additionally, the potential benefits of the use of suitable thermal management strategies is well established [5,6].…”