IE20180220A1

IE20180220A1 - A control panel device for a water service reservoir

Info

Publication number: IE20180220A1
Application number: IE20180220A
Authority: IE
Inventors: Desmond Mcalonan Roy
Original assignee: Northern Ireland Water Ltd
Priority date: 2017-09-26
Filing date: 2018-07-23
Publication date: 2019-07-24
Also published as: GB2566747A; GB2566747B; GB201715569D0; IE87127B1

Abstract

The present invention relates a user control panel device for monitoring and control of a water service reservoir of the type comprising at least one water tank, an inlet for receiving water into the tank, an outlet through which water flows out of the tank, water level sensing means and flow control valve means, wherein the user control panel device is communicatively coupled to the flow control valve means and the water level sensing means and has programmable logic controller (PLC) means operable to provide a plurality of user settable operating modes according to which control signals are transmitted from the programmable logic controller (PLC) means to the flow control valve means to control the flow of water into the tank. Also provided is a monitoring and control system for a water service reservoir comprising such a user control panel device. <Figure 1>

Description

In the water industry, water has to be sourced, taken through a treatment process and distributed to customers. Typically, the central point of distribution of water is at a high level 5 location where water gravitates from a tank or tanks through water pipes which provide the means of transporting and delivering water to customers at lower locations. An on-site tank, control room and associated on-site equipment and connecting pipe work collectively form what is known as a “service reservoir” (SR).

A service reservoir needs to have a means to control the water that gravitates into its tank. This can be achieved by controlling a valve fitted to the inlet pipe work of the SR. At the outlet pipe work of the SR, water gravitates through the outlet pipe work to customers located below the SR level of location. The outlet flow will vary depending on customer demand for water. If SR control is inadequate then the SR tank can go empty, interrupting 15 water supply to customers or if there is low customer demand the tank can overflow, needlessly losing water that has flowed into the tank.

The present invention therefore provides a user control panel device for monitoring and control of a water service reservoir of the type comprising at least one water tank, an inlet 20 for receiving water into the tank, an outlet through which water flows out of the tank, water level sensing means and flow control valve means, wherein the user control panel device is communicatively coupled to the flow control valve means and the water level sensing means and has programmable logic controller (PLC) means operable to provide a plurality of user settable operating modes according to which control signals are transmitted from 25 the programmable logic controller (PLC) means to the flow control valve means to control the flow of water into the tank.

Preferably, the control panel device provides a user settable operating mode in which an operator manually actuates a control switch provided on the control panel device to transmit 30 control signals to operate the valve means of the inlet.

Preferably, the control panel device provides a user settable operating mode in which control signals to operate the flow control valve means of the inlet are generated according to a user programmed set point. -2Preferably, the control panel device provides a user settable operating mode in which control signals to operate the flow control valve means of the inlet are generated according to a set point computed by the programmable logic controller (PLC) means.

Preferably, the control panel device provides a user settable operating mode in which a remote operator inputs a set point at user interface means of a remote telemetry station, wherein the set point is transmitted to the programmable logic controller (PLC) means which generates control signals to operate the flow control valve means of the inlet according to the set point.

Preferably, the control panel device provides a user settable operating mode in which the programmable logic controller (PLC) means uses a previously received, used or stored set point to generate control signals to operate the flow control valve means of the inlet.

Preferably, the control panel device provides a user settable operating mode in which a set point is calculated based on set points from a plurality of other water service reservoirs in a network thereof communicatively coupled to a remote master telemetry station.

Preferably, the set point corresponds to one or both of: a target volume of water in the tank and a flow rate of water into the tank at the inlet. The present invention thus provides for water level control in the tank as well as the control of flow rate of water into the tank. The set points may therefore be configured to control flow rates of water via the inlet, and also water tank levels as a result of various events. The tank also provides additional capacity (known as head room) in case there is a burst. This provides extra time to fix a downstream burst before the tank goes empty.

Preferably, the control panel device as claimed is further configured to interface with telemetry means.

