As mentioned in a previous blog, insulation provides energy savings for a steam system. Often, valves are not insulated for a variety of reasons, yet they offer a substantial energy savings as well. We would be interested in hearing from you as to what heat loss value you utilize for your valves, flanges and other steam components.
We are trying to standardize the steam trap test results plants use for testing steam traps. If you have any recommendations – please respond….
As we identify opportunities in our plants to improve efficiency, save energy, and ultimately save money, often there are incentives provided by utility and government agencies. A range of incentives are avaliable such as corporate tax credits, loan guarantees, rebates, and grants among others. A valuable tool is the Database of State Incentives for Renewables & Efficiency (DSIRE) which is funded by the US Dept. of Energy and maintained by NC State University. Here you can view federal incentive opportunities or drill down to your particular state.
Remember in physics class when the professor demonstrated the venturi effect. The experiment most likely had water or compressed air passing through a nozzle. As the fluid is constricted in the nozzle it’s velocity increases and as we know from the Law of Conservation of Energy, the pressure at the constriction decreases. This decrease in pressure will then draw in a second fluid and entrain it with the motive fluid. This principle is exactly what we see in steam ejectors where of course the motive fluid is steam. This second fluid can really be any such as air, chemicals, or flash steam.
Steam ejectors are quite simple devices with no moving parts and also are extremely durable. An ejector is commonly used as a vacuum pump to draw ingressed air from the condenser on a turbine at power plants. An ejector can also function as a thermocompressor to siphon flash steam and entrain it with the motive steam.
Proper steam trap sizing is a critical factor in obtaining efficient and reliable steam trap operation. Incorrect steam trap sizing can negate proper trap design, installation, and can cause condensate backup, steam loss or both.
Steam trap sizing is sometimes mistaken for selection of the steam trap connection size. Rather it is the proper sizing of the internal discharge orifice. (For low pressure steam heating systems, manufacturers produce steam traps with connection sizes that relate directly to capacity, orifice size). However, an industrial steam trap must be sized by selecting the proper discharge orifice. A two-inch steam trap can have the same condensate capacity as a steam trap with a half-inch connection. Once the condensate capacity is determined and the proper orifice size is calculated, the steam trap connection size can then be determined to meet the installation requirements.
Read the full Best Practice…..
http://www.plantsupport.com/download/Best%20Practices_No.25R2.pdf
Great software tool from the DOE on pumping applications and it is free……
The Pumping System Assessment Tool (PSAT) is a free online software tool to help industrial users assess the efficiency of pumping system operations. PSAT uses achievable pump performance data from Hydraulic Institute standards and motor performance data from the MotorMaster+ database to calculate potential energy and associated cost savings. The tool also enables users to save and retrieve log files, default values, and system curves for sharing analyses with other users.
http://www1.eere.energy.gov/industry/bestpractices/software_psat.html
Flash Steam is a consistent occurrence in a steam system. Whenever condensate is being released from a higher pressure steam line to a lower pressure it occurs. For example, a steam line operating at 100 psig will have a saturation temperature of 338oF. When the condensate that is formed in this steam line is discharged to the atmosphere, the condensate temperature at atmospheric conditions can not be more than 212oF. This change in energy must be converted and that is accomplished by flashing some of the condensate into steam. Keep in mind that when the condensate is flashed back into steam, the steam takes up a much larger volume and this volume needs to be accounted for when sizing condensate return lines. The amount of flash steam that is going to be produced can be calculated and should be done when designing a condensate return line, however utilizing a Flash Steam Chart can also provide a quick reference tool to help calculate the amount of flash steam that will occur. When designing condensate return lines for condensate/flash steam flow the line velocity should not exceed 4500 feet per minute. Velocities above this rate can cause water hammer issues in your return line.
For additional information of Flash Steam and Condensate Return lines refer to the following Best Practices from Swagelok Energy (www.swagelokenergy.com):
Swagelok Energy Best Practices No.7 – Flash Steam
Swagelok Energy Best Practices No 14 – Condensate Return
Great web site for past and future energy cost. Pricing is provided on natural gas, electricity, coal and even information on emissions.
http://tonto.eia.doe.gov/cfapps/STEO_TableBuilder/index.cfm
Updated Annual Energy Outlook 2009 Reference Case Service Report, April 2009
The Annual Energy Outlook 2009 (AEO2009) reference case was updated to reflect the provisions of the American Recovery and Reinvestment Act (ARRA) that were enacted in mid-February 2009. The reference case in the recently published AEO2009, which reflected laws and regulations in effect as of November 2008, does not include ARRA. The need to develop an updated reference case following the passage of ARRA also provided the Energy Information Administration (EIA) with an opportunity to update the macroeconomic outlook for the United States and global economies, which has been changing at an unusually rapid rate in recent months. Therefore, the difference between the recently published AEO2009 reference case and the updated reference case incorporating both ARRA and the updated economic forecast reflects more than the energy-related provisions in ARRA alone. Although future analyses will focus on the difference between the updated reference case and cases using that as a baseline and incorporating proposed changes in laws and regulations, users of EIA’s projections may want to understand the relative roles of ARRA and the change in the macroeconomic outlook in driving the difference between the updated reference case and the one presented in AEO2009.
It is helpful to remind ourselves the substantial benefits of insulating steam piping. Huge amounts of energy is put into producing steam and yet as we transport it from point A to point B we often allow large energy losses to radiate freely into the ambient air. Heat energy as we know moves from a higher temperature to a lower temperature and the rate of this transfer is proportional to the temperature differential and the surface area of the pipe (other factors do impact the losses such as wind speed, surface emittance, and thermal conductivity of the pipe material).
For example 100 psi steam is 338 F and if the ambient temperature is 60F, that is a 278F incentive for the heat to radiate out of the piping. Now if we use 3″ piping that is also lots of opportunity for the heat to escape. So, for every foot of 3″ piping carrying 100 psi steam and exposed to 60F ambient temperature, 778 BTUs per hour are lost. That is nearly 6.5 million BTUs or the equivalent of 21,000 lbs of steam per year lost for each foot of piping.
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