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Small Hydro Upgrading Opportunities in Southwest ChinaReport by Charles D. D. Howard, P. Eng. This is the report of a reconnaisance from January 19 to February 7, 2002. The purpose was to determine how existing small hydro plants could produce more energy by improved management of the water resources and equipment upgrades. Our party consisted of myself, wife Sherrill, Tony Tung and his assistants Cynthia Handler and Jinxing Huang from Natural Resources Canada, and Yves Grandmaitre from Power Base Systems in Carleton Place.
After preliminary discussions with the Ministry of Water Resources and the Canadian Iinternational Development Agency (CIDA) in Beijing we met with officials of the Ministry of Water Resources. Then we went on to visit small hydro sites in the countryside near the following cities: Beijing, January 21, 2002 Beijing, January 22, 2002 As an example the display was zoomed into the city of Wuhan on the Yangtze River. This showed an offline “near-real-time” hydrograph of discharge and water level with the flood warning level clearly drawn in red. A map showed the stage-storage curves for the controlled inundation areas along the river. BC Hydro has provided a flooded area-mapping tool of some kind. Drawings of the sluices are available on-line. The computer displays did not provide river stage forecasts or suggested operations for flood management facilities. This may be done off-line by some manual non-quantitative decision making progress. There is s bewildering amount of data that is displayed for the entire country. Except for the very large slow developing floods on the Yangtze, Pearl, and Yellow rivers it’s difficult to imagine how all this data is turned into information for making timely useful decisions during a flood. If ever there was opportunity and need for a Decision Support System (DSS) this is it. It was said that there is a Decision Support System that is partly functional for all of the country, but it was not made clear what the DSS actually does. The Head of this Bureau expressed some interest in learning more about Canadian flood decision support systems but we did not have time available for a technical discussion. It appeared to us that on smaller basins the data should be available every hour, not just once each day. This would require a flexible type of distributed organization familiar with local conditions in the Provinces - it may not be appropriate to centralize all of this in Beijing. Although the big basins are focal points, the cumulative cost of flood damages on all of the smaller basins may have a significant national impact. Is there an operational “Emergency Measures” type of organization in China within one of the Ministry’s or does the Ministry of Water Resources handle everything? The information displayed in the Flood Operations Center was said to be available to other Bureaus (of the MWR?) through an Intranet. After the flood operations demonstrations we reconvened in a building across the street for a meeting chaired by the Deputy Director General of the Bureau of Comprehensive Development and the Deputy Division Chief of the MWR Foreign Affairs Division. The purpose of the meeting was to get acquainted with the key people in Jianghe Mechanical & Electrical Equipment Engineering Ltd. This is a national company owned partly by the Ministry of Water Resources and several machinery manufacturers. The company has plants in Nanjing, Changsha, and Chengdu City. One of these would be the group involved with the PowerBase upgrades portion of the CIDA project. The Chinese explained that would like to focus on Guizhou Province because they have experience there with PowerBase small hydro control systems that are working well, and there is easy transport to three potential sites. The province is in the priority Western Development Authority and is advanced in hydro. The Datang He (river) powerhouse is 20 Km from Guiyang city. It has five units (2x200Kw plus 3x125 Kw) under 8 meters of head. All of the generators and turbines will be replaced here, and PowerBase systems will be used for automation. Currently there are 48 staff operating in three shifts. The Yunglu powerhouse constructed in 1998 is in Puan County in Guizhou province on the Daqiao He (river). It has two 400 Kw units and 32 staff. There are many forced outages here. Xi Longli (under construction) and Liangtian are ready to go and are more important than the others. They will receive the complete treatment, like Datang He. The province is doing these. In Sichuan province there are many forced outages at Dujiangyan where “Special equipment is needed for Chinese conditions”. Our group explained that we need a very good baseline to establish climate change benefits and that CIDA currently has six climate change projects. The largest is in China, the C5 project , which is focusing on clean development mechanisms (?) in Transport, and in Renewable Energy. The details of the baseline study have not been worked out. Two technical engineers from the Flood Operations center joined the meeting for my brief PowerPoint presentation (with Chinese subtitles) on water management decision support systems. The meeting adjourned for a banquet in the adjacent MWR dining room. The Director General other MWR senior staff joined us. The food was prepared proudly by MWR cooks. Beijing, January 23, 2002 1. How does our project affect Decision Makers, Participants (the people we are training), and Beneficiaries? Late in the afternoon after a brief stop at the established outdoor clothing market ( the "silk market") near the US Embassy we left Beijing by airplane to Chengdu Chengdu, January 24, 2002 Yongying River enters the main stem Qingyi (Tianquan) River below Yiam. Mungjing