Preferably, the operating parameters monitored by the telemetry means comprise one or more of: water pressure at the inlet of the tank; water flow rate at the inlet of the tank; water flow rate at the outlet of the tank; water levels within the tank; residual chlorine levels in water in the tank, at the inlet or at the outlet; lighting levels and heating levels of the control room. -3Preferably, the control panel device is operable to interface with the telemetry means and display values based on the monitored operating parameters of the service reservoir at display means of the control panel device.

Preferably, the programmable logic controller (PLC) means comprises: a processor unit adapted for analogue and digital input and output modules for signal processing; a programmable logic controller (PLC) specific software program for the service reservoir; communications means to provide for wired and/or wireless communication between the programmable logic controller (PLC) means and user interface means of the control panel device and between the programmable logic controller and telemetry stations. Preferably, an adjusted/corrected flow rate at the water inlet is computed by the programmable logic controller (PLC) means to offset flow from a secondary water source, such as a pumped water flow, into the tank, and control signals for the adjusted/corrected flow rate are transmitted to the flow control valve means.

Preferably, the control panel device further comprises means for mounting within a control room of the service reservoir.

Preferably, by the programmable logic controller (PLC) means of the control panel device the flow control valve means is operated to substantially balance the flow of water into the tank via the inlet with the flow of water out of the tank via the outlet based on water demand from the service reservoir.

Preferably, control signals are transmitted to the flow control valve means from a remote master telemetry station to the programmable logic controller (PLC) means of the control panel device to operate the valve means to control the flow of water into the tank.

Preferably, the control panel device is configured with a universal type plug-in to facilitate interfacing with different types of service reservoirs plant and instrumentation and local/remote telemetry stations. -4Also provided is a monitoring and control system for a water service reservoir comprising a user control panel device as described above. Preferably, the monitoring and control system further comprises telemetry means operable to monitor operating parameters of the service reservoir and to generate telemetry signals corresponding to values of the monitored operating parameters.

The advantages of the present invention include its small compact site package to improve visual appearance, suitability to location, and capital costs. The invention provides a single consistent design with expansion options. The control panel device includes a PLC means having an input and output signal structure that remains consistent and common for typical service reservoir’s used in the water industry. The control panel device provide a means to monitor the communications link between the site control panel device, a site telemetry panel and a remote master telemetry station. The control panel device system provides various control choices including full remote auto control (via remote telemetry master station) functionality; on site local auto control functionality (via the PLC) and on site local manual control functionality (via user interface means and PLC or potentiometer and PLC). The user interface means of the present invention may be provided as a human to machine interface (HMI).

The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic diagram showing a user control panel device for monitoring and control of a water service reservoir according to the invention; Figure 2 is a schematic diagram of the user control panel device of Figure 1 communicatively coupled to a water service reservoir; and Figures 3a and 3b are flow diagrams showing steps in the calculation of inlet flow set points according to the invention.

Referring to the drawings, shown is a user control panel device 1 for monitoring and control of a water service reservoir, indicated generally by the reference numeral 2, of the type comprising at least one water tank 3, an inlet 4 for receiving water from a source water -5supply into the tank 3, an outlet 5 through which water flows out of the tank for distribution to customers, water level sensing means 6 and flow control valve means 7. The inlet 4 and outlet 5 may each be configured as separate chambers through which water flows, and in which at the inlet 4 there is provided pressure sensor means 10, an inlet flow meter 11 and inlet lighting means 12; and at the outlet 5 there is provided an outlet flow meter 13, a chlorine pump means 14, outlet lighting means 15 and chlorine level analyser means 16.

The user control panel device 1 is communicatively coupled to the flow control valve means 7 and the water level sensing means 6 and has programmable logic controller (PLC) means 8.

The programmable logic controller (PLC) means 8 comprises a processor unit adapted for analogue and digital input and output modules for signal processing and a programmable logic controller (PLC) specific software program 17 for the monitoring and control of the service reservoir 2. The programmable logic controller (PLC) means 8 also includes communications means to provide for wired and/or wireless communication between the programmable logic controller (PLC) means and user interface means (HMI) 18 of the control panel device 1 and between the programmable logic controller (PLC) means 8 and telemetry stations.

