U.S. patent application number 13/822222 was filed with the patent office on 2013-07-04 for low-power residential heating system.
This patent application is currently assigned to COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES. The applicant listed for this patent is Florent Lefrancois, Cedric Paulus. Invention is credited to Florent Lefrancois, Cedric Paulus.
Application Number | 20130168459 13/822222 |
Document ID | / |
Family ID | 43983267 |
Filed Date | 2013-07-04 |
United States Patent
Application |
20130168459 |
Kind Code |
A1 |
Paulus; Cedric ; et
al. |
July 4, 2013 |
Low-Power Residential Heating System
Abstract
Method of thermal management of a building, on the basis of a
thermal system equipped with a low-power generator, characterized
in that it comprises a step (E3) of turning on the generator ahead
of time in the absence of any occupant in the building so as to
comply with a future comfort setpoint at a future instant (H), by
taking account of the energy available
(E.sub.generator.sub.--.sub.H) at the generator up until this
future instant (H) and of the energy necessary
(E.sub.heating.sub.--.sub.H) to reach the future comfort setpoint
within the building at this future instant (H).
Inventors: |
Paulus; Cedric; (La Ravoire,
FR) ; Lefrancois; Florent; (Belley, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Paulus; Cedric
Lefrancois; Florent |
La Ravoire
Belley |
|
FR
FR |
|
|
Assignee: |
COMMISSARIAT A L'ENERGIE ATOMIQUE
ET AUX ENERGIES
PARIS
FR
|
Family ID: |
43983267 |
Appl. No.: |
13/822222 |
Filed: |
September 12, 2011 |
PCT Filed: |
September 12, 2011 |
PCT NO: |
PCT/EP11/65724 |
371 Date: |
March 11, 2013 |
Current U.S.
Class: |
237/2A ; 165/267;
237/2B |
Current CPC
Class: |
F24D 15/04 20130101;
F23N 2237/06 20200101; G05D 23/1904 20130101; Y02B 30/70 20130101;
F24D 2200/12 20130101; F24D 19/1048 20130101; F24D 19/1009
20130101; F24D 19/1087 20130101; F24D 19/1039 20130101 |
Class at
Publication: |
237/2.A ;
165/267; 237/2.B |
International
Class: |
F24D 19/10 20060101
F24D019/10; F24D 15/04 20060101 F24D015/04 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 14, 2010 |
FR |
1057292 |
Claims
1. Method of thermal management of a building, on the basis of a
thermal system equipped with a low-power generator, wherein it
comprises a step (E3) of turning on the generator ahead of time in
the absence of any occupant in the building so as to comply with a
future comfort setpoint at a future instant (H), by taking account
of the energy available (E.sub.generator.sub.--.sub.H) at the
generator up until this future instant (H) and of the energy
necessary (E.sub.heating.sub.--.sub.H) to reach the future comfort
setpoint within the building at this future instant (H).
2. Method of thermal management of a building according to claim 1,
wherein the future comfort setpoint is a temperature setpoint and
in that it comprises the following steps: (E1)--Calculation of the
energy available (E.sub.generator.sub.--.sub.H) at the generator up
until the future instant (H); (E2)--Calculation of the energy
necessary (E.sub.heating.sub.--.sub.H) to reach the setpoint
temperature within the building at this instant (H);
(E3')--Comparison of the above two values and turning on of the
generator if
E.sub.generator.sub.--.sub.H<E.sub.heating.sub.--.sub.H.
3. Method of thermal management of a building according to claim 1,
wherein the future comfort setpoint is a maximum duration (tmax)
permitted so as to reach a comfort temperature in case of necessity
at the future instant (H).
4. Method of thermal management of a building according to claim 3,
wherein it comprises the following steps: (E1)--Calculation of the
energy available (E.sub.generator.sub.--.sub.H) at the generator up
until the future instant (H); (E2)--Calculation of the energy
necessary (E.sub.heating.sub.--.sub.H) to reach the setpoint
temperature within the building at this instant (H);
(E3'')--Comparison of the above two values and turning on of the
generator if H>tmax.
5. Method of thermal management of a building according to claim 4,
wherein it comprises a step of calculating a low setpoint
temperature to regulate the operation of the generator in the
absence of any occupant in the building, this low setpoint being
variable over time.
6. Method of thermal management of a building according to claim 1,
wherein it comprises a step of inputting at least one of the
following data: Inputting of at least one temperature setpoint in
the case of occupancy of the building and/or in the case of
non-occupancy; and/or Inputting of the periods of occupancy and/or
of non-occupancy of the building; and/or Inputting of a permitted
maximum duration (tmax) of operation of the generator so as to
reach a certain comfort temperature in the building.
