I agree with your second issue, and you certainly want your fuel supplier using the same BTU. On the first issue, there is little doubt that the steam industry wouold use the BTU-IT,from the International Conference on the Properties of Steam. It is a much as "declared value" as the yard being 0.9144 m.
--- On Sun, 4/12/09, Pat Naughtin <[email protected]> wrote: From: Pat Naughtin <[email protected]> Subject: [USMA:44606] Re: Steam energy To: "U.S. Metric Association" <[email protected]> Date: Sunday, April 12, 2009, 3:14 AM Dear Martin and Aaron, I see two issues: 1 You need to be more specific if you use BTUs as these vary with temperature. 2 Avoiding the use of the single coherent SI unit for energy, joule, means that you have difficulty comparing the energy used in different industries. See http://www.metricationmatters.com/docs/ObamaEnergyPower.pdf Cheers, Pat Naughtin Geelong, Australia On 2009/04/12, at 6:52 AM, Martin Vlietstra wrote: Some twenty five years ago I worked on a project for the Indian Power Generation Company to enable engineers to calculate the efficiency of their power stations. All calculations were done in metric units. From: [email protected] [mailto:[email protected]] on Behalf Of Aaron Harper Sent: 11 April 2009 21:33 To: U.S. Metric Association Cc: U.S. Metric Association Subject: [USMA:44589] Re: Steam energy Steam Enthalpy has been measured in BTUs for every power plant I have ever worked on so far. The day that I have to develop a control system using SI units, I will be in for some retraining. After 25 years of old school, I am sure it will be a bit of an effort, but at least I was taught SI, I've just never had a need to use it in practice yet. Aaron On Sat, Apr 11, 2009 at 12:27 AM, Pat Naughtin <[email protected]> wrote: On 2009/04/11, at 3:54 PM, Aaron Harper wrote: No matter what system of units are used, to speak of steam in terms of any unit of volume is not very meaningful, unless you also include the temperature and pressure of the steam. In power plants, we talk of steam in terms of mass, or we simply state the temperature and pressure of the steam which is directly related to the energy contained within the steam and available to do work. Aaron Harper Dear Aaron, What units do you use for the energy content of steam? Do you use the sole SI unit for energy: joules, kilojoules, and megajoules, etc.? Cheers, Pat Naughtin PO Box 305 Belmont 3216, Geelong, Australia Phone: 61 3 5241 2008 Metric system consultant, writer, and speaker, Pat Naughtin, has helped thousands of people and hundreds of companies upgrade to the modern metric system smoothly, quickly, and so economically that they now save thousands each year when buying, processing, or selling for their businesses. Pat provides services and resources for many different trades, crafts, and professions for commercial, industrial and government metrication leaders in Asia, Europe, and in the USA . Pat's clients include the Australian Government, Google, NASA, NIST, and the metric associations of Canada , the UK , and the USA . See http://www.metricationmatters.com for more metrication information, contact Pat at [email protected] or to get the free 'Metrication matters' newsletter go to: http://www.metricationmatters.com/newsletter to subscribe. Pat Naughtin PO Box 305 Belmont 3216, Geelong, Australia Phone: 61 3 5241 2008 Metric system consultant, writer, and speaker, Pat Naughtin, has helped thousands of people and hundreds of companies upgrade to the modern metric system smoothly, quickly, and so economically that they now save thousands each year when buying, processing, or selling for their businesses. Pat provides services and resources for many different trades, crafts, and professions for commercial, industrial and government metrication leaders in Asia, Europe, and in the USA. Pat's clients include the Australian Government, Google, NASA, NIST, and the metric associations of Canada, the UK, and the USA. See http://www.metricationmatters.com for more metrication information, contact Pat at [email protected] or to get the free 'Metrication matters' newsletter go to: http://www.metricationmatters.com/newsletter to subscribe.
