Ultrasonic multifunctional flowmeter
/div>
1 Overview
There are all kinds of flow meters in the market, but it is difficult to achieve accurate measurement for full pipe, dissatisfied pipe, open channel or river, the cost is also very expensive, and the amount of maintenance is huge. In view of this difficulty and the market demand to achieve the measurement level, German Cisco controls developed the delta2wave ultrasonic multi-function flowmeter. The main application fields of the flowmeter are as follows:
(1) measure the inflow and outflow of the sewage treatment plant, then measure the capacity of sewage treatment, and calculate the sewage charges of relevant users (departments).
(2) measure the cooling water flow of the power plant, so as to calculate the cost of natural resources occupied by the power plant.
(3) in order to calculate the working efficiency of hydraulic turbine, it is usually necessary to use the international iso60041 standard for flow calculation, and the flowmeter can achieve the flow measurement accuracy required by the standard.
(4) measure the flow of open channel, the open channel can be regular or irregular section, and it does not need special trapezoidal section.
(5) to measure the flow of the river, the river section with a width of 50m can be measured, and the maximum width can reach 150m.
(6) it is suitable for small flow measurement, usually larger than 500mm pipe diameter (mainly from the economic point of view).
2 accuracy for the flow measurement of pipelines or open channels with insufficient pipes, the fluid conditions are affected and restricted by various natural factors, such as the change of river bed, the change of liquid level, and the fluctuation of liquid wave caused by wind. If we use the method of measuring tank liquid level, or use the ultrasonic Doppler ranging method, under the ideal condition, the accuracy of the measurement can be improved, These methods are feasible. However, under the above interference factors, the measurement result is & nbsp; It is unsatisfactory because these methods can not deal with interference factors, so accurate measurement can not be carried out. The solution of using ultrasonic multi-function flowmeter is to combine liquid level measurement with high-precision multi-channel ultrasonic time-domain measurement method. In this measuring system, the number of ultrasonic probes can reach 16 pairs (32) / measuring points at most. The number of ultrasonic probes is determined according to the accuracy requirements of the system and the shape changes of the channel. The flow computer can carry out intelligent processing in a modular way. Therefore, the accuracy can be changed, which is determined by the accuracy requirements of the system and the pipeline structure of the medium to be measured.
Generally, a flow computer can process four independent measuring points at the same time, which means that each measuring point occupies four pairs of probes (eight probes). Of course, users can make reasonable and appropriate adjustment and allocation among the four points according to their needs. If high precision is needed for some points, the number of probe pairs at some points can be increased, so as to improve the flexibility. This advantage is particularly obvious in the efficiency analysis and calculation of hydraulic turbine. A flow computer is used for several measuring points nearby, and then the number of probes is allocated according to the accuracy requirements of different measuring points, so as to ensure the accuracy of water inflow and water outflow of hydraulic turbine. The whole investment cost changes with the accuracy requirements. Using delta wave ultrasonic multi-function flowmeter can meet the requirements of iso60041 for the measurement accuracy of turbine water flow: when the pipe is full, the measurement is better than 0.5% of the reading; When the tube is not full, it is better than 1% of the reading.0%。 The precision here is not the precision under ideal state, but the precision index under various disturbances and influences.
3. Economy
In the measurement of open channel flow, at present, the domestic and foreign flow meters require the first channel transformation, and build a specific structure in the channel, such as basher trough, triangular weir, rectangular weir, or PB pipe, etc. The purpose is to build an accurate section, so as to calculate the section area. Or through other methods (such as siphon), the open channel measurement (not full pipe) can be changed into full pipe measurement, which is the basic premise and method of open channel flow / not full pipe flow measurement. This needs to have certain requirements for the corresponding trough / weir, resulting in increased costs. At the same time, when the flow is relatively large, water will overflow from the top of the tank / weir, causing the risk of flood, because all kinds of tanks / weirs will shrink to varying degrees.
Delta wave does not need any civil engineering at all. It only needs to fix the guide rail with ultrasonic transmitter / receiver on the river bed or existing canal wall with screws / welding. Since a series of probes are installed on the guide rail, it is easy to replace them as a whole.
In addition, delta wave can be free of maintenance and adjustment; If there is a measurement problem, the system will alarm automatically; There is no need to maintain and repair regularly; If regular maintenance is required according to ISO standard, users can run the self diagnosis function of the flow computer, use a set of self generated self diagnosis data for transmission, comparison and inspection, and find out any errors and changes in the operation process, and find out whether there is signal loss or abnormality.
The product can also detect the content of particles in the liquid and the turbidity of the liquid when measuring the flow. It can be used for quality control in the sewage treatment plant. To a certain extent, it can play some roles of the turbidity meter, indicating that it is a multi-purpose instrument.
4 reliability
Cisco control company has a research history of nearly 10 years in the field of ultrasonic flow measurement, and the new delta wave product is the crystallization and product of these researches. It itself is a high reliability product.
The whole product is designed according to modularization, and the concept of electrical isolation of multiprocessor is introduced. The core of the motherboard is a 64 bit microprocessor, which is strictly electrically isolated from other input / output modules. All I / O boards also have their own microprocessor and independent power supply. The boards are connected and exchange data through the bus system, so local failure will not cause global paralysis.
When multi-channel measurement mode is adopted, redundant measurement can be adopted in a measurement area, that is, the same measured flow can be measured, and probes can be placed at different points as redundant measurement points, so as to improve the reliability of the system, and the measured value is smoother and more stable than single channel measurement.