The control panel device 1 is also configured to interface with telemetry means 9 in which operating parameters monitored by the telemetry means comprise one or more of: water pressure at the inlet; water flow rate at the inlet of the tank; water flow rate at the outlet of the tank; water levels within the tank; residual chlorine levels in water in the tank, at the inlet or at the outlet; lighting levels and heating levels of the control room. Values based on the monitored operating parameters are displayed at display means on the user interface means (HMI) 18of the control panel device 1.

The control panel device 1 is mounted within a control room 19 of the service reservoir 2. Heating means 20 and lighting means 21 are typically provided in the control room 19. The control panel device 1 is further configured with a universal type plug-in to facilitate interfacing with different types of service reservoirs’ instrumentation and plant and local/remote telemetry stations. -6The programmable logic controller (PLC) means 8 is operable to provide a plurality of user settable operating modes according to which control signals are transmitted from the programmable logic controller (PLC) means 8 to the flow control valve means 7 to control the flow of water into the tank 3 via the inlet 4.

In a first of such user settable operating modes an operator manually actuates a control switch provided on the control panel device 1 to transmit control signals to operate the valve means of the inlet.

In this mode the “automatic/ hand switch on the front of the control panel device 1 is switched to “hand”. An inlet control valve hand position control potentiometer knob, mounted on the front of the control panel device 1, can then be rotated by the operator between 0 and 100%, that is from valve closed (0%) through to valve fully open (100%). The PLC program 17 continues to monitor only and does not control the position of the flow control valve 7. All level, fail safe and pressure override values may be inhibited in this control mode.

In a further of said user settable operating modes the control signals to operate the flow control valve means 7 of the inlet 4 are generated according to a user programmed set point. Such a set point corresponds to one or both of: a target volume of water in the tank and a flow rate of water into the tank at the inlet and may be provided at the user interface means (HMI) 18 of the control panel device 1.

In this mode an “automatic/ hand” switch on the front of the control panel device 1 is switched to “automatic” and the operator selects “local manual control” within the local control selection screen of the user interface means (HMI) 18. An operator will set at the user interface means (HMI) 18 a flow and position value for the inlet valve set point in which the position set point is only invoked if the inlet flow meter 11 is flagged as not “healthy”.

The PLC software program 17 will then use the inlet flow control valve 7 set point to control the inlet flow by PLC program 17 sending a control signal to the inlet control valve, driving the valve to a point where the actual inlet flow or position becomes equal to the PLC derived set point. An operator using the user interface means (HMI) 18 will set override service reservoir levels’ values, the inlet pressure override value, the level fail safe set point (operates when the level device signals a fault), the corresponding service reservoir level -7override inlet valve set points and the inlet pressure override set point. If a service reservoir level override, level fail safe condition, or pressure override value is reached then the inlet control valve set point is automatically set to the corresponding set point value set for that override or fail safe. When the override or fail safe value returns to normal the PLC returns the set point to its previous value.

In another user settable operating mode the control signals to operate the flow control valve means 7 of the inlet 4 are generated according to a set point computed by the programmable logic controller (PLC) means 8.

In this mode the “automatic/ hand” switch on the front of the control panel device 1 is switched to “automatic” and a user operator selects “local auto control within the local control selection screen of the user interface means (HMI) 18. The flow value for the inlet control valve 7 set point is then calculated by the PLC software program 17 in which the detection of an inlet flow fault will invoke the use of a position set point value entered in the user interface means (HMI) 18 under local manual control as above. The calculation involves taking the average outlet flow over a minimum period of 1 previous day up to a maximum period of 8 or more days. This day time period is set by the operator using the user interface means (HMI) 18. The PLC software program 17 will then use the calculated inlet control valve 7 set point to control the inlet flow by the PLC program transmitting a control signal to the inlet control valve 7, driving the valve to a point where the actual inlet flow becomes equal to the inlet valve calculated set point.

An operator using the user interface means (HMI) 18 will set override service reservoir levels’ values, the inlet pressure override value, the level fail safe set point, the corresponding service reservoir level override inlet valve set points and inlet pressure override set point. If a service reservoir level override, level fail safe condition, or pressure override value is reached then the inlet control valve set point is automatically set to the corresponding set point value set for that override or fail safe. When the override or fail safe value returns to normal the PLC program 17 is operable to return the set point to its previous value.

