陳建平,崔偉,吳曉東,張雪
(松遼水利委員會水文局嫩江水文水資源中心,黑龍江齊齊哈爾161000)
嫩右支流水情自動測報系統(tǒng)的改進及應用
陳建平,崔偉,吳曉東,張雪
(松遼水利委員會水文局嫩江水文水資源中心,黑龍江齊齊哈爾161000)
文中介紹了嫩江右側(cè)主要支流水情自動測報系統(tǒng)的概況,重點論述了超短波通信實時傳送水位數(shù)據(jù)的原理及方法,詳細分析了超短波通信在實際應用中存在的問題,最后提出了相應的改進方案。
嫩江支流;水情測報;超短波通信;改進
水文信息的采集與傳輸對防汛抗旱、水資源管理、生態(tài)與環(huán)境保護等水情工作非常重要。目前,水文數(shù)據(jù)傳輸?shù)姆绞街饕ㄓ芯€方式和無線方式。有線通信方式常受到地形地貌、通信距離、布線條件和布線成本等因素限制,而無線通信方式相對比較靈活。由于嫩江流域有些站處在偏遠山區(qū),所以采用無線通信。
超短波通信方式目前在國內(nèi)外水利信息通信系統(tǒng)中被普遍使用,尤其在本地區(qū)或局部地區(qū)非常有效,另外超短波系統(tǒng)的設(shè)備全部由擁有者管理,不受其他單位約束,通信速率可自己決定,所以超短波在水文信息采集上的地位仍然很重要。例如,現(xiàn)在市場上日本精工的數(shù)傳電臺ND250A,數(shù)傳頻率范圍223~235 MHz,符合水利行業(yè)規(guī)定的頻段和帶寬,滿足水情信息數(shù)據(jù)實時傳輸要求。
嫩江右側(cè)主要支流水情自動測報系統(tǒng)主要由1個中心站、4個分中心站、90個遙測站(78個雨量站、12個水文站)以及2個數(shù)據(jù)上傳站構(gòu)成。該系統(tǒng)按星型網(wǎng)絡(luò)結(jié)構(gòu)設(shè)計,采用GSM/北斗混合通信組網(wǎng)方式,中心站接收系統(tǒng)所有測站數(shù)據(jù),分中心站接收各自所在地區(qū)測站數(shù)據(jù),遙測站采用一點多發(fā)或一發(fā)多收的運行機制,即遙測站同時向中心站和所在地區(qū)分中心站發(fā)送數(shù)據(jù),數(shù)據(jù)上傳站采用GPRS信道發(fā)送到中心站。
在該系統(tǒng)中,個別水文站因水位觀測井距水文站房距離較遠,一般在幾公里以內(nèi),不具備有線傳送水位數(shù)據(jù)條件,所以遙測設(shè)備采取分別安裝在站房(主站)和測井(從站)兩處,二者之間采用超短波通信方式進行數(shù)據(jù)傳輸。在水利系統(tǒng)水文監(jiān)測中,超短波通信的頻率一般在230 MHz,這一頻段的通信質(zhì)量好,傳輸信號也比較穩(wěn)定,而且有一定的繞射能力,可以避過大部分樹木或房屋的阻擋,從而實現(xiàn)主從站間數(shù)據(jù)通信。
2.1 通信架構(gòu)
采用日精ND250A數(shù)傳電臺構(gòu)建超短波通信系統(tǒng),由主站和從站兩部分組成。主站包括RTU、GSM模塊、北斗衛(wèi)星電臺、ND250A數(shù)傳電臺、數(shù)傳電臺適配器、直流電源等設(shè)備,從站包括RTU、GPS模塊、ND250A數(shù)傳電臺、上電控制器、直流電源等設(shè)備。
由于數(shù)傳電臺功耗較大,為節(jié)省電能平時不上電,電臺不工作,當從站有數(shù)據(jù)流時(一般設(shè)定水位變化為0.01 m)才上電工作,主站電臺采用常供電。在無線傳輸過程中采用握手通信方式實現(xiàn)數(shù)據(jù)傳送,即從站發(fā)送完畢后等待主站的回執(zhí)信號,若收到回執(zhí)信號,則從站對電臺斷電通信結(jié)束;否則進行第二次數(shù)據(jù)發(fā)送,以此類推。在從站未收到回執(zhí)信號的情況下,每個信號最多發(fā)送3次。主站電臺在收到并解碼數(shù)據(jù)后,將數(shù)據(jù)送給適配器,適配器將數(shù)據(jù)保存下來,當主站開始采集水位數(shù)據(jù)時發(fā)送給RTU,水位數(shù)值達到設(shè)定閾值后(一般設(shè)定水位變化為0.03 m),通過遠程通信信道(GSM或者北斗衛(wèi)星)發(fā)送至分中心站和中心站。
2.2 性能分析