River enters the main stem Tianquan River at Yiam. Wanba River Basin project in Shimian County. Hongsan Reservoir, 0.053x10^9 cm is on a tributary to the Wanba River. The total capacity will be 550 Mw. All of the engineering and construction is done in-house. Fish ladders will be provided but this seems to be the only environmental consideration. Half of the staff are women, many are in important positions. At 13:15 we left by train for Sui Ning and arrived at 16:00 where we were met by the General Manager (perhaps Chief Engineer) for the Sui Ning Minsing (peoples' prosperity) Electric Company. We immediately departed by small bus for the Fujiang (Fu River) where we toured the Sanshi (famous Star) power station. This is new, commissioned officially the day before and the decorations are still looking good. There are three 17.6 Mw units under 11.6 meters of head. The Scada system developed by Nanjing Automation Institute provides centralized control capability from the upstairs control room in an adjacent building. Even so there are four or five operators on each of the three shifts (five or six were said to be women). After touring te facility we drove back to SuiNing for a banquet. The ex-Mayor and current vice President of the power company joined us along with a number of officials, most of whom we did not meet. Then we drove to the SuiNing Guest House Hotel (two stars) where our luxury suite included carved furniture, objets d'art, and a steam bath in the shower enclosure.
January 25, 2002 Drove to Chengdu (4 hour drive) to catch the 18:50 flight to Kunming where the Director of the Yunnan Ministry of Water Resources met us at 20:30 hrs. We arrived at our hotel by 22:00, in time for a bedtime snack of chedder cheese, canned kippers, and the small bottle of French wine liberated from the Vancouver to Beijing flight. Kunming, January 26, 2002 At present Yunnan province is an industrial center for metals and plastics with a severe shortage of electric power. Residential electricity is available for only a few hours each day as the power supply is shunted to industry. The room heat is turned off in some hotels during the day. Marco Polo in Kunming described Lake Dian Qui here as teeming with fish, but urbanization has put an end to this. In 1996 a causeway to form two lakes bisected the lake. The smaller so-called "inner lake" recieves urban runoff and is heavily populated with algae, a stinking mess that has driven tourists away. The "outer lake" is in better health and seems to support fish. It receives inflows from some twenty tributary streams flowing down from the 500-meter high mountains in the watershed. The World Bank has been working on tis for some time - we were told that there is some information on the web at http://www.worldbank.org. The urban water supply amounts to 300 cubic meters per person, which has been determined to be not enough. There is a real water resources management problem here, with multiple objectives (water supply, hydro power, irrigation, environment, flood management), inadequate data, and probably some training required. The watershed area is 2300 sq km. From a million cubic meters of annual runoff the lake regulation produces 578 million cubic meters of water supply in an average year. The lake surface is 306 sq km at elevation 1887 meters and evaporation amounts to 450 million cubic meters per year. The lake has an affect on the local climate. The hills surrounding on the southwest and east reach elevations of more than 2600 meters. The flood outlet of the lake is capable of releasing 9 million cubic meters per day - the recorded maximum flood inflow was 60 million cubic meters in one day, raising the lake 20 centimeters in 24 hours. The ten downstream hydro plants cover an elevation range down to 700 meters, providing a total potential head of 1200 meters. At present the developed total capacity is about 25 Mw in plants dating back to 1912, and the developed head is probably 200 or 300 meters. The lake seems to be the responsibility of a joint committee headed up by the City of Kunming, but the County electricity company (Dian) is involved in Lake Dian Qui reservoir operations for flood control and generation at at ten existing downstream power plants, with opportunities for more development. The lake provides water for industry, municipal uses, and for irrigation. The long concrete dyke running along the east side in the city establishes the maximum lake level. The minimum level seems to have been negotiated - the total storage volume is 1.5 million cubic meters, of which about one third is storage that can be used for the various purposes. Once each day during flood season streamflow readings are reported to the power company (which is responsible for actual operations). During the dry season the reporting interval is ten days. There is an obvious conflict between reserving storage for flood management and keeping it full for other purposes. An outlet to the sea is called Haikou, and that is the name of the town where the water resources headquarters are located below the lake. The officials we met are eager to obtain a flood forecasting system and my impression is that they also could use a probabilistic reservoir operations optimization model. Siemens built the first power station below the lake, Xialongben, in 1912. It is still operating with old but updated equipment. There are now four discrete power plants at this site. The dates of construction are 1912, 1923, 1935, and 1958. This location has been a crossroads and center of habitation for a long time. A control structure on the lake outlet was constructed in 1836. Now there are several new office buildings and a small water management museum with commentary on the many photographs of the weirs and dams.
