FRESH AIR CONTROL FOR A TRANSPORT REFRIGERATION UNIT

• US 20170136848A1
• Filed: 06/03/2014
• Published: 05/18/2017
• Est. Priority Date: 11/25/2013
• Status: Active Grant

• Current Assignee: Thermo King Corporation (Trane Technologies plc)
• Original Assignee: Thermo King Corporation (Trane Technologies plc)
• Inventors: Trutnovsky, Petr, Forejt, Lubos, Cermk, Radim
• Granted Patent: US 9,908,386 B2
• Time in Patent Office: Days
• CPC Class Codes: B60H 1/00371 for vehicles carrying large numbers of passengers, e.g. buses
• CPC Class Codes: B60H 1/008 the input being air quality
• CPC Class Codes: B60H 1/00828 Ventilators, e.g. speed control B60H1/00864 takes precedence
• CPC Class Codes: B60H 1/00849 for selectively commanding the induction of outside or inside air B60H1/00842 takes precedence
• CPC Class Codes: B60H 1/00864 Ventilators and damper doors
• CPC Class Codes: B60H 2001/3282 to control the air flow

Abstract

A system and method for controlling a transport heating, ventilation, and air conditioning (HVAC) system having a fresh air intake is disclosed. The fresh airflow intake system includes a fresh air damper configured to regulate a flow of fresh air into the transport HVAC system, an evaporator fan having at least a high-speed mode and a low speed mode, and a controller. The controller is configured to determine whether a fresh air condition is met and increase a fresh airflow in response to determining the fresh air condition is met. The controller is further configured to increase an evaporator fan speed when the fresh airflow is increased.

Claims

1. A method to control a transport heating, ventilation, and air conditioning (HVAC) system having a fresh air intake, comprising:

monitoring one or more of an air quality, a set point temperature, and an ambient temperature;

determining whether a fresh air condition is met based on the monitoring;

opening a fresh air damper when the fresh air condition is met; and

increasing an evaporator fan speed in response to opening the fresh air damper,

wherein the fresh air condition includes a minimum air quality threshold, the fresh air condition being met when the monitoring identifies an air quality that is below the minimum air quality threshold.

2. The method according to claim 1, wherein opening the fresh air damper includes opening the fresh air damper to an intermediate position, the intermediate position being between an opened position and a closed position.

3. The method according to claim 1, wherein increasing the evaporator fan speed includes increasing the evaporator fan speed to an intermediate evaporator fan speed that is below a maximum evaporator fan speed.

4. The method according to claim 1, further comprising:

closing the fresh air damper when the fresh air condition is no longer met; and

decreasing the evaporator fan speed in response to closing the fresh air damper.

5. The method according to claim 4, wherein closing the fresh air damper includes closing the fresh air damper to an intermediate position, the intermediate position being between a closed and an opened position.

6. The method according to claim 4, wherein decreasing the evaporator fan speed includes decreasing the evaporator fan speed to an intermediate evaporator fan speed that is above a minimum evaporator fan speed.

8. The method according to claim 1, wherein the fresh air condition includes:

a temperature threshold range, the fresh air condition being met when the set point temperature and the ambient temperature are within the threshold range of each other.

7. (canceled)

9. A fresh airflow intake system for a transport heating, ventilation, and air conditioning (HVAC) system, comprising:

a fresh air damper configured to regulate a flow of fresh air into the transport HVAC system;

an evaporator fan having at least a high speed mode and a low speed mode; and

a controller, the controller configured to;

determine whether a fresh air condition is met,

increase a fresh airflow in response to determining the fresh air condition is met,

increase an evaporator fan speed when the fresh airflow is increased;

determine a set point temperature and an ambient temperature, and wherein the fresh air condition is met when the set point temperature is within a threshold range of the ambient temperature.

10. The fresh airflow intake system according to claim 9, further comprising one or more air quality sensors, and wherein the fresh air condition is met when the air quality determined from the one or more air quality sensors is below a minimum air quality threshold.

11. The fresh airflow intake system according to claim 10, wherein the one or more quality sensors includes a carbon dioxide sensor configured to detect an amount of carbon dioxide in a passenger compartment of a transport vehicle.

13. The fresh airflow intake system according to claim 9, the controller further configured to:

decrease the fresh airflow in response to determining the fresh air condition is no longer met; and

decrease the evaporator fan speed when the fresh airflow is decreased.

12. (canceled)

14. A method to control a transport heating, ventilation, and air conditioning (HVAC) system having a fresh air intake, comprising:

determining a passenger compartment temperature from a temperature sensor;

comparing, by a controller, the passenger compartment temperature with a set point temperature;

determining an air quality measurement from an air quality sensor;

opening a fresh air damper when the passenger compartment temperature and the set point temperature are within a threshold range and the air quality measurement is below a minimum air quality threshold; and

increasing an evaporator fan speed in response to opening the fresh air damper.

15. The method according to claim 14, wherein opening the fresh air damper includes opening the fresh air damper to an intermediate position, the intermediate position being between an opened position and a closed position.

16. The method according to claim 14, wherein increasing the evaporator fan speed includes increasing the evaporator fan speed to an intermediate evaporator fan speed that is below a maximum evaporator fan speed.

17. The method according to claim 14, further comprising:

closing the fresh air damper when the air quality measurement is above the minimum air quality threshold; and

decreasing the evaporator fan speed in response to closing the fresh air damper.

18. The method according to claim 17, wherein closing the fresh air damper includes closing the fresh air damper to an intermediate position, the intermediate position being between a closed and an opened position.

19. The method according to claim 17, wherein decreasing the evaporator fan speed includes decreasing the evaporator fan speed to an intermediate evaporator fan speed that is above a minimum evaporator fan speed.