U.S. patent application number 14/824383 was filed with the patent office on 2015-12-24 for energy measurement system for fluid systems.
The applicant listed for this patent is SolarLogic, LLC. Invention is credited to Fredric L. MILDER, Bristol STICKNEY.
Application Number | 20150369547 14/824383 |
Document ID | / |
Family ID | 49233305 |
Filed Date | 2015-12-24 |
United States Patent
Application |
20150369547 |
Kind Code |
A1 |
MILDER; Fredric L. ; et
al. |
December 24, 2015 |
ENERGY MEASUREMENT SYSTEM FOR FLUID SYSTEMS
Abstract
A primary fluid flow loop and a secondary fluid flow loop
fluidly coupled to the primary fluid flow loop. The secondary fluid
flow loop exchanges heat with at least one of a heat source and a
heat load. The secondary fluid flow loop includes an inlet and an
outlet fluidly coupling the primary fluid flow loop to the
secondary fluid flow loop. A fluid flow meter coupled to the
primary fluid flow loop. A first temperature sensor coupled to the
primary fluid flow loop, the first temperature sensor measures the
temperature of a fluid flowing in the primary fluid flow loop
upstream of the inlet of the secondary fluid flow loop. A second
temperature sensor coupled to the primary fluid flow loop, the
second temperature sensor measures the temperature of the fluid
flowing in the primary fluid flow loop downstream of the outlet of
the secondary fluid flow loop.
Inventors: |
MILDER; Fredric L.;
(Galisteo, NM) ; STICKNEY; Bristol; (Tesuque,
NM) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SolarLogic, LLC |
Sante Fe |
NM |
US |
|
|
Family ID: |
49233305 |
Appl. No.: |
14/824383 |
Filed: |
August 12, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13438081 |
Apr 3, 2012 |
9140503 |
|
|
14824383 |
|
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Current U.S.
Class: |
165/11.1 |
Current CPC
Class: |
F24D 2200/14 20130101;
F28F 27/00 20130101; F28D 15/00 20130101; G01K 17/10 20130101; F24D
2240/00 20130101 |
International
Class: |
F28F 27/00 20060101
F28F027/00 |
Claims
1. An energy measurement system for a fluid heating and cooling
system, comprising: a primary fluid flow loop; a first secondary
fluid flow loop and a second secondary fluid flow loop each being
fluidly coupled to the primary fluid flow loop, the first secondary
fluid flow loop exchanging heat with a heat load and the second
secondary fluid flow loop exchanging heat with a heat source, the
first and second secondary fluid flow loops each including an inlet
and an outlet fluidly coupling the primary fluid flow loop to each
of the first and second secondary fluid flow loops; a fluid flow
meter coupled to the primary fluid flow loop at any position along
the primary fluid flow loop other than between the respect inlets
and outlets of the first and second secondary fluid flow loops, the
flow meter measuring a volumetric fluid flow of the flow within the
primary loop at the position of the flow meter; a first temperature
sensor coupled to the primary fluid flow loop, the first
temperature sensor measuring the temperature of a fluid flowing in
the primary fluid flow loop upstream of the inlet of the first
secondary fluid flow loop; a second temperature sensor coupled to
the primary fluid flow loop, the second temperature sensor
measuring the temperature of the fluid in the primary fluid flow
loop flowing downstream of the outlet of the first secondary fluid
flow loop; and a processor in communication with the first and
second temperature sensors and the fluid flow meter, the processor
being configured to multiply the difference between the measured
temperatures of the first and second temperature sensors by the
volume flow measured by the flow meter to determine the thermal
energy consumption rate of the heat load of the first secondary
flow loop.
