Methods and systems for coordinated zone operation of a multi-zone transport refrigeration system

1. A method for providing environmental condition control of a multi-zone transport refrigeration system (MTRS) within two or more zones of a refrigerated transport unit, the refrigerated transport unit including a first zone and a second zone and the MTRS including a first zone environmental condition unit configured to provide environmental control within the first zone and a second zone environmental condition unit configured to provide environmental control within the second zone, the method comprising:

a MTRS controller determining whether a first zone environmental condition difference between a first zone measured environmental condition and a first zone desired set point environmental condition is greater than a first non-zero threshold; and

the MTRS controller coordinating operation of the first environmental condition unit and the second environmental condition unit when the first zone environmental condition difference is determined to be greater than the first non-zero threshold, wherein the MTRS controller coordinating operation of the first environmental condition unit and the second environmental condition unit includes:

providing a refrigerant flow through the first zone environmental condition unit, and

concurrently providing the refrigerant flow through the second zone environmental condition unit when the MTRS controller determines that a second zone environmental condition difference between a second zone measured environmental condition and a second zone desired set point environmental condition is greater than a second non-zero threshold, the second non-zero threshold being a lower temperature value than the first non-zero threshold to allow the MTRS controller to coordinate the refrigerant flow through the first zone environmental condition unit and the second zone environmental condition unit at the same time.

2. The method of claim 1 , further comprising:

shutting off the refrigerant flow through the first zone environmental condition unit when the first zone environmental condition is sufficiently close to the first zone desired set point environmental condition; and

shutting off the refrigerant flow through the second zone environmental condition unit when the second zone environmental condition is sufficiently close to the second zone desired set point environmental condition.

3. The method of claim 1 , operating a third zone environmental condition unit for a third zone of the refrigerated transport unit when the first zone environmental condition unit and the second zone environmental condition unit are off.

4. The method of claim 3 , wherein the first zone is a fresh temperature zone, the second zone is a fresh temperature zone and the third zone is a frozen temperature zone.

5. The method of claim 1 , wherein the first zone environmental condition difference is a first zone temperature difference, the first zone measured environmental condition is a first zone measured temperature, the first zone desired set point environmental condition is a first zone desired set point temperature, the first zone environmental condition unit is a first zone heat exchanger unit, the second zone environmental condition difference is a second zone temperature difference, the second zone measured environmental condition is a second zone measured temperature, the second zone desired set point environmental condition is a second zone desired set point temperature, the second zone environmental condition unit is a second zone heat exchanger unit.

6. The method of claim 1 , wherein the first non-zero threshold is 5° F. and the second non-zero threshold is 1° F.

7. A multi-transport refrigeration system (MTRS) for a refrigerated transport unit, the refrigerated transport including a plurality of zones, the MTRS comprising:

a first environmental condition unit configured to control an environmental condition within a first zone of the refrigerated transport unit;

a second environmental condition unit configured to control the environmental condition within a second zone of the refrigerated transport unit; and

a MTRS controller configured to control operation of the first environmental condition unit and the second environmental condition unit,

wherein the MTRS controller is configured to determine whether a first zone environmental condition difference between a first zone measured environmental condition and a first zone desired set point environmental condition is greater than a first non-zero threshold, and

wherein when the first zone environmental condition difference is determined to be greater than the first non-zero threshold, the MTRS controller is configured to coordinate operation of the first zone environmental condition unit and the second zone environmental condition unit such that the MTRS controller is configured to:

provide a refrigerant flow through the first zone environmental condition unit, and

concurrently provide the refrigerant flow through the second zone environmental condition unit when the MTRS controller determines that a second zone environmental condition difference between a second zone measured environmental condition and a second zone desired set point environmental condition is greater than a second non-zero threshold, the second non-zero threshold being a lower temperature value than the first non-zero threshold to allow the MTRS controller to coordinate the refrigerant flow through the first zone environmental condition unit and the second zone environmental condition unit at the same time,

wherein the first zone is a fresh temperature zone and the second zone is a fresh temperature zone.

