Fuel Inlet Temperature Diesel Engine

Yes. Ring the engine manufacturer for help.

So the higher the temperature goes the less dense the fuel is, so less density = greater volume- less btu per cubic unit...

You could add a fuel cooler to improve performance....

https://www.dieselplace.com/threads/new-2-4-mpg-fuel-cooler.113643/

https://forums.tdiclub.com/index.php?threads/diesel-fuel-temperatures-affect-performance-but-not-economy-ii.18607/

Thanks a lot for your comment. However, my questions is not how to deal with this, but why is it happening at the first place? The higher volume of fuel, wouldnt just mean less efficiency, more fuel consumption, but no power derate. I am not sure why the engine derates....

Your question has been answered;Less fuel density equals less fuel-per-a given volume of fuel,therefor less BTU and power per a given volume.

The injectors stay open a certain amount if TIME to admit a certain amount of fuel.

If fuel density is less,then the amount of BTU's per time interval is reduced,resulting in less power.

The engine control computer has certain parameter limits on the amount of "open time" on the injectors.

This timing is controlled to prevent injecting fuel at the wrong time, in relation to the piston position;for instance,if the open time is too long,the fuel could be injected when the piston has traveled too far down in the cylinder,which could result in a crankcase explosion.

The optimal timing and position of the fuel injection is designed from the beginning of the engine design at an optimal engine and ambient temperature.

Now,clear as mud?

https://www.engineeringtoolbox.com/fuel-oil-density-temperature-gravity-volume-correction-ASTM-D1250-d_1942.html

The graphs will help determine if the power decrease is in line with the density decrease according to temperature.

If it exceeds this decrease then further investigation is warranted (assuming someone is willing to pay for this investigation). Unfortunately many engineers assume that fluids are neat, i.e. without contaminants, and subsequently the nature of those contaminants can be a confound. The patent library is littered with examples of corrective measures for same.

I have seen entire engine blocks blown apart due to a crankcase ignition of the fuel, because the mechanic fiddled with the mechanical injector timing."But I only moved it a little bit..."

Agree with SE, probably less fuel density at high temperature.

Check the amount of dissolved air in the fuel. As the temperature rises the saturation point lowers and gas will evolve out into discrete bubbles causing problems.

It might not be the problem but is a data point you should know. If it is an emergent problem, does it correlate with a change in fuel suppliers?

Good luck.

21.03 What are the high temperature issues for diesel fuel?

"High temperatures for generator fuel occur because the engine returns 65-95% of the withdrawn fuel back to the day tank. This return fuel flow is at a temperature that is well over 100 degrees F, without cooling measures, and this can cause the temperature in the tank to rise to dangerous levels. The engines often require relatively cool fuel, usually less than 110 degrees F, as a means of cooling certain engine components. And heated fuel can become a safety concern if it is heated above its flash point temperature.

High temperature is not a common problem because most generators include a fuel cooling radiator to treat the return fuel before it is received by the day tank. The fuel cooling radiator is mounted as a slave to the generator engine coolant radiator, and utilizes the same engine fan.

The fuel cooling radiator on the engine may not be practical where the engine utilizes a remote radiator for its coolant system. In this case several methods of fuel cooling may be used:

• (a) a dedicated fuel oil radiator and fan are installed at the day tank for return flow fuel from the engine.
• (b) fuel return from the engine is directed to a gravity return flow pipe to a bulk storage tank. Since the engine consumption is only 1 / 3 of the engine fuel pump flow, the fule supply to the day tank should be increased by about 3 times to accommodate the higher flow.
• (c) A temperature sensor in the day tank activates a return flow pump to pump fuel back to the bulk storage tank, allowing the day tank to be re-filled with fuel at a lower temperature."

https://www.earthsafe.com/resources/yqa21-diesel-fuel-quality-issues-for-generators-faq

So the fuel heating is probably being caused by the return fuel, ideally the temperature of the fuel going to the engine should be below 44°C...an inline cooler may not be functioning correctly or might be non-existent or in a poor location, but you need to address any fuel overheating as a safety matter primarily, and for performance as well...I would check the fuel quality if in doubt and filter performance as well as dewatering ability...

Okay. More Google Feng Shui. Set the discriminating search parameter to 70C.

Et voilà !

Exemplar: http://westgenerator.com/index.cfm/linkservid/BE885ED3-5056-B35E-2C4FC08CA76273D0/showMeta/0/

The electronic controls for the engine will tolerate 70 degrees Celsius. This is different from the engine itself.

Check the selection box for the optional remote radiator system.

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That you are concerned about this in the first place suggests you might need a significantly larger -- albeit surely more expensive -- generator set in order to safely handle possible peak loads.

There have been some interesting discussions about how power companies profitably set rates for industry -- they like to figure that the peak load could be all the equipment starting at once and they charge accordingly. Plant engineers do their best to not let this happen.

There is an effect of increased emissions with higher temperature fuel. I don't know if this applies to your situation...

"The primary fuel temperature effects on the injection parameters are from the fuel bulk modulus of elasticity and the density with the fuel viscosity less significant as the injector nozzle flow is in a turbulent region. The developed models can predict the changes in the injection parameters versus fuel temperature. As inlet fuel temperature increases, the nozzle fuel-injection-start timing is predicted to be retarded, the injection rate to be reduced, and the needle-lift duration to be prolonged from the baseline. The variation trends of the engine performance and emissions versus fuel temperature are analyzed by considering its consequent effect on in-cylinder combustion processes. It is predicted that raising fuel temperature would result in an increase in CO, HC, PM and smoke emissions, and in a decrease in NOx "

https://doi.org/10.1115/1.3019006