U.S. patent application number 13/038311 was filed with the patent office on 2012-09-06 for method and system for limiting water boiler heat input.
Invention is credited to Sean E. Haggerty.
Application Number | 20120225395 13/038311 |
Document ID | / |
Family ID | 46753546 |
Filed Date | 2012-09-06 |
United States Patent
Application |
20120225395 |
Kind Code |
A1 |
Haggerty; Sean E. |
September 6, 2012 |
METHOD AND SYSTEM FOR LIMITING WATER BOILER HEAT INPUT
Abstract
A method to control the heat input into a boiler utilizing the
boiler return temperature to minimize the heat input and maximize
the efficiency of the boiler.
Inventors: |
Haggerty; Sean E.; (North
Haven, CT) |
Family ID: |
46753546 |
Appl. No.: |
13/038311 |
Filed: |
March 1, 2011 |
Current U.S.
Class: |
432/29 |
Current CPC
Class: |
F24D 19/1009 20130101;
F24H 9/2035 20130101; F23N 1/082 20130101 |
Class at
Publication: |
432/29 |
International
Class: |
F24H 1/00 20060101
F24H001/00 |
Claims
1. This method reduces the heat input into a water boiler and
increases the thermal efficiency of the water boiler.
2. This method reduces the fuel consumption of the water
boiler.
3. This method allows adjustment of the boiler to maintain the
thermal efficiency as the heat demand changes due to external
temperature.
4. This method reduces the average maximum temperature of the water
boiler.
5. This method reduces the maintenance and repair cost of the
boiler due to less burner time and lower Maximum Temperature.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The disclosed subject matter generally relates to a method
and system for controlling and minimizing the heat input into a
water boiler, while maintaining the same heat output. Particularly,
the disclosed subject matter relates to a method and system that
improves the overall thermal efficiency of a water boiler.
[0003] Heat Input relates to the amount of fuel oil, natural gas,
electricity, or other energy that is needed to produce a given
amount of Heat Input, commonly measure in BTUs.
[0004] Heat Output refers to the usable heat produced, by a device
such as a water boiler, from this Heat Input, also measure in
BTUs.
[0005] Minimizing the Heat Input while maintaining a given Heat
Output improves the efficiency of the water boiler.
SUMMARY
[0006] In one aspect this invention provides a method to improve
the efficiency of a water boiler. The method allows the system to
limit the heat input of the water boiler while maintaining the same
heat output of the boiler. The method accomplishes this by
monitoring the return temperature of the heating loop to limit the
heat input based on the return temperature.
[0007] In another aspect this invention provides a method to adjust
the efficiency based on the heat demand required.
[0008] These aspects, as well as others, are described in more
detail herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 depicts a Typical Single Zone Heating System; and
[0010] FIG. 2 depicts a New Single Zone Heating System according to
one embodiment disclosed herein; and
[0011] FIG. 3 is a flowchart illustrating the Control Logic to
maximize the efficiency of the boiler.
DETAILED DESCRIPTION
[0012] Although the disclosed subject matter has been shown and
described with respect to the detailed embodiments thereof, it will
be understood by those of skill in the art that various changes may
be made and equivalents may be substituted for elements thereof
without departing from the scope of the disclosed subject matter.
In addition, modifications may be made to adapt a particular
situation or material to the teachings of the subject matter
without departing from the essential scope thereof. Therefore, it
is intended that the disclosed subject matter not be limited to the
particular embodiments disclosed in the above detailed description,
but that the disclosed subject matter will include all embodiments
falling within the scope of the disclosure.
[0013] FIG. 1 illustrates a Typical Single Zone Heating System
(10). A boiler (20) converts heat input to heat output. The
thermostat (22) in the heated area turns on to indicate a heat
demand. Through the furnace controller (23), the circulator (24)
activates and circulates water through the heating loop (25). When
the circulator is active, the burner (26) activates to heat the
water. The boiler temperature is maintained with the controller
(23) on the boiler. This controller turns the burner (26) on when
the circulator (24) is on, and will remain on unless an adjustable
high temperature set point is reached or the circulator turns off.
If the high temperature is reached the burner remains off until the
water temperature drops to specific lower temperature set point, an
un-adjustable difference from the high temperature set point. The
current method allows the water temperature to continue to rise
even if the Heat Loop (25) is at a high temperature and the heat
demand is about to be satisfied.
[0014] Some water boilers integrate domestic hot water (tap water),
where the water boiler maintains a temperature range constantly for
the heat exchanger in the water boiler; these boilers have both a
high and low settable temperature limit.
[0015] FIG. 2 illustrates the New Single Zone Heating system (10).
This system has the same components as shown in FIG. 1, with the
addition of an adjustable temperature switch (27), and a relay
(28). This system monitors the return temperature of the loop with
an adjustable temperature switch (27), with a relay (28) to limit
the burner's on time, based on the return temperature. This allows
the Heat Loop's (25) return water temperature to rise and the relay
to shut off the burner based on the return temperature. Enabling
the water in the heating loop to cool to a lower temperature as the
heat demand is satisfied. The lower the water temperature when the
heat demand is satisfied, the more efficient the heating cycle
becomes.
[0016] By adjusting the maximum return temperature an effective
cycle can be maintained. This can be applied to single zone or
multiple zone systems, and water boilers with and without domestic
hot water heat exchangers.
[0017] In a multiple zone system, if another zone activates during
the cooling portion of the cycle, the cool water from the activated
zone decreases the return temperature and the burner reactivates
until the maximum is reached.
[0018] This method requires the addition thermal switch (27, FIG.
2) or thermal sensor and a relay (28, FIG. 2) to turn off the
burner, no changes beyond the boiler are required. This makes
retrofit of existing boilers easy as well as addition to new
installations.
[0019] FIG. 3 defines the Control Logic of the new system. When the
thermostat in the heated area calls for heat (110) it signals the
controller to turn on the circulator to turn on (120). As the water
flows through the Heating loop, the return temperature is monitored
(130) by the thermal switch (27, FIG. 2). If the return temperature
is below the set temperature, the relay (28, FIG. 2) remains in
its' normally closed position. Once the water temperature reaches
the set temperature the relay (28, FIG. 2) is energized to its'
open state (140) and the burner shuts off. The burner will remain
off until the heat demand is satisfied (the thermostat shuts off
the circulator), or the return temperature falls below the set
temperature (150).
[0020] As the heat output required to satisfy the heat demand
changes, due to external temperature, the set points may be
increased for colder weather, or decreased for warmer weather.
[0021] For unusual heat demands, an extreme cold day, a timer can
be added to keep the burner on when long cycles are encountered.
This bypasses the thermal switch.
[0022] This method may be applied to multiple zone system.
[0023] In a multiple zone system, if an additional zone is
activated while the relay is in the open position, the cooler water
from the activated zone decreases the return temperature and
returns the relay (28) shown in FIG. 2, to the closed (burner on)
position (160).
* * * * *