DIESEL FUELS & DIESEL FUEL SYSTEMS

Application and Installation GuideDiesel Fuels & Diesel Fuel Systems• Length of periods ofcontinuous operation; If theoperating periods are short,the amount of heat returnedto the fuel tanks will berelatively small. Fuel coolersare not generally required forengines used in applicationsrequiring intermittentoperation.• Length of time betweenperiods of operation; if thetime between periods ofoperation is long, the heat willhave an opportunity todissipate.• Volume of the fuel tank; If thevolume of the fuel tank islarge (larger than 11 000 L[3,000 gal]), it will accept agreat deal of heat before thetemperature of the fuelleaving the tank increasessignificantly.Note: Day tank sizing is critical tomaintain the desired fuel supplytemperature. Fuel coolers may berequired. For a more detaileddiscussion of required fuel tankvolume, see the Day Tank Sizing(When Serving as a Heat Sink)section in Appendix 1.• Ability of the fuel tanks todissipate heat. In marineapplications for instance, fuelin contact with the shellplating, where at least 10% ofthe inside surface area of thetank is shell plating, the heatwill be easily dissipated andthe stored fuel temperaturewill remain within a fewdegrees of the ambient watertemperature.If a shell and tube type fuel cooleris required, the following materialsare suggested for the componentslisted in Table 5.ComponentShellHeadsTubesTube SheetsBafflesSuggestedMaterialRed BrassCast IronCopper NickelBrassBrassTable 5A plate type heat exchanger mayalso be used with titanium plates forseawater cooling or stainless steelplates for fresh water cooling.Refer to Sea Water Systems in theCooling Systems Application andInstallation Guide for properinstallation and maintenanceprocedures of fuel cooler in seawater applications.Fuel HeatersJust as the ability to removeexcess heat from fuel is animportant design consideration insome applications, so is the ability toadd heat to fuel in applicationsinvolving cold environments. Dieselfuel must not be too warm or toocool. Both cases will reduce life.With mid-distillate No. 1 or No. 2diesel fuel, cold weather can causewax crystals to form in the fuelsystems, partially or completelyblocking fuel flow. The addition of asmall amount of heat to the fuel©2005 Caterpillar®All rights reserved. Page 31