7. Method of thermal management of a building according to claim 1,
wherein it comprises a step of evaluating the future exterior
temperature over several instants (H) of a future period (P).
8. Method of thermal management of a building according to claim 1,
wherein it comprises a step of auto-learning of the thermal
characteristics of the building.
9. Method of thermal management of a building according to claim 1,
wherein it comprises the calculation of the energy available
(E.sub.generator.sub.--.sub.H) at the generator up until the future
instant (H) through the following equation: E generator _ H = 1 H P
nominal ##EQU00008## where P.sub.nominal is the nominal power of
the generator, or through the following equation: E generator _ H =
1 H ( a .times. T e _ evap + b .times. T e _ evap 2 + c .times. T e
_ cond + d ) ##EQU00009## With: a, b, c, d: characteristic
parameters of a heat pump; T.sub.e.sub.--.sub.evap: input
temperature at the evaporator of the heat pump;
T.sub.e.sub.--.sub.cond: input temperature at the condenser of the
heat pump.
10. Method of thermal management of a building according to claim
1, wherein it comprises the calculation of the energy necessary
(E.sub.heating.sub.--.sub.H) to reach an interior setpoint
temperature of the building at the instant (H) through the
following equation: E heating _ H = ( CAP st + CAP it ) .times. ( T
int _ setp _ H - T int ) + GV .times. 1 H [ ( T int + ( T int _
setp _ H - T int ) / 2 ) - T ext _ H ] ##EQU00010## With:
T.sub.int: interior temperature at the present instant;
T.sub.int.sub.--.sub.setp.sub.--.sub.H: interior setpoint
temperature at the instant H; T.sub.ext.sub.--.sub.H: estimated
exterior temperature at the instant H; CAP.sub.st: short-term heat
capacity of the building; CAP.sub.lt: long-term heat capacity of
the building; GV: heat waste coefficient for the building.
11. Method of thermal management of a building according to claim
1, wherein it comprises the repetition for several instants (H) of
a future period (P) of a step of estimating the need to turn on the
generator ahead of time in the absence of any occupant in the
building so as to comply with a future comfort setpoint at a future
instant (H), by taking account of the energy available
(E.sub.generator.sub.--.sub.H) at the generator up until this
future instant (H) and of the energy necessary
(E.sub.heating.sub.--.sub.H) to reach the future comfort setpoint
within the building at this future instant (H).
12. Computer medium comprising a computer program implementing the
steps of the method of thermal management of a building according
to claim 1.
13. System for thermal management of a building comprising a
low-power generator, wherein it comprises a control unit which
implements the method of thermal management of a building according
to claim 1.
14. System for thermal management of a building according to claim
13, wherein the control unit comprises a first module for
estimating the exterior temperature over a future period, a second
module for estimating the energy available in the generator for the
period considered, a third module for learning the thermal
characteristics of the building so as to model its thermal
behaviour, a fourth module for determining the energy necessary for
the building and a fifth module for thermal driving of the
generator.
15. Building wherein it comprises a thermal management system
implementing the thermal management method claim 1.
Description
[0001] The invention relates to a method of thermal management of a
building as well as to a thermal system implementing such a method.
It also pertains to a medium comprising software implementing such
a method. Finally, it also relates to a building equipped with such
a thermal system.
[0002] During phases of unoccupancy of buildings, their temperature
is often reduced so as to save energy. Accordingly, the heating is
for example turned off for a certain period, until an interior
temperature corresponding to a low setpoint temperature is reached.
Afterwards, when the occupants return, the maximum comfort
temperature is again sought. A so-called restart phase is launched,
which consists in heating the building again so as to switch back
from the low interior temperature to the high interior
temperature.
[0003] A first solution of the prior art relies on an energy
generator operating according to a mode of regulation of the
temperature between two temperature setpoints, high and low, the
high setpoint temperature being used at times when the occupants
are present whereas the low setpoint temperature is used when they
are absent. This solution allows an energy saving with respect to a
solution in which the maximum comfort temperature were always
sought but remains very simplistic and non-optimized. Moreover, the
low setpoint temperature is often specified in a random manner by
the occupants themselves, or predefined in the factory without
taking account of the actual climate. Thus, when the occupants
return, it may happen that the heating time to reach the comfort
temperature is very long, if the temperature has been overly
reduced. In such a case, the restart phase seems interminable.
Conversely, it may happen that the low setpoint temperature has
been chosen too high and has caused needless energy consumption in
the absence of its occupants. Moreover, an occupant will have a
tendency to specify setpoint temperatures that do not correspond to
his real timetable in order to attempt to anticipate a possible
failure, or if he has heard weather forecasts for low temperature.
Thus, it is clearly apparent that the optimization of such a system
is very difficult. In practice, this results in dissatisfaction of
the occupants who do not always have their comfort temperature
within acceptable timescales and high and non-optimized energy
consumption.
