A BALL VALVE SYSTEM AND METHOD WITH EQUAL PROPORTIONAL FLOW CHARACTERISTICS

Technical Field

The present invention relates to a system and method for controlling equal proportional flow rate under constant pressure difference by means of an electrical signal for ball valves without V port feature, which are used in applications where V port ball valves are used and high precision is critical where flow characteristics are important.

Prior Art

When it comes to Ball Valves, V - Port ball valves play an important role in the valve industry. V - port valves are used in flow control applications. In addition, V - port ball valves are used in applications where precision is important thanks to their ability to provide equal proportional flow control.

Ball Valves are more convenient and practical in terms of cost and design compared to V - port valves. However, they are not preferred in applications that require sensitivity in terms of flow adjustment and flow in terms of functionality because they cannot provide the functionality required by V - port valves. Due to this factor, ball valves are converted into V port ball valves by giving the ball valves an additional V - shaped apparatus or by giving the sphere a V port transition shape.

However, this process requires additional mechanical components and application - specific valves.

Ball valves without V - port are not suitable for linear control in line characteristics and cannot provide equal proportional control of flow rate adjustment under constant pressure.

In the prior art, in equal proportional flow control applications, ball valves provide flow control with V ports. Nowadays, there is a need for configurations that provide equal proportional flow control with ball valves without V Port.

In the utility model application document TR2021/019165, which is in the prior art, a prepaid water meter that provides flow control by sensing the position of the ball valve is described. In the relevant application document, a configuration that provides equal proportional flow control under constant pressure difference with an electrical signal for ball valves without V port feature is not presented.

As a result, it is necessary to make a development in the relevant technical field due to the inadequacy of the solutions to meet the needs described above.

Brief description of the invention

The invention is inspired by the current situation and aims to solve the above - mentioned problems.

The purpose of the present invention is to provide a system and method for controlling equal proportional flow rate under constant pressure difference with an electrical signal for ball valves without V port feature.

The invention to realise the stated purpose, without requiring any special mechanical design or operation, provides flow control in equal proportion with the ball valve in applications where flow control is important in terms of precision.

This control is carried out by applying the following processes,

❖ determination of the size parameter inputs of the sphere,

❖ calculation of the field aperture according to the sphere rotation angle with multi - paradigm numerical calculation software,

❖ obtaining the normal characteristic flow rate values for each degree of rotation by considering constant the pressure difference by means of Bernoulli equation and the area calculated in the previous process,

❖ obtaining the normal characteristic flow rate percentage graph curve according to degree rotation percentage,

❖ obtaining the control signal percentage and the equal proportional graph curve, ❖ obtaining the curve equation for the normal characteristic (percentage of the required angle with respect to the percentage of the flow rate) by the least squares method,

❖ obtaining the curve equation for the equal proportional characteristic (percentage of the required flow rate with respect to the percentage of the signal) by the least squares method,

❖ detection of the control signal (e.g. 4 - 20mA, 0 - 10 V, etc.),

❖ calculation of the control signal as a percentage by the software,

❖ calculating the required flow rate percentage by entering the control signal percentage by the software into the obtained curve equation,

❖ calculating the angle percentage by entering the flow percentage calculated by the software into the curve equation,

❖ calculating the angle value required for rotation of the valve sphere according to the angle percentage calculated by the software, and

❖ reaching to the angle value required for rotation of the valve sphere by the control mechanism.

The structural and characteristic features and all advantages of the invention will be more clearly understood by means of the figures given below and the detailed description written by making references to these figures, and therefore, the evaluation should be made by taking these figures and detailed description into consideration.

Figures to Help Understanding of the Invention

Figure 1 is a schematic illustration of a preferred embodiment of the system subject of the invention.

Figure 2 is a schematic illustration of an embodiment of the system subject of the invention.

Figure 3 is a representative representation of the aperture area of the sphere in the system subject of the invention.

Figure 4 is a top view of the sphere in the system subject of the invention. Figure 5 is the top view of the sphere in the system subject of the invention and having a degree - dependent change.

Figure 6 is the normal flow characteristic graph of the ball valve in the system subject of the invention.

Figure 7 is a graph of the equal proportional flow characteristics in the system subject of the invention.

Figure 8 is the flow diagram of the method subject of the invention.

Description of Part References

1 . System

2. Ball valve

3. Flowmeter

4. Sphere

5. Actuator

6. Signal generator

7. Control unit

8. Sensor

1000. Method

A. Flowing liquid

B. Measurement point

Detailed Description of the Invention

In this detailed description, the preferred embodiments of the system (1 ) and method (1000) of subject matter of the invention are described only for a better understanding of the subject matter.

The present invention relates to a system (1 ) and method (1000) for controlling equal proportional flow rate under constant pressure difference by means of an electrical signal for ball valves (2) without V port feature, which are used in applications where V port ball valves (2) are used and high precision is critical where flow characteristics are important.

