Restricting exhaust flow causing temperature increase?

In summary, the conversation is about a situation where someone modified the exhaust pipe of a diesel fired equipment from a 30mm internal diameter to a 20mm internal diameter. The exhaust outlet temperature was 400 deg C, and it is estimated that at the constriction, the temperature would be 553 deg C assuming a gamma of 1.4. The speaker also shares a website that may be helpful, but advises to keep in mind that the temperatures are in Kelvin and to use a "k" value of 0.0466. They also mention that the value of gamma can only be assumed for air at a specific temperature, and that it may change depending on the temperature.
  • #1
IPog
1
0
We have a situation.
Someone modified the exhaust pipe from a diesel fired equipment. Exhaust gas flows out through a 30mm internal dia pipe. The modification carried out was to reduce the diameter of the pipe to 20 mm internal dia.
The Exhaust outlet temperature from the equipment was 400 deg C. I calculate that at the constriction the temperature would be 553 assuming a gamma of 1.4.
Any comments appreciated.
 
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  • #2
I found this website, it may be helpful for you. Just keep in mind that the temperatures are in Kelvin.

https://www.dieselnet.com/tech/diesel_exh.php

If this table is correct, you have to take a "k" value (gamma) of around 0.0466.

1.4 can only be assumed for air at a specific temperature because "k" changes depending on your temperature. However if the temperature change is relatively small, then you can assume it is constant.

I hope this helps...
 

Related to Restricting exhaust flow causing temperature increase?

1. How does restricting exhaust flow cause a temperature increase?

When exhaust flow is restricted, the exhaust gases are unable to flow out of the system efficiently. This leads to a buildup of heat and pressure within the system, causing an increase in temperature.

2. What are the potential consequences of restricting exhaust flow?

Restricting exhaust flow can cause damage to the engine, as the increased temperature and pressure can put stress on the components. It can also lead to decreased fuel efficiency and increased emissions.

3. Can restricting exhaust flow be beneficial in any way?

In certain situations, restricting exhaust flow can be beneficial for improving engine performance. For example, in a turbocharged engine, a limited amount of exhaust flow can be used to increase the pressure and boost power output.

4. How can I tell if my exhaust flow is being restricted?

There are a few signs that may indicate a restricted exhaust flow, such as a decrease in engine power, increased exhaust noise, and a noticeable decrease in fuel efficiency. A mechanic can also perform a diagnostic test to check the exhaust flow.

5. Can a restricted exhaust flow be fixed?

Yes, a restricted exhaust flow can be fixed by identifying and addressing the underlying cause. This could involve replacing a clogged or damaged exhaust pipe, muffler, or catalytic converter. Regular maintenance and cleaning can also help prevent exhaust flow restrictions.

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