2. The system of claim 1, further including a third temperature
sensor coupled to the primary fluid flow loop, the third
temperature sensor measuring the temperature of a fluid flowing in
the primary fluid flow loop upstream of the inlet of the second
secondary fluid flow loop; and a fourth temperature sensor coupled
to the primary fluid flow loop, the fourth temperature sensor
measuring the temperature of the fluid in the primary fluid flow
loop flowing downstream of the outlet of the second secondary fluid
flow loop; and the processor in communication with the third and
fourth temperature sensors, the processor being configured to
multiply the difference between the measured temperatures of the
fourth and third temperature sensors by the volume flow measured by
the flow meter to determine the thermal energy production rate of
the heat source of the second secondary flow loop.
3. The system of claim 1, further including a heat exchange element
exchanging heat with the primary fluid flow loop.
4. The system of claim 2, further including a heat exchange element
exchanging heat with the primary fluid flow loop.
5. The system of claim 3, further comprising a second primary fluid
flow loop in thermal communication with the primary fluid flow
loop; and wherein the second primary fluid flow loop exchanges heat
with the primary fluid flow loop through the heat exchanging
element.
6. The system of claim 4, further comprising a second primary fluid
flow loop in thermal communication with the primary fluid flow
loop; and wherein the second primary fluid flow loop exchanges heat
with the primary fluid flow loop through the heat exchanging
element.
7. The system of claim 5, further including a second fluid flow
meter coupled to the second primary fluid flow loop.
8. The system of claim 6, further including a second fluid flow
meter coupled to the second primary fluid flow loop.
9. The system of claim 7, further including a tertiary fluid flow
loop fluidly coupled to the second primary fluid flow loop, the
tertiary fluid flow loop including at least one of a heat load and
a heat source.
10. The system of claim 8, further including a tertiary fluid flow
loop fluidly coupled to the second primary fluid flow loop, the
tertiary fluid flow loop including at least one of a heat load and
a heat source.
11. A method of measuring the energy consumption and production
rates in a fluid heating or cooling system, comprising: coupling a
single fluid flow meter to a primary fluid flow loop, the primary
fluid flow loop being fluidly coupled to a first secondary fluid
flow loop and a second secondary loop, the first secondary fluid
flow loop including an inlet and an outlet fluidly coupling the
primary fluid flow loop and the first secondary fluid flow loop,
the first secondary fluid flow loop exchanging heat with a heat
load and the second secondary flow loop exchanging heat with a heat
source; measuring the volumetric fluid flow rate within the primary
fluid flow loop at any position along the primary fluid flow loop
that is not between the inlet and the outlet of the first secondary
fluid flow loop or between the inlet and the outlet of the second
secondary fluid flow loop with the fluid flow meter; measuring the
temperature of a fluid flowing in the primary fluid flow loop
upstream of the inlet of the first secondary fluid flow loop with a
first temperature sensor coupled to the primary fluid flow loop
upstream of the inlet of the first secondary fluid flow loop;
measuring the temperature of a fluid flowing in the primary fluid
flow loop downstream of the outlet of the first secondary fluid
flow loop with a second temperature sensor coupled to the primary
fluid flow loop downstream of the outlet of the first secondary
fluid flow loop; measuring the temperature of a fluid flowing in
the primary fluid flow loop upstream of the inlet of the second
secondary fluid flow loop with a third temperature sensor coupled
to the primary fluid flow loop upstream of the inlet of the second
secondary fluid flow loop; measuring the temperature of a fluid
flowing in the primary fluid flow loop downstream of the outlet of
the second secondary fluid flow loop with a fourth temperature
sensor coupled to the primary fluid flow loop downstream of the
outlet of the second secondary fluid flow loop; multiplying the
difference between the measured temperatures of the first and
second temperature sensors by the volume flow measured by the flow
meter to determine the energy consumption rate of the heat load of
the first secondary flow loop; and multiplying the difference
between the measured temperatures of the fourth and third
temperature sensors by the volume flow measured by the flow meter
to determine the energy production rate of the heat source of the
second secondary flow loop.
