TDI CHP: 1.9L Engine Power Plant

Hello,
I intend to build a small combined heat and power (CHP) system.
I would like to use a 1.9-liter TDI engine with the original 66 kW power output for this.
The problem is that the motor, due to the generator being directly coupled to the motor's crankshaft, has to deliver 42-45 kW at the shaft at a speed of approximately 1550 RPM. The motor runs at this speed 24 hours a day.

'How can I achieve, for example, a turbocharger that delivers approximately 0.7 bar of boost pressure at around 1500 RPM? I have a good acquaintance who can specifically adjust the engine control unit (ECU) programming for this particular application. The engine will never exceed 1600 RPM. The speed of approximately 1550 RPM is necessary because the generator needs to operate at that speed to feed exactly 50 Hz into the grid, which is a requirement!'
Furthermore, I need to calculate beforehand how much fuel the engine will consume per hour, but unfortunately, I don't have a calculation table for that. For cost reasons, the engine is operated with heating oil.

It would be great if someone could give me some tips on how to achieve this, and whether it's even possible.

I would be very grateful for any help.

Best regards from the electrician!

Hello,

forget it.

Internal combustion engines for passenger cars are completely unsuitable for use in combined heat and power (CHP) systems.

Timing belt replacement every 90,000 km.
At an average speed of 60 km/h, that's 1500 hours.
That means approximately 8 weeks of continuous operation. Do you want to replace the timing belt every 8 weeks and the engine every year?

The speed of 1550 rpm should ideally be within the engine's optimal operating range. You'll be hard-pressed to find a gasoline engine designed to operate at that speed. A long time ago, there was a fuel consumption curve available for a TDI engine here. Try searching for it.

Best regards, Rainer.

Hi,

Besides Rainer's arguments: What speaks against a translation? Then you could also choose any other engine speed.

@Rainer: It would be interesting to see how the constant operation at a fixed speed affects wear and tear. I imagine that this is much more favorable than frequent cold starts and constantly changing loads.

Or what?

Best regards,

Jan.

Hello,

That's what I call brave. My friends have had massive lifespan problems with engines similar to a ship diesel (V. One year has about 8600 hours. Problems usually start around 10,000-20,000 hours. You should ask VW; they might have useful information about their TDI industrial engines.

Best regards,
Christian.

Jan6K wrote:

Hi, Besides Rainer's arguments: What speaks against a translation? Then you could also choose any other engine speed. @Rainer: It would be interesting to see how the continuous operation at a constant speed affects wear and tear. I imagine that this is much more favorable than frequent cold starts and constantly changing loads. Or what? Best regards, Jan

.

Hello Jan,

Of course, a motor used as a CHP (Combined Heat and Power) system will last significantly longer based on its operating hours.
Just to put things in perspective, a year already involves a huge number of (working) hours...

Best regards, Rainer.

Hello,
I intend to build a small combined heat and power (CHP) system.
...
'How can I achieve, for example, a turbocharger that delivers approximately 0.7 bar of boost pressure at around 1500 RPM? I have a good acquaintance who can specifically adjust the engine control unit (ECU) programming for this particular application. The engine will never exceed 1600 RPM. The speed of approximately 1550 RPM is necessary because the generator needs to operate at that speed to feed exactly 50 Hz into the grid, which is a requirement!'


Hi,

My 66kW TDI engine, which uses a variable geometry turbocharger (VTG), reaches a boost pressure of 0.7 bar approximately at the RPM you mentioned. However, this only happens when the engine is properly warmed up and under full throttle.
However, I doubt that it delivers the desired power at that speed. Another thing is that the oil pressure is not particularly high at that speed, which is not exactly beneficial for its lifespan.

For a CHP (Combined Heat and Power) system, I would use a slow-rotating diesel engine without a turbocharger and with a large displacement (truck engine). And a mixture of diesel and natural gas might be the best fuel (diesel for idling speed and ignition, plus gas for power).

A highly refined car engine seems unsuitable to me as well.
An interesting question would be how long a motor with LongLive service could run continuously under those conditions.

Greetings.

Eike.

Hi there,

a completely different objection.
If I understand correctly, you want to control the frequency based on the motor speed. That's complete nonsense; you'll never be able to achieve a stable frequency that way, making it impossible to feed power into the public grid. Furthermore, it's not just the frequency that needs to be correct, but also the phase relationship; otherwise, you'll get a short circuit.
This is typically done using electronic inverters via a DC intermediate circuit. And then, it doesn't matter what comes out of the generator beforehand.