[0004] A second solution of the prior art relies on heating systems
taking the form of multifunction apparatuses which in fact
integrate two complementary generators: a basic generator of low
power, for example between 1.5 to 6 kW, used for the energy needs
under steady-state circumstances and particularly suited to heavily
insulated, so-called low energy consumption, buildings which are
under full development, and a booster generator of high power, of
possibly as much as four times the basic power, for example between
6 and 9 kW, used for short transient circumstances. This second
solution still operates according to temperature regulation on the
basis of a comfort temperature and a low temperature for the
unoccupancy phases. By virtue of the high-power generator, used
exclusively for the restart phases, the comfort temperature is in
general reached within a satisfactory time. This solution exhibits
the first drawback of demanding a high investment cost to equip a
building. It exhibits moreover a second drawback of giving rise to
periods of high peaks of energy consumption, thereby complicating
the overall energy management of a district, while demanding
subscriptions from each individual to an electrical network suited
to their occasional needs for high power, this generally exhibiting
a significant cost for short periods of use. Finally, it still
exhibits the same drawback of fine tuning as the first solution of
the prior art, in particular in respect of the choice of the value
of the absence setpoint temperature.
[0005] Thus, a general object of the invention is to propose an
improved solution for the thermal management of a building, which
solves all or some of the previous drawbacks.
[0006] For this purpose, the invention relies on a method of
thermal management of a building, on the basis of a thermal system
equipped with a low-power generator, characterized in that it
comprises a step (E3) of turning on the generator ahead of time in
the absence of any occupant in the building so as to comply with a
future comfort setpoint at a future instant (H), by taking account
of the energy available (E.sub.generator.sub.--.sub.H) at the
generator up until this future instant (H) and of the energy
necessary (E.sub.heating.sub.--.sub.H) to reach the future comfort
setpoint within the building at this future instant (H).
[0007] The future comfort setpoint can be a temperature setpoint
and the method can comprise the following steps: [0008]
(E1)--Calculation of the energy available
(E.sub.generator.sub.--.sub.H) at the generator up until the future
instant (H); [0009] (E2)--Calculation of the energy necessary
(E.sub.heating.sub.--.sub.H) to reach the setpoint temperature
within the building at this instant (H); [0010] (E3')--Comparison
of the above two values and turning on of the generator if
E.sub.generator.sub.--.sub.H<E.sub.heating.sub.--.sub.H.
[0011] The future comfort setpoint can be a maximum duration (tmax)
permitted so as to reach a comfort temperature in case of necessity
at the future instant (H).
[0012] The method can comprise the following steps: [0013]
(E1)--Calculation of the energy available
(E.sub.generator.sub.--.sub.H) at the generator up until the future
instant (H); [0014] (E2)--Calculation of the energy necessary
(E.sub.heating.sub.--.sub.H) to reach the setpoint temperature
within the building at this instant (H); [0015] (E3'')--Comparison
of the above two values and turning on of the generator if
H>tmax.
[0016] The method of thermal management of a building can comprise
a step of calculating a low setpoint temperature so as to regulate
the operation of the generator in the absence of any occupant in
the building, this low setpoint being variable over time.
[0017] The method of thermal management of a building can comprise
a step of inputting at least one of the following data: [0018]
Inputting of at least one temperature setpoint in the case of
occupancy of the building and/or in the case of non-occupancy;
and/or [0019] Inputting of the periods of occupancy and/or of
non-occupancy of the building; and/or [0020] Inputting of a
permitted maximum duration (tmax) of operation of the generator so
as to reach a certain comfort temperature in the building.
[0021] The method can comprise a step of evaluating the future
exterior temperature over several instants (H) of a future period
(P).
[0022] The method can comprise a step of auto-learning of the
thermal characteristics of the building.
[0023] The method of thermal management of a building can comprise
the calculation of the energy available
(E.sub.generator.sub.--.sub.H) at the generator up until the future
instant (H) through the following equation:
E generator _ H = 1 H P nominal ##EQU00001##
[0024] where P.sub.nominal is the nominal power of the generator,
or through the following equation:
E generator _ H = 1 H ( a .times. T e _ evap + b .times. T e _ evap
2 + c .times. T e _ cond + d ) ##EQU00002##
With:
[0025] a, b, c, d: characteristic parameters of a heat pump;
T.sub.e.sub.--.sub.evap: input temperature at the evaporator of the
heat pump; T.sub.e.sub.--.sub.cond: input temperature at the
condenser of the heat pump.
