Abstract:
A valve system has a main valve that is adjustable for output flow and pressure. The system also includes an output flow transducer, an output pressure transducer, and a fluid depth transducer. A microcontroller is operatively coupled to the valve, the output flow transducer, the output pressure transducer, and the fluid depth transducer. The microcontroller operates the valve to selectively control the output flow, the output pressure, and the fluid depth according to inputs received from a user.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the priority of U.S. Provisional Patent Application No. 61/273,333 entitled “MULTI-PROCESS ELECTRONIC CONTROL VALVE SYSTEM,” filed Aug. 3, 2009, the contents of which are hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     This disclosure relates to control valves in general and, more specifically, to control valve systems for fluid wells. 
     BACKGROUND OF THE INVENTION 
     In some areas of the world, access to ground water supplies must be carefully monitored. Existing wells should not be drawn down below a certain level, while at the same time farmers and rancher need reliable access to the well water that is available. In situations where water is plentiful, it is often the case that the amount of water being drawn from a well will need to be within a certain flow rate or pressure range to be suitable to the water system utilizing the well (for example, an irrigation system). 
     In some cases, access to well water may only be needed on a seasonal or sporadic basis. For example, in times of heavy rain, little or no water may be needed for irrigation. In times like these, it is important for 
     What is needed is a system and method for addressing the above and related concerns. 
     SUMMARY OF THE INVENTION 
     The invention of the present disclosure, in on aspect thereof, comprises a valve system. The system has a main valve that is adjustable for output flow and pressure. The system also includes an output flow transducer, an output pressure transducer, and a fluid depth transducer. A microcontroller is operatively coupled to the valve, the output flow transducer, the output pressure transducer, and the fluid depth transducer. The microcontroller operates the valve to selectively control the output flow, the output pressure, and the fluid depth according to inputs received from a user. 
     In some embodiments, the main valve is hydraulically operated and may be diaphragm actuated and pilot controlled. The system may include one ore more electrically actuated solenoid pilot valves attached to the main valve and controlling the main valve in response to a signal from the microcontroller. One pilot valve may be normally open, and when de-energized by the microcontroller act to close the main valve. A needle valve may be operatively connected to the main valve to control the opening speed of the main valve. Another may be connected to the main valve to control the closing speed of the main valve. A check valve may be provided to prevent fluid flow in a reverse direction through the main valve. 
     In some embodiments, a control panel is operatively coupled to the microcontroller for receiving user inputs. A rain holdoff control may be provided for signaling the microcontroller to close the main valve. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a control valve system installed on a well according to aspects of the present disclosure. 
         FIG. 2  is a diagram of a valve assembly according to aspects of the present disclosure. 
         FIG. 3  is schematic diagram of a valve control unit according to aspects of the present disclosure. 
         FIG. 4  is a flow diagram of one method of operation of the valve control system of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The multi-process electronic control valve system as disclosed herein provides at least three functions relating to the control and flow of fluids. These functions are pressure, flow, and fluid depth. Although the embodiments are described with particular reference to an embodiment to be utilized with water wells, it is understood that the device of the present disclosure is readily adaptable to any fluid flow control application needing the functionality disclosed herein. Therefore the examples of the multi-process electronic control valve system in this specification is meant to be exemplary only, and not meant to be limiting in any way. 
     Referring now to  FIG. 1 , a schematic diagram of a control valve system installed on a well according to aspects of the present disclosure is shown. The system  100  is installed onto a water well  102  or other fluid reservoir. The system  100  selectively controls a pressure output, a flow rate, and a well depth, as will be described herein. A water level  104  of the well  102  may be monitored and reported by a depth transducer  106 . An electrical signal indicating a depth of the water  104  or other fluid may be transmitted electronically on an electronic signal line  108 . This information is monitored and utilized by the control unit  110 . In the present disclosure, all transducer signal lines may be analog or digital depending upon the transducer employed. A pump  112  may be submerged in the well  102  or may be placed remotely therefrom. The pump  112  provides fluid under pressure to a valve assembly  200  that may be connected to a well output  114 . In some embodiments, the control unit  110  may also activate and deactivate the pump  112  by pump signal line  113 . 
     The control unit  110  may connect to the valve assembly  200  by at least two signal lines. An open signal line  116  may provide a signal from control unit  110  to valve assembly  200  indicating to open or increase the opening of the valve assembly  200 . A close signal line  118  interconnecting the control unit  110  and the valve assembly  200  may provide for a signal indicating that the valve assembly  200  should be partially or fully closed. 