Before you start, check with the electricity providers to find out what conditions you need to meet in order to be able to feed electricity back into the grid.

greetings
dieter

I agree that it's a good idea to contact Volkswagen directly and inquire about the industrial TDI engines.

A generator connected to the grid will never have enough load stiffness with a 1.9 rating.
We had a 560kW generator here, which had a V12 turbocharged diesel engine with a displacement of no less than 27 liters. As correctly pointed out, the speed must be maintained under all circumstances, even with large load changes on the generator. The best solution for this is to use controllers that not only regulate the generator but also provide the engine control system with corresponding correction data, minimizing the response time.
A large displacement engine and a significant amount of rotating mass can be extremely helpful.
btw: The industrial TDI units can be programmed with fixed speeds.

The speed (1550) is certainly too low for the 1.9 engine. It runs best at around 1900-2100 RPM. Consider using a planetary gearbox for reduction.

The issue with phase alignment isn't as critical as it seems. For example, you can use asynchronous generators (yes, they exist, even for island operation). These generators adapt to the grid. The energy supplier can provide information on this.

CU Gremlin.

@rainerk.
Hello,
Why shouldn't he be able to use the engine? The 110 model is also used and sold as an industrial engine, isn't it?

Hi,

"Industrial engine" doesn't automatically mean 24/7 operation. There are many applications where the engine only runs intermittently, or even powers a vehicle.

Best regards,

Jan.

Take a look at Volkswagen; they offer not only industrial engines but also marine engines. Mostly, these are SDI 5-cylinder engines, but sometimes also TDI 5-cylinder engines. There are many differences between these engines and those used in passenger cars.
I also think it's a lot of nonsense to go with a conventional TDI. Why would you? You can buy a motor from a Mercedes 508D for half the price or even less. It also only has 4 cylinders, but it has a 3.7-liter displacement. It can handle everything you need with its 80 horsepower.

Hi,
According to a general rule of thumb, the lifespan of an engine with a similar design is proportional to the piston diameter. This suggests that a truck engine would be more durable, or at least, if it must have a TDI designation, the 2.8L 4-cylinder engine of the current LT model would be a good choice.
Furthermore, the rated speed is closer to the desired 1550 RPM. I don't know how that works with ship engines.
Is the 508 engine different from the one in the 208? The 208 has a smaller engine, only 2.3L. However, it has a lower RPM than the 2.4L engine in the 207.
Several years ago, there were also CHP (Combined Heat and Power) systems that used the old 1.6-liter diesel engine. I seem to vaguely recall that they had significant problems with reliability.

I might have been a bit hasty. The 508 was probably the predecessor to the 509 or 709. Indeed, that's already a truck engine.

Hi christian...mir kam die Idee mit dem 508 Motor. Damit meine ich den einer total alten Blechbüchse die wir mal bei der Firma hatten. Denke so an Baujahr um die 70...der war erstklassig Hubraum ohne ende, sprang immer an, hat alles verbrannt und hatte eben diesen riesigen Hubraum. Ach und der Motor war grün lackiert und hatte nicht eine Ölschmiererei. Suby part, or by segment.

Okay, I've been looking into VW Marine's recommendations, and they specify an oil change for boat engines every 200 hours. That would be roughly every 8 days in a combined heat and power plant. However, a significant amount of electricity and heat would need to be generated for it to become profitable.
Here's the link: http://www.volkswagen-marine.com/deutsch/mo_ve120.htm#

200 hours...

It's not surprising. The load on an engine in a car is completely different. In a boat or a combined heat and power (CHP) system, a high torque is constantly required.
In a car, this would likely be equivalent to 200 hours (16,000 km at 80 km/h) of continuous campervan operation.

Normally, when driving, you mostly roll along; hardly anyone has to or can drive a car with an empty tank at full throttle for 200 hours.

Best regards, Rainer.

Was that some kind of can?
http://www.db407.de/
(naturally with 80 horsepower instead of 70, as indicated by the website's description).
At least then they would be direct injectors.
Changing the oil could also be a problem. Perhaps a side-stream filter would be worthwhile for CHP systems.