Page 30: of Maritime Reporter Magazine (October 15, 1980)
Review (continued from page 28) the PC2-6 with an output of 750 hp per cylinder at 520 rpm, a mean effective pressure of 21.5 kilograms per square centimeter, and a piston speed of 7.97 meters per second. The PC2-6 is offered in two versions — as an in-line with 6, 8, or 9 cylinders, and in
V-form with 12, 14, 16, or 18 cylinders.
Using a multi-pulse converter (MPC) supercharging system, to- gether with a modified combustion chamber and a new injection tim- ing, remarkable results are said to have been achieved with spe- cific fuel consumption (ISO con- ditions). At maximum continuous rating the fuel rate is 142 grams per hp hour, for continuous serv- ice operation the rate is 140 grams per hp hour, and at optimized con- ditions a fuel rate of 137 grams per hp hour was achieved.
The PC2-6, as do all other Piel- stick engines of the medium-speed type, runs on the heaviest resid- ual fuels — up to 4,000 seconds
Fairbanks Morse Engine Di- vision is the U.S. licensee for
S.E.M.T. Pielstick PC engines.
During the past year, Stork-
Werkspoor Diesel of Amsterdam has directed its research and de- velopment activities towards new engine types, thermodynamic con- siderations, and use of heavy fuels.
The new 12-cylinder, V-form
TM 620 has been tested and meas- ured on all special V-form com- ponents. As a consequence, a sin- gle medium-speed engine of only 12 cylinders with a rating of 22,- 000 bhp (16,200 kw) is now avail- able.
Fuel consumption is of great importance today, and at SWD developments are made constantly on many engine details to reach the lowest values possible. Great care is required, however, as var- ious measures in the direction of maximum economy can result si- multaneously in an increase in the thermal load, and the load ad- vantages achieved by controlling the thermal load must retained.
Nevertheless, respectable fuel consumption rates have been achieved, especially at somewhat reduced loads. For the TM 620 engine, a fuel rate of 190 grams per kw hour has been attained.
Research is continuing in this area.
From the beginning, the TM 410 and TM 620 engines have been developed to run on heavy fuel. As a consequence, only small adaptations are necessary for the fuels of inferior quality that are expected to appear on the market in the near future. These fuels will have a higher content of larg- er molecules, which can lead to slower burning and increased fouling.
Another risk, however, is caused by mixing problems (com- patibility) of oils from different sources, which can seduce oil companies to use light aromatic oils as a remedy. As a result, more and more often fuels with poor ignition properties appear on the market. The latter problem was attacked first by Stork, and has led to the introduction of air-inlet heating at part load in cases where the use of such fuels can- not be avoided.
Subsequently, trials have been run at SWD with a specially for- mulated "future" fuel. This fuel oil had a Conradson carbon num- ber of about 20, 11 percent as- phalt, and a viscosity of approxi- mately 4,800 sec RI at 100 F. The trials took place in a 9-cylinder
TM 410 engine, and the objec- tive was to investigate the par- tial load range in particular, be- cause it was there that the great- est fouling was feared, especi- ally as a result of gas blow-back in the inlet passage.
SWD found the results "aston- ishing." First, the engine started immediately and ran if possible more quietly than usual. Obvi- ously this fuel, as opposed to the (continued on page 33)
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