Note: Descriptions are shown in the official language in which they were submitted.
CA 02225768 2002-04-29
1
AIR- CONDITIONING APPARATUS
FIELD OF INVENI~
The invention relates to an air-conditioning apparatus which regulates the
temperature in at least one room by ventilation with heated or cooled air to a
predetermined desired temperature value.
BACK~ZROUN~ OF THE I~N~(ENTION
Air-conditioning apparatuses are used to create in the air-conditioned rooms
comfortable conditions of occupation at any time of year, as they hold the
temperature and humidity of the room air within fixed limits' and provide for
a
sufficient ventilation with fresh air.
In winter the supply air temperature is higher than the room air temperature
when
the air is also meant to warm the room, and in summer the supply air is
injected at
a lower temperature in order to hold the room at the desired cooled room air
temperature.
Ordinarily, to achieve this, a conventional air-conditioning apparatus
circulates
too high an amount of air, the temperature of which has been adapted to the
heating and cooling requirement. This is regarded as disadvantageous as a
large
volume of air is circulated even after the desired temperature has already
been
2 5 reached. Moreover, the danger exists that the supply air will be blown
into the
room through the supply air channel and will immediately leave the room to be
air-
conditioned through the exhaust air channel. There takes place very little
mixing
of the new supply air with the air present in the room.
CA 02225768 2002-04-29
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Further, when air-conditioning several rooms, there is the problem that
different desired temperatures are sought in the different rooms. An
adaptation of the temperatures which takes into consideration the comfort in
each room is possible only with difficulty.
Underlying the present invention is the problem of providing an air-
conditioning apparatus which operates economically, ensures more
comfortable room conditions and an optimal mixing of the room air with the
supply air, in order to achieve a rapid adaptation to the desired heating,
cooling, humidifying and dehumidifying values.
In accordance with an aspect of the present invention there is provided an air-
conditioning apparatus for controlling a temperature condition in at least one
room to achieve a selected room temperature condition by ventilation using
temperature adjusted supply air comprising:
a supply air motor for supplying air at a supply air pressure through a
supply air channel to the at least one room;
cooling-heating means for adjusting a temperature of the supply air;
means for regulating an increase in pressure in the at least one room
relative to an outside pressure, to vary the room pressure in correspondence
to the selected room temperature.
Underlying the invention is the perception that the greater the excess
pressure is in a room to be air-conditioned, the better is the ventilation by
the
supply air blown through the room. Therefore, the room warms up faster, the
efficiency of the
CA 02225768 2002-04-29
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installation is improved and great temperature fluctuations in the room are
avoidable for example, very warm at the top and very cool at the bottom, as
are
also temperature differences over the length and width of the room.
A good flow of air through the room ensures that in the shortest possible time
and
with a smaller amount of air, a room is heated, cooled, humidified or
dehumidified.
The smaller amount of supply air blown in is found pleasant. Because of the
faster adaptation to the desired heating, cooling, humidifying and
dehumidifying
values, the efficiency of the air-conditioning apparatus is improved.
to
In particular, the desired value for the regulator of the exhaust air motor is
determined in dependence on the outside temperature and/or on the supply air
temperature and/or on the supply air pressure. This regulating of the exhaust
air
motor, in dependence on the outside temperature andlor.on the supply air
temperature andlor on the supply air pressure, is important for the
optimization of
the air flow The higher the supply air temperature or the supply air pressure
is,
the greater the excess pressure would have to be for a favorable flow of air
through the room to be air-conditioned with the supply air. The lower,
however,
the outside temperature is, the higher as a rule, therefore, the excess
pressure in
the room to be air-conditioned has to be. There must, therefore, be present a
greater excess pressure for ensuring an optimal flow of air through the room
with
the blown-in supply air.
On the one hand, preferably the actual value for the regulator of the exhaust
air
motor is determined by a pressure difference between the channels, which is
calculated from the difference between the absolute value of the pressure in
the
supply air channel and the absolute value of the pressure in the exhaust air
channel. It will then tie the case that, for example, excess pressure
disturbances
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will occur in the air-conditioning apparatus in several rooms as a result of
opening
of windows in individual rooms, and therefore this results in an undesired
rise in
the excess pressure in the other rooms, taking place through the regulation of
the
exhaust air motor, by reason of the pressure loss in one room.
