Heat pump system having a maximum percent demand re-calculation algorithm controller

• US 9,759,466 B2
• Filed: 03/05/2014
• Issued: 09/12/2017
• Est. Priority Date: 03/05/2014
• Status: Active Grant

• Current Assignee: Lennox Industries Incorporated (Lennox International Incorporated)
• Original Assignee: Lennox Industries Incorporated (Lennox International Incorporated)
• Inventors: Goel, Rakesh, Berg, Eric, Hrejsa, Pete
• Primary Examiner(s): Crenshaw, Henry
• Application Number:
  US14/198,046
• Publication Number:
  US 20150253050A1
• Time in Patent Office: 1,287 Days
• Field of Search: 62 81, 62157, 62160, 621766, 62198, 622387
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/46 Improving electric energy efficiency or saving
• CPC Class Codes: F24F 11/52 Indication arrangements, e.g. displays
• CPC Class Codes: F24F 11/58 using Internet communication
• CPC Class Codes: F24F 11/62 characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
• CPC Class Codes: F24F 11/63 Electronic processing
• CPC Class Codes: F24F 11/77 by controlling the speed of ventilators
• CPC Class Codes: F24F 11/86 by controlling compressors within refrigeration or heat pump circuits
• CPC Class Codes: F24F 11/871 by controlling outdoor fans
• CPC Class Codes: F24F 2110/10 Temperature
• CPC Class Codes: F24F 2140/00 Control inputs relating to system states
• CPC Class Codes: F24F 2140/12 Heat-exchange fluid pressure
• CPC Class Codes: F24F 2140/50 Load
• CPC Class Codes: F25B 13/00 Compression machines, plants or systems, with reversible cycle defrosting cycles F25B47/02
• CPC Class Codes: F25B 2313/029 Control issues
• CPC Class Codes: F25B 2500/02 Increasing the heating capacity of a reversible cycle during cold outdoor conditions
• CPC Class Codes: F25B 2700/1931 Discharge pressures
• CPC Class Codes: F25B 2700/195 of the condenser
• CPC Class Codes: F25B 49/005 of safety devices F25B49/02 and F25B49/04 take precedence
• CPC Class Codes: F25B 49/02 for compression type machines, plants or systems

Abstract

One aspect presents a controller that comprises a control board, a microprocessor located on and electrically coupled to the control board, and a memory coupled to the microprocessor and located on and electrically coupled to the control board. The controller is configured to receive an operating parameter signal and recalculate a first maximum heating % demand to a second maximum heating % demand that is greater than the first maximum heating % demand, when a value of the operating parameter signal exceeds a predetermined value, and operate the HP system based on the second maximum heating % demand.

Claims

1. A heat pump (HP) system, comprising:

an indoor system comprising an indoor heat exchanger equipped with an indoor blower;

an outdoor system comprising an outdoor heat exchanger equipped with an outdoor fan, said indoor system and said outdoor system being fluidly coupled together by refrigerant tubing that forms a refrigerant system;

an operating parameter sensor associated with said indoor system or said outdoor system and configured to provide an operating parameter signal of said indoor system or said outdoor system; and

a controller coupled to said HP system, wherein, prior to receiving a refrigerant high pressure trip signal from a refrigerant high pressure trip sensor, the controller is configured to;

operate said HP system based on a first maximum heating % demand;

determine whether said operating parameter signal indicates that a current heating % demand exceeds said first maximum heating % demand;

responsive to a determination that said operating parameter signal indicates that the current heating % demand exceeds said first maximum heating % demand, set said first maximum heating % demand to a second maximum heating % demand that is greater than said first maximum heating % demand and operate said HP system based on said second maximum heating % demand;

wherein said controller sets said first maximum heating % demand as follows;

first maximum heating % demand/% indoor airflow rate=A+{B×

((ODT_ref+C)/(ODT+D))^N},

wherein;

first maximum heating % demand is an initial maximum limit heating % demand of said HP system, ODT_ref is a reference outdoor temperature in degrees Fahrenheit adjusted for a given HP system, ODT is the outdoor temperature in degrees Fahrenheit, % indoor airflow rate=indoor airflow rate/indoor airflow rate @100% heating demand, where indoor airflow rate is airflow output of the indoor system, and where A, B, C, D, and N are real numbers; and

wherein said controller sets said second maximum heating % demand as follows;

second maximum heating % demand/% indoor airflow rate=A+{B×

((ODT_ref+C)/(ODT+D))^N},

wherein;

second maximum heating % demand is the maximum heating % demand after recalculation of said first maximum heating % demand of said HP system, ODT_ref is a reference outdoor temperature in degrees Fahrenheit adjusted for a given HP system, ODT is the outdoor temperature in degrees Fahrenheit, % indoor airflow rate=indoor airflow rate/indoor airflow rate @100% heating demand, where indoor airflow rate is airflow output of the indoor system, and where A, B, C, D, and N are real numbers selected such that said second maximum heating % demand value is greater than said first maximum heating % demand.

