Method and system for transport container refrigeration control

Patent metadata

Field	Value
Publication number	US-9766009-B2
Application number	US-201114130958-A
Country	US
Kind code	B2
Filing date	Jul 7, 2011
Priority date	Jul 7, 2011
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

A method of refrigeration control through a refrigeration system of a refrigerated transport container includes performing a defrost cycle on the refrigeration system by activating a heat source; and restarting the refrigeration system after the defrost cycle has completed, wherein restarting the refrigeration system includes performing a liquid slugging avoidance process including: initiating a compressor of the refrigeration system at a speed; opening a pressure equalization valve in parallel with the compressor in response to the initiating; opening a liquid valve in series between a condenser and an evaporator after opening of the pressure equalization valve; and closing the pressure equalization valve after a period of time.

First claim

The invention claimed is:

1. A method of refrigeration control through a refrigeration system of a refrigerated transport container, comprising:
performing a defrost cycle on the refrigeration system by activating a heat source; and
restarting the refrigeration system after the defrost cycle has completed, wherein restarting the refrigeration system includes performing a liquid slugging avoidance process including:
initiating a compressor of the refrigeration system at a speed;
opening a pressure equalization valve in parallel with the compressor in response to the initiating;
opening a liquid valve in series between a condenser and an evaporator after a predetermined amount of time has elapsed from opening of the pressure equalization valve, the liquid valve and the pressure equalization valve both being open at the same time; and
closing the pressure equalization valve after a period of time.

2. The method of claim 1 , further comprising increasing the speed of the compressor after closing of the pressure equalization valve.

3. The method of claim 2 , wherein increasing the speed of the compressor occurs after a predetermined amount of time has elapsed from the closing of the pressure equalization valve.

4. The method of claim 1 , further comprising initiating an evaporator fan motor after opening the pressure equalization valve.

5. The method of claim 4 , wherein initiating the evaporator fan motor occurs after a predetermined amount of time has elapsed from opening the pressure equalization valve.

6. The method of claim 1 , wherein closing the pressure equalization valve occurs after a predetermined amount of time has elapsed from opening the liquid valve.

7. The method of claim 1 , wherein closing the pressure equalization valve occurs after a predetermined amount of time has elapsed from initiating the compressor.

8. The method of claim 1 , wherein performing the defrost cycle includes:
determining a defrost energy consumption by the heat source during the defrost cycle;
determining a time delay until a next defrost cycle in response to the defrost energy consumption during the defrost cycle.

9. A refrigeration system, comprising:
a condenser;
a compressor in serial communication with the condenser;
an evaporator in serial communication with the condenser and the compressor;
a heat source for thawing an evaporator coil during a defrost cycle;
a pressure equalization valve arranged in parallel with the compressor;
a liquid valve in series between the condenser and the evaporator;
a controller for controlling the pressure equalization valve and the liquid valve to implement a liquid slugging avoidance process upon restart of the compressor after a defrost cycle;
wherein:
the liquid slugging avoidance process includes;
initiating the compressor at a speed;
opening the pressure equalization valve in response to the initiating;
opening the liquid valve after a predetermined amount of time has elapsed from opening the pressure equalization valve, the liquid valve and the pressure equalization valve both being open at the same time; and
closing the pressure equalization valve after a period of time.

10. The refrigeration system of claim 9 , wherein the liquid slugging avoidance process includes increasing the speed of the compressor after closing of the pressure equalization valve.

11. The refrigeration system of claim 10 , wherein increasing the speed of the compressor initiates after a predetermined amount of time has elapsed from the closing of the pressure equalization valve.

12. The refrigeration system of claim 9 , wherein the liquid slugging avoidance process includes initiating an evaporator fan motor after opening the pressure equalization valve.

13. The refrigeration system of claim 9 , wherein closing the pressure equalization valve occurs after a predetermined amount of time has elapsed from opening the liquid valve.

14. The refrigeration system of claim 9 , wherein closing the pressure equalization valve occurs after a predetermined amount of time has elapsed from initiating the compressor.

15. The refrigeration system of claim 9 , wherein the defrost cycle includes:
determining a defrost energy consumption by the heat source during the defrost cycle;
determining a time delay until a next defrost cycle in response to the defrost energy consumption during the defrost cycle.

16. A refrigeration system, comprising:
a condenser;
a compressor in serial communication with the condenser;
an evaporator in serial communication with the condenser and the compressor;
a heat source for thawing an evaporator coil during a defrost cycle;
a pressure equalization valve arranged in parallel with the compressor;
a liquid valve in series between the condenser and the evaporator; and
a controller for controlling the pressure equalization valve and the liquid valve to implement a liquid slugging avoidance process upon restart of the compressor after a defrost cycle;
wherein:
the liquid slugging avoidance process includes;
initiating the compressor at a speed;
opening the pressure equalization valve in response to the initiating;
opening the liquid valve after a first predetermined amount of time has elapsed from opening the pressure equalization valve, the liquid valve and the pressure equalization valve both being open at the same time;
increasing an evaporator fan motor after the first predetermined amount of time has elapsed from opening the pressure equalization valve;
closing the pressure equalization valve after a second predetermined amount of time has elapsed from opening the liquid valve; and
increasing the compressor speed after a third predetermined amount of time has elapsed from closing the pressure equalization valve.

Assignees

• Peyaud Fabienne
• Goux Jeanphilippe
• Choquart Virginie
• Carrier Corp

Inventors

• Peyaud Fabienne
• Goux Jeanphilippe
• Choquart Virginie

Classifications

• F25B41/04

  Mechanical Engineering · mapped topic

• F25B49/02

  for compression type machines, plants or systems · CPC title

• F25B2600/112

  of evaporator fans · CPC title

• F25B2700/2117

  of an evaporator · CPC title

• F25B2700/21171

  of the fluid cooled by the evaporator · CPC title