采用超短波通信的水文站在實際運行過程中主要出現(xiàn)采集的水位數(shù)據(jù)不變,由于整個超短波通信系統(tǒng)設(shè)備組成較多,出現(xiàn)此類故障的原因也比較復雜,需要對采集的水位數(shù)據(jù)、設(shè)備的供電狀態(tài)、通信的交互連接等情況作出研判,從而定位故障點,查明故障原因。但從長期運行維護監(jiān)測數(shù)據(jù)來看,發(fā)生故障的原因主要是主從站兩邊的時鐘不同步,主站采用北斗衛(wèi)星校時,從站采用GPS校時,由于衛(wèi)星資源時常被占用,造成每次校時耗時長,校時困難,這給系統(tǒng)運行維護工作帶來很大不便。所以如何保證主從站兩邊需要傳送數(shù)據(jù)時時間窗口能夠達到一致,變得尤為重要。
2.3 改進方案
為使水位數(shù)據(jù)報送能夠更加及時準確,通過近幾年對整個超短波通信系統(tǒng)設(shè)備原理學習和實際運行維護過程的經(jīng)驗總結(jié),現(xiàn)提出以下幾項改進方案:
1)從站數(shù)傳電臺供電可以由有數(shù)據(jù)流時上電改為長供電,必要時可以改為較大容量的蓄電池,以提供長時間供電,保證電臺時刻準備傳送數(shù)據(jù),以此避免由于主從站時間窗口不同步,與主站建立通信連接時,從站電臺仍處于斷電狀態(tài),造成數(shù)據(jù)通信失敗。
2)因主從站數(shù)據(jù)采集時間間隔為每6 min一次,所以可以增大主站電臺收信時間窗口,使從站發(fā)信時間窗口在主站時間窗口之內(nèi),預留出因通信不暢從站重復發(fā)送數(shù)據(jù)時間,使主站在時間窗口內(nèi)接收從站發(fā)來的數(shù)據(jù)。
3)可以將水文站從站設(shè)備RTU更換為采用2.4G無線短傳技術(shù)設(shè)備,在安裝調(diào)試時只需主站進行時鐘校時,從站會在每隔6 min自主與主站建立通信連接,此時進行時鐘校時,保證主從站時鐘同步,使水位數(shù)據(jù)正常傳送主站。
在實際應用中,我們已經(jīng)對個別水文站進行了改進,并取得了良好的效果。
超短波通信因其通信質(zhì)量好、傳輸信號比較穩(wěn)定、適宜短距離數(shù)據(jù)傳輸?shù)葍?yōu)點,在嫩江右側(cè)主要支流水情自動測報系統(tǒng)水位數(shù)據(jù)傳送中發(fā)揮重要的作用。通過對超短波通信相關(guān)設(shè)備的改進,不僅減少了時鐘校時帶來的工作量,也使水位數(shù)據(jù)報送能夠更加及時準確,極大提高了嫩江流域洪水預報精度,為嫩江及松花江流域的防汛工作提供重要水文數(shù)據(jù)支撐。
[Abstract]The K-means cluster analysis is used to identify the category of the water quality monitoring section in buffer zone of provincial boundaries of Songhuajiang basin.The analysis results show that the 51 water quality monitoring sections are divided into 7 categories and the optimization analysis is made for the monitoring sections of each category.Based on the natural attributes including the nature geographical location and the optimization principle of monitor index,the former 51 monitor sections are reduced to 39 in buffer zone of provincial boundaries of Songhuajiang,the 12 sections are streamlined,which could reduce the monitoring workload and save the monitoring costs.