On the other-hand, preferably the actual value for the regulator of the
exhaust air
motor is formed by the room pressure difference which is calculated from the
difference between the outside pressure and the room pressure.
1 o Here above all, the room excess pressure varies exclusively over a
predetermined
temperature range of the outside temperature and/or of the supply air
temperature, with a change in the outside temperature or of the supply air
temperature, in which with an outside temperature below this temperature
range,
the room excess pressure has in each case a certain constant value, and, with
an
outside temperature or supply air temperature above this temperature range,
the
room excess pressure always has a further definite constant value. Above all,
with rising outside temperature, in that temperature range, the room pressure
falls
from a maximum excess pressure to a minimal excess pressure.
2 o Thereby account is taken of tyro opposite demands. On the one hand, for a'
good
flow of air through the room to be air-conditioned, it is required that the
excess
pressure be as high as possible. On the other hand, the excess pressure must
not be too great, because it is otherv~rise felt to be disagreeable, and with
too
great excess pressure, doors open themselves or no longer can be opened or are
closed only with a high expenditure of force.
So that a comfortable regulation will be accomplished and an excess pressure
will
be ensured independently from the height of the floor level of the room to be
air-
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conditioned, the room difference pressure is measured at a height or level
over 0
(room height). Room height corresponds to outside elevation in respect to sea
level.
According to one embodiment of the invention, the temperature of the supply
air
and the channel pressure of the supply air are coupled with one another in
such a
manner that both, in dependence on the value of the room temperature to the
value of the supply air temperature and also in dependence on the value of the
room temperature to the desired value of the room temperature, the channel
1 o pressure of the supply air is raised or lowered in the room, rooms or room
zones.
The advantages herewith achieved lie especially in that a great volume of air-
conditioned air is not unnecessarily circulated, but always only that volume
is
used that is required for a maximally rapid adaptation of the actual room
values to
the predetermined desired values.
In this manner not only are savings in energy achieved, but people in the room
find it considerably more agreeable when a relatively strong air movement
takes
place only when the temperature of the blown-in air deviates from the actual
2 o temperature. With conventional air-conditioning apparatuses, in contrast,
especially during the morning warming-up phase, even at a room temperature
that
lies far below the desired value, only slightly warmed supply air is blown
into the
rooms at a high channel pressure. This was hitherto felt to be disagreeable by
the
persons concerned, but it was regarded as unavoidable.
According to the present embodiment of the invention, heated air with the
higher
channel pressure is blown into the room only if the temperature of the supply
air
lies clearly above the' predetermined desired temperature of the room and
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therewith, in the warming-up phase, lies far above the actual value of the
room.
By a relation regulation in which the channel pressure of the supply air is
set in a
fixed relation to the supply air temperature, a corresponding coupling of
channel
pressure of the supply air pressure to the supply air temperature can be
realized
especially advantageously.
Preferably the channel pressure of the supply air into the room, the rooms, or
the
room zones is adjusted over the range of the supply air motor.
1 o For a selecting arrangement, a choice can be made between two delivery
volume
relations.
In the first place, for the heating case in which the desired value of the
room
temperature is less than the actual value of the room temperature, the,
channel
pressure of the supply air is lowered with rising room temperature.
Correspondingly, for the cooling case in which the desired value of the room
temperature is greater than the actual value of the room temperature, the
channel
pressure of the supply air is lowered with falling room temperature. In the
second
place, for the heating case in which the desired value or the actual value of
the
2 o room temperature is less than the supply air temperature and the actual
value of
the room temperature is less than the desired value of the room temperature,
the
channel pressure of the supply air is raised with rising supply air
temperature.
Correspondingly, for the cooling case in which the desired value or actual
value of
the room temperature is greater than the supply air temperature and the actual
2 5 value of the room temperature is greater than the desired value of the
room
temperature, the channel pressure is raised with falling supply air
temperature.
The increase of the charinel pressure of the supply air is found to be
pleasant.