12. A method of measuring the energy consumption rate in a fluid
heating or cooling system, comprising: coupling a single fluid flow
meter to a primary fluid flow loop, the primary fluid flow loop
being fluidly coupled to a first secondary fluid flow loop and a
second secondary loop, the first secondary fluid flow loop
including an inlet and an outlet fluidly coupling the primary fluid
flow loop and the first secondary fluid flow loop, the first
secondary fluid flow loop exchanging heat with a heat load and the
second secondary flow loop exchanging heat with a heat source;
measuring the volumetric fluid flow rate within the primary fluid
flow loop at any position along the primary fluid flow loop that is
not between the inlet and the outlet of the first secondary fluid
flow loop or between the inlet and the outlet of the second
secondary fluid flow loop with the fluid flow meter; measuring the
temperature of a fluid flowing in the primary fluid flow loop
upstream of the inlet of the first secondary fluid flow loop with a
first temperature sensor coupled to the primary fluid flow loop
upstream of the inlet of the first secondary fluid flow loop;
measuring the temperature of a fluid flowing in the primary fluid
flow loop downstream of the outlet of the first secondary fluid
flow loop with a second temperature sensor coupled to the primary
fluid flow loop downstream of the outlet of the first secondary
fluid flow loop; multiplying the difference between the measured
temperatures of the first and second temperature sensors by the
volume flow measured by the flow meter to determine the energy
consumption rate of the heat load of the first secondary flow loop.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/438081, filed Apr. 3, 2012, entitled ENERGY
MEASUREMENT SYSTEM FOR FLUID SYSTEMS, the entire contents of each
of which are hereby incorporated by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] n/a
FIELD OF THE INVENTION
[0003] The present invention relates to a method and system for
measuring energy transfer in fluid heating and cooling systems.
BACKGROUND OF THE INVENTION
[0004] Some homes and businesses employ hydronic (water-based) or
other fluid heating systems to heat living spaces, pools, spas,
walkways, driveways, hot water for washing, etc., or for process
heat. Fluid heating systems distribute heated fluid through a
series of heat exchanging pipes that are positioned throughout the
heating loads. Conventional hydronic systems use on-demand sources,
such as boilers and chillers, to thermally adjust fluids that
circulate throughout the system.
[0005] In fluid heating and cooling systems it is desirable to
measure the heat energy transferred into and out of each heat
source and load. Measuring and monitoring heat transfer from a
fluid system is necessary for receiving financial rebates, such as
renewable energy credits, as well as for controlling the various
heat sources and loads.
[0006] For fluid systems having multiple heat sources and loads,
measuring and monitoring heat energy transfer from each of the heat
sources and loads may be expensive. In particular, because
available energy meters, such as a British Thermal Unit (BTU)
meters, need to be affixed to the fluid system at each measurement
point, for example, at each heat source or load, a system may often
include several expensive BTU meters.
[0007] In general, a BTU meter includes a flow meter and a
temperature sensor, the data from which are combined according to
mathematical formula to determine the heat energy transfer from a
particular heat source or load. The flow meter component of the BTU
meter is expensive, with the temperature sensors being a comparably
inexpensive component. In particular, a current fluid system having
three heat loads requires three expensive flow meters and six
thermistors to accurately measure the heat consumption of each
load.
[0008] Therefore, what is needed is an effective and cost efficient
heat energy measurement system that reduces the number of flow
meters in the system without losing measurement accuracy.
SUMMARY OF THE INVENTION
[0009] The present invention advantageously provides for an energy
measurement system and method for a fluid heating and cooling
system. The system includes a primary fluid flow loop. At least one
secondary fluid flow loop is included and fluidly coupled to the
primary fluid flow loop. The secondary fluid flow loop exchanges
heat with at least one of a heat source and a heat load. The
secondary fluid flow loop includes an inlet and an outlet fluidly
coupling the primary fluid flow loop to the secondary fluid flow
loop. A fluid flow meter coupled to the primary fluid flow loop is
included. A first temperature sensor is coupled to the primary
fluid flow loop, the first temperature sensor measuring the
temperature of a fluid flowing in the primary fluid flow loop
upstream of the inlet of the secondary fluid flow loop. A second
temperature sensor is coupled to the primary fluid flow loop, the
second temperature sensor measuring the temperature of the fluid
flowing in the primary fluid flow loop downstream of the outlet of
the secondary fluid flow loop.