[0026] The method of thermal management of a building can comprise
the calculation of the energy necessary
(E.sub.heating.sub.--.sub.H) to reach an interior setpoint
temperature of the building at the instant (H) through the
following equation:
E heating _ H = ( CAP st + CAP it ) .times. ( T int _ setp _ H - T
int ) + GV .times. 1 H [ ( T int + ( T int _ setp _ H - T int ) / 2
) - T ext _ H ] ##EQU00003##
With:
[0027] T.sub.int: interior temperature at the present instant;
T.sub.int.sub.--.sub.setp.sub.--.sub.H: interior setpoint
temperature at the instant H; T.sub.ext.sub.--.sub.H: estimated
exterior temperature at the instant H; CAP.sub.st: short-term heat
capacity of the building; CAP.sub.lt: long-term heat capacity of
the building; GV: heat waste coefficient for the building.
[0028] The method of thermal management of a building can comprise
the repetition for several instants (H) of a future period (P) of a
step of estimating the need to turn on the generator ahead of time
in the absence of any occupant in the building so as to comply with
a future comfort setpoint at a future instant (H), by taking
account of the energy available (E.sub.generator.sub.--.sub.H) at
the generator up until this future instant (H) and of the energy
necessary (E.sub.heating.sub.--.sub.H) to reach the future comfort
setpoint within the building at this future instant (H).
[0029] The invention also pertains to a computer medium comprising
a computer program implementing the steps of the method of thermal
management of a building such as described above.
[0030] The invention also pertains to a system for thermal
management of a building comprising a low-power generator,
characterized in that it comprises a control unit which implements
the method of thermal management of a building such as described
above.
[0031] The control unit can comprise a first module for estimating
the exterior temperature over a future period, a second module for
estimating the energy available in the generator for the period
considered, a third module for learning the thermal characteristics
of the building so as to model its thermal behaviour, a fourth
module for determining the energy necessary for the building and a
fifth module for thermal driving of the generator.
[0032] The invention also pertains to a building characterized in
that it comprises a thermal management system implementing the
thermal management method such as described above.
[0033] These objects, characteristics and advantages of the present
invention will be set forth in detail in the following description
of a particular mode of execution given without limitation in
conjunction with the attached figures among which:
[0034] FIG. 1 schematically illustrates a thermal system for a
building according to a mode of execution of the invention.
[0035] FIG. 2 represents the comparative evolution of interior
temperatures of a building with or without the mode of execution of
the invention according to a first scenario.
[0036] FIGS. 3 and 4 represent the comparative evolution of
interior temperatures of a building with or without the mode of
execution of the invention according to a second scenario.
[0037] The mode of execution of the invention defines a thermal
system for managing the energy of a building, within the framework
of the heating of a building. However, the concept of the invention
remains applicable to any thermal management of the building, for
its air-conditioning, its ventilation, etc.
[0038] The thermal system according to the mode of execution of the
invention takes the form of a heating system, comprising a single
generator of low power and a control unit, comprising one or more
hardware means and/or software means, including a microprocessor
for example, implementing the thermal management method which will
be described subsequently.
[0039] The thermal system according to the mode of execution of the
invention takes the form of an apparatus comprising a heat pump and
exhibiting the various modules represented schematically in FIG. 1.
The first module 10 implements a function for estimating the
exterior temperature over a future period P. The second module 20
implements a function for estimating the energy available in the
generator for the period P considered. The third module 30
implements a function for learning the thermal characteristics of
the building so as to model its thermal behaviour. The fourth
module 40 implements a function for determining the energy
necessary for the heating of the building over the period P.
Finally, the fifth module 50 fulfils the function for thermal
management of the building, for driving the heating. Finally, the
thermal system comprises a man machine interface, not represented,
which allows a resident to input his occupancy periods, and/or a
setpoint comfort temperature, and/or a value of maximum heating
time, which will be explained subsequently.
[0040] The concept of the invention consists in eliminating the
power peaks for the heating restart phases, for example when the
occupants enter an unoccupied building, by anticipating their entry
by heating the building on the basis of a low power, at least
partially before their entry, in a manner calculated for energy
optimization. Accordingly, the thermal system studies in advance
the thermal situation over a future period P within the
building.
[0041] This concept will now be detailed by describing more
precisely the various modules of the thermal system according to
the mode of execution of the invention. By way of example, the
thermal system will anticipate the situation according to an hourly
period, that is to say hour by hour, and for a period P
corresponding to the next 24 hours: as a variant, the same
principle will be able to be implemented for any future period
other than 24 hours and for any time interval other than an
hour.
[0042] The function of the first module 10 of the invention is
therefore to estimate the exterior temperature outside the building
for each hour of the next 24 hours. Accordingly, any existing
procedure can be implemented, such as that described in document
EP2146309, the invention not pertaining to this module
specifically.
