149results about How to "Satisfy economy" patented technology

An intelligent automatic-transmission matching method on the basis of working conditions and driving intention includes the following steps of acquiring data of driving habits and working conditions; analyzing data, modeling and emulating; integrating the recognition algorithm and the data models with the gear shifting schedules; and finally testing on vehicles. By the intelligent automatic-transmission matching method on the basis of working conditions and driving intention, vehicles can be adaptable to different driving habits and working conditions automatically and have high drivability and low combined oil consumption on different working conditions. The intelligent automatic-transmission matching method can accord with the gear shifting schedules having requirements to drivability, economy and dynamic property simultaneously, and thereby corresponding gear shifting schedules can be provided according to different driving habits and driving conditions on the basis of researching technologies of engines and transmissions.

The invention provides a speed regulation and energy management method for range extender of electric car which satisfies with both drive ability and economy of the whole car, when capacity of a power battery is lower than a start threshold, the range extender starts automatically for providing energies to the power battery, a low-voltage battery set and a drive motor; or when request power of a driver is larger than energy capable of being provided by the power battery, the extender starts; after the extender starts, a corresponding revolving speed level is entered according to the request power; according to fuel oil consumption curve and emission curve of the motor, working revolving speed range of the motor is determined, several revolving speed levels are selected in the working revolving speed range of the motor are selected, and powers of the range extender which are corresponded to the revolving speed levels are required to cover requirements for dynamic characteristic of the whole car; then corresponding signals are decoupled via controller of the whole car for being sent to a motor controller and a generator controller. Then the speed regulation and energy management of the range extender satisfy with both drive ability and economy of the whole car.

The invention discloses an active control type hybrid power for a pure electric bus and a control method of the active control type hybrid power system, and aims to solve the problems that the existing electric bus power supply is not suitable for charging and discharging in large current and is low in brake energy and storage efficiency. The control type hybrid power comprises a lithium ion battery group, a control circuit and a super capacitor, wherein the positive pole of the lithium ion battery group is connected with one end of an inductance coil L of the control circuit, and the negative pole of the lithium ion battery group is connected with an insulated gate bipolar transistor T of the control circuit and the negative pole of the super capacitor; and the negative pole of the super capacitor is connected with the negative pole of an ampere meter A1 of the control circuit. The control method of the active control type hybrid power comprises the following steps of: actively controlling the starting stage of the pure electric bus; actively controlling the beginning step of the pure electric bus; actively controlling the stable running stage of the pure electric bus; actively controlling the brake reducing stage of the pure electric bus; actively controlling the accelerating stage of the pure electric bus; and actively controlling the circulate running and stopping stage of the pure electric bus.

The invention relates to a driving system for an electric vehicle. A clutch pedal is eliminated, and only an accelerator pedal and a brake pedal are kept; a clutch control unit controls a clutch driving motor to disengage a clutch under the condition that gear shifting is needed; the clutch driving motor is a linear motor (or a rotary motor and a cam mechanism), and a complicated speed-reducing torque-increasing device and a transmission mechanism in the conventional clutch operating mechanism are not needed; an automatic transmission control unit sends an instruction according to a vehicle automatic gear shifting rule, and a gear selecting and shifting motor drives a gear selecting and shifting execution mechanism to finish a gear shifting action; the clutch control unit controls the clutch driving motor to move in an opposite direction, so that the clutch is engaged, the power of a vehicle driving motor is transferred through a gearbox, and an automatic speed change function is realized; and the vehicle driving motor is only simply controlled in the process, so that the requirement on the manufacturing technology of the driving motor is reduced.

The invention relates to an optimal configuration and operation method for reactive compensation of a wind farm. The optimal configuration and operation method is characterized by comprising the following steps of: (1) analyzing the reactive output characteristics of the wind farm, and installing a reactive compensation device in the wind farm and configuring a volume for the reactive compensation device; and (2) detecting reactive powers of a fan outlet and an interconnection point of the wind farm, and mechanically controlling the static reactive compensation and the dynamic reactive compensation of the wind farm. The optimal configuration and operation method is designed reasonably, the combination operation of the static reactive compensation and the dynamic reactive compensation of the wind farm is realized, and the reactive powers of the wind farm and a power grid are ensured under the optimal condition of the reactive compensation device of the wind farm, therefore the effect of maintaining power grid stabilization is achieved, the reactive compensation property of the wind farm is improved, the reactive compensation equipment investment is reduced, and the reactive compensation economic and technological requirements of the wind farm are satisfied.