[0010] In another embodiment, a method includes coupling a fluid
flow meter to a primary fluid flow loop, the primary fluid flow
loop being fluidly coupled to a secondary fluid flow loop, the
secondary fluid flow loop including an inlet and an outlet fluidly
coupling the primary fluid flow loop and the secondary fluid flow
loop, the secondary fluid flow loop exchanging heat with at least
one of a heat source and a heat load. A first temperature sensor is
coupled to the primary fluid flow loop upstream of the inlet and
measures the fluid flow rate with the fluid flow meter. The
temperature of a fluid flowing in the primary fluid flow loop
upstream of the inlet is measured with the first temperature
sensor. A second temperature sensor is coupled to the primary fluid
flow loop downstream of the secondary loop outlet coupling. The
temperature of the fluid flowing in the primary fluid flow loop
downstream of the outlet is measured with the second temperature
sensor.
[0011] In yet another embodiment, the system includes a primary
fluid flow loop. A plurality of secondary fluid flow loops are
fluidly coupled to the primary fluid flow loop, each secondary
fluid flow loop exchanging heat with at least one of a heat source
and a heat load, each secondary fluid flow loop including an inlet
and an outlet fluidly coupling the primary fluid flow loop to the
secondary fluid flow loop. A fluid flow meter is coupled to the
primary fluid flow loop, the fluid flow meter being positioned on
the primary fluid flow loop at any position other than between the
inlet and outlet of each secondary fluid flow loop. A first
temperature sensor is coupled to the primary fluid flow loop, the
first temperature sensor measures the temperature of a fluid
flowing in the primary fluid flow loop upstream of the inlet of the
secondary fluid flow loop. A second temperature sensor is coupled
to the primary fluid flow loop, the second temperature sensor
measures the temperature of the fluid flowing in the primary fluid
flow loop downstream of the outlet of the secondary fluid flow
loop. A second primary fluid flow loop exchanging heat with the
first primary fluid flow loop is included. One or more solar
collectors is included and exchanging heat with the second primary
fluid flow loop.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] A more complete understanding of the present invention, and
the attendant advantages and features thereof, will be more readily
understood by reference to the following detailed description when
considered in conjunction with the accompanying drawings
wherein:
[0013] FIG. 1 is a system schematic of an exemplary energy
measurement system for a fluid heating and cooling system
constructed in accordance with the principles of the present
invention; and
[0014] FIG. 2 is a flow chart showing and exemplary method of
measuring and calculating an energy consumption rate of each of the
heating sources and loads of a fluid heating and cooling
system.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Now referring to the drawings in which like reference
designators refer to like elements, there is shown in FIG. 1 a
schematic of an exemplary energy measurement system for a hydronic
system constructed in accordance with the principles of the present
invention and designated generally as "10." Of note, the system
components have been represented where appropriate by conventional
symbols in the drawings, showing only those specific details that
are pertinent to understanding the embodiments of the present
invention so as not to obscure the disclosure with details that
will be readily apparent to those of ordinary skill in the art
having the benefit of the description herein. Moreover, while
certain embodiments or figures described herein may illustrate
features not expressly indicated on other figures or embodiments,
it is understood that the features and components of the system and
devices disclosed herein may be included in a variety of different
combinations or configurations without departing from the scope and
spirit of the invention.
[0016] The system 10 may be associated with or otherwise in
communication with a fluid heating and cooling system 12 for a
house or other building. The fluid system 12 may include insulated
and non-insulated thermally conductive pipes of varying diameters
and sizes to circulate a working fluid to various system
components. In particular, a working fluid such as boiler fluid or
water is circulated by the fluid system 12, by for example a pump,
around a primary fluid flow loop 14. In the exemplary embodiment
shown in FIG. 1, the primary fluid flow loop 14 is a closed loop
fluid piping system that circulates the working fluid at a
programmed or predetermined flow rate. For example, the working
fluid may be circulated at a constant flow rate or a variable flow
rate depending on the energy demand of particular loads and sources
in thermal communication with the primary fluid flow loop 14. As
such, the flow rate of the working fluid may be different depending
on the time of day, available power sources, operating loads,
etc.