2. The HP system of claim 1, wherein said controller is further configured to increment a heating % demand towards said second maximum heating % demand when a discharge air temperature of said indoor system is equal to or less than a discharge air temperature set point of said indoor system.

3. The HP system of claim 2, wherein said controller increments said heating % demand as follows:

Incremented heating % demand=current heating % demand+D×

(second maximum heating % demand current heating % demand),

wherein D is a real number having a value between zero and 1.

4. The HP system of claim 1, wherein said controller is configured to test operating parameters of said HP system at a set time interval and reset operating parameters of said HP system to operational settings based on said first maximum heating % demand.

5. The HP system of claim 1, wherein said controller is configured to reset said HP system to operational settings based on said first maximum heating % demand when an outdoor temperature reaches a predetermined value.

6. The HP system of claim 1, wherein said HP system, when operating based on said second maximum heating % demand, is further configured to receive the refrigerant high pressure trip signal from a refrigerant high pressure trip sensor and recalculate said second maximum heating % demand to a third maximum heating % demand based on a current heating % demand existing when said controller receives said refrigerant high pressure trip signal and operate said HP system based on said third maximum heating % demand.

7. The HP system of claim 6, wherein said controller recalculates said third maximum heating % demand, as follows:

Third maximum heating % demand=B×

current heating % demand at trip signal,

wherein;

B is a real number having a value between zero and 1.

8. A heat pump (HP) system controller, comprising:

a control board;

a microprocessor located on and electrically coupled to said control board; and

a memory coupled to said microprocessor and located on and electrically coupled to said control board and having a controller couplable to an operating parameter sensor associated with an indoor system or an outdoor system of a heat pump (HP) system;

wherein, prior to receiving a refrigerant high pressure trip signal from a refrigerant high pressure trip sensor, said controller is configured to;

operate said HP system based on a first maximum heating % demand;

determine whether an operating parameter signal indicates that a current heating % demand exceeds said first maximum heating % demand;

responsive to a determination that said operating parameter signal indicates that the current heating % demand exceeds said first maximum heating % demand, set said first maximum heating % demand to a second maximum heating % demand that is greater than said first maximum heating % demand and operate said HP system based on said second maximum heating % demand;

wherein said controller sets said first maximum heating % demand as follows;

first maximum heating % demand/% indoor airflow rate=A+{B×

((ODT_ref+C)/(ODT+D))^N},

wherein;

first maximum heating % demand is an initial maximum limit heating % demand of said HP system, ODT_ref is a reference outdoor temperature in degrees Fahrenheit adjusted for a given HP system, ODT is the outdoor temperature in degrees Fahrenheit, % indoor airflow rate=indoor airflow rate/indoor airflow rate @100% heating demand, where indoor airflow rate is airflow output of the indoor system, and where A, B, C, D, and N are real numbers; and

wherein said controller sets said second maximum heating % demand as follows;

second maximum heating % demand/% indoor airflow rate=A+{B×

((ODT_ref+C)/(ODT+D))^N},

wherein;

second maximum heating % demand is the maximum heating % demand after recalculation % demand of said HP system, of said first maximum heating ODT_ref is a reference outdoor temperature in degrees Fahrenheit adjusted for a given HP system, ODT is the outdoor temperature in degrees Fahrenheit, % indoor airflow rate indoor airflow rate/indoor airflow rate @100% heating demand, where indoor airflow rate is airflow output of the indoor system, and where A, B, C, D, and N are real numbers selected such that said second maximum heating % demand value is greater than said first maximum heating % demand.

9. The HP system controller of claim 8, wherein said controller is further configured to increment said heating % demand towards said second maximum heating % demand when a discharge air temperature of said indoor system is equal to or less than a discharge air temperature set point of said indoor system.

10. The HP system controller of claim 9, wherein said controller increments said heating % demand as follows:

Incremented heating % demand=current heating % demand+D×

(second maximum heating % demand current heating % demand),

wherein D is a real number having a value between zero and 1.

11. The HP system controller of claim 8, wherein said controller is configured to test operating parameters of said HP system at a set time interval and reset operating parameters to operational settings of said HP system based on said first maximum heating % demand.

12. The HP system controller of claim 8, wherein said controller is configured to reset said HP system to operational settings based on said first maximum heating % demand when an outdoor temperature reaches a predetermined value.

13. The HP system controller of claim 8, wherein said HP system, when operating based on said second maximum heating % demand, is further configured to receive a refrigerant high pressure trip signal from the refrigerant high pressure trip sensor and recalculate said second maximum heating % demand to a third maximum heating % demand based on a current heating % demand existing when said controller receives said refrigerant high pressure trip signal and operate said HP system based on said third maximum heating % demand.

14. The HP system controller of claim 13, wherein said controller recalculates said third maximum heating % demand, as follows:

Third maximum heating % demand=B×

current heating % demand at trip signal,

wherein;

B is a real number having a value between zero and 1.