The invention discloses an urban unmanned electronic railcar taxi traffic system. The traffic system comprises a combined rail, an unmanned electronic railcar taxi running on the combined rail and a central control computer of the traffic system, wherein the central control computer of the traffic system controls the running state of the unmanned electronic railcar tax on the combined rail. The technical scheme of the invention is as follows: the system consists of a high-speed rail, a speed-changing rail, a low-speed rail, an on-off rail, stations, a driving system, the central control computer of the system, a charge system, a detection system, a human-computer interaction system and a special vehicle. The urban unmanned electronic railcar taxi traffic system is integrated with the advantages of the subway, cars, buses and elevators, meets the requirement of rapidness, safety, economy, convenience and environmental protection of modern urban traffics, and the problem of urban traffic jam is solved fundamentally.

The invention provides an intelligent tool magazine system suitable for a numerical control machine tool. The intelligent tool magazine system comprises a tool encoding detection unit, a tool magazinemachinery unit, a tool magazine master control unit, an auxiliary tool changing unit and a manipulator unit. The invention also provides a control method of the intelligent tool magazine suitable forthe numerical control machine. The control method comprises the following steps: providing the intelligent tool magazine system, performing code initialization on the intelligent tool magazine system, and re-building a real-time encoding database; and searching for empty tool spacings, tools with insufficient service life and damaged tools in the intelligent tool magazine system by retrieving a database with a retrieval command, performing tool selection control, and examining the tools at an NC end and programs after tool changing. The control method has the following advantages: initialization of tool magazines with repeated tool numbers and searching of the empty tool spacings, tools with insufficient service life and damaged tools can be realized, and the standby tools can be automatically changed in real time during machining. Meanwhile, classification of process tools and process studies on the tools can be achieved. A one-step one-tool-number process is realized.

The invention provides an intelligent optimal scheduling method for wind and solar energy storage grid-connected power generation. The intelligent optimal scheduling method comprises the steps that (1) historical wind electricity data and solar electricity data are collected, and wind electricity and solar electricity output prediction error distribution before a day and in a day at different time scales is obtained; (2), wind electricity and solar electricity predicted output values are obtained according to meteorological data (illumination and temperatures) with an existing wind electricity output predicting system and a solar electricity output predicting system; (3), a wind electricity output scene value and a solar electricity output scene value are determined through the step (1) and the step (2); (4), an intelligent wind and solar energy storage gird-connected power generation scheduling model is established, wherein the intelligent wind and solar energy storage gird-connected power generation scheduling model comprises a scheduling optimized objective function model and a scheduling constraint condition model, and the scheduling optimized objective function model comprises a day-ahead scheduling model, a intraday scheduling model and a real-time scheduling model; (5), a first wind and solar energy storage power generation day-ahead combined scheduling value is obtained through optimization; (6), a wind and solar energy storage power generation intraday combined scheduling value, a wind energy storage power generation intraday scheduling value and a solar energy storage power generation intraday scheduling value are obtained; (7) a real-time wind and solar energy storage scheduling value is obtained.

The invention belongs to the technical field of monitoring of ground source heat pump air conditioners and relates to a mixed ground source heat pump monitoring system and method based on a health assessment technology, and the system and method can be used for solving the technical problems that the development of the monitoring and controlling technology of the existing ground source heat pump mixed system is not perfect enough and the like. The monitoring system comprises a monitoring subsystem, a load forecasting subsystem and a health assessment subsystem, wherein the health assessment subsystem and a controlling subsystem are connected. The monitoring method comprises the following steps: using the monitoring subsystem to collect data and store the data into a data storage device; using the load forecasting subsystem to extract the data collected by the monitoring subsystem, perform load forecasting and further store the load forecast data into the data storage device again; using the health assessment subsystem to store health index into the data storage device; and using the controlling system to control correspondingly. The system provided by the invention has the advantages that the health condition is assessed reasonably, the automation level of the system is improved, the labor intensity of management is reduced, and the cold and hot balance during the long term operation of the system is ensured; and the economical efficiency of the system under the condition of short term operation is ensured and the like.

