Hydronic system and method for operating such hydronic system

Patent metadata

Field	Value
Publication number	US-10890351-B2
Application number	US-201716333354-A
Country	US
Kind code	B2
Filing date	Sep 19, 2017
Priority date	Nov 22, 2016
Publication date	Jan 12, 2021
Grant date	Jan 12, 2021

Abstract

A hydronic system (HS) that comprises at least one hydronic circuit (HC) and a control (CT) for controlling the operation of said at least one hydronic circuit (HC) via a control path (CP), whereby said control (CT) comprises a feed forward controller (FFC). Operation of the system is improved by the hydronic system (HS) further comprising a control improvement path (CIP) running from the at least one hydronic circuit (HC) to the control (CT). Due to the control improvement path (CIP), the control (CT) can be improved in the case of the hydronic system (HS) becoming instable and/or showing poor system control.

First claim

What is claimed is:

1. A hydronic system (HS) comprising:
at least one hydronic circuit (HC; 10 ; 20 ),
a control (CT) for controlling the operation of said at least one hydronic circuit (HC; 10 ; 20 ) via a control path (CP) that communicates an exchange of control signals and operating parameters, whereby said control (CT) comprises a feed forward controller (FFC; 23 ) and an alternative controller (AC), and
a control improvement path (CIP) running from said at least one hydronic circuit (HC; 10 ; 20 ) to said control (CT),
wherein said alternative controller (AC) can replace the feed forward controller (FFC) and the feed forward controller (FFC) can replace the alternative controller (AC),
whereby said control (CT) can be improved in the case of said hydronic system (HS) becoming instable and/or showing poor system control.

2. The hydronic system as claimed in claim 1 , characterized in that said at least one hydronic circuit ( 10 ) comprises a control valve ( 12 ) as a variable flow resistance and a static flow resistance ( 13 ), which are connected in series by a piping ( 19 , 19 ′), whereby said control valve ( 12 ) is controlled by a valve control device ( 14 ), in that a flow sensor ( 18 ) is provided for measuring the flow (Φ) of a fluid flowing through said circuit, and in that a valve authority determining device ( 16 ) is associated with said hydronic circuit ( 10 ), whereby said valve authority determining device ( 16 ) is connected to said valve control device ( 14 ) in order to receive information about the actual opening position of said control valve ( 12 ), and whereby said valve authority determining device ( 16 ) is further connected to said flow sensor ( 18 ) in order to receive information about the actual fluid flow (Φ) flowing through said circuit.

3. The hydronic system as claimed in claim 2 , characterized in that a storage ( 15 ) is associated with said valve authority determining device ( 16 ), which storage ( 15 ) contains and provides said valve authority determining device ( 16 ) with, information on a valve characteristic of said control valve ( 12 ).

4. The hydronic system as claimed in claim 2 , characterized in that an outlet of said valve authority determining device ( 16 ) is connected to said feed forward controller (FFC).

5. The hydronic system as claimed in claim 1 , characterized in that a frequency detector ( 31 ) for detecting oscillations is provided in said hydronic system, and that said frequency detector ( 31 ) is in operative connection with said control (CT).

6. The hydronic system as claimed in claim 5 , characterized in that said control (CT) comprises oscillation suppressing means ( 32 , 33 , 35 ), and that said frequency detector ( 31 ) is in operative connection with said oscillation suppressing means ( 32 , 33 , 35 ).

7. The hydronic system as claimed in claim 6 , characterized in that said feed forward controller (FFC) comprises a physical model ( 27 ) of said hydronic circuit, and that said oscillation suppressing means ( 32 , 33 , 35 ) has an effect on input and/or output signals of said physical model ( 27 ).

8. The hydronic system as claimed in claim 6 , characterized in that said oscillation suppressing means comprises at least one filter ( 32 , 33 ).

9. A method for operating a hydronic system according to claim 5 , comprising the steps of:
a. monitoring a flow through said hydronic system and/or a set point signal (F sv , PS sv ) by means of said frequency detector ( 31 );
b. acting on said control (CT), when an oscillation is detected by said frequency detector.