We had lunch at the "Two Cannons" restaurant located about 30 km from Kunming at Anning, which means "safe and quiet place". The place is famous for its hot springs and there are resorts along the river. After lunch we drove along the Pudu River. Nearest to Anning the river is retained within stone walls. Downstream the flood plain opens out to a wide valley with intensive agriculture. Further downstream the river is contained with steep rock walls and the riverbed is strewn with huge boulders - testimonials to some powerful floods. Data communications would not be difficult for although there is no cell phone service in the valley there are telephone lines on poles all along the road as it winds along beside the river. The first plant in the cascade below Xialongban is called Caijia. A weir upstream from the plant diverts the river into a concrete power canal running beside the road. There appears to be another canal on the opposite bank but we could not determine its destination - perhaps irrigation for the terraced hillside. The bypass reach was completely dewatered except for a small amount of leakage that gathered in pools among the rocks. The plant has three 500 Kw units and employs 13 operators. When we were there the units were running at 400 Kw, 260 Kw, and 200 Kw. For maximum plant efficiency they probably should have shared the limited amount of water by loading the units equally.
Further downstream is Shilouti with 46 meters of head in a long penstock running underneath the road. Again, the bypass reach was completely dewatered except for a small amount of leakage and local groundwater inflow. There are three units at this plant. While we were there they were running at 0, 2800, and 2600 Kw. The turbines are Russian, the generators Norwegian, and the Honeywell control systems are from the USA. There is no provision for fish passage at either of these plants but at Shilouti behind the plant there are privately owned large fish rearing tanks.
The power stations are located in an arid rocky valley below the intensive fertile agricultural areas. Two or three small streams enter the river at the city of Fumin. It is not clear how a flow forecasting system could be useful in this valley above Fumin because the valley is narrow without significant local inflows. Forecasts at Fumin and probably further downstream could be useful for determining how to operate the lake at Kunmimg to minimize flooding at Fumin.
Kunming, January 27, 2002 Kunming, January 28, 2002 In the evening we took a flight to Guiyang, which is located north and east of Kunming, arriving about 9:30 PM. We were met by officials of the Provincial Water Resources Bureau and taken to the Provincial electricity company's four star hotel located at the center of the city. The drive into town passed by brightly illuminated buildings, colored lighting displays in the parks, and a huge stainless steel abstract winged sculpture floating in a green-lit cloud of foaming dry ice. Guiyang, January 29, 2002 The Hoanggoushu Falls were said to be the highest in China at 72 meters and 81 meters wide. During our visit in the dry (and cold) season there was little water. They were said to be spectacular during the rainy season. We did a lot of walking and climbed a lot of stairs in making our way around the site. Atmosphere is added along the walkways by stone guardrails carved into uniusual shapes. At various vantage points there are people who offer to take your photograph in traditional local minority (Miao people) costumes they supply, with the Falls as a backdrop. The river below the falls is crossed by a swaying pedestrian suspension bridge complete with hundreds of small locks attached to the chains that support the fragile bridge deck. The locks are a tradition for newly weds who attach the locks and then come back years later to see if they can find and open their lock.
The underground Dragon Cave and its associated small hydro plant are located a short drive away from the Falls. The boat ride through the high cathedral-like gothic chambers of the cave was very interesting. The boat trip is slightly less than one kilometer to where it opens to the outside world and admits a waterfall that brings the river into the cave. There are several more kilometers of caves that eventually will be opened to the public boat tour.