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Moreover, the efficiency of the heating and cooling apparatus is improved, as
will
be stated again further below.
According to a further embodiment of the invention, the channel pressure of
the
supply air varies exclusively over a predetermined temperature range of the
supply air temperature. If the supply air temperature presents a value below
this
temperature range, then the channel pressure of the supply air is allocated in
each case to a certain constant magnitude. If the supply air temperature
presents
a value above the temperature range, then the channel pressure of the supply
air
1o is allocated in each case to a further determined constant magnitude.
In particular, with a supply air temperature higher with respect to the room
temperature, the channel pressure rises over the predetermined temperature
range of the channel pressure from its minimum performance up to its maximum
performance with rising supply air temperature, and it correspondingly falls
v~ith
falling supply air temperature.
Through the two regulating systems of the supply air channel pressure
behavior,
on the one hand, it is made possible for the efficiency of the air-
conditioning
2 o apparatus to be improved. With higher channel pressure of the supply air,
there
is achieved also a more rapid and better flow through the room, and therewith
a
faster heating up of the rooms. On the other hand, for reasons of comfort, too
great an air flow should be avoided, since this is felt to be disagreeable.
The
opposite demands are now optimally satisfied.
Here, the regulating circuit which regulates the channel pressure of the
supply air
is subordinated to the temperature regulating circuit; the desired supply
channel
pressure value being yet in a fixed relation.to the actual value of the supply
air
CA 02225768 2002-04-29
temperature. Herewith there is avoided any excessive increasing or decreasing
in
the temperature regulation. The room temperature swings back faster to the
desired temperature value.
With air-conditioning for several rooms, the heated supply air is made
available
through a common supply air channel. In the case of different desired and
actual
temperatures of all the rooms, however, each room has a different heating
requirement. In order to take this circumstance into account, according to a
further form of execution of the invention, in the simultaneous air-
conditioning of
1 o several rooms or room zones, the individual rooms or room zones are
connected
in each case through a supply air and an exhaust air line allocated to them
from
the central supply air and exhaust air channels, and in the individual supply
air
andlor exhaust air lines, throttle valves are arranged through which the
channel
pressure of the supply air is adjusted in the rooms or room zones.
Thereby undesired air movements are avoided in rooms, the actual and desired
values of which are alike or approximately alike. Moreover it is achieved
that, for
example, in the case of a fully open fresh air control valve, an excessive
amount
of fresh air is not worked up.
The regulation of the control valves can occur additionally in dependence on
supply air pressure or on the speed of the supply air motor.
In such an independent regulation of supply air temperature and individual
room
2 5 temperature, a situation can arise in which a single room has to be heated
as
rapidly as possible, but other rooms that already lie at their desired
temperature
are to be heated up as little as possible. When the supply air temperature
rises,
the individual regulatibn of these warm rooms will tend to close the control
valves.
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Therewith, ~ however, these rooms and the persons present in them are cut off
from
the fresh air supply.
This problem is advantageously solved according to a further embodiment, in
which at a supply air temperature that lies above the desired temperature, in
rooms the actual temperature of which corresponds to the desired temperature,
the requisite minimum volume of fresh air also is blown. In this manner it is
achieved that these rooms are supplied with sufficient fresh air;
nevertheless, a
possible warming of the rooms by reason of a supply air temperature that lies
1 o above the desired temperature is avoided insofar as possible. The minimum
opening required for.the prescribed minimum fresh air volume depends on the
supply air temperature and on the fresh air component of the supply air, for
the
fresh air component of the supply air is reduced, if possible, during the
warming-
up phase in the morning for a maximally rapid heating up; being replaced by
return air.
According to one embodiment, the exhaust air channel and the supply air
channel
are connected with one another through a return air channel, in which case at
least one air exhaust throttle control valve is provided in the return air
channel,
2 o and at least one fresh air throttle control valve is provided in the fresh
air channel
engaged ahead of the supply air channel.
According to a further embodiment, the minimum cross section of the throttle
control valves is adjusted in dependence on the opening of the fresh air
throttle
control valve, of the exhaust air throttle control valve and of the mixing air
throttle
control valve, so that in each regulation situation there is ensured the
minimum
amount of fresh air.