The invention discloses a full-automatic grapefruit package production line, which is assembled by a rack, a transmission mechanism, a feeding mechanism, a cleaning mechanism, a drying mechanism, a material arranging mechanism, a film wrapping mechanism and a grading mechanism, wherein the rack is mutually and successively connected with the rack of each mechanism in a welding mode, the transmission mechanism is composed of the roll shaft transmission parts of the cleaning mechanism and the drying mechanism and the belt transmission parts of the feeding mechanism, the material arranging mechanism and the film wrapping mechanism. The invention overcomes the defects of low production efficiency, large labor strength, single function and low automaticity of the existing grapefruit package technology, has the advantages of artful design, simple structure, convenient manufacture, low cost and wide application range and can be used for directly packaging the grapefruit of different kinds and sizes in different producing areas. The invention efficiently, reliably, conveniently and directly reduces product loss and wastage and expands market sales range so as to satisfy the requirements of economic growth and improved living standards as well as improve economic benefit.

The invention discloses a preparing method for a profile steel concrete column for an urban mass transit elevated railway station. The method comprises the following steps that steel or a steel plate is prepared and used for preparing a first profile steel part, and a plurality of hole positions for penetrating are formed in a first web; locating welding is carried out on the first web and a first wing edge plate so that a first profile part can be formed; a second profile steel part and a third profile steel part are prepared; the second profile steel part and the third profile steel part are assembled at the two opposite sides of the first wing edge plate of the first profile steel part respectively to form a cross-shaped steel column; bolt screws are welded to the first profile steel part, the second profile steel part and the third profile steel part respectively. The invention further discloses the profile steel concrete column for the urban mass transit elevated railway station. By applying the profile steel concrete column for the urban mass transit elevated railway station and the preparing method thereof, the profile steel concrete column has good pressure bearing performance, is high in deformation ability, resists fatigue, and is good in impact resistance; the requirements for structural safety and project economy are met, and feasibility and working procedure arrangement of site construction are involved.

The present invention provides a rubber composition which makes it possible to improve the handling stability, ride comfort, and elongation at break in a balanced manner and at the same time to achieve satisfactory processability and fuel economy; and also provides a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition including a masterbatch that includes: a modified natural rubber with a phosphorus content of 200 ppm or less; and microfibrillated plant fibers. The rubber composition preferably has a ratio (E*a / E*b) of a complex modulus E*a in an extrusion direction to a complex modulus E*b in a perpendicular direction to the extrusion direction, both measured at a temperature of 70° C. and a dynamic strain amplitude of 2% under an initial elongation of 10%, of 1.05 to 6.00, wherein the complex modulus E*a is 7 to 100 MPa.

In an internal combustion engine equipped with a variable compression ratio mechanism, the occurrence of knocking is reduced during deceleration. When it is determined that a target compression ratio of the variable compression ratio mechanism is greater than a threshold PRSL during the deceleration, an air bypass valve interposed in a passage for bypassing a compressor of an exhaust turbo supercharger is opened to return intake air upstream (between the compressor and a throttle valve) of the throttle valve to upstream of the compressor, thereby reducing intake pressure upstream of the throttle valve and reducing in-cylinder compression pressure to reduce the occurrence of knocking.

Provided are a process for producing a thick high-strength steel plate having the satisfactory toughness of a heat-affected zone in high heat input welding and a thick high-strength steel plate obtained by the process. The process comprises heating a continuously cast slab to a temperature which is higher than 1,100 C but is 1,300 C or lower, subsequently rolling the slab at a steel surface temperature of 850 C or higher so as to result in a cumulative draft of 50% or more, and then cooling the slab from a steel surface temperature of 800 C or higher to 500 C or lower while applying accelerated cooling, the continuously cast slab having a given composition to which boron and vanadium have been added in combination, and the amount of residual oxygen (OTi) which remains after deoxidation with strong deoxidizing elements and can be removed with titanium, which is a weak deoxidizing element, the amount of effective boron (Bef) present in solution in the austenitic base that has not been transformed, and the carbon equivalent (Ceq) in the continuously cast slab being defined by respective expressions.

