Systems and methods for intelligently controlling a hybrid cascade boiler system

Patent metadata

Field	Value
Publication number	US-11326802-B2
Application number	US-202017002020-A
Country	US
Kind code	B2
Filing date	Aug 25, 2020
Priority date	Aug 25, 2020
Publication date	May 10, 2022
Grant date	May 10, 2022

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, from a supply water temperature sensor, supply water temperature data indicative of a temperature of water supplied from a boiler system associated with the boiler system controller;
receive, from a return water temperature sensor, return water temperature data indicative of a temperature of water returning to the boiler system;
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 set point temperature;
retrieve, from a memory associated with the controller, a boiler operation schedule corresponding to operation of a plurality of boilers; 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 based on the boiler operation schedule, the plurality of boilers comprising at least one condensing boiler and at least one non-condensing boiler, 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 comprises:
in response to the current load demand value being less than or equal to a first load demand threshold, output a control signal for the at least one condensing boiler to transition to the heating mode for heating water in the boiler system; and
in response to the current load demand value being greater than a second load demand threshold, output a control signal for the at least one non-condensing boiler to transition to the heating mode for heating water in the boiler system.

2. The non-transitory, computer-readable medium of claim 1 , wherein the set point temperature is defined by a user.

3. The non-transitory, computer-readable medium of claim 1 , wherein the second load demand threshold is greater than the first load demand threshold, 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 greater than the first load demand threshold and less than or equal to the second load demand threshold, output a control signal for the at least one condensing boiler and the at least one non-condensing boiler to transition to the heating mode for heating water in the boiler system.

4. 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 boiler data indicative of a type and a capacity of boiler available for heating;
determine, based on the current load demand value, a required boiler capacity necessary to satisfy the current load demand value; 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 comprises:
in response to the current load demand value being less than or equal to the first 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 for heating water in the boiler system; and

in response to the current load demand value being greater than the 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 for heating water in 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:
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 set point temperature, and the flow data.

6. The non-transitory, computer-readable medium of claim 5 , wherein the instructions, when executed by the one or more processors, further cause the boiler system controller to:
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 at least one condensing boiler and the at least one non-condensing boiler to transition to the heating mode for heating water in the boiler system, the second load demand threshold being greater than the first load demand threshold.

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 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 set point temperature, and the ambient air temperature data.

8. The non-transitory, computer-readable medium of claim 7 , wherein the instructions, when executed by the one or more processors, further cause the boiler system controller to:
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 at least one condensing boiler and the at least one non-condensing boiler to transition to the heating mode for heating water in the boiler system, the second load demand threshold being greater than the first load demand threshold.

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:
retrieve, from the 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 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 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.

10. The non-transitory, computer-readable medium of claim 9 , wherein the predetermined parallel control setting is defined by a user.

Assignees

• Rheem Mfg Co

Inventors

• Thurlkill Stephen
• Revilla Jorge Miguel Gamboa

Classifications

• G05D23/1931

  to control the temperature of one space · CPC title

• F24H15/414

  using electronic processing, e.g. computer-based · CPC title

• F24H15/365

  of two or more burners, e.g. an array of burners · CPC title

• F24H15/254

  Room temperature · CPC title

• F24H15/219

  after heating · CPC title