[0017] Fluidly coupled to the primary fluid flow loop 14 are one or
more secondary fluid flow loops 16. Each secondary fluid flow loop
16 may include piping of the same, smaller, or larger diameter than
that of the primary fluid flow loop 14 such that flow of fluid into
the secondary fluid flow loop 16 may be accelerated or decelerated
depending on the desired rate of heat transfer from the working
fluid. Each secondary fluid flow loop 16 may include an inlet 18,
which diverts a portion of the fluid flow from the primary fluid
flow loop 14 into the secondary fluid flow loop 16, and an outlet
20 directing the flow of fluid exiting the secondary fluid flow
loop 16 back into the primary fluid flow loop 14. In an exemplary
embodiment, each secondary fluid flow loop 16 includes a single
inlet 18 and a single outlet 20, but it is further contemplated
that more than one inlet 18 and outlet 20 may be included with each
secondary fluid flow loop 16.
[0018] The secondary fluid flow loop 16 may be in thermal
communication with at least one of a heat source 22 and a heat load
24. For example, in an exemplary fluid system 12, heat sources 22
may include a heat storage unit and a boiler generating heat from
the combustion of renewable or non-renewable resources, among other
heat sources 22. Exemplary heat loads include domestic hot water, a
heat storage tank, mass zones, such as radiant heating of a
concrete slab, and non-mass zones in the household such as
baseboard heaters. The secondary fluid flow loop 16 may selectively
exchange heat with one or more of the heat sources 22 and loads 24
with user control of the fluid system 12. For example, one or more
controllable valves (not shown) may in fluid communication with the
primary fluid flow loop 14 to facilitate or prevent the flow of
fluid into the inlets 18 of each secondary fluid flow loop 16.
[0019] Coupled to the primary fluid flow loop 14 is a fluid flow
meter 26. Although illustrated in the drawings by convention as a
sideways triangle, it is understood that flow meter 26 may be any
meter known in the art that may measure the volume flow rate of the
fluid flowing through the primary fluid flow loop 14. In an
exemplary embodiment, one flow meter 26 is coupled to or otherwise
in communication with a fluid flow circulating through the primary
fluid flow loop 14. Owing to the fact that the primary fluid flow
loop 14 is a closed loop system, the flow meter 26 may be
positioned at any location along the primary fluid flow loop 14 to
measure the fluid flow as long as the fluid flow meter 26 is not
positioned between the inlet 18 and the outlet 20 of any of the
secondary loops 16. The flow meter 26 may be operable to measure
the flow of fluid whether the fluid is flowing clockwise or
counter-clockwise within the primary fluid flow loop 14.
[0020] Coupled to or otherwise in communication with the primary
fluid flow loop 14 are at least a first temperature sensor 28 and a
second temperature sensor 30. The first temperature sensor 28 and
the second temperature sensor 30 may be thermistors or
thermocouples operable to measure the temperature of the fluid
flowing within the primary fluid flow loop 14 at various positions.
In an exemplary embodiment, the first temperature sensor 28 may be
positioned on or within the primary loop 14 at a position upstream
from the inlet 18 of a particular heat source 22 or heat load 24.
For example, each heat source 22 or heat load 24 may include at
least one first temperature sensor 28 upstream from its
corresponding inlet 18 such that the temperature of the fluid
entering each particular heat source 22 or heat load 24 may be
measured. The working fluid entering the inlet 18 and circulating
through the secondary fluid flow loop 16 may exchange heat with the
heat source 22 or heat load 24 because the piping of the secondary
flow loop 16 is sufficiently thin to facilitate heat transfer from
or to the working fluid.