1 Overview
There are all kinds of flow meters in the market, but it is difficult to achieve accurate measurement for full pipe, dissatisfied pipe, open channel or river, the cost is also very expensive, and the amount of maintenance is huge. In view of this difficulty and the market demand to achieve the measurement level, German Cisco controls developed the delta2wave ultrasonic multi-function flowmeter. The main application fields of the flowmeter are as follows:
(1) measure the inflow and outflow of the sewage treatment plant, then measure the capacity of sewage treatment, and calculate the sewage charges of relevant users (departments).
(2) measure the cooling water flow of the power plant, so as to calculate the cost of natural resources occupied by the power plant.
(3) in order to calculate the working efficiency of hydraulic turbine, it is usually necessary to use the international iso60041 standard for flow calculation, and the flowmeter can achieve the flow measurement accuracy required by the standard.
(4) measure the flow of open channel, the open channel can be regular or irregular section, and it does not need special trapezoidal section.
(5) to measure the flow of the river, the river section with a width of 50m can be measured, and the maximum width can reach 150m.
(6) it is suitable for small flow measurement, usually larger than 500mm pipe diameter (mainly from the economic point of view).
2 accuracy for the flow measurement of pipelines or open channels with insufficient pipes, the fluid conditions are affected and restricted by various natural factors, such as the change of river bed, the change of liquid level, and the fluctuation of liquid wave caused by wind. If we use the method of measuring tank liquid level, or use the ultrasonic Doppler ranging method, under the ideal condition, the accuracy of the measurement can be improved, These methods are feasible. However, under the above interference factors, the measurement result is & nbsp; It is unsatisfactory because these methods can not deal with interference factors, so accurate measurement can not be carried out. The solution of using ultrasonic multi-function flowmeter is to combine liquid level measurement with high-precision multi-channel ultrasonic time-domain measurement method. In this measuring system, the number of ultrasonic probes can reach 16 pairs (32) / measuring points at most. The number of ultrasonic probes is determined according to the accuracy requirements of the system and the shape changes of the channel. The flow computer can carry out intelligent processing in a modular way. Therefore, the accuracy can be changed, which is determined by the accuracy requirements of the system and the pipeline structure of the medium to be measured.
Generally, a flow computer can process four independent measuring points at the same time, which means that each measuring point occupies four pairs of probes (eight probes). Of course, users can make reasonable and appropriate adjustment and allocation among the four points according to their needs. If high precision is needed for some points, the number of probe pairs at some points can be increased, so as to improve the flexibility. This advantage is particularly obvious in the efficiency analysis and calculation of hydraulic turbine. A flow computer is used for several measuring points nearby, and then the number of probes is allocated according to the accuracy requirements of different measuring points, so as to ensure the accuracy of water inflow and water outflow of hydraulic turbine. The whole investment cost changes with the accuracy requirements. Using delta wave ultrasonic multi-function flowmeter can meet the requirements of iso60041 for the measurement accuracy of turbine water flow: when the pipe is full, the measurement is better than 0.5% of the reading; When the tube is not full, it is better than 1% of the reading.0%。 The precision here is not the precision under ideal state, but the precision index under various disturbances and influences.
3. Economy
In the measurement of open channel flow, at present, the domestic and foreign flow meters require the first channel transformation, and build a specific structure in the channel, such as basher trough, triangular weir, rectangular weir, or PB pipe, etc. The purpose is to build an accurate section, so as to calculate the section area. Or through other methods (such as siphon), the open channel measurement (not full pipe) can be changed into full pipe measurement, which is the basic premise and method of open channel flow / not full pipe flow measurement. This needs to have certain requirements for the corresponding trough / weir, resulting in increased costs. At the same time, when the flow is relatively large, water will overflow from the top of the tank / weir, causing the risk of flood, because all kinds of tanks / weirs will shrink to varying degrees.
Delta wave does not need any civil engineering at all. It only needs to fix the guide rail with ultrasonic transmitter / receiver on the river bed or existing canal wall with screws / welding. Since a series of probes are installed on the guide rail, it is easy to replace them as a whole.
In addition, delta wave can be free of maintenance and adjustment; If there is a measurement problem, the system will alarm automatically; There is no need to maintain and repair regularly; If regular maintenance is required according to ISO standard, users can run the self diagnosis function of the flow computer, use a set of self generated self diagnosis data for transmission, comparison and inspection, and find out any errors and changes in the operation process, and find out whether there is signal loss or abnormality.
The product can also detect the content of particles in the liquid and the turbidity of the liquid when measuring the flow. It can be used for quality control in the sewage treatment plant. To a certain extent, it can play some roles of the turbidity meter, indicating that it is a multi-purpose instrument.
4 reliability
Cisco control company has a research history of nearly 10 years in the field of ultrasonic flow measurement, and the new delta wave product is the crystallization and product of these researches. It itself is a high reliability product.
The whole product is designed according to modularization, and the concept of electrical isolation of multiprocessor is introduced. The core of the motherboard is a 64 bit microprocessor, which is strictly electrically isolated from other input / output modules. All I / O boards also have their own microprocessor and independent power supply. The boards are connected and exchange data through the bus system, so local failure will not cause global paralysis.
When multi-channel measurement mode is adopted, redundant measurement can be adopted in a measurement area, that is, the same measured flow can be measured, and probes can be placed at different points as redundant measurement points, so as to improve the reliability of the system, and the measured value is smoother and more stable than single channel measurement.
蘇公網(wǎng)安備 32058302001350號
