US 2026/0029162 A1 · INTERNAL RECIRCULATION WITH LOW PULSE FIRE CONTROL

Abstract

A method of heating water in a tankless water heating appliance in conditions of low water flow or no water flow is disclosed. A water supply is introduced into a heat exchanger configured to transfer heat to the water supply from a burner when the water supply is contained in the heat exchanger. A pulse fire duration is determined for the burner and a pre-defined condition of the water supply is sensed. When the pre-defined condition is sensed, the burner is activated to fire for the pulse fire duration, and the burner is deactivated after the pulse fire duration is elapsed. The pre-defined condition of the water supply is monitored, such that when the pre-defined condition is sensed again, the burner is activated to fire for another pulse fire duration, and the burner is deactivated after the another pulse fire duration is elapsed.

Claims42

Dependent claims

A method of heating water in a tankless water heating appliance in conditions of low water flow or no water flow, the method comprising:

introducing a water supply into a heat exchanger configured to transfer heat to the water supply from a burner when the water supply is contained in the heat exchanger;
determining a pulse fire duration for the burner based on at least one of (i) a target temperature change (° F.) of the water supply upstream of, downstream of, or within the heat exchanger;
(ii) a volume (gallons) of the water supply contained in the heat exchanger;
(iii) a minimum rated heating capacity (BTU/hour);
or a combination thereof;
sensing a pre-defined condition of the water supply, the pre-defined condition being selected from the group consisting of (i) a temperature indicative of a water temperature of the water supply upstream of, downstream of, or within the heat exchanger;
(ii) a minimum rate of temperature change of the water supply upstream of, downstream of, or within the heat exchanger;
and (iii) a minimum temporal flow condition of the water supply;
when the pre-defined condition is sensed,
activating the burner to fire for the pulse fire duration to transfer heat to the water supply contained in the heat exchanger, and
deactivating the burner to terminate the transfer of heat to the water supply contained in the heat exchanger after the pulse fire duration is elapsed;
and
monitoring for the pre-defined condition of the water supply, such that
when the pre-defined condition is sensed again,
activating the burner to fire for another pulse fire duration to again transfer heat to the water supply contained in the heat exchanger, and
deactivating the burner to again terminate the transfer of heat to the water supply contained in the heat exchanger after the another pulse fire duration is elapsed.

13 more elements

A tankless water heating appliance configured to heat water in conditions of low water flow or no water flow, the tankless water heating appliance comprising:

a heat exchanger configured to transfer heat to the water from a heat source when the water is contained in the heat exchanger;
at least one sensor configured to sense a pre-defined condition of the water, the pre-defined condition being selected from the group consisting of (i) a temperature indicative of a water temperature of the water upstream of, downstream of, or within the heat exchanger;
(ii) a minimum rate of temperature change of the water supply upstream of, downstream of, or within the heat exchanger;
and (iii) a minimum temporal flow condition of the water;
and
a controller configured to:
calculate a pulse fire duration for the heat source based on at least one of (i) a target temperature change (° F.) of the water upstream of, downstream of, or within the heat exchanger;
(ii) a volume (gallons) of the water contained in the heat exchanger;
(iii) a minimum rated heating capacity (BTU/hour);
or a combination thereof;
receive, from the at least one sensor, a signal indicating when the pre-defined condition is sensed;
and
when the pre-defined condition is sensed:
activate the burner to fire for the pulse fire duration to transfer heat to the water contained in the heat exchanger, and
deactivate the burner to terminate the transfer of heat to the water contained in the heat exchanger after the pulse fire duration is elapsed;
and
monitor for the pre-defined condition of the water, such that when the pre-defined condition is sensed again:
activate the burner to fire for another pulse fire duration to again transfer heat to the water contained in the heat exchanger, and
deactivate the burner to again terminate the transfer of heat to the water contained in the heat exchanger after the another pulse fire duration is elapsed.

16 more elements

A tankless water heating appliance configured to heat water in conditions of low water flow or no water flow, the tankless water heating appliance comprising:

a heat exchanger configured to transfer heat to the water from a heat source when the water is contained in the heat exchanger;
at least one sensor configured to sense a pre-defined condition of the water, the pre-defined condition being selected from the group consisting of (i) a temperature indicative of a water temperature of the water upstream of, downstream of, or within the heat exchanger;
(ii) a minimum rate of temperature change of the water supply upstream of, downstream of, or within the heat exchanger;
and (iii) a minimum temporal flow condition of the water;
and
a controller configured to:
calculate a pulse fire duration for the heat source based on at least one of (i) a target temperature change (° F.) of the water upstream of, downstream of, or within the heat exchanger;
(ii) a volume (gallons) of the water contained in the heat exchanger;
(iii) a minimum rated heating capacity (BTU/hour);
or a combination thereof;
receive, from the at least one sensor, a signal indicating when the pre-defined condition is sensed;
and
when the pre-defined condition is sensed:
activate the burner to fire for the pulse fire duration to transfer heat to the water contained in the heat exchanger, and
deactivate the burner to terminate the transfer of heat to the water contained in the heat exchanger after the pulse fire duration is elapsed;
and
monitor for the pre-defined condition of the water, such that when the pre-defined condition is sensed again:
activate the burner to fire for another pulse fire duration to again transfer heat to the water contained in the heat exchanger, and
deactivate the burner to again terminate the transfer of heat to the water contained in the heat exchanger after the another pulse fire duration is elapsed;
and
wherein the heat exchanger comprises a coiled conduit shaving a plurality of rotations extending between an inlet of the heat exchanger and an outlet of the heat exchanger, the number of plurality of rotations being selected to increase the volume of the water to be heated in the coiled conduit of the heat exchanger.

18 more elements

Dependencies are inferred from the claim text.

Internal recirculation with low pulse fire control

Life of this patent

Internal recirculation with low pulse fire control

Life of this patent

Abstract

Claims42