The invention discloses a vehicle fuel cell hydrothermal management system which comprises a first heating loop, a second heating loop, a third heating loop, a first cooling loop, a second cooling loop, a deionized water circulation system, a fuel cell stack and a control system; the first heating loop is a fuel cell stack heating loop, and the temperature of a fuel cell stack is increased by heating a cooling liquid through a PTC heating device; the second heating loop is a passenger compartment auxiliary heating loop, and the PTC heating device directly supplies heat to a passenger compartment; the third heating loop is a fuel cell passenger compartment heating loop, and the passenger compartment is heated through waste heat generated by work of the fuel cell stack; the first cooling loop is a radiator cooling loop, and heat generated by working of the fuel cell stack is transferred to the radiator through the heat exchanger and exchanges heat with the outside; and the second cooling loop is an air-conditioning auxiliary cooling loop and assists the heat dissipation of the fuel cell stack by utilizing phase-change heat transfer of a refrigerant of the air-conditioning system.

The invention discloses a coordinative optimization configuration method for the capacity of a photovoltaic array, an energy storage device and a transformer of a photovoltaic charging station. The method comprises the following steps: firstly, determining a target function of the photovoltaic charging station, acquiring basic data of the photovoltaic charging station, and determining constraint conditions of the photovoltaic electric automobile charging station; secondly, optimizing the target function by applying an NSGA-II multi-objective genetic algorithm to obtain an optimization result;and finally, selecting the most reasonable construction requirement based on a construction investment budget of a investor according to the optimization result, and performing corresponding hardwarefacility configuration in the photovoltaic electric automobile charging station according to the construction requirement. The coordinative optimization configuration method disclosed by the inventionis applicable to all types of cities with the photovoltaic electric automobile charging station; an energy control strategy-based photovoltaic charging station optimization configuration method for coordinative optimization of the capacity of the photovoltaic array, the energy storage device and the transformer; and a theoretical foundation and a technical support are provided for construction and operation of an electric automobile charging station with a photovoltaic power generation system, so as to guarantee the economy, the environmental friendliness and the reliability of the construction and the operation of the charging station.

The invention discloses an optimal configuration closing method for an energy storage system of an independent type micro power grid. The method comprises the steps that a self-sufficiency probability requirement of the micro power grid is determined; an optimal configuration module of the energy storage system of the micro power grid is established; aimed at the optimal configuration module of the energy storage system, a rain-flow counting method is used to estimate the service life of a storage battery, and an investment coefficient is obtained; and load data and wind power data of one year are predicted, a proper operation strategy is adapted in the simulated operation process, and according to the optimization searching range, a traversal algorithm or particle swarm optimization is used to search configuration of the energy storage system. The method satisfies economical performance, provides the self-sufficiency probability requirement, and pursuits the system stability; the system stability is kept when the economical performance is optimal; and a balance is made among investment, operation and pollution treatment cost.

The invention discloses a mechanical excavation method for a hard-rock tunnel with the medium-short length and belongs to the field of construction methods. The mechanical excavation method comprises the steps that first, a plurality of parallel and vertical grooves are cut on a tunnel face in a tunnel profile at certain intervals, and each vertical groove enables rock on the two sides of the vertical groove to form a free face with the certain depth; and then crushing equipment is utilized to apply extruding stress to each free face of the two sides of the corresponding vertical groove, so that the rock of the two sides of the vertical grooves is crushed, and excavation of the tunnel is achieved. Compared with the prior art, the requirement of the construction, limited in blasting vibration, of the new built rock tunnel with the medium-short length for the aspects such as the economy, efficiency and the safety risk can be met; and meanwhile the construction efficiency is greatly improved compared with the prior art.

The invention discloses a motor torque control method aiming at different driving modes. The motor torque control method aiming at the different driving modes comprises the following steps that (1) anaccelerator pedal position signal, an accelerator pedal change rate signal, a gear signal, a motor voltage signal and a battery SOC signal are acquired through a high-speed CAN bus to judge an immediate driving mode of a driver; the driving mode comprises an economic mode and a power mode; (2) the motor voltage signal is acquired, and initial motor target torque is determined according to the current voltage of a motor; and (3) the initial motor target torque is adjusted to final motor target torque according to the driving mode result judged in the step (1);and the final motor target torqueis the motor torque corresponding to a pedal working mode under the corresponding pedal opening under the specific working condition. According to the motor torque control method aiming at the different driving modes, the motor torque is rapidly adjusted according to the driving modes of a driver, the economical and dynamic requirements of the whole electric vehicle are met, and the endurance mileage of the whole vehicle and the output accuracy of the motor target torque are improved.

