Management of liquid conduit systems

1. A method for controlling pressure conditions within a liquid conduit system comprising

defining a zone within the liquid conduit system, wherein pressure within the zone is influenced by one or more actuator valves;

defining a first function to be minimised, the first function expressing the average pressure within the zone (AZP);

defining a second function to be minimised, the second function expressing the pressure variability within the zone (PVZ);

minimising the first and second functions;

determining a Pareto efficient solution to a problem of optimal minimisation of both the first and second functions; and

controlling the one or more actuator valves in dependence on the Pareto efficient solution.

2. A method according to claim 1 , wherein one or more locations of the one or more actuator valves are selected in dependence on the Pareto efficient solution.

3. A method according to claim 1 , wherein the zone comprises a plurality of conduits, and each conduit is represented by a weighting factor for constraining the second function.

4. A method according to claim 3 , wherein the weighting factor is generated in dependence on a criticality risk-based parameter of the conduit.

5. A method according to claim 3 , wherein the weighting factor is generated in dependence on a vulnerability risk-based parameter of the conduit.

6. A method according to claim 1 , wherein the Pareto efficient solution is obtained using a series of single-objective mixed integer non-linear programs.

7. A method according to claim 1 , wherein the Pareto efficient solution is obtained using a scalarization method.

8. A method according to claim 1 , wherein the first function is formulated as a weighted sum of nodal pressures within the zone, where a respective weighting factor for each nodal pressure is representative of lengths of conduit connected to corresponding nodes.

9. A computer program product comprising computer executable instructions embodied in a non-transitory computer readable medium for carrying out the method of claim 1 .

10. An apparatus for controlling a liquid conduit system comprising a zone containing one or more actuator valves, the apparatus comprising one or more processors configured to

minimise a first function and a second function, wherein the first function expresses an average pressure within the zone (AZP) and the second function expresses a pressure variability within the zone (PVZ);

calculate a Pareto efficient solution to a problem of optimal minimisation of both the first and second functions; and

control the one or more actuator valves in dependence on the Pareto efficient solution.

11. An apparatus according to claim 10 , wherein one or more of the locations of the one or more actuator valves are selected in dependence on the Pareto efficient solution.

12. An apparatus according to claim 10 , wherein the zone comprises a plurality of conduits, a corresponding weighting factor is ascribed to each conduit, and each weighting factor is applied within the second function.

13. An apparatus according to claim 12 , wherein the weighting factor is generated in dependence on a criticality risk-based parameter of the conduit.

14. An apparatus according to claim 12 , wherein the weighting is generated in dependence on a vulnerability risk-based parameter of the conduit.

15. An apparatus according to claim 10 , wherein the Pareto efficient solution is obtained using a series of single-objective mixed integer non-linear programs.

16. An apparatus according to claim 10 , wherein the Pareto efficient solution is obtained using a scalarization method.

17. An apparatus according to claim 10 , wherein the first function is formulated as a weighted sum of nodal pressures within the zone, where a respective weighting factor for each nodal pressure is representative of lengths of conduit connected to corresponding nodes.