[0021] After the working fluid exchanges heat with the heat source
22 or the heat load 24 of the secondary fluid flow loop 16, the
temperature of the working fluid may change as it exits the
secondary fluid flow loop 16 through the outlet 20. The second
temperature sensor 30 may be positioned on or within the primary
loop 14 at a position downstream from the outlet 20 to measure the
temperature of the fluid flowing in the primary fluid flow loop 14
after mixing of the secondary loop 16 fluid flowing out of the
outlet 20 with the primary loop 14. The change in temperature of
the primary loop 14 fluid from just upstream of the inlet 18, where
it enters the secondary loop 16, to just downstream of the outlet
20, where it exits the secondary loop 16, may be directly
correlated along with the measured fluid flow within the primary
loop 14 to an energy consumption rate of the heat source 22 or heat
load 24 on the secondary loop 16. In particular, the portion of the
primary fluid flow loop 14 disposed between the inlet 18 and the
outlet 20 may be insulated and/or sufficiently thick such that
minimal or negligible heat transfer occurs from the working fluid
when circulating through the primary fluid flow loop 14 between the
inlet 18 and the outlet 20 of the secondary loop 16.
[0022] Optionally, the entire primary fluid flow loop 14 may be
insulated such that minimal or negligible heat transfer occurs from
the working fluid at any portion of the primary fluid flow loop 14.
The temperature measurement of the working fluid at the second
temperature sensor 30 represents both temperature of the fluid in
the primary fluid flow loop 14 after mixing of one of the secondary
loop 16 outlet's 18 fluid flowing into the primary loop 14 exiting
a first heat source 22 or heat load 24 of another heat source 22 or
heat load 24 as well as the inlet 18 temperature of a second heat
source 22 or heat load 24. For example, as shown in FIG. 1, six
temperature sensors are shown coupled to the primary fluid flow
loop 14 and labeled as T4-T9. The measured temperature at T4
represents both the temperature of the working fluid downstream of
the outlet 20 of the heat storage heat source 22 and the
temperature of the working fluid flowing into the boiler 22.
Similarly, the measured temperature at T5 represents both the
temperature of the working fluid in the primary fluid flow loop 14
downstream of the outlet 20 of the boiler heat source 22 and the
temperature of the working fluid flowing into the domestic hot
water heat load 24. Accordingly, the exemplary system 10 in FIG. 1
includes three heat loads 24, one heat source 22, and a heat
storage tang that can be either a heat load 24 or a heat source 22
and different moments during operation of the system 12, and
includes six temperature sensors and one flow meter 26 to measure
the energy consumption of each of the heat sources 22 and heat
loads 24.
[0023] The first temperature sensor 28 and the second temperature
sensor 30 and the flow meter 26 may each be in electrical or
wireless communication with an energy measurement unit 32, the
energy measurement unit having a processor 34 configured to
correlate the measured temperatures and the flow rate to an energy
consumption rate or other energy related data. The energy
measurement unit 32 may further be operable to display the
instantaneous, average, or cumulative energy consumption or
consumption rates for each heat source 22 or heat load 24 at any
point in time.
[0024] Continuing to refer to FIG. 1, the primary fluid flow loop
14 may be in thermal communication with a heat exchanging element
36, such as a coil or other thermally conductive component. The
heat exchange element 36 operably and thermally connects the
primary fluid flow loop 14 to a second primary fluid flow loop 38.
For example, as shown in FIG. 1, the heat exchange element 36
provides a thermally conductive medium through which the working
fluid circulating within the primary fluid flow loop 14 and a
working fluid, such as glycol, circulating within the second
primary fluid flow loop 28, exchange heat. The second primary fluid
flow loop 38 may be at least partially disposed outside of the
building or house in which the fluid system 12 is installed and the
primary fluid flow loop 14 may be disposed within the house or
building.
