US 10,914,475 B2Granted

Methods and system for controlling a combination boiler

AssigneeLochinvar, LLC

InventorCurtis George Gagne

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Abstract

A combination boiler provides heated water to a boiler loop and domestic hot water (DHW) to a domestic water loop. The combination boiler includes a primary heat exchanger (PHE) connected to the boiler loop and a burner to provide heat to the primary heat exchanger. A secondary heat exchanger (SHE) transfers heat energy from the boiler loop to the domestic water loop. A controller monitors a PHE inlet temperature and a DHW output temperature, obtains a pre-heat initialization temperature threshold and a pre-heat cancellation temperature threshold, and detects a low temperature condition. A pre-heat operation is initiated responsive to the low temperature condition by circulating heated water from the PHE to the SHE. The burner is selectively fired at least in part according to an outlet temperature of the PHE.

Claims22

Dependent claims

A combination boiler for providing heated water to a boiler loop and domestic hot water (DHW) to a domestic water loop, the combination boiler comprising:

a primary heat exchanger connected to the boiler loop, wherein the boiler loop is the only loop connected to the primary heat exchanger;
a burner configured to provide heat to the primary heat exchanger;
a secondary heat exchanger configured to transfer heat energy from the boiler loop to the domestic water loop;
and
a controller configured to:
monitor a primary heat exchanger inlet temperature and a DHW output temperature;
obtain a pre-heat initialization temperature threshold and a pre-heat cancellation temperature threshold;
detect a low temperature condition when at least one of the primary heat exchanger inlet temperature and the DHW output temperature falls below the pre-heat initialization temperature threshold;
initiate a pre-heat operation of the combination boiler responsive to the low temperature condition by circulating heated water from the primary heat exchanger to the secondary heat exchanger;
and
end the pre-heat operation without firing the burner when both of the primary heat exchanger inlet temperature and the DHW output temperature exceed the pre-heat cancellation temperature threshold.

8 more elements

A method of controlling a combination boiler, the combination boiler having a primary heat exchanger connected to a boiler loop but not to a domestic water loop, a burner configured to provide heat to the primary heat exchanger, and a secondary heat exchanger configured to transfer heat energy from the boiler loop to the domestic water loop, the method comprising:

(a) storing heated water at the primary heat exchanger;
(b) obtaining a pre-heat initialization temperature threshold and a pre-heat cancellation temperature threshold;
(c) monitoring a primary heat exchanger inlet temperature and a domestic hot water (DHW) output temperature;
(d) detecting a low temperature condition when at least one of the primary heat exchanger inlet temperature and the DHW output temperature falls below the pre-heat initialization temperature threshold;
(e) initiating a pre-heat operation of the combination boiler responsive to the low temperature condition by circulating the heated water from the primary heat exchanger to the secondary heat exchanger to provide liquid heat transfer from the boiler loop to the domestic water loop by the secondary heat exchanger;
and
(f) ending the pre-heat operation without firing the burner when both of the primary heat exchanger inlet temperature and the DHW output temperature exceed the pre-heat cancellation temperature threshold.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/265,055Filed 14 Sep 2016
Published: US 2018/0073749 A115 Mar 2018
Granted: 9 Feb 2021
Term ends: Not estimatedThe source records don’t support an estimate.

Classification17 codes

F24D 19/1069
For the combination of central heating and domestic hot water: regulation in function of the temperature of the domestic hot water
F24H 1/124
In which the water is kept separate from the heating medium: using fluid fuel
F24D 3/08
Hot-water central heating systems: in combination with systems for domestic hot-water supply
F24H 1/52
Water heaters for central heating incorporating heaters for domestic water: incorporating heat exchangers for domestic water