The invention provides a novel method for measuring and calculating well pattern thickening potential comprising following steps: 1. determining oil well single well economic limit recoverable reserves; 2. determining the relationship between the average single well increased recoverable reserves of a close-spaced well and the well density; 3. determining the density of the economic limit well pattern; 4. calculating the drilling well workload of well pattern thickening; 5. calculating the potential of well pattern thickening for increasing recovery efficiency. The novel method for measuring and calculating well pattern thickening potential can satisfy the demand of calculating technical economical policy limit such as economic limit well pattern density and limit thickening potential of extra high water reservoir, and can be more objective in evaluating the exploitation potential of oil reservoirs and guiding the oil field development production practice.

The invention belongs to the field of environment production water treatment. A phosphorus-free cleaning prefilming agent mainly comprises two components that are independently packaged, wherein component A is a phosphorus-free complexing agent, the component B is a phosphorus-free pickling agent, and the weight part ratio of the component A to the component B is (10-30):(4-7). The agent mainly comprises sodium gluconate and boric acid, wherein sodium gluconate is classic organic acid and has certain iron ion chelation and corrosion inhibition effects; and the cleaning prefilming agent is phosphorus-free and biodegradable, has excellent corrosion inhibition and scale inhibition effects, and can meet sewage discharge standard. Boric acid is commonly used inorganic acid in industrial and civil applications, and no discharge concentration of boron is found in the current wastewater discharge standard. Boric acid can be used as rust inhibitor, lubricant and thermal oxidization stabilizer and the wastewater discharge standard can also be met. The two components are reasonably compounded and applied to ensure good cleaning and prefilming effect, without generating corrosion.

The invention provides a double powered variable transmission for an electric automobile. In the stepless transmission, an output shaft of a main power motor extends into a connector and is connected with a left end shaft of a sun gear; the sun gear is engaged with a planet gear on the periphery thereof; an axis of the planet gear passes through a left inner bore and a right inner bore of a planet carrier; the planet gear is engaged with an internal tooth of a gear ring at the same time; the gear ring is engaged with a worm through a worm wheel ring; the worm is coaxially connected with an output shaft of a regulating motor; the right end of the planet carrier is fixed with the left end of a variable speed output shaft; and the right end of the variable speed output shaft extends out of an end cover. The variable transmission has stepless variable transmission ratio, leads the rotating speed of the main power motor to be within 4,000 revolutions / minute, realizes that the electric automobile not only meets the requirement of low speed large torque, but also accords with the requirement of high speed mobility, has the characteristics of simple structure, easy assembly, light weight, low manufacturing cost, stable transmission, reliable performance, easy implementation, wide application range and the like, and can meet the requirement on economy and whole automobile cost of the electric automobile.

The invention relates to a power assembly for a miniature pure electric vehicle; wherein, a first transmission shaft is connected with an output shaft of a motor by an automatic clutch; a first gear of a first shaft and a second gear of the first shaft are fixedly sheathed on the first transmission shaft; a first gear of a second shaft and a second gear of the second shaft are hollowly sheathed with on a second transmission shaft; a variable synchronous joint sleeve is arranged between the first gear of the second shaft and the second gear of the second shaft; the variable synchronous joint sleeve is connected with the second transmission shaft by a spline and can move axially on the second transmission shaft; the second transmission shaft is also fixedly sheathed with a decelerating active gear which is often meshed with a decelerating driven gear on the second transmission shaft. The power assembly takes the motor as power, adopts self-adaptive control of the motor, an automatic clutch and a speed change mechanism, so that the whole power assembly is simple and compact in structure, easy in assembly, light in weight, low in cost and comfortable in operation, not only fundamentally solves the problem of environmental pollution but also effectively reduces the producing cost of the electric vehicle.

