Testing Times for Plant Operators BY IAN CAMERON
While gas turbines and large diesel engines may catch the eye in any power generation application, the fuels and lubricants they use make the difference between effective operation and a potential multimillion-dollar disaster. The constant monitoring and testing of a plant is a vital element in any maintenance program and that includes safeguarding the quality of fuel and lubricants, checking the quality of water used or the amount of debris that may be present in fluids within the system.
Yet an apparently straightforward process can be fraught with difficulties not least if problems that are present are not instantly detected or defective fluids manage to cause critical damage while the results of checks on their quality and potential threat are awaited. Despite the very best intentions of otherwise diligent staff working on engines in remote locations, critical damage can occur to a plant and machinery even when strict maintenance and testing programs are being rigorously observed.
Critical operational situations may occur in power stations in the vital period between fluid samples leaving a site and the results of the analysis being returned from specialized test laboratories often situated many hundreds of kilometers away. As labs often will carry out a broad range of in-depth tests on fuel, lube and water samples, by the time the results are fed back to far-away operators, it could be too late. In the period between samples, leaving the site and the results returned, potentially disastrous damage may have been done to the machinery, leading to site shutdown and an ultimate repair bill running into millions.
Kittiwake, a U.K. company, specializes in machine condition monitoring, fuel and lube oil analysis, and supplies testing equipment in small, portable kits that can be used on-site often on ships but increasingly at land-based power stations. Kittiwake offers four integrated ranges of oil analysis equipment and sampling consumables that the company said allow engineers to quickly and routinely monitor fuels and lubes onsite rather than send away samples for testing in labs. Its on-site products include online sensors that continuously assess oil quality and debris build-up in fluids, oil test kits and fuel and portable lube oil “laboratories,” which Kittiwake said closely monitor viscosity, acid number, water content and other issues.
Tom Kent, a Kittiwake applications engineer, said, “It may seem like we are competing with laboratories, but in reality on-site and lab testing can definitely work in unison. We are honest enough to admit that a power station operator may get more detailed results about their samples from a laboratory. And if your power plant is, say, on the mainland in the United Kingdom or the United States, you can easily get the results of your samples from them within two days.
“But if you are in a remote location such as parts of Africa or the Far East, then you will struggle to get quick lab results, as you may have to post samples to a distant lab unless you have your own testing capability. That is why such areas are a big market for us,” Kent added. He further explained, “While laboratories may be very thorough in their analysis of sample fluids, they may often come back with test results which are simply too minutely detailed for the needs of the site engineer who just wants the basic information to ensure his power station can continue to operate safely and efficiently. There is a clear benefit in knowing what is going on at an exact point in time not just when the engineer can get to a machine for a routine, scheduled sample and analysis.
On-site kits enable rapid testing and action, and online sensors remove sampling errors, which are often responsible for unrepresentative samples.” Historically, Kittiwake, founded in 1992 and based in Littlehampton, West Sussex, England, has seen its onsite testing equipment mainly purchased by the marine industry, especially for vessels at sea for long periods or for those docking in far-flung ports without close access to lab testing capabilities. The company has also detected increased interest in its test equipment from wind power operators.
Much of Kittiwake’s on-site test equipment is rebranded by both engine builders and oil suppliers and sold to customers. Although Kittiwake had its origins in the marine sector, they are seeing increasing interest from land-based power stations. “Naturally, if an operator were running a plant on the edges of a big city, then he would have potentially two or three labs he could quickly send his samples to and that is fine.
But for others, sited more remotely, the equipment we offer gives a straightforward answer to the question of whether any of the fluids being used in the station have a potential fault or need replacing. And the kits are not a luxury item they are cheap compared to the cost of failure. If a power plant had to close for days, weeks or longer because of damage caused by faulty fluids, the cost of that can run into millions,” Kent said.
The company said that for on-site oil analysis, its test equipment is available in metal or industrial roller cases, which makes them easier to carry. Its fuel and lube test cabinet can be wall mounted on-site. The on-site labs can monitor and evaluate the threats from a number of potential dangers including water in oil and insolubles, the build-up of combustion-related debris and oxidation products in oil.
The test equipment can also assess the total base number (TBN) of oil, which can avoid fouling within the engine, the total acid number (TAN), which is a measure of both the weak organic and strong inorganic acids in oil, and also the oil’s viscosity. Also offered within the kits are density meters for distillate and residual fuel oils, a compatibility tester to ensure the stability and compatibility of fuel types, a cloud point detector that measures the temperature at which wax crystals could form in oil, and also a flash-point tester that assesses a material’s flammability. Kent concluded, “The on-site kits can provide answers in five minutes compared to possibly weeks in a lab, by which time damage may have been done.”