Systems and methods for intelligently controlling a hybrid cascade boiler system

Patent metadata

Field	Value
Publication number	US-11739971-B2
Application number	US-202217662256-A
Country	US
Kind code	B2
Filing date	May 6, 2022
Priority date	Aug 25, 2020
Publication date	Aug 29, 2023
Grant date	Aug 29, 2023

Abstract

The disclosed technology includes a controller for a cascade boiler system having both condensing and non-condensing boilers. The controller can receive supply water temperature data and return water temperature data to determine a current temperature differential in the system. The controller can determine a current load demand value using the current temperature differential and a set point temperature. If the current load demand value is less than or equal to a first load demand threshold, the controller can output a control signal for a condensing boiler to transition to a heating mode. If the current load demand value is greater than a second load demand threshold, the controller can output a control signal for a non-condensing boiler to transition to a heating mode.

First claim

What is claimed is:

1. A non-transitory, computer-readable medium storing instructions that, when executed by one or more processors, cause a boiler system controller to:
receive supply water temperature data;
receive return water temperature data;
determine a current temperature differential value based at least in part on the supply water temperature data and the return water temperature data;
determine a current load demand value based at least in part on the current temperature differential value and a setpoint temperature;
retrieve boiler data indicative of a type and a capacity of boiler available for heating from among a plurality of boilers, the plurality of boilers comprising at least one condensing boiler and at least one non-condensing boiler;
determine, based on the current load demand value, a required boiler capacity necessary to satisfy the current load demand value; and
instruct one or more boilers from among the plurality of boilers to transition to a heating mode for heating water in the boiler system by:
in response to the current load demand value being less than or equal to a first predetermined load demand threshold:
selecting a size-appropriate condensing boiler, the size-appropriate condensing boiler having a capacity corresponding to the required boiler capacity; and
outputting a control signal to the size-appropriate condensing boiler to transition to the heating mode;

in response to the current load demand value being greater than a second load demand threshold:
selecting a size-appropriate non-condensing boiler, the size-appropriate non-condensing boiler having a capacity corresponding to the required boiler capacity; and
outputting a control signal to the size-appropriate non-condensing boiler to transition to the heating mode, wherein the second load demand threshold is greater than the first load demand threshold.

2. The non-transitory, computer-readable medium of claim 1 , wherein instructing the one or more boilers from among the plurality of boilers to transition to the heating mode for heating water in the boiler system further comprises:
in response to the current load demand value being greater than the first load demand threshold and less than or equal to the second load demand threshold, output a control signal for the size-appropriate condensing boiler and the size-appropriate noncondensing boiler to transition to the heating mode for heating water in the boiler system.

3. The non-transitory, computer-readable medium of claim 1 , wherein the supply water temperature data is indicative of a temperature of water supplied from a boiler system associated with the boiler system controller.

4. The non-transitory, computer-readable medium of claim 3 , wherein the return water temperature data is indicative of a temperature of water returning to the boiler system.

5. The non-transitory, computer-readable medium of claim 1 , wherein the instructions, when executed by the one or more processors, further cause the boiler system controller to:
retrieve, from a memory associated with the boiler system controller, a predetermined parallel control setting configured to cause the controller to operate the plurality of boilers in a parallel control mode; and
wherein instructing the one or more boilers from among the plurality of boilers to transition to the heating mode for heating water in the boiler system further comprises:
in response to the current load demand value being less than or equal to the first load demand threshold and based on the predetermined parallel control setting, output a control signal for a plurality of size-appropriate condensing boilers from among the plurality of boilers to transition to the heating mode for heating water in the boiler system in the parallel control mode; and
in response to the current load demand value being greater than the second load demand threshold and based on the predetermined parallel control setting, output a control signal for a plurality of size-appropriate non-condensing boilers from among the plurality of boilers to transition to the heating mode for heating water in the boiler system in the parallel control mode.

6. The non-transitory, computer-readable medium of claim 5 , wherein the predetermined parallel control setting is defined by a user.

7. The non-transitory, computer-readable medium of claim 1 , wherein:
the instructions, when executed by the one or more processors, further cause the boiler system controller to:
receive, from a flow sensor, flow data indicative of a flow of water in the boiler system, and

determining the current load demand value further comprises:
determining the current load demand value based at least in part on the current temperature differential value, the setpoint temperature, and the flow data.

8. The non-transitory, computer-readable medium of claim 1 , wherein:
the instructions, when executed by the one or more processors, further cause the boiler system controller to:
receive, from an ambient air temperature sensor, ambient air temperature data indicative of a temperature of ambient air, and

determining the current load demand value further comprises:
determining the current load demand value based at least in part on the current temperature differential value, the setpoint temperature, and the ambient air temperature data.

9. The non-transitory, computer-readable medium of claim 1 , wherein the instructions, when executed by the one or more processors, further cause the boiler system controller to modulate an output of the size-appropriate condensing boiler.

10. The non-transitory, computer-readable medium of claim 1 , wherein the instructions, when executed by the one or more processors, further cause the boiler system controller to modulate an output of the size-appropriate non-condensing boiler.

11. The non-transitory, computer-readable medium of claim 1 , wherein the instructions, when executed by the one or more processors, further cause the boiler system controller to:
retrieve, from a memory associated with the boiler system controller, a time-defined rotation setting configured to cause the controller to select a predetermined group of boilers of the plurality of boilers to transition to the heating mode.

12. The non-transitory, computer-readable medium of claim 11 , wherein the predetermined group of boilers is a first predetermined group of boilers, and
wherein the instructions, when executed by the one or more processors, further cause the boiler system controller to:
in response to determining that the first predetermined group of boilers has operated for a predetermined amount of time, output a first control signal to the first predetermined group of boilers to cause the first predetermined group of boilers turn off and a second control signal to a second predetermined group of boilers to cause the second predetermined group of boilers to transition to the heating mode.

13. The non-transitory, computer-readable medium of claim 12 , wherein the predetermined amount of time is defined by a user.

14. The non-transitory, computer-readable medium of claim 11 , wherein the predetermined group of boilers is defined by a user.

15. The non-transitory, computer-readable medium of claim 1 , wherein the instructions, when executed by the one or more processors, further cause the boiler system controller to:
retrieve, from a memory associated with the controller, a predetermined sequential control setting configured to cause the controller to operate the plurality of boilers in a sequential control mode; and
wherein instructing the one or more boilers f

Assignees

• Rheem Mfg Co

Inventors

• Thurlkill Stephen
• Revilla Jorge Miguel Gamboa

Classifications

• F24F11/65 Primary

  for selecting an operating mode · CPC title

• F24F11/64

  using pre-stored data · CPC title

• G05B19/042 Primary

  using digital processors (G05B19/05 takes precedence) · CPC title

• G05D23/1917

  using digital means · CPC title

• F24H1/22

  Water heaters other than continuous-flow or water-storage heaters, e.g. water heaters for central heating · CPC title