Automated re-melt control systems

Patent metadata

Field	Value
Publication number	US-11592144-B2
Application number	US-202016854524-A
Country	US
Kind code	B2
Filing date	Apr 21, 2020
Priority date	Sep 9, 2016
Publication date	Feb 28, 2023
Grant date	Feb 28, 2023

Abstract

A system may automatically control a pipeline heating system to maintain a desired temperature and/or to provide flow assurance of process fluid along a pipeline. The system may identify the occurrence and location of the solidification of a given process fluid or the melting of the given process fluid by monitoring temperatures along the pipeline and identifying from the monitored temperatures the occurrence and location of a latent heat signature associated with the solidification or melting of the given process fluid. The system may calculate and display fill percentages of the solidified process fluid at locations along the pipeline. The system may determine the percentage of a given section of pipeline that is filled with solid and/or liquid process fluid on a meter-by-meter basis. The system may perform automated re-melt operations to resolve plugs of solidified process fluid that may occur in the pipeline.

First claim

What is claimed is:

1. A control system for use with a pipeline that transports a process fluid and a heating system that applies thermal energy to the pipeline, the control system comprising:
a sensor network configured to record pipeline data, the sensor network comprising a plurality of temperature sensors at a plurality of locations along the pipeline; and
a controller in electronic communication with the sensor network, the controller comprising a processor and memory storing specific computer-executable instructions that, when executed by the processor, cause the controller to:
receive the pipeline data from the sensor network;
determine, based on the pipeline data, a plurality of rates of change of a plurality of temperatures at the plurality of locations along the pipeline over time;
determine, based on one or more of the plurality of rates of change, that a plug of solidified process fluid is in the pipeline at a first location; and
cause, via electronic communication with a client system, a graphical user interface of a client system to display a representation of the plug at the first location.

2. The control system of claim 1 , wherein the sensor network comprises a fiber optic based distributed temperature sensing (DTS) system.

3. The control system of claim 2 , wherein execution of the instructions by the processor further causes the controller to:
generate, based on the pipeline data, a distribution of solidified process fluid along a section of the pipeline that includes the first location of the plug; and
cause, via communication with a client system, the distribution to be displayed via a graphical user interface of the client system.

4. The control system of claim 3 , wherein the controller, to generate the distribution of the solidified process fluid, calculates a plurality of fill percentages representing, respectively, an amount of process fluid that is present at each location of a subset of the plurality of locations included in the section of the pipeline.

5. The control system of claim 4 , wherein execution of the instructions by the processor further causes the controller to:
control the heating system to uniformly heat the section of the pipeline to a pre-melt temperature that is a predetermined number of degrees below a melting point of the solidified process fluid; and
cause the heating system to initiate a re-melt process in which the heating system increases the temperature of the section of the pipeline to at least the melting point of the solidified process fluid.

6. The control system of claim 5 , wherein execution of the instructions by the processor further causes the controller to:
receive, from the sensor network, a subset of the pipeline data during the re-melt process;
determine, based on the subset of the pipeline data, that at least a portion of the solidified process fluid in the section of the pipeline has undergone a spatially non-uniform phase change; and
cause the heating system to stop the re-melt process and to return the temperature of the section of the pipeline to near a melting point of the solidified process fluid.

7. A method for thermal management of a pipeline, comprising:
recording pipeline data corresponding to temperature characteristics of the pipeline;
determining a plurality of pipeline temperature rates of change corresponding to a plurality of locations along the pipeline over time;
determining based on a first pipeline temperature rate of change of the plurality of pipeline temperature rates of change, that a plug of solidified process fluid is in the pipeline at a first location; and
displaying a representation of the plug at the first location.

8. The method of claim 7 , wherein the pipeline data is recorded by a sensor network that comprises a fiber optic based distributed temperature sensing (DTS) system.

9. The method of claim 7 , further comprising:
instructing a heating system to apply power to heaters in a first heating zone of the pipeline corresponding to the first location; and
instructing the heating system to maintain a second heating zone of the pipeline at a stagnant line set point temperature.

10. The method of claim 9 , further comprising:
generating, based on the pipeline data, a distribution of solidified process fluid along a section of the pipeline that includes the first location; and
displaying a graphical representation of the distribution of the solidified process fluid along the section of the pipeline.

11. The method of claim 10 , further comprising:
determining, based on the pipeline data, that a length of the plug is greater than a predetermined length;
instructing the heating system to uniformly heat the section of the pipeline to a pre-melt temperature that is a predetermined number of degrees below a melting point of the solidified process fluid; and
instructing the heating system to initiate a re-melt process in which the heating system increases the temperature of the section of the pipeline to at least the melting point of the solidified process fluid.

12. The method of claim 11 , further comprising:
determining, during the re-melt process, that the solidified process fluid in the section of the pipeline is undergoing a spatially non-uniform phase change based on a latent heat signature in the pipeline data corresponding to a drop in heating rate that occurs when the solidified process fluid undergoes a solid-to-liquid phase change.

13. The method of claim 12 , further comprising:
instructing, during the re-melt process in response to determining that the solidified process fluid in the section of the pipeline is undergoing the spatially non-uniform phase change, the heating system to stop the re-melt process and to maintain the temperature of the section of the pipeline near the melting point of the solidified process fluid.

14. The method of claim 10 , wherein generating the distribution of the solidified process fluid along the section of the pipeline comprises:
calculating a fill percentage representing an amount by which the first location of the pipeline is filled with solidified process fluid.

15. The method of claim 14 , wherein calculating the fill percentage representing the amount by which the first location of the pipeline is filled with solidified process fluid comprises:
calculating the fill percentage representing the amount by which the first location of the pipeline is filled with solidified process fluid based on the first pipeline temperature rate of change.

16. A system for use with a pipeline that transports a process fluid and a heating system that applies thermal energy to the pipeline, the system comprising:
a sensor network configured to record temperature data for a pipeline, the temperature data including temperature measurements for each of a plurality of locations along the pipeline over time; and
a controller in electronic communication with the sensor network, the controller comprising a processor and memory storing computer-executable instructions that, when executed by the processor, cause the controller to:
receive the temperature data from the sensor network;
determine, based on the temperature data, a rate of change of temperature of a first location of the plurality of locations of the pipeline;
determine, based on the rate of change of temperature, that solidified process fluid is present in the pipeline at the first location;
determine, based on the temperature data, a fill percentage representing an amount of solidified process fluid estimated to be present at the first location; and
electronically communicat

Assignees

• Nvent Services Gmbh

Inventors

• Chakkalakal Franco A
• Allenspach Mike
• Kalar Kent

Classifications

• F17D5/005

  of gas pipelines, e.g. alarm · CPC title

• F17D5/00

  Protection or supervision of installations (arrangements for protecting foundations E02D31/00; protecting pipes from damage or internal or external wear F16L57/00, against corrosion and scale F16L58/00; investigation of the fluid-tightness of structures G01M3/00) · CPC title

• F17D3/01 Primary

  for controlling, signalling, or supervising the conveyance of a product · CPC title

• F17D1/08 Primary

  for liquids or viscous products (water-main or service pipe systems E03B7/04; domestic hot-water supply systems F24D17/00) · CPC title

• F17D1/084

  for hot fluids (F17D1/086 takes precedence) · CPC title