[0025] A second fluid flow meter 40 may be coupled to the second
primary fluid flow loop 38 to measure the flow rate of the
circulating glycol. The second flow meter 40 may be positioned at
any position along the second primary fluid flow loop 38. A
tertiary fluid flow loop 42 may be fluidly coupled to the second
primary fluid flow loop 38 in a similar or the same manner as the
secondary fluid flow loop 16 is fluidly coupled to the primary
fluid flow loop 14. For example, the tertiary fluid flow loop 42
may include an inlet 18 and an outlet 20 fluidly coupling the
tertiary fluid flow loop 42 to the second primary fluid flow loop
38. A heat source 22 or a heat load 24 may be in thermal
communication with the tertiary fluid flow loop 42. In an exemplary
embodiment, the second flow meter 40 may be positioned at any
position along the second primary fluid flow loop 38, so long as it
is not being between an inlet 18 and outlet 20 of any tertiary
fluid flow loop 42. For example, an outdoor spa or other heat load
24 may be in thermal communication with the tertiary fluid flow
loop 42 which may transfer heat from the heated glycol fluid to the
spa. A renewable heat source 22 may be in thermal communication
with the glycol circulating within the tertiary fluid flow loop 42.
For example, solar collectors may be integrated with the tertiary
fluid flow loop 42 to heat the glycol. In particular, one or more
solar panels may be angled or otherwise positioned on the roof of a
building to collect solar rays and transfer solar energy to the
glycol fluid. It is further contemplated that other heat generating
sources 22 or loads 24 may be in fluid communication with the
tertiary loop 42 to either heat or cool the circulating glycol.
[0026] A third temperature sensor 44 and a fourth temperature
sensor 46 may be coupled to the second primary fluid flow loop 38
in a similar manner compared to the first temperature sensor 28 and
the second temperature sensor 30. In particular, the third
temperature sensor 44 and the fourth temperature sensor 46 may be
thermistors operable to measure the temperature of the fluid
flowing within the second primary fluid flow loop 38 at various
positions. In an exemplary embodiment, the third temperature sensor
44 may be positioned on or within the second primary loop 28 at a
position upstream from the inlet 18 of a particular heat source 22
or heat load 24. For example, each heat source 22 or heat load 24
may include at least one third temperature sensor 44 upstream from
its corresponding inlet 18 such that the temperature of the glycol
fluid entering each particular heat source 22 or heat load 24 may
be measured. The glycol fluid entering the inlet 18 and circulating
through the tertiary fluid flow loop 42 may exchange heat with the
heat source 22 or heat load 24 because the piping of the tertiary
fluid flow loop 42 is sufficiently thin to facilitate heat transfer
from or to the working fluid.
[0027] After the working fluid exchanges heat with the heat source
22 or the heat load 24, for example, the outdoor spa of the
tertiary fluid flow loop 42, the temperature of the glycol fluid
may change as it exits the tertiary fluid flow loop 42 through the
outlet 20. The fourth temperature sensor 46 may be positioned on or
within the second primary loop 38 at a position downstream from the
outlet 20 to measure the temperature of the fluid in the second
primary loop 38 after the mixing of the tertiary fluid flow loop 42
fluid exiting the outlet 20 with the secondary primary fluid flow
loop 38. The change in temperature of the fluid in the second
primary fluid flow loop 38 from just before it enters the tertiary
loop 42 to just after it exits the tertiary loop 42 may be directly
correlated along with the measured fluid flow to an energy
consumption rate of each heat source 22 or heat load 24.
[0028] For example, as shown in FIG. 1, three temperature sensors
are shown coupled to the second primary fluid flow loop 38 and
labeled as T1-T3. The measured temperature at T2 represents both
the temperature of the second primary fluid flow loop 38 glycol
fluid downstream of the outlet 20 of the outdoor spa 24 and the
temperature of the working glycol flowing in the second primary
fluid flow loop 38 before entering the collectors 22. The measured
temperatures at T3 and T1 may not necessarily be the same
temperature as heat may be transferred from the second primary
fluid flow loop 38 to the primary fluid flow loop 14 through the
heat exchanging element 36. The glycol fluid circulating at T3 may
travel from outside of the building to inside of the building to
exchanging heat with the primary fluid flow loop 14.