10. The method as claimed in claim 9 , characterized in that oscillation suppressing means ( 32 , 33 , 35 ) are activated in said control (CT), when an oscillation is detected by said frequency detector ( 31 ).

11. The method as claimed in claim 9 , characterized in that said feed forward controller (FFC) is replaced by an alternative controller (AC), when an oscillation is detected by said frequency detector ( 31 ).

12. A hydronic system (HS) comprising:
at least one hydronic circuit (HC; 10 ; 20 );
a control (CT) for controlling the operation of said at least one hydronic circuit (HC; 10 ; 20 ) via a control path (CP), whereby said control (CT) comprises a feed forward controller (FFC; 23 ); and
a control improvement path (CIP) running from said at least one hydronic circuit (HC; 10 ; 20 ) to said control (CT), by means of which control improvement path (CIP) said control (CT) can be improved in the case of said hydronic system (HS) becoming instable and/or showing poor system control,
wherein a frequency detector ( 31 ) for detecting oscillations is provided in said hydronic system, said frequency detector ( 31 ) being in operative connection with said control (CT),
wherein said control (CT) comprises an alternative controller (AT), and
wherein said frequency detector ( 31 ) is in operative connection with switching means for switching between said feed forward controller (FFC) and said alternative controller (AC).

13. A method for operating a hydronic system according to claim 12 , comprising the steps of:
a. monitoring a flow through said hydronic system and/or a set point signal (F sv , PS sv ) by means of said frequency detector ( 31 );
b. replacing said alternative controller (AC) by said feed forward controller (FFC), when an oscillation is detected by said frequency detector ( 31 ).

14. The hydronic system as claimed in claim 12 , wherein switching between the feed forward controller (FFC; 23 ) and the alternative controller (AC) is done by a selector switch ( 34 ).

15. A method for operating a hydronic system (HS), the hydronic system comprising at least one hydronic circuit (HC; 10 ; 20 ) and a control (CT) for controlling the operation of said at least one hydronic circuit (HC; 10 ; 20 ) via a control path (CP), whereby said control (CT) comprises a feed forward controller (FFC; 23 ), and a control improvement path (CIP) running from said at least one hydronic circuit (HC; 10 ; 20 ) to said control (CT), by means of which control improvement path (CIP) said control (CT) can be improved in the case of said hydronic system (HS) becoming instable and/or showing poor system control, wherein said at least one hydronic circuit ( 10 ) comprises a control valve ( 12 ) as a variable flow resistance and a static flow resistance ( 13 ), which are connected in series by a piping ( 19 , 19 ′), whereby said control valve ( 12 ) is controlled by a valve control device ( 14 ), in that a flow sensor ( 18 ) is provided for measuring the flow (Φ) of a fluid flowing through said circuit, and wherein a valve authority determining device ( 16 ) is associated with said hydronic circuit ( 10 ), whereby said valve authority determining device ( 16 ) is connected to said valve control device ( 14 ) in order to receive information about the actual opening position of said control valve ( 12 ), and whereby said valve authority determining device ( 16 ) is further connected to said flow sensor ( 18 ) in order to receive information about the actual fluid flow (Φ) flowing through said circuit,
said method comprising the steps of
a. providing a valve characteristic of said control valve ( 12 ), which comprises the dependency of the flow coefficient (kv) of said valve on the opening position of said valve;
b. moving said control valve ( 12 ) into a first opening position having a first flow coefficient (kv valve,1 );
c. measuring the flow (Φ 1 ) of said circulating fluid through said control valve ( 12 ) in said first opening position;
d. moving said control valve ( 12 )

Assignees

• Belimo Holding Ag

Inventors

• Reider Forest
• Thuillard Marc
• Mischler Stefan
• Aeberhard Ronald

Classifications

• F24D2220/044

  Flow sensors · CPC title

• F24F11/84 Primary

  using valves · CPC title

• F24D19/1036

  Having differential pressure measurement facilities · CPC title

• F24D19/1009

  for central heating · CPC title