Un-partitioned HVAC module control for multi-zone and high performance operation

Patent metadata

Field	Value
Publication number	US-10286748-B2
Application number	US-201514923897-A
Country	US
Kind code	B2
Filing date	Oct 27, 2015
Priority date	May 20, 2014
Publication date	May 14, 2019
Grant date	May 14, 2019

Abstract

A method controls the discharge of temperature-conditioned air from a plurality of zone outlets of an automotive HVAC system via an open architecture multi-zone HVAC unit having a single blower fan, an evaporator downstream of the blower and a heater downstream of the evaporator, wherein each zone in the module includes a temperature mix door for proportioning hot and cold air, which is controlled by a separate Discharge Temperature Maintenance control (DTM control), and an output valve for controlling a zonal output flow rate. The output valve of each zone outlet is placed in an output valve position associated with a target resistance; and the single blower fan is operated at a minimum voltage required for generating a total requested blower output flowrate.

First claim

What is claimed is:

1. A method of controlling a discharge of temperature-conditioned air from a plurality of zone outlets of an automotive HVAC module system via an open architecture multi-zone HVAC unit having a single blower fan, an evaporator downstream of the blower and a heater downstream of the evaporator, wherein each zone in the module includes a temperature mix door for proportioning hot and cold air, which is controlled by a separate Discharge Temperature Maintenance control (DTM control), and an output valve for controlling a zonal output flow rate, the method comprising the steps of:
reading a blower level request for each of the zone outlets;
converting each zonal blower level request to a zonal flowrate request;
calculating a total output flowrate request as a summation of all zonal flowrate requests;
reading a mix door position that has been set by the DTM control for each of the zone outlets;
reading a DTM sensor temperature for each of the zone outlets;
determining a pressure downstream each mix door but before the output valve for each zone;
determining, for each zone outlet, a target resistance for each output valve based on the zonal flowrate request and on the pressure downstream of the mix door;
placing the output valve of each zone outlet in an output valve position associated with the target resistance; and
operating the single blower fan at a minimum voltage required for generating the total output flowrate request.

2. The method of claim 1 , further comprising the steps of:
setting an initial blower operating voltage;
determining a minimum resistance for each of the output valves using pre-calibrated flow resistance table as a function of an outlet valve position;
determining for each of the output valves a respective individual normalized resistance deviation of the calculated individual output valve resistance from the individual minimum attainable output valve resistance;
placing each output valve in an adjusted output valve position associated with the respective individual normalized resistance deviation; and
modifying the blower operating voltage to operate the single blower fan at a minimum voltage required for generating the total output flowrate request with the outlet valve position of at least one of the output valves set to the minimum attainable output valve resistance.

3. The method of claim 2 , further comprising the step of determining the adjusted output valve position for each zone based on an average mixing pressure downstream of each mix door.

4. The method of claim 3 , further comprising the steps of
calculating an average zonal mixing pressure for each zone in a mixing chamber between each one of the mix doors and an associated output valve, the average mixing pressure being the arithmetic mean of the hot air pressure and the cold air pressure downstream of each mix door, and
determining a desired output valve resistance from the average mixing chamber pressure.

5. The method of claim 2 , further comprising the steps of:
determining an individual normalized resistance deviation of the calculated individual output valve resistance from the individual minimum attainable output valve resistance for each of the output valves;
wherein the step of adjusting the blower voltage brings at least one of the individual normalized resistance deviations below a predetermined threshold ratio such that at least one of the outlet valves is fully open.

6. The method of claim 2 , wherein a minimum attainable resistance of each output valve is based on predetermined stored output valve calibration data.

7. The method of claim 5 , wherein the threshold ratio for the individual normalized resistance deviations amounts to at most 5 percent.

8. The method of claim 1 , wherein each output valve is initially set to a fully open position with minimal flow resistance until each output valve in an output valve position associated with the respective individual normalized resistance deviation sets a different output valve position.

9. The method of claim 2 , wherein the blower operating voltage is initially set to a minimum operating voltage until the blower operating voltage is adjusted.

10. The method of claim 1 , further comprising the step of:
converting for each zone a DTM sensor measured temperature to a zonal hot air flowrate percentage of the zonal flowrate request.

11. The method of claim 10 , further comprising the step of reading an evaporator outlet temperature and a heater outlet temperature for determining the hot air flowrate percentages.

12. The method of claim 11 , further comprising the step of calculating a total hot air flow rate request from all zonal hot air flowrates.

13. The method of claim 1 , further comprising the steps of:
calculating an evaporator pressure downstream of the evaporator;
calculating a heater pressure downstream of the heater;
wherein the step of adjusting the blower voltage takes a pressure drop associated with each mix door position into consideration.

14. The method of claim 13 , wherein the evaporator pressure is determined from a total air flow and an evaporator pressure drop, which is determined from predetermined stored evaporator calibration data.

15. The method of claim 13 , wherein the heater pressure is determined from a total hot air flow rate and a heater pressure drop, which is determined from predetermined stored heater calibration data.

16. The method of claim 1 , wherein each output valve position is determined by using the calculated required resistance through a calibrated look-up table for the output valves.

17. The method of claim 1 , wherein a pressure drop of each of the temperature mix doors is determined by at least the following steps:
looking up a hot air resistance value associated with the mix door position;
determining a hot air pressure drop from the hot air resistance value, the zonal flow rate request, and from a zonal hot air flowrate percentage of the zonal flowrate request;
looking up a cold air resistance value associated with the mix door position;
determining a cold air pressure drop from the cold air resistance value, the zonal flow rate request, and from a zonal cold air flowrate percentage of the zonal flowrate request.

18. The method of claim 1 , wherein the output valves comprise a plurality of parallel mode valves.

19. The method of claim 1 , wherein the output valves comprise at least one dedicated flow control valve.

Assignees

• Mahle Int Gmbh

Inventors

• Xia Yanping
• Wang Mingyu
• Liu Wen
• Kadle Prasad S
• Kinmartin Jeffrey C

Classifications

• B60H2001/002

  to front and rear part of passenger compartment · CPC title

• B60H1/00864

  Ventilators and damper doors · CPC title

• B60H1/00064 Primary

  for sending air streams of different temperatures into the passenger compartment · CPC title

• B60H1/32

  Cooling devices {(B60H1/00478, B60H1/005 take precedence)} · CPC title

• B60H1/00835

  Damper doors, e.g. position control (construction or arrangement of damper doors B60H1/00664; B60H1/00864 takes precedence) · CPC title