US2026029162A1PendingUtilityA1
Internal recirculation with low pulse fire control
Est. expiryJul 28, 2042(~16 yrs left)· nominal 20-yr term from priority
F24H 15/238F24H 15/219F24H 15/215F24H 15/36F24H 9/2035
62
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Claims
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.
Claims
exact text as granted — not AI-modified1 . 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.
2 . The method of claim 1 , wherein the step of determining the pulse fire duration for the burner includes determining the pulse fire duration according to the following equation:
Pulse
fire
duration
(
s
)
∝
Target
Temp
Change
(
∘
F
.
)
×
Volume
(
gal
)
×
Density
of
Water
(
lbs
gal
)
Minimum
Rated
Heating
Capacity
(
BTU
hr
)
×
3600
s
.
3 . The method of claim 1 , wherein the step of sensing the pre-defined condition of the water supply includes sensing the temperature indicative of a water temperature of the water supply, and sensing the temperature indicative of the water temperature of the water supply comprises sensing at least one of an inlet temperature at an inlet of the heat exchanger and an outlet temperature at an outlet of the heat exchanger.
4 . The method of claim 1 , wherein the target temperature change of the water supply upstream of, downstream of, or within the heat exchanger includes a range between 1° F. to 49° F. and is detected based on at least one of an inlet temperature at an inlet of the heat exchanger and an outlet temperature at an outlet of the heat exchanger.
5 . (canceled)
6 . The method of claim 1 , wherein the step of sensing the pre-defined condition of the water supply includes sensing the minimum temporal flow condition of the water supply based on at least one of an inlet temperature at an inlet of the heat exchanger and an outlet temperature at an outlet of the heat exchanger.
7 . (canceled)
8 . The method of claim 1 , wherein step of introducing the water supply includes introducing the water supply into a plurality of rotations of a coiled conduit of the heat exchanger.
9 - 15 . (canceled)
16 . The method of claim 1 , wherein the step of activating the burner to fire for the pulse fire duration includes activating the burner for 5 seconds to 35 seconds.
17 . (canceled)
18 . (canceled)
19 . The method of claim 1 , wherein the method of heating water in the tankless water heating appliance avoids freezing of the water supply contained in the heat exchanger, wherein the step of sensing the pre-defined condition of the water supply includes sensing a temperature indicative of a minimum water temperature of the water supply upstream of, downstream of, or within the heat exchanger, and the step of activating the burner to fire for the pulse fire duration to transfer heat to the water supply contained in the heat exchanger includes pulsed activation of the burner to fire such that heat is transferred to the water supply contained in the heat exchanger, thereby avoiding the freezing of the water supply in the heat exchanger of the tankless water heating appliance.
20 - 24 . (canceled)
25 . The method of claim 1 , wherein the method of heating water in the tankless water heating appliance avoids overheating of the water supply contained in the heat exchanger, wherein the sensing step comprises sensing a temperature indicative of a water temperature of the water supply upstream of, downstream of, or within the heat exchanger, and the activating step comprises pulsed activation of the burner to fire to transfer heat to the water supply contained in the heat exchanger, thereby avoiding the overheating of the water supply in the heat exchanger of the tankless water heating appliance.
26 - 30 . (canceled)
31 . The method of claim 1 , wherein the method of heating water in the tankless water heating appliance includes heating the water supply in response to a minimum user demand for the water supply established by detecting a flow draw for a predetermined draw duration, wherein the sensing step comprises sensing a minimum temporal flow condition of the water supply, and the activating step comprises activation of the burner to fire to transfer heat to the water supply contained in the heat exchanger when the flow of the water supply exceeds the minimum temporal flow condition, and the deactivating step comprises deactivating the burner to terminate the transfer of heat to the water supply contained in the heat exchanger, thereby triggering monitoring for the pre-defined condition of the water supply.
32 - 37 . (canceled)
38 . 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.
39 . The tankless water heating appliance of claim 38 , wherein the controller is configured to calculate the pulse fire duration according to the following equation: Pulse fire duration(s)
∝
Target
Temp
Change
(
∘
F
.
