Administrative location of the Koksay HPP cascade: Zhualin district of Zhambyl region, on the existing pressure pipeline laid on the left bank of the cross-border Koksay river; 84 km to the west of the city of Taraz and 25 km to the east of the district center B. Momyshuly.
About the Koksay River.
According to the water regime, the Koksay River belongs to the group of rivers of glacier-snow feeding. The rise in water consumption as a result of the beginning of snowmelt in the mountains begins in mid-April, early – in the beginning of April, late – in the end of April. The highest annual water expenditures occur in the period from the 3rd decade of June to the 2nd decade of July, often in high water there are two significant peaks of similar values: the first in June, the second in July. The number of peaks in the flood can reach 5 ÷ 7, the flood ends at the end of September ÷ beginning of October. The average duration of flood is 160 days. During this time, up to 75% of the annual flow passes. In October, the river enters the pool stage, which continues until April of the next year.
Water consumption gradually decreases, the lowest are usually observed at the end of March. In October-November, short-term rain floods are possible as a result of liquid precipitation.
Average annual water consumption on the river Koksay for the period 1980 ÷ 93 years (12 years) is equal to 1.19 m3/s. In connection with the short years of observations, the average water consumption obtained was 1.19 m2/s and was adjusted according to the schedule of the relationship between the average water consumption and the river Kurkureusu – Chon-Kurchan, according to which the series of observations is 73 years (1931, 1933, 1935 ÷ 2005) and obtained equal to 1.27 m3/s. This expense was adopted as the norm for Koksay River.
The variation and asymmetry indices Cv and Cs are taken by analogy (Kurkureusu) equal to 0.16 and 0.32, respectively. With the help of the axis of ordinates of the curves of the three-parameter gamma distribution, the average annual water consumption in the river is obtained Koksay: Q50% = 1.25 m3 / s; Q75% = 1.13 m3/s; Q90% = 1.02 m3/s. Annual distribution of runoff on the river Koksay is average for 12 years based on actual observations (1980 ÷ 1993)
Annual maximum water consumption on the river Koksay is usually observed in June-July, when high-altitude glaciers and snowfields melt most intensively. The average date of passing the annual maximum, according to the observations on the river analogue Aksy. The average maximum water consumption on the river Koksay – wintering for the period 1980-94 is equal to 4.12 m3/s. The highest maximum, equal to 5.60 m2/s, was observed in 1985; the lowest maximum is 1.48 m3 / s – in the low-water 1982.
In connection with the short years of observation of the passage of the maximum flow of water on the river Koksay, calculated maximums for the latter were calculated using the river analogue Aksay-HPP, the basin of which is located in one zone to the west of the Koksay basin.
On the Koksay River there is a low water period during the open river bed and a winter low water period. The low flow period of the open channel period goes directly into the winter one. During the period of low water, river runoff is fed mainly by groundwater. This period is characterized by low water consumption. The average monthly flow rate corresponding to the most low-water thirty-day period of the open channel and winter low-water period was taken as the main characteristic of the minimum flow.
Observation of the regime of solid runoff on the river Koksay is not conducted. The only river in this area for which there are materials for suspended sediment discharge is Kurkureusu, for which there are materials for 1956 ÷ 80. However, its catchment is 454 km2, 8 times more than the catchment of the river Koksay. There are differences in the water regime, the highest water content of the river. Kurkureusu in July and August, and on the river Koksay – June-July, which could not but affect the distribution of sediment flow in the year. It should be noted that both rivers are characterized by low sediment loadings, as are the rivers of the neighboring basin of the Talas river, located in similar physiographic conditions. The average annual turbidity of water for 15 years on the river Kurkureusu is equal to 130 g/m3. The basins of the Koksai and Kurkureusu rivers are in the zone of turbidity of about 100 g/m3
The granulometric composition of suspended sediment is approximately characterized by data on the gauge station Kurkureusu – Chon-Kurchan.
Level mode of the Koksay river, due to the lack of observation materials for the water horizons, was compiled from information about the river Kurkureusu located in this area and has an approximate character. In general, the level mode is similar to the mode of water flow. The exception is the winter months, when due to the ice formations in the river bed, causing congestion and even freezing of the bed, there are sharp rises in the water level, often exceeding the summer in the flood period. In winter, the channel is covered with ice, which is heterogeneous and consists of frozen sludge, snow, and snowballs. Rising water levels in winter can reach 1.5-2.0 m. Ice formations on the river. Koksay caused by sustained cold spells in late October-November. First, border ices, fat, then sludge, bottom ice and ice appear in the river. The average date of the beginning of ice phenomena, according to the dependence of the latter on the height of the alignment, falls on the middle of the first decade of November, the early – middle of the III decade of October, the late end of the III decade of November. The end of ice phenomena: the average date is the beginning of the 3rd decade of March, the early one is the beginning of the first decade of March, and the late one is the middle of the 1st decade of April. The average number of days with ice phenomena per year is 140, the smallest is 110.
Local conditions: infrastructure and socio-economic environment.
The nearest regional center (20-35 kilometers) is Bauyrzhan Momyshuly (in Kazakh Бауыржан Момышұлы атындағы, until 1992 – Burnjye) – a village in Kazakhstan, the administrative center of Zhualinsky district of Zhambyl oblast, also the administrative center and the only settlement of the rural district B. Momyshuly. From the construction site of the hydroelectric power station to the village there are various types of roads from asphalt to bulk.