A further user settable operating mode enables a remote operator to input set point at the user interface means (HMI) 18 of a remote telemetry station, wherein the set point is -8transmitted to the programmable logic controller (PLC) means 8 which generates control signals to operate the flow control valve means 7 of the inlet 4 according to the set point.

In this mode an “automatic/ hand” switch on the front of the control panel device 1 is switched to “automatic”. An off-site operator sends a request to the PLC to establish remote telemetry control. If the PLC has no fault signals, that site functions are functional, then the PLC program 17 sends an acceptance signal to the on-site telemetry panel means 9 which in turn sends a signal via radio link to the off-site telemetry terminal. Remote control is now established.

The off-site operator will set via the remote telemetry terminal override service reservoir levels’ values, the inlet pressure override value, the level fail safe set point and corresponding service reservoir level override inlet valve set points and inlet pressure override set point.

If a service reservoir level override, level fail safe condition, or pressure override value is reached then the inlet control valve set point is automatically set to the corresponding set point value set for that override or fail safe. When the override or fail safe value returns to normal the PLC program 17 returns the set point to its previous value.

Another user settable operating mode is configured so that the programmable logic controller (PLC) means 8 uses a previously received, used or stored set point to generate control signals to operate the flow control valve means 7 of the inlet 4.

In this mode an off-site operator at a remote telemetry terminal will set from the remote terminal a flow value for the inlet control valve set point. The PLC program 17 will then use the off-site operator’s inlet control valve set point to control the inlet flow. Alternatively, in this mode the PLC program 17 will continue to use a set point value that has been generated on site as previously calculated by the PLC program 17. Figs. 3a and 3b show the steps 100 by which the PLC calculates the inlet flow set point.

In another user settable operating mode a set point is calculated based on set points from a plurality of other water service reservoirs in a network thereof communicatively coupled to a remote master telemetry station. -9In this mode the remote telemetry system calculates the flow set point relevant to other sites in a specified network system of service reservoirs. The remote telemetry terminal will set from the remote terminal the flow value for the inlet control valve set point.

An adjusted/corrected flow rate at the water inlet 4 is computed by the programmable logic controller (PLC) means 8 to offset flow from a secondary water source, such as a pumped water flow, into the tank 3, and control signals for the adjusted/corrected flow rate are transmitted to the flow control valve means 7. Accordingly, by the programmable logic controller (PLC) means 8 of the control panel device 1 the flow control valve means 7 is operated to substantially balance the flow of water into the tank 3 via the inlet 4 with the flow of water out of the tank 3 via the outlet 5 based on water demand from the service reservoir 2.

Accordingly, if a pumped water supply is installed at the inlet of the gravity fed service reservoir 2 as an additional inlet source, the associated control panel 1 and inlet flow meter 11 can be hard wired to the control panel 1 such that the PLC program 17 will off-set any inlet flow set point to take into account this pumped inlet flow. At a previously determined time of day, the average flow will be calculated for the pre-defined number of days - the time period. A new inlet flow set point will be the average flow calculated. At that time also, the PLC program 17 will compare the actual service reservoir level against a target level previously inputted by an operator via the user interface means (HMI) 18 or remote telemetry. If there is a difference in the actual level and the target level then the PLC program 17 will automatically adjust the new inlet flow set point to increase or decrease depending on whether the actual level is lower than the target level or higher respectively. Alternatively, if the actual level is higher than the target level the new inlet flow set point can remain unchanged.

Control signals may also be transmitted to the flow control valve means 7 from a remote master telemetry station to the programmable logic controller (PLC) means 8 of the control panel device 1 to operate the flow control valve means 7 to control the flow of water into the tank 3.

The present invention provides for fine control of the flow of water through a service reservoir through the incorporation of the specialist software program 17 which allows for the different control user settable operating mode. All required on site process variables - 10and control signals are displayed on the user interface means (HMD 18 of the control panel device 1 via the specialist software Program 17. The control program 17 is formulated and installed such that once the site has been commissioned and handed over there should no need for additional program modification to meet the specified process measurement and control requirements of the service reservoir.