)
×
Volume
(
gal
)
×
Density
of
Water
(
lbs
gal
)
Minimum
Rated
Heating
Capacity
(
BTU
hr
)
×
3600
s
40 . The tankless water heating appliance of claim 38 , wherein when the at least one sensor is configured to sense the temperature indicative of a water temperature of the water supply, the at least one sensor is configured to detect at least one of an inlet temperature at an inlet of the heat exchanger and an outlet temperature at an outlet of the heat exchanger.
41 . The tankless water heating appliance of claim 38 , wherein the target temperature change is in a range between 1° F. to 49° F., and the target temperature change is based on at least one of an inlet temperature at an inlet of the heat exchanger and an outlet temperature at an outlet of the heat exchanger.
42 . (canceled)
43 . The tankless water heating appliance of claim 38 , wherein the at least one sensor is configured to sense the minimum temporal flow condition of the water supply based on at least one of an inlet temperature at an inlet of the heat exchanger and an outlet temperature at an outlet of the heat exchanger.
44 . The tankless water heating appliance of claim 38 , wherein the at least one sensor is configured to sense the minimum temporal flow condition of the water supply using a flow detector configured to sense flow of the water supply.
45 . The tankless water heating appliance of claim 38 , wherein the heat exchanger comprises a coiled conduit having a plurality of rotations.
46 - 50 . (canceled)
51 . The tankless water heating appliance of claim 38 , wherein the heat source has a minimum heating capacity from 11,000 BTU/hr to 26,000 BTU/hr.
52 . (canceled)
53 . The tankless water heating appliance of claim 38 , wherein the pulse fire duration is between 5 seconds to 35 seconds.
54 . (canceled)
55 . The tankless water heating appliance of claim 38 , wherein the tankless water heating appliance is configured to heat water without the need for the heat source being other than a burner.
56 . The tankless water heating appliance of claim 38 , wherein the tankless water heating appliance is configured to avoid freezing of the water contained in the heat exchanger, wherein the at least one sensor is configured to sense a temperature indicative of a minimum water temperature of the water supply upstream of, downstream of, or within the heat exchanger, and the heat source is configured to transfer heat to the water contained in the heat exchanger, thereby avoiding the freezing of the water in the heat exchanger of the tankless water heating appliance.
57 - 63 . (canceled)
64 . The tankless water heating appliance of claim 38 , wherein the tankless water heating appliance avoids overheating of the water contained in the heat exchanger, wherein the at least one sensor is configured to sense a temperature indicative of a water temperature of the water upstream of, downstream of, or within the heat exchanger, and the heat source is configured to transfer heat to the water contained in the heat exchanger, thereby avoiding the overheating of the water supply in the heat exchanger of the tankless water heating appliance.
65 - 69 . (canceled)
70 . The tankless water heating appliance of claim 38 , wherein the tankless water heating appliance heats the water in response to a minimum user demand for the water established by detecting a flow draw for a predetermined draw duration, wherein the at least one sensor is configured to sense a minimum temporal flow condition of the water, and the heat source is configured to transfer heat to the water contained in the heat exchanger when the flow of the water exceeds the minimum temporal flow condition, and the heat source is deactivated to terminate the transfer of heat to the water contained in the heat exchanger, thereby triggering the controller to monitor for the pre-defined condition of the water.
71 - 76 . (canceled)
77 . 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.
78 . The tankless water heating appliance of claim 77 , the plurality of rotations including at least 17 rotations, thereby providing an increased volume of the water to be heated in the coiled conduit between the inlet and the outlet.
79 . The tankless water heating appliance of claim 77 , the plurality of coils having a capacity of at least 0.5 gallons for the water to be heated in the coiled conduit between the inlet and the outlet, thereby providing an increased volume of the water to be heated in the coiled conduit between the inlet and the outlet.
80 . The tankless water heating appliance of claim 77 , the plurality of coils including a conduit having an uncoiled length of at least 40 feet, a cross-sectional area of at least 0.8 square inches, or an uncoiled length of at least 40 feet and a cross-sectional area of at least 0.8 square inches, thereby providing an increased volume of the water to be heated in the coiled conduit between the inlet and the outlet.Join the waitlist — get patent alerts
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