Dynamic leak detection system in propane heat exchangers

Patent metadata

Field	Value
Publication number	US-2023194162-A1
Application number	US-202117556115-A
Country	US
Kind code	A1
Filing date	Dec 20, 2021
Priority date	Dec 20, 2021
Publication date	Jun 22, 2023
Grant date	—

Abstract

Systems and processes for detecting leaks into a refrigeration system having a heat exchanger where the process side is configured to operate at a higher pressure than the refrigerant side. The system includes a refrigerant circulation system including a refrigerant feed pipe fluidly connected to and configured to provide a refrigerant to an inlet of the refrigerant side of the heat exchanger, as well as a refrigerant effluent pipe fluidly connected to and configured to receive a refrigerant from an outlet of the refrigerant side of the heat exchanger. One or more sensors are provided, the sensors being configured to measure a property of the refrigerant, such as temperature, pressure, or flow rate, for example. Additionally, the system for detecting leaks includes a digital control system configured to provide an alert when a signal from at least one of the one or more sensors is indicative of a leak from the process side of the heat exchanger to the refrigerant side of the heat exchanger.

First claim

What is claimed:

1 . A natural gas processing facility, comprising:
a feed line providing a mixture of acid gases, methane, ethane, propane, and optionally butane and other heavier hydrocarbons; a compression section comprising one or more compressors configured to receive the mixture from the feed line, increase a pressure of the mixture and output a compressed mixture of methane, ethane, propane, and acid gases; a flow line for providing the compressed mixture to a stripper, the stripper configured to separate the compressed mixture into an overhead product comprising the acid gases, methane, ethane, and at least a portion of the propane and a bottoms product comprising propane and any butane and other heavier hydrocarbons; a propane chiller configured to receive the overhead product, chill the overhead product, and output a chilled overhead product; a flow line for providing the chilled overhead product to a deethanizer, the deethanizer configured to separate the chilled overhead product into an overhead fraction comprising the acid gases, methane and ethane, and a bottoms product comprising propane and any butane and other heavier hydrocarbons; an overhead condenser configured to condense at least a portion of the overhead fraction, provide reflux to the deethanizer, and to output an overhead vapor product comprising methane, ethane, and acid gases; a closed loop refrigeration system configured to provide a refrigerant to each of the propane chiller and the overhead condenser; one or more sensors configured to measure a property of the refrigerant, wherein the one or more sensors are disposed along a refrigerant feed line providing a refrigerant flow to the propane chiller or to the overhead condenser, along a refrigerant effluent flow line from the propane chiller or the overhead condenser, or both; a digital control system configured to:
receive a signal from each of the one or more sensors;
provide an alert when a signal from one of the one or more sensors is indicative of a leak of acid gases into the closed loop refrigeration loop.

2 . The system of claim 1 , wherein the one or more sensors comprise a pressure sensor configured to measure a pressure of the refrigerant in the refrigerant system; a temperature sensor configured to measure a temperature of the refrigerant in the refrigerant system; and a flow rate sensor configured to measure a flow rate of the refrigerant flow in the refrigerant system.

3 . The system of claim 1 , wherein the one or more sensors comprise:
a feed temperature sensor disposed along a refrigerant feed line providing a refrigerant flow to the propane chiller, and an effluent temperature sensor along a refrigerant effluent flow line from the propane chiller, and wherein the digital control system is configured to provide an alert based upon a temperature of the effluent temperature sensor, a difference in temperature between the feed temperature sensor and the effluent temperature sensor, or both; and a condenser feed temperature sensor disposed along a refrigerant feed line providing a refrigerant flow to the overhead condenser, and an effluent temperature sensor along a refrigerant effluent flow line from the overhead condenser, and wherein the digital control system is configured to provide an alert based upon a temperature of the condenser effluent temperature sensor, a difference in temperature between the condenser feed temperature sensor and the condenser effluent temperature sensor, or both.

