Comments on: Can anyone please give some advice on boiler efficiency testing? http://www.boiler-scrappage.info/can-anyone-please-give-some-advice-on-boiler-efficiency-testing/ Replace Your Inefficient Boiler Tue, 09 Feb 2010 17:12:14 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Mollie64 http://www.boiler-scrappage.info/can-anyone-please-give-some-advice-on-boiler-efficiency-testing/comment-page-1/#comment-13 Mollie64 Tue, 10 Nov 2009 10:18:37 +0000 http://www.boiler-scrappage.info/can-anyone-please-give-some-advice-on-boiler-efficiency-testing/#comment-13 I am not sure what is meant by net or gross efficiency other than making the calculations based on the net or gross heating value of the fuel. Also it is not clear what the problem is that you are trying to address. Is it a guarantee problem or a lost of performance over time question? As I am sure you know the gross heating value of a fuel is based on the energy released when you burn the fuel. The net heating value deducts the energy lost from the heating of the water vapor that is produced either by the combustion process or in the case of coal the moisture content of the coal. The use of the net heating value will result in a calculation showing a larger efficiency since the denominator of the final calculation will be smaller. Likewise using the gross heating value will result in a lower efficiency. If you are trying to compare the actual performance with the guaranteed performance, the basis for the guarantee should state which heating value to use. For comparison purposes of time neither is best, you can use either one as long as you are consistent. I am not sure what is meant by net or gross efficiency other than making the calculations based on the net or gross heating value of the fuel. Also it is not clear what the problem is that you are trying to address. Is it a guarantee problem or a lost of performance over time question?

As I am sure you know the gross heating value of a fuel is based on the energy released when you burn the fuel.

The net heating value deducts the energy lost from the heating of the water vapor that is produced either by the combustion process or in the case of coal the moisture content of the coal.

The use of the net heating value will result in a calculation showing a larger efficiency since the denominator of the final calculation will be smaller. Likewise using the gross heating value will result in a lower efficiency.

If you are trying to compare the actual performance with the guaranteed performance, the basis for the guarantee should state which heating value to use.

For comparison purposes of time neither is best, you can use either one as long as you are consistent.

]]> By: Marisol Sage http://www.boiler-scrappage.info/can-anyone-please-give-some-advice-on-boiler-efficiency-testing/comment-page-1/#comment-12 Marisol Sage Tue, 10 Nov 2009 04:08:01 +0000 http://www.boiler-scrappage.info/can-anyone-please-give-some-advice-on-boiler-efficiency-testing/#comment-12 To be honest Stephen, this is best left to someone who knows what they are doing, you could easily be mislead. Good luck. To be honest Stephen, this is best left to someone who knows what they are doing, you could easily be mislead. Good luck.

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