The system (1 ) of subject matter of the invention, the schematic representation of which is shown in Figure 1 includes the following;

❖ ball valve (2) having an outlet element which opens and closes depending on the condition in installations containing flowing liquid (A), and which controls and transmits the liquid (A) flowing through it,

❖ flowmeter (3), which is used to control the flow rate and to observe that the flow rate progresses in equal proportionally and thus measures the amount of flow in the ball valve (2),

❖ sphere (4) for switching the flow of liquid (A) on and off,

❖ actuator (5) for rotating the sphere (4) and transmitting the position information of the sphere (5),

❖ signal generator (6) which provides a variable current / voltage electrical signal to the flowmeter (3) and actuator (5),

❖ having a microprocessor that provides complex numerical calculations, receives the position information of the sphere (4) and the pressure information of the flowing liquid (A) between the inlet and outlet of the sphere (4) by means of electrical signals from the signal generator (6), and software loaded into the microprocessor, which performs the functions of the embedded system and the functions of the algorithms and the decision mechanism that determines the behaviour of the actuator (5), a computer or similar control unit (7) that enables the sphere (4) to perform equal proportional flow by means of the parameters obtained as a result of the area calculations performed by the software it has, controls all these operations in a cycle thanks to the microprocessor, software, equations and parameters, and decides at which angle and how long the sphere (4) will rotate, performs these operations automatically and thus adjusts the flow characteristic curve in equal proportion. System (1 ) provides flow control in equal proportion with ball valve (2) in applications where flow control is important in terms of precision, without requiring any special mechanical design or operation.

All calculations in the system (1 ) are performed by means of the software in the control unit (7).

The following calculations are performed using the sphere (4) span area representation in Figure 3 and the parameters in the sphere (4) top view in Figure 4.

Sphere (4) Aperture Area Calculation with Integral Formula;

Ball Valve (2) Reference Starting Angle

Ball Valve (2) Opening Reference Angle;

If the total rotation angle is assumed to be 90 degrees for the ball valve (2), the maximum value of the rotation angle forming the opening is eturnmax and the initial value of the opening formation is

With these assumptions, at’s are calculated for all and if are calculated with the obtained results, the intersection area for each degree value is calculated. Degree values can be changed according to the desired precision.

Calculation of the intersection of the sphere (4) whose top view is given in Figure 5 depending on the degree is realised as follows;

With the help of Bernoulli's equation, the theoretical flow rate is calculated with the help of the following formula according to the constant pressure difference;

A _g = Ball Valve (2) inlet cross section constant,

Ac = Ball Valve (2) cross section is variable, Ac=i4fc. rtn, 2 = flow rate point 1 and point 2,

Pi ,2 = pressure point 1 and point 2, p = specific gravity, g = gravitational acceleration,

If the equation of the velocity ratio are arranged by taking into account the Bernoulli equation and the flow rate equation,

According to the constant pressure difference (AP), the expression of the flow rate depending on the cross - section is Equation No. 3.

% rhi,2 is calculated for each

For each Ak value is calculated. According to this degree, the Flow Percentage is calculated by accepting AP as constant from Bernoulli equation.

The polynomial equation of the degree percentage and flow percentage graph is extracted with R=99 (Least squares method). This polynomial equation is embedded into the software as Normal Characteristic.

Afterwards, the same process is obtained for the Equal Proportional graph according to the required flow rate and signal percentage. The obtained polynomial equation is embedded in the software.

Calculation of the percentage of the required flow rate according to the percentage of the signal from the algorithm equal proportional equation,

Then calculate the angle degree to be travelled according to the value of the flow percentage, s= Angle Degree,

Thanks to these calculations, with the polynomial constants obtained as output, the ball valve (2) moves according to the incoming signal percentage and the Equal Proportional percentage.

The flow characteristic curve without applying algorithm to the sphere (4) in Figure 4 is shown in Figure 6.

Figure 7 shows the flow characteristic curve with the algorithm applied to the sphere (4) in Figure 4. From the flow characteristic curves shown in Figure 6 and Figure 7, the behaviour of the flow depending on the opening and closing degrees of the sphere (4) (opening - closing degree flow amount) is observed. In Figure 6 (without the implementation of the algorithm), the amount of water flow (depending on the opening degree of the sphere (4)) suddenly accelerates and reaches the saturation point. In this case, no matter what the opening degree of the sphere (4) is, since the flow has reached the saturation point, the movement adjustment range of the opening degree that the sphere (4) will show against the flow amount is very small.

In Figure 7 (the implemented version of the algorithm), the variation of the water flow rate depending on the opening degree of the sphere (4) is observed. No matter what the opening - closing degree of the sphere (4) is, the flow increases or decreases in the same proportion. In this case, it is quite easy to control the flow.