[0043] By way of example, the exterior temperature can be obtained
through a first estimation of the average exterior temperature
T.sub.ext.sub.--.sub.avg.sub.--.sub.P over the next 24 hours, as a
function of the maximum exterior temperature
T.sub.ext.sub.--.sub.max.sub.--.sub.P-1 and/or minimum exterior
temperature T.sub.ext.sub.--.sub.min.sub.--.sub.P-1 measured for
the previous period of 24 hours, and/or of the exterior temperature
measured at the present instant. Accordingly, the thermal system is
equipped with an exterior thermometer allowing it to ascertain at
any instant the measured exterior temperature T.sub.ext.
[0044] The average exterior temperature over the next 24 hours may
depend on the hour of the calculation and be defined by the
following formulae:
At 6 H:
T.sub.ext.sub.--.sub.avg.sub.--.sub.P=(T.sub.ext.sub.--.sub.meas-
ured.sub.--.sub.6H+T.sub.ext.sub.--.sub.max.sub.--.sub.P-1)/2
At 10 H:
T.sub.ext.sub.--.sub.avg.sub.--.sub.P=T.sub.ext.sub.--.sub.meas-
ured.sub.--.sub.10H
At 15 H:
T.sub.ext.sub.--.sub.avg.sub.--.sub.P=(T.sub.ext.sub.--.sub.min-
.sub.--.sub.P-1+T.sub.ext.sub.--.sub.measured.sub.--.sub.15H)/2
At 22 H:
T.sub.ext.sub.--.sub.avg.sub.--.sub.P=T.sub.ext.sub.--.sub.meas-
ured.sub.--.sub.22H
[0045] Thereafter, on the basis of the estimated average exterior
temperature for the period P, the time profile of the exterior
temperature for this period P is estimated by the following sine
function:
T.sub.ext.sub.--.sub.H.sub.--.sub.P=[(T.sub.ext.sub.--.sub.min.sub.--.su-
b.P+T.sub.ext.sub.--.sub.max.sub.--.sub.P)/2]+[(T.sub.ext.sub.--.sub.min.s-
ub.--.sub.P-T.sub.ext.sub.--.sub.max.sub.--.sub.P)/2]*sin
[((H+n)-9).pi./12]
With:
[0046] T.sub.ext.sub.--.sub.H.sub.--.sub.P: estimated exterior
temperature at the hour H of the period P,
T.sub.ext.sub.--.sub.min.sub.--.sub.P: minimum exterior temperature
of the next 24 hours, T.sub.ext.sub.--.sub.max.sub.--.sub.P maximum
exterior temperature of the next 24 hours, n: actual hour of the
day.
[0047] To apply this function, the module 10 therefore estimates
beforehand the values of minimum
T.sub.ext.sub.--.sub.min.sub.--.sub.P and maximum
T.sub.ext.sub.--.sub.max.sub.--.sub.P average exterior temperature
for the next 24 hours.
[0048] Accordingly, the following formulae can be used:
At 6H:
T.sub.ext.sub.--.sub.min.sub.--.sub.P=T.sub.ext.sub.--.sub.measur-
ed.sub.--.sub.6H and
T.sub.ext.sub.--.sub.max.sub.--.sub.P=2*T.sub.ext.sub.--.sub.avg.sub.--.s-
ub.P-T.sub.ext.sub.--.sub.measured.sub.--.sub.6H
At 10H:
T.sub.ext.sub.--.sub.min.sub.--.sub.P=T.sub.ext.sub.--.sub.min.s-
ub.--.sub.p-1 and
T.sub.ext.sub.--.sub.max.sub.--.sub.P=2*T.sub.ext.sub.--.sub.avg.sub.--.s-
ub.P-T.sub.ext.sub.--.sub.min.sub.--.sub.P-1
At 15H:
T.sub.ext.sub.--.sub.min.sub.--.sub.P=T.sub.ext.sub.--.sub.min.s-
ub.--.sub.P-1 and
T.sub.ext.sub.--.sub.max.sub.--.sub.P=T.sub.ext.sub.--.sub.measured.sub.--
-.sub.15H
At 22H:
T.sub.ext.sub.--.sub.min.sub.--.sub.P=2*T.sub.ext.sub.--.sub.avg-
.sub.--.sub.P-T.sub.ext.sub.--.sub.max.sub.--.sub.P-1 and
T.sub.ext.sub.--.sub.max.sub.--.sub.P=T.sub.ext.sub.--.sub.max.sub.--.sub-
.P-1
[0049] Following the above description, it is therefore apparent
that the first module 10 needs a single datum as input, the past
and present exterior temperature. The latter can be measured or
estimated.
[0050] As a variant, the above calculation could integrate or be
replaced with forecast data, transmitted for example by a
meteorological remote server.
[0051] The second module 20 implements a function for estimating
the energy available in the generator for the period P considered.