[Key words]Songhuajiang basin;buffer zone of provincial boundaries;monitoring section;classification analysis
Design of sand protection and sand fixation measures for water conveyance open channel crossing desert
WANG Feng
The key point of biological protection sand fixation is finding out the some situations as the basis of the protective design, including the terrain,the geomorphy vegetation status and the scope of protection zone in the project area,the wind gap,the main wind direction in different area and the cause and harm of the quicksand.The desert plants are exposed to the surface of the mobile sand in the initial stage,the wind erosion is serious and fixed survival is hard.The unique characteristic of the desert plant is used to forming the horizontal network foot system with tens of meters in the short term,which could weaken the movement of quicksand and reach the purpose of stabilizing sand soil surface.
water conveyance open channel;cross desert;sand protection and sand fixation;design
Scheme demonstration of dam site of Watuo hydropower station in Jinheriver of Tibet
QI Li-wei,DU Xing-yang,NING Wei-qi
[Abstract]The optional range of dam site of Watuo hydropower station is about 5.73km long river from the end of Jinhe hydropower station reservoir to the lower reaches of the site of The Lezhu hydropower station.The paper analyzes and demonstrates comprehensively the dam site of Watuo hydropower station from the topography and geology condition,the project layout,the division layout,and so on.The final selection of the dam site is located at downstream 2.5km of Jinhe river in Lieba village of Karuo district of Changdu city.
[Key words]Watuo hydropower station;dam site;scheme demonstration
Application of form in underwater concrete casting construction
CAI Guang-zhe,LIU Zhan-jun,LIU Hai-fu,HAN Chuang
[Abstract]Theintegralnonformstrippingcansolvemanycommonproblemsexistingintheunderwaterconcretecastingconstruction, including the poor stability of form supporting,the poor tightness,the poor integrity,the large underwater workload,the poor quality of concrete casting appearance,and so on.The application of integral non form stripping in underwater concrete casting construction could improves the project safety and saves the project cost,which has a good application prospect for the underwater concrete casting aspects with the complex dimension complex,the high dimension accuracy and the short construction period.
[Key words]form;underwater concrete casting;application
Analysis of concrete temperature control and crack prevention measures in Sanwan hydraulic project
HUANG Ju
[Abstract]According to the high requirement of temperature control and crack prevention measures in severe cold area,combining with the concrete construction of Sanwan hydro-junction project in Liaoning province,the paper studies the standard and demand of temperature control design in the concrete construction by using the numerical simulation software,obtains the rational casting thickness of concrete and the standard of the temperature control in different position,and introduces the specific temperature control and crack prevention measures for the project.The project practice has proved that,the concrete construction with the temperature control and crack prevention measures achieves the anticipated effect basically and the hazardous temperature cracks did not appear.
[Key words]concrete;temperature control;crack prevention measure
Analysis of mechanics and durability performance of rubber particle concrete
SHEN Chang-yue,LI Xiao-lin
[Abstract]The addition of rubber particles in concrete could effectively improve some properties of concrete.Through the orthogonal experiment with the three factors and three levels,the paper analyzes the development laws of mechanics performance and durability performance for the rubber particles concrete and compares the differences with the reference concrete.The test results show that, after the rubber particles are incorporated into the concrete,the compressive strength,the bending strength and the elastic modulus of the concrete are decrease,but the impermeability,frost resistance and abrasion resistance are increase significantly.Considering the mechanics performance and durability performance of rubber concrete,the rubber particles content of rubber concrete should be controlled within15±5%.
[Key words]rubber particles concrete;mechanics performance;durability performance
Study on layered water intake water temperature numerical simulation for Fengman reconstruction project
LIU Feng,DONG Yan-chao,ZHANG Zi-qi,ZHOU Rong-lei
[Abstract]The statistical information shows that the layered water intake facilities are set to control the water intake area,which could improve effectively the water temperature of water discharge.Through the establishment of three dimensional water temperature mathematical model,the paper further studies the relationship of water intake temperature and water intake elevation of inlet of the layered water intake for the stop logs gate and demonstrates the effect of layered water intake according to the water temperature vertical distribution of typical month in rainy year,dry year and the normal year.
[Key words]layered water intake;water temperature;numerical simulation;Fengman hydropower station
Frequency calculation of lowest tidal level of Yingkou station
NI Wan-nan,CHEN Li-xiang,GU Hong-liang,WANG Jing-jing
[Abstract]By analyzing the corresponding relationship of the statistic parameters between the lowest tidal level(negative value series) and the highest tidal level(positive value series)in the Pearson-III type distribution,the paper finds out the calculation method of the lowest tidal level,calculates the design lowest tidal level of Yingkou station and estimates the design lowest tidal level by using the extreme-I distribution.At last,the rational design value of the lowest tidal level is selected.
[Key words]design tidal level;frequency calculation;Yingkou station
Classification analysis of water quality monitoring section in buffer zone of provincial boundaries of Songhuajiang basin
PENG Jun,LIU Hong-chao,ZHENG Guo-chen,JIANG Hou-zhu
TV123
B
1002—0624(2017)08—0069—02
2017-02-22