The village is located 60 km south-west of Taraz, on the Zhualinsky Plateau between the spurs of the Tian Shan, Karatau and Kirgiz ridges, at an altitude of 1000 m above sea level. Through the village flows the river Teris (a tributary of the river Asa).
Railway station Burnoye on the line Shymkent – Taraz.
There are printing house, a mill, workshops for the repair of agricultural machinery, oil and bread factories, a wool spinning and textile factory, a grain receiving station. Almaty-Tashkent highway passes through the village.
The village got its present name in honor of the Panfilov’s hero Bauyrzhan Momyshuly. In 1995, a memorial monument and a museum of the hero were opened.
As of January 1, 2016, the population of the village was 11,241 people (5,695 men and 5,546 women).
All HPP equipment would be purchased from the world-famous Austrian company Global Hydro Energy GmbH, a leader in the field of small hydropower technologies with a long history of successful projects around the world. The company is a first-class manufacturer of Kaplan, Pelton and Francis turbines with capacity from 100 kW to 25 MW.
There are several types of technologies for generating electricity using various types of turbines:
Characteristics of the turbine:
for difference (pressure) 1 – 18 m;
for maximum flow of water at river/channel hydroelectric power plants;
straight-through horizontal and vertical design with a pond;
dimensions of construction 500 – 3200 mm, with 4 or 5 blades;
Kaplan turbine impeller blades are made of bronze or stainless steel;
excellent efficiency also in the partial load range due to the use of two-stage regulation, the Kaplan turbine is quite competitive at the global level.
Characteristics of the turbine:
pressure – 50 – 300 m;
power 100 – 3000 KW;
for difference (pressure) from 50 to 150 m;
typical series 3,8/4,8 – F 90;
high efficiency with constant water flow;
the impeller is placed directly on the generator shaft.
Due to the characteristics of the angle of inclination, speed and volume of water on the Koksai River, an active Pelton hydraulic turbine is used for the project..
Description of the selected technology.
The bucket turbine (foreign name – Pelton Turbines, Pelton’s turbine) differs significantly from the design of jet turbines, since water is fed through special nozzles in the form of a fast-flowing jet onto turbine blades.
Pelton turbine blades have a special shape of a biconcave bucket – the blade in the middle divides the water jet into two streams, which significantly improves the efficiency of the bucket and slows the wear of the blades. Since the jet is directed tangentially, hitting the blade, the water easily turns the turbine wheel. After turning the wheel, the jet hits the next paddle. Work is performed at atmospheric pressure due to the conversion of the kinetic energy of a jet of water.
As a rule, a bucket turbine consists of 40 blades. With a high head, the flow rate is quite low – from 5 l/s at small hydropower plants and up to 1 cubic meter/s at large ones. Since the water consumption is low and the supply pipes are made of small diameter, the jet-bucket hydroelectric power plants have relatively compact dimensions. High pressure is achieved in mountainous or hilly terrain through the use of a pressure pipe.
The operation of the bucket turbine is controlled by a nozzle. Moving the nozzle closer or further to the turbine blades or changing its flow area, you can adjust the flow rate of water, respectively, change the speed of rotation of the turbine and the output power of the hydroelectric power station.
Since the turbine blades are constantly supplied with water under high pressure, the buckets are worn out over time. This is especially noticeable if there is a high concentration of abrasive particles in water. To resist erosion, buckets are usually made from tungsten carbide or high alloyed alloys. Recently, the use of more accessible blades made of plastic or composite materials has been practiced in small hydropower engineering. Despite the fact that they have a lower resource, the design of the turbine makes it easy to change quickly worn out, but at the same time cheaper buckets for new ones during the shutdown of the hydroelectric station for maintenance in the minimum amount of time.
To avoid shock loads and axial distortions in the Pelton turbine, not one but several nozzles are usually installed, uniformly placed on the bucket turbine body. The classic design – two nozzles on a horizontally mounted turbine, six on the vertical. Practical studies have shown that using more than six nozzles causes excessive resistance and becomes critical when the turbine starts.
The main advantage of the Pelton Bucket Turbine is its high efficiency – up to 95%. Even when used in small hydropower, you can easily achieve an efficiency of 90%. When using multiple nozzles, turbine efficiency remains high even at incomplete flow rates. Another advantage of such a hydropower plant is the possibility of a simplified design of hydroelectric power plants, when the turbine and the generator are installed on the same shaft or are joined directly to each other by a flexible joint without a transmission or drive system. High speed jet up to 600 km/h allow you to spin the turbine up to 3000 revolutions per minute. In addition to reducing the cost of equipment and maintenance of hydroelectric power plants, by eliminating intermediate drives, it is possible to save about 2% -7% of irreplaceable energy losses.
The project envisages the construction of a cascade of small hydropower plants with an installed capacity of 17.84 MW/h.
As part of the project nowadays we completed:
- Specifications for the use of irrigation water from the Koksay River for the production of electricity;
- Feasibility proposal;
- Capacity distribution scheme (receipt, coordination with the local executive body and “KEGOC” JSC);
- Architectural planning task for the design of a cascade of hydroelectric power plants;
- Technical conditions for connecting the hydroelectric power station to the lines of 35 kW;
- An investment contract has been signed for the granting of preferences by the Investments Committee of the Ministry of Investment and Development of the Republic of Kazakhstan;
- The equipment for the first and second phases of the construction of hydroelectric power plants is made;
- Construction and installation works are going on.