The cave was discovered in 1986 when the dam and reservoir for the power station was constructed. The reservoir is formed inside the mountain behind the concrete arch that spans a large opening that was made by the river in the side of the mountain. The limestone rock outcrops here show signs of solution channels so it's likely that the geotechnical exploration for the dam opened up access to the cave when these channels were tracked down and sealed to contain the small head pond. The overflow dam provides a spillway that drops water inside an open cavity surrounding the old river bed approximately 20 meters below. This reach of the river is bypassed by the penstock, which carries water to the power station a few dozen meters downstream. The bypass reach is a water park (dry at the time) filled with weird natural and man made formations, including an amazing bridge supported by stone dragons.The Rongong power station here has 2 units - one with a capacity of 400 Kw and one with 320 Kw. The plant is in desperate shape. It could benefit from a complete renovation, scrapping everything except the turbines and generators. The lone woman operator warmed herself in front of two glowing electric hotplates on the floor. A local minority dance troupe of Bu Yi people performed on a outdoor stage overlooking the lake (the power station head pond) with local children doing impromptu dances in the sparse bushes behind. A "wedding" ceremony involved myself and a couple of the other males in our group, and the pretty young women dancers. It was quite realistic, including the fee for the priest, and the "brides" who had their hands out for grocery money.
January 30, 2002 Our guideswork in the Guizhou Center for Rural Electric Power. Their experience includes work on more than 70 small hydro plants and many transformer stations across the Province. They have worked previously with Yves Grandmaite installing electrical control equipment from Powerbase Systems. The three made a comfortable group of traveling companions, and we were together all of the waking hours for the next few days. We passed through Maijiang and left the pavement to follow a dirt track through rich agricultural valleys to finally reach the Qingshui River. A wide dam spans the river here to produce about 15 meters of head and a reservoir that supports a local "sport" fishery. Coarse plastic netting is suspended on floats just below the reservoir surface near the dam. We were told that it's purpose is to discourage local fisherman during the winter season. The right bank powerhouse (Longxi) was completed in 1970. The electrical equipment is decidedly obsolete and in need of replacement. For example, a huge control panel has dozens of breakers for only two units (600 Kw and 700 Kw). The 600 Kw unit was shut down because there was not enough water to run both. The units have hydraulic governor and control systems with huge oil storage tanks on the generator floor (An oil slick is visible in the tailrace area). This ungainly hydraulic system is required to operate the Heath-Robinson (Rube Goldberg) style rack and pinion arrangement for operating the wicket gates located far below on the turbine floor. This old equipment could be replaced by a much simpler system with hydraulic cylinders located on the turbine floor. The plant intake suffers from poor hydraulic design. A transitory vortex with a core diameter of 10 to 15 centimeters at the intake may be the ccause of the power generation fluctuations visible on the meter, and probably reduces the output. When both units are running the vortex is probably stronger. A sharp corner at the junction of the approach channel and the building causes the vortex.
On the outside wall of the powerhouse the high water mark of a recent flood indicates that the generators have been under water at least once since the plant was commissioned. This suggests that the spillway capacity should be checked with possible provision for adding another control gate. The existing motorized control gate at the right end of the dam currently is not operable. But the best plan for this plant would be to decommission it and move the water through the new plant Xi Longxi (New Longxi) now under construction at the left end of the dam. A design revision for Xi Longxi seems feasible because the construction seems to have barely started. This concept would require a power replacement agreement between the owner of the old powerhouse (the County) and the owner of the new powerhouse (the Province). The new installation will make more efficient use of the water at less cost than a retrofit at Longxi - both sides would benefit by cooperation. Perhaps now with a potential for CIDA funding there would be interest in looking at this alternative to refurbishment.
Director of the Maijiang County Water Bureau took us to lunch in the best restaurant in town. After lunch we visited another small hydro plant located down another narrow dirt road along the edge of another intensively farmed valley. This plant (Niyang Xien) is 31 years old. The control room sits on top of a reinforced concrete cylinder that provides a flood proof bunker for the two 500 Kw horizontal axis units located below. The head here is 37 meters. The 180 Kw output of the only unit that is operational suggested that it might be economical to operate for a shorter duration. This would store water and allow operation at higher more efficient output, with less cavitation. The idea was deemed impractical because there is no head pond but we wondered how much water could be stored in between the riverbanks at the existing low discharge.
