Method, arrangement, and computer program product for operating an HVAC installation

Patent metadata

Field	Value
Publication number	US-11060744-B2
Application number	US-201716067898-A
Country	US
Kind code	B2
Filing date	Feb 9, 2017
Priority date	Feb 22, 2016
Publication date	Jul 13, 2021
Grant date	Jul 13, 2021

Abstract

A method, system (100), and a computer program product comprising a non-transient computer-readable medium (190) having stored thereon computer program code configured to control one or more processors (180) of a computer (170) for operating an HVAC installation (200, 300), wherein a set of enthalpies (H1,i, H2,i, H1,o, H2,o) and flow rates (ϕ1, ϕ2) as variables of the HVAC installation (200, 300) is monitored and used for controlling the operation of said HVAC installation (200, 300), comprising the steps of: (a) dividing said set of enthalpies (H1,i, H2,i, H1,o, H2,o) and flow rates (ϕ1, ϕ2) into a first and second subset; (b) measuring each variable of said first subset with a related sensor (110, 120) arranged in said HVAC installation (200, 300); and (c) determining the variables of said second subset from the measured variables of said first subset by using a mathematical and/or empirical relationship between the variables of said first and second subset.

First claim

The invention claimed is:

1. A method for operating an HVAC installation ( 200 , 300 ) using a computer system ( 170 ) comprising one or more processors ( 180 ) controlled by computer program code, wherein a set of enthalpies (H 1,i , H 2,i , H 1,o , H 2,o ) and flow rates (ϕ 1 , ϕ 2 ) as variables of the HVAC installation ( 200 , 300 ) is monitored and used for controlling the operation of said HVAC installation ( 200 , 300 ), comprising the steps of:
a. dividing said set of enthalpies (H 1,i , H 2,i , H 1,o , H 2,o ) and flow rates (ϕ 1 , ϕ 2 ) into a first and second subset;
b. measuring each variable of said first subset with a related sensor ( 110 , 120 ) arranged in said HVAC installation ( 200 , 300 ); and
c. determining the variables of said second subset from the measured variables of said first subset by using a mathematical and/or empirical relationship between the variables of said first and second subset.

2. The method of claim 1 , wherein at least one non-calibrated auxiliary sensor ( 121 ′) is provided to measure one variable of said second subset, and said at least one non-calibrated auxiliary sensor ( 121 ′) is calibrated by using the respective determined variable of said second subset.

3. The method of claim 1 , wherein at least one of said variables of said first subset is kept constant.

4. The method of claim 3 , wherein the actual value of said constant variable is only once measured with a sensor.

5. The method of claim 1 , wherein a set of values associated with a heat exchanger ( 103 ) of the HVAC installation ( 300 ) is determined, the set comprising: flow rates (ϕ 1 , ϕ 2 ) and enthalpy differences (ΔH 1 , ΔH 2 ) of a first fluid ( 1 ) and a second fluid ( 2 ) in a configuration for exchanging thermal energy (Q) between the fluids ( 1 , 2 ) through the heat exchanger ( 103 ),
the enthalpy differences (ΔH 1 , ΔH 2 ) each being a difference between a fluid inlet enthalpy (H 1,i , H 2,i ) and a fluid outlet enthalpy (H 1,o , H 2,o ) of the fluids ( 1 , 2 ) when entering and exiting the heat exchanger ( 103 ), respectively,
the method comprising:
measuring a subset of values comprising at least two values of: the flow rates (ϕ 1 , ϕ 2 ) and the enthalpy differences (ΔH 1 , ΔH 2 ); and
determining the complete set of values, using the measured subset of the values.

6. The method of claim 5 , wherein a full or complete set of values of an energy balance equation set up with respect to an energy related envelope boundary ( 113 , 114 , 115 ) of a heat exchanger ( 103 , 104 , 105 ) is determined.

7. The method of claim 6 , wherein the energy balance equation comprises at least one efficiency factor (η) representing a thermodynamic loss with respect to the respective envelope boundary ( 113 , 114 , 115 ).

8. The method of claim 5 , wherein at least one of the values of the flow rates (ϕ 1 , ϕ 2 ) and the enthalpy differences (ΔH 1 , ΔH 2 ) is used for calibrating a non-calibrated auxiliary flow sensor ( 121 ′) or a non-calibrated auxiliary enthalpy sensor ( 111 ′, 112 ′) for acquiring the value of one of the flow rates (ϕ 1 ϕ 2 ) or enthalpy differences (ΔH 1 , ΔH 2 ), respectively.

9. The method of claim 8 , wherein the non-calibrated auxiliary enthalpy sensor ( 111 ′, 112 ′) comprises at least one of: a non-calibrated auxiliary temperature sensor and a non-calibrated auxiliary humidity sensor used in conjunction with a look up table or function for determining a value of at least one of said enthalpies (H 1,i , H 2,i , H 1,o , H 2,o ).

