Pneumatic control valve flow characteristics and structural characteristics of ideal 2)

because, as in a closed area change situation, the influence of the number, also has the pressure change of pneumatic valve, causing the change of pressure variation. Pneumatic valve pressure remains the same, the ideal of flow control pneumatic valve flow characteristics, the structure characteristics of the manipulation of the pneumatic valve pneumatic valve core displacement is the relationship in the process of cross section area and the fluid flow, it is the decision of the pure pneumatic valve core size and geometry shape, and control of the pneumatic valve geometry, but also contributed to the downstream pressure constant quantitative parameters, so. 。 。 On the characteristics of object technology, appropriate control of pneumatic valve flow characteristic of the choice of pneumatic valve flow characteristic is through the flow control pneumatic valve flow, compared with the displacement ( Relative to the control of the pneumatic valve opening) In the following aspects of the general relationship between regulating the flow of pneumatic valve pneumatic control valve core section and pneumatic seat, can operation process. But as a result, such as changes in a closed area, the influence of the number is actually pressure pneumatic valves also produces change, causing the change of pressure variation. Pneumatic valve pressure remains the same, the ideal of flow control pneumatic valve flow characteristics, the structure characteristics of the manipulation of the pneumatic valve pneumatic valve core displacement is the relationship in the process of cross section area and the fluid flow, it is the decision of the pure pneumatic valve core size and geometry shape, and the control of the pneumatic valve geometry, but also contributed to the pressure parameter, therefore, pneumatic control valve flow characteristics and structural characteristics of the same number of downstream ideal situation is not the same. Important reason, using the linear flow characteristic such as percentage, parabolic four quickly. In the process of practical application, pneumatic pressure control valve are always changing, and then the characteristics of the flow characteristics of known as workflow, pneumatic control valve and processing facilities often use serial or parallel, the change of the flow resistance loss in practice, the deformation of pneumatic valves away due to pressure changes into the work flow characteristic of ideal characteristics. The ideal flow control characteristics of pneumatic valve is in the usual straight, such as percentage, quick opening between the three linear and parabolic flow characteristic, such as the percentage of in the meantime, such as percentage can be used to replace normal, quick opening characteristics and two important mediation and processor type. Therefore, the characteristics of the pneumatic valve is the choice of how to operate, line selection and equal percentage flow characteristic. Now, control of the pneumatic valve more reference the experience of the choice of base flow characteristic, can from the following several aspects: balance, from the mediation system, according to the anatomy of the picture quality is a heat exchange device automatically mediation system, this is the object of mediation, transmitter, mediation and the synthesis of instrumentation and control pneumatic valve, etc. Amplification of the transmitter parameters K and K of the mediation document amplifier parameters, K amplifier parameters of the actuator, pneumatic valve control amplifier parameters K group, enlarge the intermediary object K parameter. Very, very important, the total magnification K for the system parameters: K = K to K * * * * K K K K, K and K, K, K, respectively for the transmitter, conciliation documents, authority, and the realization of the control of pneumatic valves, mediation mediation system can enlarge the object is to maintain order quality indicator parameters, working condition of change; To enlarge the scope of work of the mediation system in the body of the general parameters remain the same. Typically, transmitter, modem ( Have a good environment) And administrative organs of the amplification parameter is a constant, but the mediator object is always by all sorts of changes in parameters under the premise of operation after amplification, so the characteristics of the object is nonlinear. Control pneumatic valve characteristics, therefore, appropriate to expand the pneumatic valve offset the change of the object parameters, expand the mediation parameters change, the general amplifier system parameters remain the same or similar, the same quality so as to mobilize the mediation system. Therefore, the choice of the control flow rate characteristics of pneumatic valve should meet: K * K = constant view with the load of smaller phenomenon deepening the amplifier parameters, with large load better choice and change parameters under the same proportion Zoom cover control pneumatic valve, arrived in two, it will cause another results in the synthesis of two kinds, the general Zoom parameters remain the same, similar to the linear relationship. When mediation object parameters is linear amplifier, the linear flow characteristic should be quoted, would bring the total magnification parameters remain the same. Environment from the pipe weight control pneumatic valve and pipeline facilities, often even in adoption process, due to the system piping is different, and the change of the pressure drop of the power control pneumatic valve existed vascular resistance, so the working flow characteristic and ideal pneumatic valve pneumatic valve flow characteristics are different. Must be chosen with the system function, according to the required operating characteristics, and then weigh the pipeline ideal position, select the appropriate characteristics. Pneumatic control valve, and all the technical infrastructure and system pressure pipeline, is called the total pressure of the system. Pneumatic valve pneumatic control valve fully open and system pressure Δ Pmin the proportion of the total pressure Δ p called S value, namely: S = Δ Pmin/Δ p weighing process pipeline conditions, can choose the corresponding ideal in the following table feature modeling.