The method (1000) of subject matter of the invention, the flow diagram of which is shown in Figure 8 includes the following steps;

❖ determining the parameter inputs of the diameter, passage diameter and width of the sphere (4), in the ball valve (2) and entering them into the software in the microprocessor of the control unit (7) (1001 ),

❖ calculation of the area aperture by means of a multi - paradigm numerical calculation software according to the rotation angle informations of the sphere (4) by means of the control unit (7) providing complex numerical calculations (1002),

❖ obtaining the normal characteristic flow rate values for each rotation degree by means of the control unit (7), the Bernoulli equation and the area calculated in the previous process, assuming the pressure difference to be constant (1003),

❖ obtaining the graphical curve of the normal characteristic flow rate percentage according to the degree rotation percentage by means of the control unit (7) (1004), ❖ obtaining the control signal percentage and the equal proportional graphic curve by means of the control unit (7) as a result of the electrical signals transmitted from the signal generator (6) (1005),

❖ obtaining the curve equation for the normal characteristic (percentage of the required angle according to the percentage of flow rate) by the least squares method by means of the control unit (7) (1006),

❖ obtaining the curve equation for the equal proportional characteristic (percentage of the flow rate required according to the percentage of the signal) by the least squares method by means of the control unit (7) (1007),

❖ detecting by the microprocessor in the control unit (7) of the control signal (e.g. 4 - 20mA, 0 - 10 V, etc.) transmitted by means of the actuator (5) via the signal generator (6) (1008),

❖ calculation as percentage of the control signal transmitted from the signal generator (6) by means of the software and parameters in the microprocessor in the embedded system of the control unit (7), thanks to the parameters obtained as a result of the equations obtained in steps 1003 and 1004 and embedded in the software (1009),

❖ calculation of the required flow percentage by entering the control signal percentage by the software into the curve equation with the least squares method by means of the software in the microprocessor (1010),

❖ calculating the angle percentage by entering the calculated required flow percentage into the curve equation by the least squares method by means of the software and parameters in the control unit (7) (1011 ),

❖ calculating the angle value at which the sphere (4) should rotate by means of the software and parameters in the control unit (7) according to the calculated angle percentage (1012),

❖ as a result of actuator (5) rotates the sphere (4) in the on - off direction as a result of calculation processes and incoming electrical signals and provides position feedback,

❖ querying whether the sphere (4) has reached the angle value required for rotation by means of the software and parameters in the control unit (7) (1013) and reaching the rotation of the sphere (4) to the required angle value by means of the actuator (5) (1014).

In the method (1000) of subject matter of the invention, firstly the ball (4) diameter, ball (4) passage diameter and ball (4) width informations of the ball valve (2) are obtained by applying measurement techniques with a measuring apparatus (1001 ). With the control unit (7), which provides complex numerical calculations, the process of calculating the area opening according to the rotation angle is applied (1002). The normal characteristic flow rate value is obtained for each degree of rotation by assuming the Bernoulli equation and the area and pressure difference (AP) calculated in 1002 are constant (1003). In the next step, the control unit obtains the graphical curve of the Normal Characteristic flow rate percentage according to (7) degree rotation percentage (1004). As a result of obtaining the control signal percentage and the equal proportional graphical curve, the control unit (7) subtracts all curves (1005). The control unit (7) obtains the curve equations of normal characteristic (1006) and equal proportional characteristic (1007) by using the least squares method (1006) with the curves of items 1004 and 1005 extracted by the least squares method.

In one embodiment of the invention, the system (1 ) comprises a sensor (8) which measures the pressure of the flowing liquid (A) at different measurement points (B), thus calculates the difference in the pressure of the flowing liquid (A) between the inlet and outlet of the sphere (4) and sends the calculation made to the actuator (5) (Figure 2).

The signal generator (6) used in the system (1 ) of subject matter of the invention ensures that the data transmitted from the sensor (8) is transmitted to the microprocessor in the control unit (7). At this point, any sensor (8) related to the actuator (5) which generates a feedback signal (0-10V, 4-20mA) in accordance with the system (1 ) can be used. The microprocessor interprets the signals received through the signal generator (6) by means of the software contained therein and performs the measurement operations (1008). In steps 1003 and 1004, the microprocessor calculates the percentage of the control signal by means of the parameters obtained as a result of the equations obtained and embedded in the software (1009). By defining the control signal percentage as input to the equation of the equal proportional characteristic curve by the software, the flow rate percentage is calculated (1010). The flow percentage calculated by software (7) is defined as input to the equation created for normal characteristic and the angle percentage is calculated (1011 ). According to the calculated angle percentage, the angle value at which the sphere (4) should rotate is determined (1012).

The actuator (5) rotates the sphere (4) in the on - off direction as a result of calculation processes and incoming electrical signals and provides position feedback (1013). When the position of the sphere (4) reaches the calculated degree, the microprocessor, which is the decision mechanism, stops the sphere (4) with all the information received from the peripheral units (1014). All these operations performed by the actuator (5) are controlled in a cycle by means of the microprocessor, software, equations and parameters in the control unit (7) and the actuator (5) decides how much to turn at which angle of the sphere (4).

This is done automatically, so that the flow characteristic curve can be adjusted proportionally.