8. The MTRS of claim 7 , wherein the MTRS controller is configured to:

shut off the refrigerant flow through the first zone environmental condition unit when the first zone environmental condition is sufficiently close to the first zone desired set point environmental condition, and

shut off the refrigerant flow through the second zone environmental condition unit when the second zone environmental condition is sufficiently close to the second zone desired set point environmental condition.

9. The MTRS of claim 7 , further comprising a third zone environmental condition unit configured to control the environmental condition of a third zone of the refrigerated transport unit, wherein the MTRS controller is configured to:

operate the third zone environmental condition unit for the third zone of the refrigerated transport unit when the first zone environmental condition unit and the second zone environmental condition unit are off.

10. The MTRS of claim 9 , wherein the first zone is a fresh temperature zone, the second zone is a fresh temperature zone and the third zone is a frozen temperature zone.

11. The MTRS of claim 7 , wherein the first zone environmental condition difference is a first zone temperature difference, the first zone measured environmental condition is a first zone measured temperature, the first zone desired set point environmental condition is a first zone desired set point temperature, the first zone environmental condition unit is a first zone heat exchanger unit, the second zone environmental condition difference is a second zone temperature difference, the second zone measured environmental condition is a second zone measured temperature, the second zone desired set point environmental condition is a second zone desired set point temperature, the second zone environmental condition unit is a second zone heat exchanger unit.

12. The MTRS of claim 7 , wherein the first non-zero threshold is 5° F. and the second non-zero threshold is 1° F.

13. A refrigerated transport unit comprising:

a transport unit having an internal spaces that includes a plurality of zones;

a multi-transport refrigeration system (MTRS) including:

a first environmental condition unit configured to control an environmental condition within a first zone of the refrigerated transport unit;

a second environmental condition unit configured to control the environmental condition within a second zone of the refrigerated transport unit; and

a MTRS controller configured to control operation of the first environmental condition unit and the second environmental condition unit,

wherein the MTRS controller is configured to determine whether a first zone environmental condition difference between a first zone measured environmental condition and a first zone desired set point environmental condition is greater than a first non-zero threshold, and

wherein when the first zone environmental condition difference is determined to be greater than the first non-zero threshold, the MTRS controller is configured to coordinate operation of the first zone environmental condition unit and the second zone environmental condition unit such that the MTRS controller is configured to:

provide a refrigerant flow through the first zone environmental condition unit, and

concurrently provide the refrigerant flow through the second zone environmental condition unit when the MTRS controller determines that a second zone environmental condition difference between a second zone measured environmental condition and a second zone desired set point environmental condition is greater than a second non-zero threshold, the second non-zero threshold being a lower temperature value than the first non-zero threshold to allow the MTRS controller to coordinate the refrigerant flow through the first zone environmental condition unit and the second zone environmental condition unit at the same time,

wherein the first zone is a fresh temperature zone and the second zone is a fresh temperature zone.

14. The refrigerated transport unit of claim 13 , wherein the MTRS controller is configured to:

shut off the refrigerant flow through the first zone environmental condition unit when the first zone environmental condition is sufficiently close to the first zone desired set point environmental condition, and

shut off the refrigerant flow through the second zone environmental condition unit when the second zone environmental condition is sufficiently close to the second zone desired set point environmental condition.

15. The refrigerated transport unit of claim 13 , wherein the MTRS further includes a third zone environmental condition unit configured to control the environmental condition of a third zone of the refrigerated transport unit, wherein the MTRS controller is configured to:

operate the third zone environmental condition unit for the third zone of the refrigerated transport unit when the first zone environmental condition unit and the second zone environmental condition unit are off.

16. The refrigerated transport unit of claim 15 , wherein the first zone is a fresh temperature zone, the second zone is a fresh temperature zone and the third zone is a frozen temperature zone.

17. The refrigerated transport unit of claim 13 , wherein the first zone environmental condition difference is a first zone temperature difference, the first zone measured environmental condition is a first zone measured temperature, the first zone desired set point environmental condition is a first zone desired set point temperature, the first zone environmental condition unit is a first zone heat exchanger unit, the second zone environmental condition difference is a second zone temperature difference, the second zone measured environmental condition is a second zone measured temperature, the second zone desired set point environmental condition is a second zone desired set point temperature, the second zone environmental condition unit is a second zone heat exchanger unit.