Accordingly, the simplest calculation consists in considering the
nominal power P.sub.nominal (in kJ/h) of the generator so as to
deduce therefrom the energy available through the following
formula:
E generator _ H = 1 H P nominal ##EQU00004##
With:
[0052] E.sub.generator.sub.--.sub.H: energy available (in kJ) at
the generator up until the hour H; H: the hour from among the next
24 hours for which the energy available at the generator is
estimated.
[0053] Naturally, this calculation is suited to the type of
generator used. The above formula is very suited to heating based
on electrical resistance. However, if the generator is an extracted
air/fresh air heat pump, the energy available can be calculated
through the following equation:
E generator _ H = 1 H ( a .times. T e _ evap + b .times. T e _ evap
2 + c .times. T e _ cond + d ) ##EQU00005##
With:
[0054] a, b, c, d: parameters characteristic of the heat pump;
T.sub.e.sub.--.sub.evap: input temperature at the evaporator of the
heat pump; T.sub.e.sub.--.sub.cond: input temperature at the
condenser of the heat pump; H: the hour from among the next 24
hours for which the energy available at the generator is
estimated.
[0055] In the case of an air/air heat pump, such as illustrated in
FIG. 1, it is possible to consider the following relations:
T.sub.e.sub.--.sub.evap=T.sub.int
T.sub.e.sub.--.sub.cond=T.sub.ext.sub.--.sub.H
[0056] Naturally, the second module 20 does not pertain
specifically to the above equations and any model for calculating
the energy available at a certain hour H in the course of a next
period P can be implemented. In this case, the input data of the
module will be suited to this other calculation model.
[0057] The third module 30 implements a function for learning the
thermal characteristics of the building so as to model its thermal
behaviour.
[0058] Accordingly, the mode of execution of the invention
considers the thermal model represented by the following
equation:
E heating _ H = ( CAP st + CAP it ) .times. ( T int _ setp _ H - T
int ) + GV .times. 1 H [ ( T int + ( T int _ setp _ H - T int ) / 2
) - T ext _ H ] ##EQU00006##
With:
[0059] E.sub.heating.sub.--.sub.H: heating energy necessary up
until the hour H (in kJ); T.sub.int: interior temperature at the
present instant (in K); T.sub.int.sub.--.sub.setp.sub.--.sub.H:
interior setpoint temperature at the hour H (in K); T.sub.ext-H:
estimated exterior temperature at the hour H; CAP.sub.st:
short-term heat capacity of the building (in fact representing the
furniture mainly) (in kJ/K); CAP.sub.lt: long-term heat capacity of
the building (in fact representing the walls mainly) (in kJ/K); GV:
heat waste coefficient for the building (in kJ/(hK)); H: the hour
from among the next 24 hours for which the energy available at the
generator is estimated.
[0060] This equation can be written in a matrix manner as:
E.sub.heating.sub.--.sub.H=.theta..sup.T.phi.
where .theta..sup.T is the transpose of the matrix .theta..
[0061] With .theta.=[CAP.sub.st CAP.sub.lt GV]
.phi.=[(T.sub.int.sub.--.sub.setp.sub.--.sub.H-T.sub.int)(T.sub.int.sub.-
--.sub.setp.sub.--.sub.H-T.sub.int).SIGMA..sub.1.sup.H[(T.sub.int+(T.sub.i-
nt.sub.--.sub.setp.sub.--.sub.H-T.sub.int)/2)-T.sub.ext.sub.--.sub.H]]
[0062] This module 30 implements an auto-adaptation of the thermal
parameters of the building as a function of the knowledge of the
actual restart phases. Accordingly, for each restart phase it
compares the energy actually expended by the generator with that
predicted by the model hereinabove and adjusts the thermal
parameters if these two values differ.
[0063] The actual heating energy can either be directly measured by
an energy meter situated on the heating circuit for example, or be
estimated as a function of the operating time of the generator and
an energy consumption model such as those set forth within the
framework of the description of the second module 20.
[0064] The auto-adaptation of the thermal parameters CAP.sub.st,
CAP.sub.lt, and GV, can be based on the following algorithm:
.theta.(j)=.theta.(j-1)+K(j)e(j)
where j represents the day considered.
[0065] The matrices e and K represent respectively the a priori
error between the measured heating need and the estimated heating
need, and the adaptation gain to be applied to take account of this
error. These two matrices are calculated in the following
manner:
The a priori error:
e(j)=E.sub.heating(j)-.phi..sup.T(j).theta.(j-1)
Adaptation gain:
K(j)=(P(j-1).phi.(j))/(.lamda./.mu.+.theta..sup.T(j)P(j-1).theta.(j))
[0066] The matrix P is updated in the following manner:
P(j)=1/.lamda.[P(j-1)-P(j-1).phi.(j).phi..sup.T(j)P(j)/[(.lamda./.mu.+.t-
heta..sup.T(j)P(j-1).theta.(j))]]
Where the coefficient .lamda. is a forget factor and the
coefficient .mu. a weighting factor.
