Method of controlling the discharge of temperature-conditioned air

Patent metadata

Field	Value
Publication number	US-9776471-B2
Application number	US-201514801862-A
Country	US
Kind code	B2
Filing date	Jul 17, 2015
Priority date	May 20, 2014
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

HVAC unit has a single blower fan, an evaporator downstream of the blower and a heater downstream of the evaporator, wherein each zone outlet includes a temperature mixing door for controlling portions of hot and cold air and an output valve for controlling a zonal output flow rate. A method is devised to control the discharge of temperature-conditioned air from a plurality of zone outlets of an automotive HVAC system via such an HVAC unit by the steps of reading an operator-requested zonal discharge blower level for each of the zone outlets; converting each zonal discharge blower level request to a zonal flowrate request; calculating a total requested output flowrate as a summation of all zonal flowrate requests; and adjusting a blower voltage to a minimum voltage required for generating the total requested output flowrate.

First claim

What is claimed is:

1. A method of controlling 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 of the zone outlets is allocated to a different zone within a passenger compartment of a vehicle, including at least a driver zone and a front passenger zone, wherein each of the plurality of zone outlets in the module includes a designated temperature mixing door for proportioning hot and cold air and an output valve for controlling a zonal output flow rate, the method comprising the steps of:
reading a blower level request individually set by an operator for each of the zone outlets;
converting each zonal blower level request to a zonal flowrate request;
calculating a total requested output flowrate as a summation of all zonal flowrate requests; and
adjusting a blower voltage of the single blower to a minimum voltage required for generating the total requested output flowrate by the single blower.

2. The method of claim 1 , further comprising the steps of:
setting an initial blower operating voltage;
calculating a blower pressure;
calculating an individual output valve resistance for each of the outlet valves
determining an individual normalized resistance deviation of the calculated individual output valve resistance from an 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.

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

4. The method of claim 2 , wherein the threshold value for the individual normalized resistance deviations amounts to at most 10 percent.

5. The method of claim 4 , wherein the threshold value is a function of the total requested output flowrate or of the blower voltage.

6. The method of claim 2 , wherein the threshold ratio for the individual resistance deviations is calibratable.

7. The method of claim 1 , wherein the blower voltage is initially set to a minimum operating voltage until the blower voltage is adjusted.

8. The method of claim 1 , wherein the blower pressure is determined by the step of:
calculating a blower pressure rise based on the blower operating voltage and the total requested flowrate.

9. The method of claim 1 , further comprising the steps of:
reading a temperature level request for each zone;
converting zonal temperature level request into a hot air flow rate percentage of total air flow rate for each zone; and
calculating a zonal discharge cold air flow rate percentage by subtracting the zonal discharge hot air flowrate percentage from 100%.

10. The method of claim 9 , comprising the further step of calculating a total heater air flowrate request from a sum of the products of each zonal discharge hot air flowrate percentage and a respective one of the zonal flowrate requests.

11. 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;
calculating a plurality of individual mixing zone pressures downstream of the temperature mixing doors;
wherein the step of adjusting the blower voltage takes the mixing zone pressures into consideration.

12. The method of claim 11 , wherein the evaporator pressure is determined as the difference between the blower pressure and the evaporator pressure drop, which is determined from predetermined stored evaporator calibration data.

13. The method of claim 11 , wherein the heater pressure is determined as the difference between the evaporator pressure and the heater pressure drop, which is determined from predetermined stored heater calibration data.

14. The method of claim 11 , wherein the individual mixing zone pressures are determined based on the evaporator pressure, the heater pressure, and individual temperature mixing door positions of the plurality of temperature mixing doors.

15. The method of claim 1 , further comprising a preceding step of determining that a mode request corresponds to a normal mode.

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. A method of controlling 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 mixing door for proportioning hot and cold air 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 requested output flowrate as a summation of all zonal flowrate requests; and
adjusting a blower voltage to a minimum voltage required for generating the total requested output flowrate;
wherein a position of each of the temperature mixing doors is determined by solving the following equations for mixing door resistances first
R mix,i cold ( PC i cold Q i targ ) 2 −R mix,i hot ( PC i hot Q i targ ) 2 =R htr k [Σ 1 N ( PC i hot Q i targ )] 2

R mix,i hot =Function( R mix,i cold )
with
R mix,i cold representing a hot path resistance of an individual one of the mixing doors,
R mix,i hot representing a hot path resistance of the individual one of the mixing doors,
PC i cold representing a cold air percentage of the individual one of the mixing doors,
PC i hot representing a hot air percentage of the individual one of the mixing doors,
Q i targ representing the zonal flowrate request, and
R htr k representing an airflow resistance of the heater; and

and then performing a calibrated table look-up.

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

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

Classifications

• B60H2001/00092

  of air deflecting or air directing means inside the device · CPC title

• B60H1/0073

  Control systems or circuits characterised by particular algorithms or computational models, e.g. fuzzy logic or dynamic models · CPC title

• B60H1/00864 Primary

  Ventilators and damper doors · CPC title

• B60H1/00064

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

• B60H2001/002

  to front and rear part of passenger compartment · CPC title