The inputs and overrides have the facility to be adjusted directly from the user interface means (HMI) 18 of the control panel device 1 and the remote telemetry. All instrumentation is ranged and scaled from the user interface means (HMI) 18 of the control panel device 1 to eliminate any need for expertise to modify the PLC Program 17.

All proportional, integral and differential (PID) and associated control parameters are configurable directly from the user interface means (HMI) 18 of the control panel device 1. All operating parameters are configurable from the user interface means (HMI) 18 of the control panel device 1. Process variable labels are inputted through the user interface means (HMI) 18 of the control panel device 1 to all relevant screens.

Site corporate asset register (CAR) data is inputted through the user interface means (HMI) 18 of the control panel device 1 to all relevant screens. The system is designed to be fault tolerant and can take auto-corrective action and system operating parameters can be adjusted or set remotely. The system monitors the maintenance status of the flow control valve, flow meters, level instrument and chlorine residual analyser.

By virtue of the designed and developed system, the need for technical personnel to carry out maintenance visits is very much reduced. The control panel device 1 has been designed and developed for the water industry ubiquitous service reservoir 2 which typically has an elevated site containing an inlet chamber 4, water tank 3, control room 19, telemetry capability 9, outlet chamber 5 complete with 4-20mA instrumentation and an electrically driven inlet water flow control valve 7.

The control panel device 1 is installed in the service reservoir control room 19 and, once connected to the service reservoir instrumentation, the inlet control valve 7 and the site telemetry 9, provides complete monitoring and control of the service reservoir 2, both locally and remotely. -11 The control panel device 1 has been designed and developed to provide a compact common system that remotely controls an unattended, unmanned gravity fed water service reservoir 2. All monitoring and control activities of the service reservoir 2 are contained within the control panel 1. By installing the control panel 1 within the control room 19 of the service reservoir 2 and hard wiring it to all the necessary service reservoir on-site plant and instrumentation the service reservoir 2 can be monitored and automatically controlled such that the demand for service reservoir 2 water from customers downstream of the service reservoir 2 can be automatically balanced with a controlled flow of water into the service reservoir 2. Also, the flow of water into the service reservoir 2 can be set to match the average customer demanded flow, over a previous number of days, from the service reservoir 2. Further, the control panel 1 includes additional automatic override correction if the service reservoir 2 water level falls outside of normal automatic control expected real time level.

Further, use of telemetry means 9, which is optional, installed on-site at the service reservoir 2, together with a remote telemetry computer terminal will facilitate remote monitoring and modification of the service reservoir 2 control parameters within the on-site control panel device 1 via a communication cable connected from the on-site telemetry means 9 to the control panel device 1.

Additionally, as override and fail safe parameters are incorporated into the control system and as the water level of the service reservoir 2 can be maintained at a chosen high level, resilience is created for the service reservoir water distribution storage capacity. This provides a buffer against the impact of a downstream burst water main pipe such that the risk of the burst water main emptying the service reservoir 2 is reduced.

The on-site control panel device 1 automatically and accurately controls the service reservoir 2 process such that attendance by operational and technical personnel is minimised, thereby increasing the operational and maintenance efficiency of the service reservoir 2.

The control panel device 1 of the present invention may include additional instrumentation as required or as desired with corresponding software expansion modules. -12 It is to be understood that the invention is not limited to the specific details described herein which are given by way of example only and that various modifications and alternations are possible without departing from the scope of the invention as defined in the appended claims.

Claims

1. A user control panel device for monitoring and control of a water service reservoir of the type comprising at least one water tank, an inlet for receiving water into the tank, an outlet through which water flows out of the tank, water level sensing means and flow control valve means, wherein the user control panel device is communicatively coupled to the flow control valve means and the water level sensing means and has programmable logic controller (PLC) means operable to provide a plurality of user settable operating modes according to which control signals are transmitted from the programmable logic controller (PLC) means to the flow control valve means to control the flow of water into the tank.

2. A user control panel device as claimed in Claim 1, in which the control panel device provides a user settable operating mode in which an operator manually actuates a control switch provided on the control panel device to transmit control signals to operate the valve means of the inlet.