[0067] Naturally, this module could allow auto-adaptation of any
thermal model of the abode, is not limited to that described
hereinabove. Moreover, this auto-adaptation could be fine-tuned
according to various procedures.
[0068] The fourth module 40 implements a function for determining
the energy necessary for the heating of the building over the
period P.
[0069] It therefore comprises as input the following parameters:
[0070] The thermal model defined by the third module described
hereinabove; [0071] An estimation of the exterior temperature for
the period P, provided by the first module; [0072] An interior
setpoint temperature profile.
[0073] It implements the thermal model of the building, fine-tuned
by the module described above, to obtain the energy necessary to
reach the setpoint temperature at an hour H of the period P through
the formula:
E heating _ H = ( CAP st + CAP it ) .times. ( T int _ setp _ H - T
int ) + GV .times. 1 H [ ( T int + ( T int _ setp _ H - T int ) / 2
) - T ext _ H ] ##EQU00007##
[0074] The fifth module 50 fulfils the function for thermal
management of the building, for driving the heating system.
[0075] In particular, it compares the results of the second and
fourth modules 20, 40 with the aim of turning on the generator
ahead of time in an appropriate manner to obtain the setpoint
temperature at any hour H, while using reduced heating power. This
turning on ahead of time is particularly relevant for managing the
changes of occupancy of the building, corresponding to the restart
phases explained above.
[0076] The thermal system described hereinabove exhibits the
advantage of high autonomy since it allows its implementation in
any unknown environment.
[0077] Its auto-learning and its design allow it to determine in an
autonomous manner and to acquire all the parameters necessary for
its optimal operation. Thus, it will advantageously take the form
of a single apparatus, grouping together in one and the same casing
all the modules described hereinabove and the generator as such.
Optionally, a man machine interface can make it possible to
manually modify certain parameters if necessary, such as the
setpoint temperatures.
[0078] During its first turning on, it comprises initialization
parameters which can be average values, specified in the factory,
without the need for high accuracy.
[0079] As a variant however, the thermal system of the invention
might not comprise the modules 10 and 30, these functions being
able to be outsourced to any other system, communicating with the
thermal system so as to transmit the significant parameters to it.
Thus, as we have seen, the future exterior temperature could be
transmitted by a meteorological base, and the intrinsic thermal
parameters of the building could be specified by the constructor of
the building, or calculated by any other independent device.
[0080] Thus, the thermal system of the invention implements the
method for managing the thermal energy of the abode comprising the
following steps E1, E2, E3': [0081] E1--Calculation of the energy
available E.sub.generator.sub.--.sub.H (in kJ) at the generator up
until a future hour H; [0082] E2--Calculation of the necessary
energy E.sub.heating.sub.--.sub.H to reach the setpoint temperature
within the building at this hour H; [0083] E3'--Comparison of the
above two values and turning on of the generator as soon as
E.sub.generator.sub.--.sub.H<E.sub.heating.sub.--.sub.H.
[0084] This method thus makes it possible to guarantee that the
time remaining up until the hour H is sufficient for the generator
to reach the setpoint temperature at the desired hour H by
operating in a normal circumstance, without demanding a particular
power.
[0085] As a remark, the invention therefore makes it possible to
turn on the generator ahead of time so as to best follow the
temperature setpoints sought while operating with a normal
operation, without high-power mode to manage the restart phases. As
a remark, this turning on ahead of time can stray slightly from the
rule fixed in step E3' hereinabove without departing from the
concept of the invention.
[0086] Thus, step E3' can more generally consist in turning on the
generator ahead of time so as to comply with a future temperature
setpoint, by taking account of the energy available
E.sub.generator.sub.--.sub.H (in kJ) at the generator up until a
future hour H and of the energy necessary
E.sub.heating.sub.--.sub.H to reach the setpoint temperature within
the building at this hour H.
[0087] The above method operates well for managing programmed
restarts, on the basis of setpoint temperatures defined in advance.
However, certain unforeseen situations may arise in which a
resident returns to his residence earlier than envisaged, or at an
indeterminate instant. In such a case, he has no means of speeding
up the heating of his residence since this heating depends solely
on the limited power of his single generator.
[0088] To cater for a minimum of comfort to cope with these
situations, the thermal system contrives matters so that at any
instant, the time necessary to reach a comfort setpoint temperature
corresponding to the occupancy of the building, is not greater than
a predefined threshold tmax, thereby guaranteeing this resident
that the comfort temperature will be obtained in a reasonable
predetermined time.