[0029] The second flow meter 40, the third temperature sensor 44,
and the fourth temperature sensor 46 may further being in
communication the energy measurement 32 and the processor 34 such
that the temperatures at T1-T3 may be correlated to an energy
consumption rate in the second primary fluid flow loop 38.
Moreover, temperatures at T1-T9 as well as the flow rates measured
from the two flow meters 26 and 40, may be correlated by the
processor 34 to determine the overall energy consumption and
transfer rates of the system 10 in both the primary fluid flow loop
14 and the second primary fluid flow loop 38 in addition to the
energy consumption and transfer rate of each secondary, tertiary
and primary loop.
[0030] Now referring to FIG. 2, an exemplary method of calculating
an energy consumption rate of sources 22 and loads 24 of the
primary fluid flow loop 14 includes coupling the fluid flow meter
26 to the primary fluid flow loop 14 (Step 100). The primary fluid
flow loop 14 is fluidly coupled to the secondary fluid flow loop
16. The secondary fluid flow loop 16 includes the inlet 18 and the
outlet 20 fluidly coupling the primary fluid flow loop 14 and the
secondary fluid flow loop 16. The secondary fluid flow loop 16
exchanges heat with at least one of the heat sources 22 and the
heat loads 24. The first temperature sensor 28 is coupled to the
primary fluid flow loop 14 upstream of the inlet 18 (Step 102). As
discussed above, a thermistor may be coupled upstream from each
inlet 18 of each secondary loop 16. The fluid flow rate is measured
with the fluid flow meter 26 (Step 104). The temperature of a fluid
flowing into the inlet 18 is measured with the first temperature
sensor 28 (Step 106). A second temperature sensor 30 is coupled to
the primary fluid flow loop 14 downstream of the outlet 20 (Step
108). As discussed above, a thermistor may be coupled downstream
from each outlet 20 of each secondary loop 16. The temperature of
the fluid flowing in the primary loop 14 after the mixing of the
secondary loop 16 outlet's 20 fluid with the primary loop 14 is
measured with the second temperature sensor 30 (Step 110).
[0031] The measured temperatures from the first temperature sensor
28 and the second temperature sensor 30 and the measured flow rate
may be correlated by the processor 24 to an energy consumption or
transfer rate for the system 10 and/or each individual heat source
22 and heat load 24 (Step 112). In an exemplary calculation, the
measured temperature and flow rate data are measured every second
or any predetermined time interval (Y). For example, the measured
temperature at T4 (T.sub.x) may be subtracted from the measured
temperature at T5 (T.sub.x+1) and multiplied by the flow rate (F),
time (Y) and a constant (K) to convert the calculated quantity into
units, for example, BTUs, KWH, for each heat source 22 or load 24.
Thus, the equation K*Y*(T.sub.x+1-T.sub.x)*F is used to calculate
the energy contribution rate for each heat source 22 or the energy
consumption rate for each heat load 24, or the energy transfer rate
between the second primary fluid flow loop 38 and the first primary
loop 14 across the heat exchanger 36. Based on the measured energy
consumption rate, the fluid flow rate and/or the operation of each
heat source 22 and heat load 24 may be further modified or
terminated based on the measured energy consumption rate. For
example, if a particular heat load 24 is consuming too much energy,
the particular load 24 may be shut down by operation of one or more
controls on the energy measurement 32 or another control
device.
[0032] It will be appreciated by persons skilled in the art that
the present invention is not limited to what has been particularly
shown and described herein above. In addition, unless mention was
made above to the contrary, it should be noted that all of the
accompanying drawings are not to scale. A variety of modifications
and variations are possible in light of the above teachings without
departing from the scope and spirit of the invention, which is
limited only by the following claims.
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