10. The method of claim 5 , wherein at least one of the values of the flow rates (ϕ 1 , ϕ 2 ) is a predetermined constant value.

11. The method of claim 10 , wherein the predetermined constant value is determined using a temporary flow sensor ( 121 , 121 ′, 122 ), temporarily placed for measuring the value of the respective flow rate (ϕ 1 , ϕ 2 ).

12. The method of claim 5 , wherein at least one of the values of the flow rates (ϕ 1 , ϕ 2 ) is determined by means of an operational parameter of at least one of: a pump ( 131 ), a fan ( 132 ), a valve and a damper configured to respectively move, direct, block, split or merge at least one of the fluids ( 1 , 2 ).

13. The method of claim 12 , wherein the at least one operational parameter is a variable operational parameter of a drive ( 141 , 142 ) of the pump ( 131 ), fan ( 132 ), valve or damper.

14. The method of claim 5 , further comprising:
recording in a computer ( 170 ) at least one measurement data set ( 200 ) which includes a plurality of data points ( 202 ) representing measured values of at least one of the enthalpy differences (ΔH 1 , ΔH 2 ) in dependence of values of the respective flow rate (ϕ 1 , ϕ 2 );
calculating by the computer ( 170 ) a curve ( 212 ) or lookup table of values of the enthalpy difference (ΔH 1 , ΔH 2 ) from the at least one measurement data set ( 200 ); and
predicting the enthalpy difference (ΔH 1 , ΔH 2 ) or the respective flow rate (ϕ 1 , ϕ 2 ) by looking up a corresponding value of the respective flow rate (ϕ 1 , ϕ 2 ) or of the enthalpy difference (ΔH 1 , ΔH 2 ), respectively, based on the curve ( 212 ) or lookup table.

15. The method of claim 14 , wherein calculation of the curve ( 212 ) or lookup table involves calculating based on the at least one measurement data set ( 200 ) a function of an inlet enthalpy difference (ΔH in ) and/or an outlet enthalpy difference (ΔH out ),
the inlet enthalpy difference (ΔH in ) being a difference between a first fluid inlet enthalpy (H 1,i ) and a second fluid inlet enthalpy (H 2,i ), and
the outlet enthalpy difference (ΔH out ) being a difference between a first fluid outlet enthalpy (H 1,o ) and a second fluid outlet enthalpy (H 2,o ).

16. The method of claim 14 , wherein calculation of the curve ( 212 ) or lookup table involves calculating based on the at least one measurement data set ( 200 ) a function of an inlet temperature difference (ΔT in ) and/or an outlet temperature difference (ΔT out ),
the inlet temperature difference (ΔT in ) being a difference between a first fluid inlet temperature (T 1,i ) and a second fluid inlet temperature (T 2,i ), and
the outlet temperature difference (ΔT out ) being a difference between a first fluid outlet temperature (T 1,o ) and a second fluid outlet temperature (T 2,o ).

17. The method of claim 14 , wherein at least one of the values of the flow rates (ϕ 1 , ϕ 2 ) and the enthalpies (H 1,i , H 2,i , H 1,o , H 2,o ) is temporarily measured by means of at least one of a temporarily placed flow sensor ( 120 , 121 , 121 ′, 122 ) and a temporarily placed enthalpy sensor ( 110 , 111 , 111 ′, 112 , 112 ′), respectively, preferably during a commissioning of the heat exchanger ( 103 ), for establishing a curve fit of the curve ( 212 ) of values of the enthalpy difference (ΔH 1 , ΔH 2 ) with respect to the at least one measurement data set ( 200 ).

18. The method of claim 17 wherein establishing the curve fit is based on at least one curve fit coefficient (k 1 , k 2 ).

19. The method of claim 18 , wherein the at least one curve fit coefficient (k 1 , k 2 ) is derived from a power fit function of the thermal energy (Q) exchanged dependent on the value of the respective flow rate (ϕ 1 , ϕ 2 ).

20. The method of claim 18 , wherein the at least one curve fit coefficient (k 1 , k 2 ) is derived from an enthalpy fit function of the value of the enthalpy difference (ΔH 1 , ΔH 2 ) dependent on the value of the respective flow rate (ϕ 1 , ϕ 2 ).

21. The method of clai

Assignees

• Belimo Holding Ag

Inventors

• Reider Forest
• Thuillard Marc
• Schmidlin Peter
• Mischler Stefan
• Aeberhard Ronald
• Chan Hou Yin
• Goh Wee Ming

Classifications

• F24F11/64 Primary

  using pre-stored data · CPC title

• F24F11/52

  Indication arrangements, e.g. displays · CPC title

• F24F11/84

  using valves · CPC title

• F24F11/30 Primary

  for purposes related to the operation of the system, e.g. for safety or monitoring · CPC title

• F24F2110/00

  Control inputs relating to air properties · CPC title