[0089] Accordingly, the method for the thermal management of the
abode comprises a step which consists in verifying that in the case
of immediate turning on of the generator, the time necessary to
reach the comfort setpoint temperature does not exceed the
threshold tmax.
[0090] Thus, even if step E3' verifies that
E.sub.generator.sub.--.sub.H>E.sub.heating.sub.--.sub.H, if
H>tmax then the generator is turned on, according to a step
E3'.
[0091] Thus ultimately, the concept of the invention relies on a
step E3 of turning on the generator ahead of time so as to comply
with a comfort setpoint, be it a temperature or a duration of
heating, by taking account of the energy available
E.sub.generator.sub.--.sub.H (in kJ) at the generator up until a
future hour H and of the energy necessary
E.sub.heating.sub.--.sub.H to reach the setpoint within the
building at this hour H.
[0092] As a remark, with such an approach, the occupant no longer
needs to indicate a low temperature setpoint to the thermal system:
just the maximum time tmax defined hereinabove suffices to manage
the thermal environment of the abode in its unoccupancy periods.
This is markedly more user-friendly, economical and satisfactory.
However, it can moreover also operate with a low setpoint
temperature, for example a no-freeze temperature below which the
system must not descend.
[0093] The method for the thermal management of the abode comprises
a prior step of inputting all or some of the following data, by an
occupant or a builder: [0094] Inputting of at least one comfort
temperature in the case of occupancy of the building; [0095]
Inputting of the periods of occupancy and/or of absence from the
building; [0096] Inputting of a permitted maximum duration tmax of
heating of the building.
[0097] The steps of the above-described method will preferably be
implemented for any future hour H of the future period P
considered. They will be particularly relevant for the hours H for
which the building switches from an unoccupied to an occupied
state, that is to say the management of the restart phases.
[0098] Moreover, the invention has been illustrated to cater for
the heating of a building but it is naturally apparent that it
could easily be implemented to manage its air-conditioning.
[0099] Thus, the solution adopted caters well for the objects of
the invention and exhibits the following advantages: [0100] it
limits the power peaks by avoiding recourse to a high-power
complementary generator; [0101] It satisfies the thermal comfort of
the residents while saving costs; [0102] It makes it possible to
use low-power generators, which are sufficient for well insulated
buildings.
[0103] FIGS. 2 to 4 illustrate by way of example the operation of
the solution described in comparison with the two prior art
solutions presented in the preamble.
[0104] The first solution of the prior art relies on a 2-kW
generator operating between two setpoint temperatures T1 and T2,
for example 16 and 19.degree. C. At the instant t1, which must
correspond to the occupancy hour of the building, the temperature
setpoint switches from T1 to T2. The generator turns on at this
instant t1 and reaches the setpoint temperature T2 along the slope
11.
[0105] The second solution of the prior art relies on a 2-kW basic
generator and a 6 kW complementary generator. At the instant t1, it
reaches the setpoint value along the slope 12, much more rapidly
since the high-power generator is used for this restart phase.
[0106] The thermal system according to the invention in fact
determines the instant t0 preceding the instant t1, for which it is
necessary to turn on the generator, to reach the setpoint
temperature T2 at the instant t1, according to a slope 13 parallel
to that of the first solution. By virtue of this solution, the
user's comfort is satisfied, without resorting to high heating
powers.
[0107] FIG. 3 represents the behaviour of the two solutions of the
prior art in a scenario of lengthy absence. Such a scenario is
distinguished from the previous in that it is possible to allow the
interior temperature to descend lower in order to make greater
savings. However, this complicates the restart phase.
[0108] During the absence, the regulation is done around the low
setpoint temperature T1 at 12.degree. C. At the instant t1, the
occupant returns home and raises the temperature setpoint to the
value T2 of 19.degree. C. The first solution reaches the high
setpoint along the slope 21, in about 12H, slower than the slope 22
of the second solution, which reaches the setpoint in 4H, despite
its high power which is no longer satisfactory in such a scenario.
As a remark, the curve 27 illustrates the exterior temperature
variation during this period.
[0109] FIG. 4 illustrates the same scenario with the thermal system
of the invention. During the absence period, the interior
temperature 24 is not regulated around the low setpoint T1 but
around a setpoint represented by the curve 25, calculated
automatically by the system, which thus varies over time, since it
depends in particular on the exterior temperature, and is about
2.degree. C. above T1. Thus, at the instant t1, only a reduced time
is required in order for the slope 23 to reach the setpoint, in
about 6H. In this solution, the thermal system has therefore
automatically determined the heating necessary during the absence
to reach these 6H of heating upon return, without knowing the
instant of this return, thereby making it possible to cater for the
occupant's desire for comfort, at minimum cost.
* * * * *