4 . The system of claim 1 , wherein the one or more sensors comprise:
a feed pressure sensor disposed along a refrigerant feed line providing a refrigerant flow to the propane chiller, and an effluent pressure sensor along a refrigerant effluent flow line from the propane chiller, and wherein the digital control system is configured to provide an alert based upon a pressure of the effluent pressure sensor, a difference in pressure between the feed pressure sensor and the effluent pressure sensor, or both; and a condenser pressure temperature sensor disposed along a refrigerant feed line providing a refrigerant flow to the overhead condenser, and a condenser effluent pressure sensor disposed along a refrigerant effluent flow line from the overhead condenser, and wherein the digital control system is configured to provide an alert based upon a pressure of the condenser effluent pressure sensor, a difference in pressure between the condenser feed pressure sensor and the condenser effluent pressure sensor, or both.

5 . The system of claim 1 , wherein the one or more sensors comprise:
a feed temperature sensor disposed along a refrigerant feed line providing a refrigerant flow to the propane chiller, and an effluent temperature sensor along a refrigerant effluent flow line from the propane chiller, and wherein the digital control system is configured to provide an alert based upon a temperature of the effluent temperature sensor, a difference in temperature between the feed temperature sensor and the effluent temperature sensor, or both; a condenser feed temperature sensor disposed along a refrigerant feed line providing a refrigerant flow to the overhead condenser, and an effluent temperature sensor along a refrigerant effluent flow line from the overhead condenser, and wherein the digital control system is configured to provide an alert based upon a temperature of the condenser effluent temperature sensor, a difference in temperature between the condenser feed temperature sensor and the condenser effluent temperature sensor, or both; a feed pressure sensor disposed along a refrigerant feed line providing a refrigerant flow to the propane chiller, and an effluent pressure sensor along a refrigerant effluent flow line from the propane chiller, and wherein the digital control system is configured to provide an alert based upon a pressure of the effluent pressure sensor, a difference in pressure between the feed pressure sensor and the effluent pressure sensor, or both; and a condenser pressure temperature sensor disposed along a refrigerant feed line providing a refrigerant flow to the overhead condenser, and a condenser effluent pressure sensor disposed along a refrigerant effluent flow line from the overhead condenser, and wherein the digital control system is configured to provide an alert based upon a pressure of the condenser effluent pressure sensor, a difference in pressure between the condenser feed pressure sensor and the condenser effluent pressure sensor, or both.

6 . The system of claim 1 , wherein the closed loop refrigeration system comprises a compressor for compressing the refrigerant, wherein the one or more sensors comprise a sensor configured to measure a load on the turbine, and wherein the control system is configured to provide an alert when a turbine work load is indicative of leak.

7 . The system of claim 1 , wherein the control system is configured to isolate the propane chiller when the one or more sensors are indicative of a leak in the propane chiller, and wherein the control system is configured to isolate the overhead condenser when the one or more sensors are indicative of a leak in the overhead condenser.

8 . A system for detecting leaks into a refrigeration system, the system comprising:
a heat exchanger comprising a process side and a refrigerant side, the process side configured to operate at a higher pressure than the refrigerant side; a refrigerant circulation system including:
a refrigerant feed pipe fluidly connected to and configured to provide a refrigerant to an inlet of the refrigerant side of the heat exchanger;
a refrigerant effluent pipe fluidly connected to and configured to receive a refrigerant from an outlet of the refrigerant side of the heat exchanger;

Assignees

• Saudi Arabian Oil Co

Inventors

• Prasetiyo Soelistiono Koesoemo
• Almimouny Yazeed Menwer
• Almansour Moath Khalid

Classifications

• F25J2220/66

  Separating acid gases, e.g. CO2, SO2, H2S or RSH · CPC title

• F25J2215/66

  Butane or mixed butanes · CPC title

• F25J2215/60

  Methane · CPC title

• F25J3/0219

  Refinery gas, cracking gas, coke oven gas, gaseous mixtures containing aliphatic unsaturated CnHm or gaseous mixtures of undefined nature · CPC title

• F25J2270/20

  Quasi-closed internal or closed external hydrogen refrigeration cycle · CPC title