From Niyang Xien we worked our way back out along the dirt road to the highway. We headed back towards Guiyang and turned off the highway and into the Wu Dong "suburban" district to visit the two adjacent Da Tong He (Big Pond River) power stations. The river here carries effluent from the City and is heavily polluted, so the hydro plants are running basically on sewage.
The plant on the left bank is somewhat newer than the other and appears to be in better condition. The three existing thirty-eight year old 125 Kw horizontal axis units in the "very old" powerhouse on the right bank will be replaced with one 400 Kw unit located in a new intake to be constructed. The head here is 8 meters. Across the river on the left bank, the "newer" plant has two 200 Kw units that will be replaced or upgraded. This will happen after the right bank improvements are completed. The control systems here are in bad condition - during our short visit we witnessed 25 percent oscillations in power output from one of the units. The cause is probably a problem with the excitation field. Eventually both of these plants will be automated. Arriving back in Guiyang we went immediately to a dinner meeting the Director of the Provincial Water Bureau. At this meeting the decision was made to buy Powerbase equipment for Xi Longdi. After the equipment purchase the local engineers from the Guizhou Center for Rural Electric Power would come to Canada for three weeks of training. Guilin, January 31, 2002 February 1, 2001
We all boarded the bus and drove out to Ban Shan Wei power station, which is owned by Pin Luo County. The station manager here he runs a first class operation. It is an older plant (1980) but is well maintained and he seems to be very considerate for his staff and proud of their high morale. There are 190 people working here on the plant, the power canal and in other activities. Seventy employees are female, and 98 deal with manufacturing uses for the electricity. The organization has been restructured and now has a Board of Directors with the station manager as Chairman. He plans to issue shares to the employees. This is a run of river operation with a power canal off the Li River. They operate 5000 hours or more per year. There are 9 Mw total here operating under 10.5 meters of head. There are two 1.25 Mw units and two at 3.2 Mw of different design. One of the 1.6 Mw units has been upgraded and the other will soon be reconditioned. There are two Kaplans and two fixed propeller units. The station manager expressed interest in a station optimization system to load the units, and to track the performance of the operators. He was receptive to our offer to e-mail a sample screen (in Chinese) so they would have a better idea of what they would be buying. During high water periods they sell surplus power to three industries in the area, which provides net revenue. About four Km downstream there is a plant owned by others with six 100 Kw units, and another plant a further 23 Km downstream with six 200 Kw units. The station manager said his goals now are, 1) to reduce manpower, 2) to increase efficiency, and 3) to write job descriptions and establish salaries for the workers. He expects this will take about two months. After that he will get on with the automation and start looking for other plants to buy or to build. There is a high level of maintenance and polish at this plant. This looks like a good opportunity for a station optimization program with operator performance tracking. The system would operate initially from keyboard input and could be tied in later when the automation becomes operational. February 2, 2002 We stopped for lunch with the mayor in town and he told us that the local caves are the largest in Asia, and that the county exports 40,000 tons of Li Tarot root to North America and elsewhere. There are 400,000 people in the county. Next we drove out to the Da Jiang (big river) station through a village market and a lovely broad agricultural valley with market vegetables and many neat rows of short orange trees. Here there four big gray horizontal axis Francis 500 Kw units, a reservoir, and an irrigation operation. Nothing was running while we were there because all of the water was being stored for irrigation in the spring. This old station (1971) is in pretty desperate shape but it will be receiving money from Beijing under the regional development incentive strategy for the Southwest. The control room should be stripped out and replaced with new equipment for automation. The station operates for only 7 months of the year but the 132 employees are paid for 12 months of labor. There are 15 supervisors, 3 retirees, 42 operators and 37 dam safety and irrigation maintenance personnel. In all there are 23 women and 5-percent of the staff are minorities (the minority population in this area is 10-percent). Although it has been operating for 30 years there has been no money accumulated for routine maintenance or upgrading. They