The invention discloses an electric vehicle powertrain parameter matching method, a control device and equipment. The matching method comprises the following steps: obtaining a value range of at leastone design parameter of a motor; Determine the value of each design parameter which can meet the vehicle dynamic calibration requirements within the range of the target parameters; Determining the motor type when each design parameter adopts the corresponding target parameter value; According to the contour map of motor efficiency corresponding to the motor type, the calculation efficiency of themotor is determined when each design parameter adopts the corresponding target parameter value respectively. According to the relationship between the design parameters corresponding to the motor type and the motor weight, determining the motor weight in which each design parameter adopts the corresponding target parameter value; According to the calculation efficiency and the weight of the motor, the optimal design parameters of the motor which meet the requirements of the vehicle operation economy are determined. It solves the problem that the whole vehicle dynamic performance and economy simulation can not be carried out when the powertrain parameters are matched.

The invention relates to a digital control apparatus of a micro gas turbine. A micro gas turbine operation panel and a micro gas turbine system state element are connected with a general input and output module, a micro gas turbine measurement part is connected with a signal modulation module and then is connected with an analog / digital conversion module, and the general input and output module is connected with a micro gas turbine switch value executing part; and an external interface (XINTF) is connected with a micro gas turbine analog quantity executing part, and a digital signal processor (DSP) is connected with an upper computer through a serial communication interface. The digital control apparatus which allows hardware resources to have a certain margin and the interface to be designed in standardization can be used for a plurality of micro gas turbines, can automatically adjust the starting, shutdown, cold running, loading running and the like of the micro gas turbines, satisfies the requirements of the micro gas turbines in economy and service life, can realize the modification of control parameters through software, and can also be used for micro gas turbines having different performances.

The invention relates to hand-wiping paper and a preparation method of the hand-wiping paper. The hand-wiping paper provided by the invention comprises a hand-wiping paper body, wherein the hand-wiping paper body comprises at least two layers of single hand-wiping paper sheets, and a single sheet adhesive layer is arranged between the single hand-wiping paper sheets. The product is obtained by carrying out pulping on the raw materials, namely bamboo fibers and water by adopting a hydropulper, carrying out pulp grinding, carrying out paper making, and carrying out forming and compounding. The stiffness of the hand-wiping paper prepared by adopting the method provided by the invention is superior to that of the commercially available hand-wiping paper, the flexibility of the hand-wiping paper provided by the invention is twice of that of the original single-layer hand-wiping paper, point-to-point double-layer compounding is adopted, the paper sheets are hollow, and the water absorbability is 2.5 times of that of the original hand-wiping paper; meanwhile, the bamboo fibers with the original color are adopted during the whole manufacturing process, the raw materials including bleached wood pulp are not needed, and thus the prepared hand-wiping paper is environmentally friendly and healthy and is friendly to the skin.

The invention relates to a control method of a micro gas turbine. A digital signal processor DSP is adopted as a central processing unit CPU in a digital control device of the micro gas turbine, and the software of the micro gas turbine is divided into a drive layer, an intermediate layer and an application layer according to the modular design idea. The drive layer is the bottommost layer of the control software, a drive layer program is called by an intermediate layer program to finish the program design of a specific function module, and the control function is performed by an application layer program according to the control requirement of the micro gas turbine. According to the control method, the working conditions such as starting, stopping, cold running, load running and the like of the micro gas turbine can be automatically adjusted, so that the requirements of the micro gas turbine in the aspects of economy and service life are met; and meanwhile, when the control law of the micro gas turbine is changed, the control parameters can be changed by the software, so that the control method can be widely applied to gas turbines with different control law requirements.

The invention relates to the technical field of reactor pressure vessel simulation test, and specifically discloses a reactor pressure vessel distributed simulation structure in integral simulation test. The simulation structure comprises a reactor core simulation container and a ring cavity simulation container; the whole reactor core simulation container has a cylindrical structure, the upper end of the lower end of the reactor core simulation container are connected through flanges, the lower part of the reactor core simulation container is provided with a nozzle, the nozzle is connected to the ring cavity outlet adapter arranged in the lower end of the ring cavity simulation container through a pipeline, wherein the ring cavity simulation container simulates the upper part of a reactor container prototype ring cavity, and the pipeline connecting the reactor core simulation container and the ring cavity simulation container simulates the lower part of a reactor container prototype ring cavity. The simulation structure simulates the circular channel of a reactor pressure vessel prototype downward ring cavity, can better satisfy the geometric similarity principle and the dynamics principle, satisfies the economic and related simulation principle, and at the same time, is simple in structure. Moreover, the downward ring cavity simulation and the reactor core simulation are separated, and thus the measurement of reactor core flow is more convenient.