3. A user control panel device as claimed in Claim 1 or Claim 2, in which the control panel device provides a user settable operating mode in which control signals to operate the flow control valve means of the inlet are generated according to a user programmed set point.

4. A user control panel device as claimed in any one of the preceding claims, whereby the control panel device provides a user settable operating mode in which control signals to operate the flow control valve means of the inlet are generated according to a set point computed by the programmable logic controller (PLC) means. 5. 21. A monitoring and control system for a water service reservoir as claimed in Claim

5. A user control panel device as claimed in any one of the preceding claims, whereby the control panel device provides a user settable operating mode in which a remote operator inputs a set point at user interface means of a remote telemetry station, wherein the set point is transmitted to the programmable logic controller (PLC) means which generates control signals to operate the flow control valve means of the inlet according to the set point.

6. A user control panel device as claimed in any one of the preceding claims, whereby the control panel device provides a user settable operating mode in which the - 14programmable logic controller (PLC) means uses a previously received, used or stored set point to generate control signals to operate the flow control valve means of the inlet.

7. A user control panel device as claimed in any one of the preceding claims, whereby the control panel device provides a user settable operating mode in which a set point is calculated by the PLC means based on set points from a plurality of other water service reservoirs in a network thereof communicatively coupled to a remote master telemetry station.

8. A user control panel device as claimed in any one of the preceding claims, in which the set point corresponds to one or both of: a target volume of water in the tank and a flow rate of water into the tank at the inlet.

9. A user control panel device as claimed in any one of the preceding claims, which is further configured to interface with telemetry means.

10. A user control panel device as claimed in Claim 9, in which the operating parameters monitored by the telemetry means comprise one or more of: water pressure in the tank; water flow rate at the inlet of the tank; water flow rate at the outlet of the tank; water levels within the tank; residual chlorine levels in water in the tank, at the inlet or at the outlet; lighting levels and heating levels of the control room.

11. A user control panel device as claimed in Claim 10, in which the control panel device is operable to interface with the telemetry means and display values based on the monitored operating parameters of the service reservoir at display means of the control panel device.

12. A user control panel device as claimed in any one of the preceding claims, in which the programmable logic controller (PLC) means comprises: a processor unit adapted for analogue and digital input and output modules for signal processing; a programmable logic controller (PLC) specific software program for the service reservoir; communications means to provide for wired and/or wireless communication between the programmable logic controller (PLC) means and user interface means of the control panel device and between the programmable logic controller and telemetry stations.

13. A user control panel device as claimed in any one of the preceding claims, in which an adjusted/corrected flow rate at the water inlet is computed by the programmable logic controller (PLC) means to offset flow from a secondary water source, such as a pumped water flow, into the tank, and control signals for the adjusted/corrected flow rate are transmitted to the flow control valve means.

14. A user control panel device as claimed in any one of the preceding claims, further comprising means for mounting within a control room of the service reservoir.

15. A user control panel device as claimed in any one of the preceding claims, in which by the programmable logic controller (PLC) means of the control panel device the flow control valve means is operated to substantially balance the flow of water into the tank via the inlet with the flow of water out of the tank via the outlet based on water demand from the service reservoir.

16. A user control panel device as claimed in any one of the preceding claims, in which control signals are transmitted to the flow control valve means from a remote master telemetry station to the programmable logic controller (PLC) means of the control panel device to operate the valve means to control the flow of water into the tank.

17. A user control panel device as claimed in any one of the preceding claims, whereby the control panel device is configured with a universal type plug-in to facilitate interfacing with different types of service reservoirs’ instrumentation and plant and local/remote telemetry stations. 18. A monitoring and control system for a water service reservoir comprising a user control panel device as claimed in any one of the preceding claims. 19. A monitoring and control system as claimed in Claim 18, further comprising telemetry means operable to monitor operating parameters of the service reservoir and to generate telemetry signals corresponding to values of the monitored operating parameters. 20. A user control panel device for monitoring and control of a water service reservoir as claimed in Claim 1 substantially as herein described with reference to and as shown in the accompanying drawings.

18. Substantially as herein described with reference to and as shown in the accompanying drawings.