     A flow transducer  120  may be provided on or near the output  114  for providing an electric signal on signal line  121  to the control unit  110  indicating the flow rate of the output  114 . A pressure transducer  122  may provide a signal on signal line  123  to the control unit  110  indicating a pressure at the output port  114 . It will be appreciated that the control unit  110 , having the combined signals from the depth transducer  106 , the flow transducer  120 , and the pressure transducer  122  may signal the valve assembly  200  to open or close in order to selectively control the depth, flow rate, or pressure of the output  114 . 
     In the present embodiment, the control unit  110  provides for user selection of the monitoring and control function of the system  100 . In order to facilitate interaction with the user, the control unit  110  may provide various I/O devices, including a view screen  124  and a keypad  126 . Via interaction with the system  100 , using the view screen  124  and keypad  126 , a user can control various modes of operation and parameters of the system  100 . 
     Referring now to  FIG. 2 , a diagram of a valve assembly  200  according to aspects of the present disclosure is shown. The valve assembly  200  interacts with the control unit  110  to open and close in response to signals therefrom. The valve assembly  200  may be able to open or close fully, as well as having a high degree of fine tuning and adjustability between the fully closed and fully open positions. A main valve  202  is provided that interposes the pump  112  and the output port  114 . In the present embodiment, the main valve  202  is a hydraulically operated diaphragm actuated and pilot controlled globe valve, but in other embodiments the valve could be victaulic, threaded, or another type of valve. In the present embodiment, the main valve  202  will close with an elastomer on metal seal. In the configuration of the present embodiment, shown in  FIG. 2 , the main valve  202  is interconnected with a needle valve  204  that controls the closing speed of the valve  202 . In order to control the amount of overshoot or hysteresis of the system  100 , the needle valve  204  may be set to a suitable speed to allow the main valve  202  to close with sufficient speed so as to be responsive, but also prevents it from closing so fast as to cause an undesirable amount of overshoot when closing the valve. In some embodiments, the needle valve  204  may be adjustable by the end user. 
     Some embodiments will provide an isolation ball valve  206  in series with the needle valve  204 . A strainer  208  may be provided to protect the components of the fluid circuit from contamination. A check valve  210  may also operate to prevent reverse flow through the needle valve circuit as well. In the present embodiment, the actual closing of the main valve  202  is controlled by an electric solenoid  212 . In the present embodiment, the solenoid  212  is a normally open electric solenoid pilot valve. The solenoid  212  may be electrically connected to the control unit  110  to receive signals therefrom and to close the main valve  202  in response. 
     In order to affect an opening of the main valve  202 , a separate valve circuit is provided for a second solenoid  214 . The solenoid  214  in the present embodiment is a normally open electric solenoid pilot valve. In response to a signal from the control unit  110 , the solenoid  214  will open to cause the main valve  202  to open and thereby increase flow rate and pressure on the output port  114 . An isolation ball valve  216  is provided in parallel with the solenoid  214 . Additional isolation ball valves  218 ,  226  are provided in series. As on the closing side, the opening side provides a needle valve  220  that may be tuned in order to control the opening speed of the valve  202 . As before, the opening speed may be set to provide a requisite degree of responsiveness from the main valve  202  while being slow enough to prevent an undesirable amount of overshoot. A check valve  222  is provided in the circuit to prevent undesirable reverse flow of fluids through the fluid circuit. A strainer  224  aids in preventing contamination of the components. 
     The present embodiment shown in  FIG. 2  provides a position transmission assembly  228  that interconnects with the main valve  202 . This allows the relative degree of opening or closing of the valve  202  to be provided back to the control unit  110 . In some embodiments, this information may be available to the user. In the present embodiment, the information provided by the position transmission assembly  228  is not necessarily needed by the control unit  110 . 
     Referring now to  FIG. 3 , a schematic diagram  300  of a valve control unit according to aspects of the present disclosure is shown.  FIG. 3  provides one possible way in which the control unit  300  can be constructed. It will be appreciated that the control unit  300  is an expansion or elaboration on the control unit  110  shown in  FIG. 1 . The control unit  300  may be based around a microcontroller  302 . The microcontroller  302  may be an integrated circuit or a general purpose microprocessor that has been programmed according to the functionality described herein. The microcontroller  302  is provided to a power supply Vcc  301  and a ground source  304 . These may be based upon a battery system or may be a part of the commercial electric grid. A console  306  connects to the microcontroller  302  via data bus  307 . A video display  308  and a keypad  310  are provided to allow a user to interact with the microcontroller  302 . 
