System and method for cryogenic vaporization using ambient air vaporizer

Patent metadata

Field	Value
Publication number	US-11976789-B2
Application number	US-202117517110-A
Country	US
Kind code	B2
Filing date	Nov 2, 2021
Priority date	Mar 11, 2021
Publication date	May 7, 2024
Grant date	May 7, 2024

Abstract

A vaporization system and control method are provided. Liquid cryogen is provided to first ambient air vaporizer (AAV) units. When an output superheated vapor temperature is less than a threshold, the liquid cryogen is provided to second AAV units. When greater than or equal to the threshold, it is determined whether the second AAV units are defrosted. When defrosted, the liquid cryogen is provided to the second AAV units. When not defrosted, it is determined whether ice has formed on the first AAV units. When not formed, it is again determined whether the superheated vapor temperature is less than the threshold. When formed, it is determined whether a current ambient condition is favorable to defrosting the second AAV units. When not favorable, the liquid cryogen is provided to the second bank of AAV units. When favorable, it is again determined whether the superheated vapor temperature is less than the threshold.

First claim

What is claimed is:

1. A method for controlling a cryogenic vaporization system, the method comprising:
providing, via at least one control valve of the cryogenic vaporization system, a liquid cryogen to a first bank of ambient air vaporization (AAV) units;
outputting a superheated vapor from the first bank of AAV units;
determining, by a controller of the cryogenic vaporization system, whether a temperature of the output superheated vapor is less than a temperature threshold;
when the temperature of the output superheated vapor is less than the temperature threshold, switching, via the at least one control valve, the provision of the liquid cryogen to a second bank of AAV units, wherein the second bank of AAV units is connected in parallel with the first bank of AAV units;
monitoring defrosting of the second bank of AAV units using at least one of an infrared (IR) camera and a temperature sensor associated with the second bank of AAV units
when the temperature of the output superheated vapor is greater than or equal to the temperature threshold, determining, by the controller, whether the second bank of AAV units is defrosted;
when the second bank of AAV units is defrosted, switching, via the at least one control valve, the provision of the liquid cryogen to the second bank of AAV units.

2. The method of claim 1 , further comprising detecting, via a sensor, the temperature of the output superheated vapor.

3. The method of claim 1 , further comprising:
when the second bank of AAV units is not defrosted, determining, by the controller, whether ice has formed on the first bank of AAV units;
when ice has not formed on the first bank of AAV units, repeating steps beginning with the determination of whether the temperature of the output superheated vapor is less than the temperature threshold.

4. The method of claim 3 , further comprising monitoring formation of the ice on the first bank of AAV units using at least one of an IR camera and a temperature sensor associated with the first bank of AAV units.

5. The method of claim 3 , further comprising:
when ice has formed on the first bank of AAV units, determining, by the controller, whether a current ambient condition is favorable to defrosting the second bank of AAV units;
when the current ambient condition is not favorable to defrosting of the second bank of AAV units, switching, via the at least one control valve, the provision of the liquid cryogen to the second bank of AAV units; and
when the current ambient condition is favorable to defrosting the second bank of AAV units, repeating steps beginning with the determination of whether the temperature of the output superheated vapor is less than the temperature threshold.

6. The method of claim 5 , further comprising determining the current ambient condition based on at least one of current ambient weather monitored at a weather station coupled to the controller, a remaining runtime for the first bank of AAV units, a temperature at the second bank of AAV units, and frost and ice profiles and behavior at the second bank of AAV units.

7. A cryogenic vaporization system, the system comprising:
a first bank of ambient air vaporization (AAV) units configured for receiving a liquid cryogen and outputting a cryogenic vapor;
a second bank of AAV units configured for receiving the liquid cryogen and outputting the superheated vapor, the second bank of AAV units being connected in parallel with the first bank of AAV units;
at least one control valve providing liquid cryogen to one of the first bank of AAV units and the second bank of AAV units;
a sensor that detects a temperature of the superheated vapor output from the first bank of AAV units and the second bank of AAV units;
a first plurality of sensors configured for measuring a surface temperature at the second bank of AAV units, the first plurality of sensors comprising at least one of an infrared (IR) camera and a temperature sensor;
a controller configured to:
determine, via the sensor, whether the temperature of the superheated vapor is less than a temperature threshold;
control the at least one control valve to switch the provision of the liquid cryogen to the second bank of AAV units, when the temperature of the output superheated vapor is less than the temperature threshold;
determine whether the second bank of AAV units has defrosted based on the first plurality of sensors, when the temperature of the output superheated vapor is greater than or equal to the temperature threshold; and
control the at least one control valve to switch the provision of the liquid cryogen to the second bank of AAV units, when the second bank of AAV units is defrosted.

8. The cryogenic vaporization system of claim 7 , further comprising a second plurality of sensors measuring a surface temperature at the first bank of AAV units, wherein the controller is further configured to:
determine whether ice has formed on the first bank of AAV units based on the second plurality of sensors, when the second bank of AAV units is not defrosted; and
when ice has not formed on the first bank of AAV units, repeat steps beginning with the determination of whether the temperature of the output superheated vapor is less than the temperature threshold.

9. The cryogenic vaporization system of claim 8 , wherein the second plurality of sensors comprises at least one of an infrared (IR) camera and a temperature sensor associated with the first bank of AAV units.

10. The cryogenic vaporization system of claim 8 , further comprising a weather station coupled to the controller and monitoring a current ambient weather condition, wherein the controller is further configured to:
determine, based on the weather station, whether a current ambient condition is favorable to defrosting the second bank of AAV units, when ice has formed on the first bank of AAV units;
when the current ambient condition is not favorable to defrosting of the second bank of AAV units, control the at least one control valve to switch the provision of the liquid cryogen to the second bank of AAV units; and
when the current ambient condition is favorable to defrosting the second bank of AAV units, repeat steps beginning with the determination of whether the temperature of the output superheated vapor is less than the temperature threshold.

11. The cryogenic vaporization system of claim 10 , wherein the controller is further configured to:
determine the current ambient condition based on at least one of the current ambient weather condition, a remaining runtime for the first bank of AAV units, a temperature at the second bank of AAV units, and frost and ice profiles and behavior at the second bank of AAV units.

Assignees

• Liang Chao
• Rosen Lee J
• Potratz Seth A
• Tuo Hanfei
• Ranjan Rakesh
• Praxair Technology Inc

Inventors

• Liang Chao
• Rosen Lee J
• Potratz Seth A
• Tuo Hanfei
• Ranjan Rakesh

Classifications

• F17C9/04 Primary

  Recovery of thermal energy · CPC title

• F17C2223/0161

  cryogenic, e.g. LNG, GNL, PLNG · CPC title

• F17C2250/032

  using computers · CPC title

• F17C2250/0631

  Temperature · CPC title

• F17C7/04 Primary

  with change of state, e.g. vaporisation · CPC title