| In China,the freshwater fishery has long been pursuing economic benefits,overexploiting rivers,lakes and reservoirs.Especially the net cage fishery seriously damages the ecological environment of the water body.At present,China has banned and gradually banned the traditional cage fish farming.In order not to affect the normal farming operations of fishermen,we can choose a more environmentally friendly electric fence fish blocking system.The electric fence fish blocking system uses the electric reaction of fish to stop or guide fish,without side effects to fish,and does not affect the normal drainage,convection and flood discharge of the river,significantly reducing the damage to the environment.Therefore,the electric fence fish blocking system is the key facility and the most effective means to maintain the water ecological balance,protect the water ecological environment and ensure the safety of water intake.It satisfies the requirements of the ecological fishery culture,conforms to the national policy of environmental protection,and improves the safety and the quality of the fishery products in China.It is beneficial to the sustainable development of modern fishery breeding.The electrical discharging fences of the electric fence system drives fish by releasing electric pulse through the water body.In engineering,the water resistance is influenced by geomagnetic field,ion concentration,inductance capacitance effect and so on,and therefore should be considered as an equivalent resistance.The equivalent resistance of water between grids directly affects the current and discharging time,which has a great impact on the effect of driving fish.However,the current engineering planning stage of electric fence fish blocking system lacks scientific mechanism model and effective calculation method to help and guide the engineers to design.The existing problems are as follows:(1)The electric fence fish blocking system lacks the mechanism model of fish blocking process which can be quantitatively calculated,and the basic theory is lacking.The users have no concept of electric fence fish blocking system;(2)The number of node machines,electrode spacing and discharge frequency are usually estimated by the engineer in the electric fence fish blocking project planning according to experience,but there are often great deviations due to the different conductive capacities of different water bodies.Unavoidably,excessive equipment surplus leads to high input,or insufficient equipment surplus leads to poor interception effect,and cut-off voltage and discharge frequency are also artificially set,so it is difficult to ensure energy saving and low cost operation.There is no decision support system related to the planning of electric fence fish blocking project in the market.It takes many changes and debugging to achieve good and economic fish blocking effect,which is time-consuming and laborious,and is not conducive to the technical promotion of electric fence fish blocking system.According to the above problems,this paper innovatively establishes the working flow mechanism model of the electric fence fish blocking system,which provides the theoretical basis and scientific support for the engineering planning of the electric fish trapping system,and fills the research blank.Then the decision algorithm of engineering planning was designed and a decision support system for engineering planning of electric fence fish blocking system for ecological aquaculture was developed.By measuring the equivalent load of the water body,the design parameters of the electric fence fish blocking system are analyzed and calculated,so as to improve the fish trapping effect,reduce the purchase cost and reduce the operating cost.The main work completed in this paper is as follows:(1)The working principle of electric fence fish blocking system was studied and analyzed,and the mechanism model of the process of pulse discharge blocking fish of electric fence system was established according to the principle of electromagnetism and the physiological characteristics of fish.Calculation model,contains the electric field intensity are block fish sensitive voltage and field strength and thickness between calculation model,the interception frequency and intercept distance calculation model,dynamic model and a wide range of water discharge process of equivalent load calculation model,quantitative reflects the scope of electrical pulse frequency,pulse width,fish can feel the pulse exciting voltage amplitude,discharge cut-off voltage,intercept range,intercepted fish size,speed,and the relationship between the equivalent load of the water body.(2)The requirement analysis and frame design of the electric fence fish blocking engineering planning and decision support system are carried out,and then the decision algorithms required by the electric fence fish blocking engineering planning and decision support system are designed.According to the mechanism model of the fish-blocking process,considering various influencing factors and combining with various constraints,the planning model of the electric fence fish blocking engineering with pulse discharge is established.By using the multi-objective programming algorithm of operations research,the lowest discharge frequency and the least number of equipment are the optimal ones on the basis of ensuring good fish blocking effect.Analyze and calculate the distance between electrodes,the number of electrodes,the discharge frequency and the number of nodal machines to ensure the effectiveness of interception,save energy and reduce the cost of system purchase.Then,according to the decision-making model and algorithm of electric fence fish blocking engineering planning,a special decision support system for electric fence fish blocking engineering planning is developed.(3)The laboratory verification and field verification of the planning decision support system of the electric fence fish blocking project are carried out.The laboratory verifies that the decision support system can meet the functional requirements.Field measurement and calculation were carried out at the site of Dazhou Dengzi River,Chongqing Tongliang Longfei Bridge and Chongqing Tongliang Fujia Bridge Electric Fence Fish Blocking Project for field verification.Measurement records the scene environment parameters and design parameters,as the measured values,and then the data input into the decision support system to obtain the system recommended value.Compared with consistent system recommended value and the measured values shows that the recommendation result of the electric fence fish blocking engineering planning decision support system is accurate and reliable.It has higher application value in actual engineering and has certain guiding significance to engineering personnel. |