     It can be seen that the microcontroller  302  provides open signal line  116  and closed signal line  118  to the respective pilot valves  214 ,  212 . This enables the microcontroller  302  to affect the opening and closing of the main valve  202 . It is understood that a relay network may actually be provided by the open and closed signal lines  116 ,  118 , if such are needed to effectively power and operate the solenoids  212 ,  214 . 
     The transducers for depth  106 , flow  120 , and pressure  122  may provide their data on signal lines  108 ,  121  and  123 , respectively. These may be read by the microcontroller  302 . It is understood that various signal conditioning and/or analog to digital conversion may take place between the microcontroller  302  and the various transducers. 
     In operation, a user will interact with the microcontroller  302  using the keypad  310  and the display screen  308 . At this point, a user may indicate to the microcontroller  302  which of the selective operations is desired. Operations available to the user may include, but are not limited to: operating the pump  112  and/or valve assembly  200  to maintain a desired fluid level  104  in the well  102 ; maintaining a specified pressure; and maintaining a specified flow rate. It will be appreciated that, in some instances, more than one of these functions may be controlled at a time. However, in other cases owing to limitations of water supply and pressure, it may only be possible to control one of the desired parameters based upon a selection from the user. For example, if the well has plenty of water, the amount of pressure may be the most critical due to limitations of the downstream irrigation system. In other cases, the amount of water flow required (e.g., for crops) may take precedent over the pressure being generated. 
     Referring now to  FIG. 4 , a flow diagram  400  of one method of operation of the valve control system  100  of the present disclosure is shown. At step  402 , it may be determined whether the system has been set on rain hold. If the system has been set on rain hold, this would indicate that the user did not desire for the control unit  110  to do anything. In this case, the control program may end (or restart) and continue querying at step  402  until such time as the rain hold has been released. 
     If at step  402  there is no rain hold, at step  404  the determination may be made by the control unit as to whether the pressure monitoring function has been selected by the user. If so, at step  406  a reading may be taken of the pressure transducer  122  in order to determine whether or not the desired pressure has already been achieved. If the desired pressure has not been achieved, the valve may be adjusted at step  408  and the pressure checked again at step  406 . Through iterations of adjusting the valve  408 , it can be determined when the pressure is within the desired threshold at step  406 . Once the desired pressure has been achieved, the control loop will end or repeat until a different parameter is selected or until the rain hold is re-engaged. 
     It will be appreciated that the step of adjusting the valve  408  may include signaling the valve  202  to open further, or close further, depending on the reading from the appropriate transducer. It may also require several steps of adjusting in order to achieve the desired flow rate or pressure. 
     If the pressure monitor function has not been selected at step  404 , it may be determined at step  410  whether the flow monitor function has been selected. If so, the flow transducer  120  may be checked or queried at step  412  to determine if the flow rate is within the specified range. If not, the valve may be adjusted at step  414 . The flow rate may be again checked at step  412  and the adjustment and checking process repeated until the flow rate is within the desired parameters. At this point, the controller terminates or continues monitoring or waiting for an additional command. 
     If at step  410  the flow monitor function has not been selected, this indicates that the depth control function has been selected by the user. At step  416 , a depth reading may be taken by the depth transducer  106 . Depending upon the signal return from the depth transducer  106 , the valve may be adjusted at step  418 . It will be appreciated that changes in depth may occur much more slowly than changes in flow rate or pressure. Therefore, it may be desirable to limit the amount of valve adjustment that can occur at step  418 . It is also understood that the valve assembly  200  cannot be opened beyond full capacity. Thus, the query at step  412  may also include an accounting of the position of the main valve  202 . If at step  416  the depth  104  has fallen below the specified parameter indicating that the valve assembly  200  should be closed off, the control loop simply waits for further additional commands, as there is no further need to adjust the valve at step  418 . 
     Thus, the present invention is well adapted to carry out the objectives and attain the ends and advantages mentioned above as well as those inherent therein. While presently preferred embodiments have been described for purposes of this disclosure, numerous changes and modifications will be apparent to those of ordinary skill in the art. Such changes and modifications are encompassed within the spirit of this invention as defined by the claims.