weld metal on the runners every year to replace what is lost to cavitation. Now that the federal money is coming in they have built a new office building and a basketball court. Behind the plant there are two large rectangular concrete lined fish rearing ponds (currently empty). Guilin to Chenzhou, February 4, 2002 Man Tian Xian is a small Federal project with a local drainage area of 435 sq. Km. It is located above the much larger Federal project, Dong Jiang (4x 120.5 Mw, with 100 cms per unit) the drainage area is 5200 sq. km. Dong Jiang operates as a peaking project and has a major impact on the river flows. The Chenzhou folks have no information about the operation of Dong Jiang so they assume that each month will be a copy of the previous month. If they can monitor the reservoir level and have some idea of the local inflows they may be able to develop some ideas for how the project might be operated based on the time of year and the expected runoff situation. This would seem to be a reasonable basis for discussion with the Federal people. Below Dong Jiang there are two local inflow streams. Le Xi has an average flow of roughly 3 cms and further downstream Chun Jiang contributes about 10 cms. The local drainage area is assumed to be 4273 sq. Km but this must be checked, along with all of the numbers that were provided. Below Dong Jiang, 13.4 Km is the Shi Mian Tian project with three 9.3 Mw bulb units under 7.94 meters of head. 42.26 Km below Shi Mian Tian is the Yong Xing dam with two 12.5 Mw bulb units operating under 6.76 meters of head. This is the project I visited last year. The local drainage area is 3861 sq Km and Chun Jiang (8 cms) is the only major tributary. From Yong Xing to the Yao Tian dam (four 12.5 Mw Kaplan units under 11 meters of head) the distance is 60.32 Km and the local drainage area is 2326 sq. Km. There are four tributaries. On the east side (left bank) the first is Xi He (15 cms) and below that on the same side is Xiao Shui (2 cms). On the west side (right bank) the first is Yang Sha Jian (3 cms) and below that on the same side is Xia Jiang (6 cms). These flow estimates may not be even approximately correct - their source could not be confirmed while we were in Chenzhou. According to the local staff they have all of the data that is needed to establish the Decision Support System, including stage-storage (surface areas for the one meter operating range of the dam's head ponds), efficiency curves, rough zones, and tailwater curves. There may be some backwater effect from downstream dams under some conditions of pond levels and discharge but this could not be confirmed. Chenzhou to Shanghai, February 5, 2002 Shanghai, February 6, 2002 Shanghai, February 7, 2002 River level gauges between the dams on three tributaries will be located part way upstream from the main stem Dong Jiang river. The selected tributaries are Chun Jiang below the Dong Jiang project on the east side; Zhu Jiang below Shi Mian Tian on the east side; and Xi He on the east side between the Yong Xing and Yao Tian projects. The intention is to monitor the largest streams between each dam and these are believed to be the largest. All of this will need to be confirmed by site visits by someone who speaks Chinese and really understands what is needed for the hydrologic forecast and the DSS system. We briefly discussed instrumentation types with emphasis on simple equipment that requires minimal maintenance. This monitoring system must operate reliably in Chinese conditions with minimal maintenance. Measurement accuracy should be consistent (not unduly expensive) with the uncertainties in the forecasting capabilities of the hydrologic model. Specifically we discussed avoiding tipping bucket rain gauges if suitable accumulating gauges can be supplied. Data loggers may not be required if the data can be transmitted directly to a central computer located at one of the dams and tied in to the SCADA system. There will need to be some close coordination with the SCADA supplier (Wuhan University?). The data from all of the sensors could be dropped clean at the SCADA system in one of the plants, retransmitted, and picked up again at the control center in Chezhou where it will interface with the forecasting and DSS computer. It was assumed that data from the dam locations Shi Mian Tan, Yong Xing, and Yao Tia, can be carried on the Chenzhou SCADA system. At all other locations a cell phone based communication system or direct line of sight transmission will be necessary. This concept needs to be confirmed. It was fortunate that we were able to connect in Shanghai and have an opportunity to reconsider concepts for the monitoring system. He was working with cost data from systems he had installed elsewhere for other purposes. For this project the equipment might be less sophisticated and less costly, but this will need to be determined by further discussions with Omnitronics and other potential vendors. Shanghai, February 7, 2002 |
