Turbine Generator Package Shop Test Report-Atlin Hydro Project

Transcription

1 Turbine Generator Package Shop Test Report-Atlin Hydro Project 2

2 Content 1. Overview of the factory 2. Visual inspection of the turbines, generator, and valves. 3. Pelton runner non-destructive tests (NDT) 4. Turbine/TIV functional tests. 5. Review detail test reports prepared by factory 6. Summary 3

3 1. Overview of the factory Chongqing Yunhe Industry Group, located in Chongqing in the Southwest of China, has been building hydro power equipment since The company has provided the hydro power equipment not only to domestic customers, but also to India, Peru, Nepal, and Vietnam. With multiple expansions in recent years, the company has been recognized by Chinese government as a key enterprise to be able to supply a wide rage of small to medium size hydro equipment. The company has been developing turbines from heads of 5 m to 1200 m, with unit capacity from 100 KW to 100,000 KW. 2. Visual Inspection of the Turbines, Generator, and Valves. The whole Atlin unit (includes turbine, generator and valves) has been constructed with high quality material which conform to Contract specifications. Throughout the design and manufacture of the equipment, the factory maintained attention to quality. The weld joints and machining surfaces are finished nicely. Hydraulic pipe connections are neatly arranged and firmly clamped. The entire unit has been pre-assembled in the shop. The key components, the turbine wheels (runners), are cast as a single unit using high-tensile stainless steel alloys, and each bucket is hand-ground and polished. No visual defects were observed. 4

4 After reviewing the generator operating at rated speed we believed the equipment is decent quality, easy to control, and has less vibration than most existing units. For example, the units installed at other similar hydro plants in BC have a typical vibration of 0.06 mm to mm, whereas the Atlin unit had a vibration of only mm, which is well within acceptable limits by any recognized vibration severity chart.. 3. Pelton Runner non-destructive test. Prior to the engineers arriving, the factory had completed all the shop tests, however, to go beyond a visual inspection for defects on wheel surfaces, a request for further tests was sent to the factory to double check that critical specifications conformed to the Contract. Factory personnel repeated the tests with the owner representatives and engineers present to observe, include the dye-penetration tests on bucket surfaces, UT tests on runner hub, and bucket surface hardness check. The test results have shown that runners were designed and manufactured properly, and within specified parameters. 4. Turbine/TIV (turbine inlet valve) functional tests. 5

5 The tests were divided into 5 major groups: TIV opening and closing tests The tests were carried out by using a TIV control panel, with a single push button for each function. The TIV would complete a full opening cycle and then automatically lock it at the full open position. Likewise, by pushing the close button it closed hydraulically, assisted by the equipped counter weight, and safely locked in fully closed position. From the tests, we found both TIVs operated smoothly, and the auxiliary control system are easy to install and maintain. Nozzle deflector closing tests. Based on the Contract specifications, the deflectors are designed to close within 2 sec by preloaded spring to achieve the fail-safe mode in an emergency shutdown. The actual tests demonstrated that the deflectors can safely be closed within 1 sec from the fully open position. Needle nozzle operating tests 6

6 The nozzles were also designed with the self-closing function, which will safely shut down the machine in the event of hydraulic power system failure. This technology is also recently used by major European companies, such as VA Tech and Voith Hydro. The test results are as follows: At fully closed position the needle spear clearance is less than 0.01 mm which is better than 0.03 mm specified by Contract Spec. Nozzles can be safely self-closed by dumping the hydraulic oil. Needle stroke is inspected and matches with provided drawing. Nozzle design allows inspection and maintenance much easier by simply removing only the nozzle mouth ring. Needles are nitride case hardening which will give a longer life time for those parts. Generator operating tests Based on the completion of all electrical tests, we completed the generator final tests in two scenarios; running at normal speed and, at extreme condition runaway speed. At both operating conditions, the generator performed well. The guide bearings ran smoothly at low temperatures, and the vibrations were lower than specified tolerances. The photo shows a coin stands still on the top of bearing cover even at runaway speed which reflects the operating stability of the unit. 7

7 5. Review detailed test reports prepared by factory Four test reports have been provided by the factory including: turbine test report generator test report outsourcing component test report, and Non-destructive test (NDT) report. After reviewing the above documents, the engineer believes they are well documented, easy to read, and all results conform to specifications in the Contract. 6. Summary Based on final reviewing the major technical issues with the factory design engineers and the shop witness tests, we have concluded that the Atlin turbine unit has been well designed, the shop construction is of high quality, and all the components function properly. Yunhe claim to have installed a quality assurance program conforming to ISO Most of the objective evidence in the factory supported this claim. The quality of the Atlin machines conformed to specifications and many attributes were well within specified tolerances. 8