Document NENKR90LOqG2ZBrEZpb0nr5GV

r Typical eonvbuitlon-alr conditioning system for o 2-cycle 9 prnsyre-chorgod engine uses a humidifier and aftercooler Conditioned Combustion Air Jacks Diesel Output * New ways are opened up to more power from a given liu cylinder, with no thermal-lead increase, by conditioning com* bustion air for high-compWf sion engines; In climates wM M< * ' TllS CSEATUT CtlALLCNCB (0 (He .. diocLensine industry has always been ^ development of more efficient and eco* ' nmalcal prime movera. Notable achieve* : osi* since 1936 include (1) diesel* snpoe supercharging to Increase power t. output by 50% (2) production of highly r* fltiible and efficient gas-dicael atmoo* ' pt>rlc and supercharged engines and j' 0) development of spark-ignited high* ^ compression supercharged engines using fc. o*tura|.gu fuel. Hrertnel efficiency of high ambient temperatures oodj j,. "Her runs to nlmost 40%. 1 Higher ratings and reduced specific low relative humidities the re f U1 consumption are made possible by suits are especially satisfactory: ^winning design and research studies. .J s result we see increased compres* By W B CROOKS, ChM fngiW'i and i i MILLER, Project foglMlt PA# Ceepen-Btmmer Carp L on at(i'nPherlc gas eti* , ** ^Proved turbochorgers, scaveng- ! systems. Ignition and gao-injeetion . j *nd materials. 4 *,r' Today tnutsh attention is ` ". ,oword conditioning combos* lion air as an added step in developing more power from an engine of given sise. Before 1946, need for cooling combustion air Hid not exist on moat engines because specific output was, relatively low. All gas engines were low*cornpression types. Load*carrying ability was limited by inability to ef ficiently burn the rich fuel charge pres ent in their cylinders. Overload caphchj of 10% in these engines was more than enough to tako care of changes in oxygen content of air with temperature. For instance, at I20-F intake temperature, content is only 5% less than at 90 F. Engines had sufficient reserve load-carrying capacity at elevated temperatures. - Supercharged Engines- During this same period 4-cycle supercharged die sels were rated et HS-psi brake mean effective pressure (bmep) with turbo charger pressure ratios up to 1.3. Air reaching engine was at 140 F on a 90-F ambient day. Combustion-air tempera ture was not an Important (actor. When- atmospheric gas-engino com pression pressures were upped from 100 to 450 psi, conditioning of combustion air became economically justifiable. Developments in supercharged ges-die.sels and spark-ignited high-compression gas engines raised bmep to 160 psi be fore detonation limited output and pointed the way toward study ol con ditioning systems for combustion air. Equipment. Radiator-type beat ex changer between turbocharger end airinlet manifold was first conditioner tried. Cooling medium woe water. On low-rated supercharger diesels we could see no advantages. But later developments on 4-cycle high-compression supercharged gas and dieael engines, having turbochargers with pressure ratios of 2 to 2.5, showed m *" ' Kur ,.J, IHOINEEDINO AND MANAOGMCNT SECTION 101