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to
With regulated channel pressure for the supply air and for the exhaust air,
the
opening positions of the throttle control valves allocated relative to one
another in
a room or in a room zone are equal.
Analogously to the heating regulation, there can also take place a cooling
regulation.
For the temperature regulation, regulators are used. In practice, these
regulators
tend to an overswinging and underswinging of the regulating value.
According to a further embodiment of the invention, in each case the setting
value
of at least one regulator, especially of the temperature regulator, is
connected to a
subordinated switching arrangement, and the switching arrangement, in the case
of an overswinging (exceeding) of the regulating value, selects a value
predetermined for it, as the setting value, which clearly lies under the value
chosen simultaneously by the regulator.
Such a behavior can advantageously be obtained by an additional control
arrangement and a minimum-selection arrangement. This additional control
2 o arrangement delivers, in dependence on the regulating difference, a
predetermined minimal value for the setting magnitude when an overswinging of
the regulating value occurs, and a predetermined maximal value of the setting
value when the actual value of the temperature (the regulating value) lies
below
the desired value. The minimum selection arrangement then in each case selects
the minimum, from the values made available by the regulator and the
additional
control arrangement and forwards the selected value as the setting value. In
this
manner the additional control arrangements always take over the control of the
setting value when by reason of the setting value of the regulator, an
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lI
overswinging (exceeding) occurs in the regulating value.
According to a further embodiment of the invention, there are provided a fresh
air
control valve in a fresh air channel engaged on an inlet side of the supply
air
channel, a mixed air control valve in a return air channel connecting the
supply air
channel with the exhaust air channel, and a discharge air control valve in a
discharge air channel connecting to the exhaust air channel, in which
situation the
settings of the fresh air control valve, of the discharge air control valve
and of the
mixed air control valve 'are regulated in common dependence on the speed of
the
1 o supply air motor or on the channel pressure of the supply air, and in
which up to a
certain minimal opening for ensuring a fresh air minimum, with increasing
speed
of the supple air motor and /or with rising channel pressure of the supply
air, the
opening cross sections of the fresh air control valve and of the discharge air
control valve can be reduced and the opening cross section of the mixed air
control valve can be increased.
The opening position of the fresh air control valve and the opening position
of the
exhaust air control valve are always of equal size. The opening position of
the
mixed air control valve is always the difference of the opening position of
the fresh
2 o air or exhaust air control valve to 100%, for example, if the opening
positions of
the fresh air control valve and exhaust air throttle control valve are each
case
70°~, then the opening position of the mixed air control valve is 30%.
If the mixed
air control valve has an opening position of 70%, then the opening positions
of
the fresh air and exhaust air control valves are in each case 30°~.
In a further preferred embodiment of the invention, more than one room is air-
conditioned from a central installation. In the case of different heating
requirements for the individual rooms, it is also necessary to make available
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through the supply air a sufficient heating capacity for all the rooms. This
can be
achieved inter alia by the means that the heating required is measured in
accordance to the actual temperature of the coldest room, in order to bring
also
this room to the desired temperature in a short time. Accordingly, in one form
of
execution of the invention, in the simultaneous air-conditioning of several
rooms,
the actual temperature of each room is fed to a central regulating
arrangement,
and a temperature value to be determined individually from these individual
actual
values, is supplied as an actual value for the heating regulator
l0 According to a further embodiment of the invention, a humidifying
arrangement is
provided which humidifies the supply air in the supply air channel, in which
process the humidifying arrangement is regulated both in dependence on the
room moisture or the exhaust air moisture as well in dependence on the supply
air
temperature.
According to a further embodiment of the invention, there are provided a frrst
heating device installed in the supply air channel, a cooling device located
after
the first heating device in the supply air channel, and a second heating
device
installed after the cooling device in the supply air channel for the heating,
cooling
2 o and dehumidifying of the supply air, the second heating device being
regulated for
the desired moisture value in dependence on the actual moisture value.
In particular with a rising actual humidity value which already lies above the
desired humidity value, the heating performance of the second heating device
2 5 rises.
The heating performance of the second heating device is regulated either with
a
regulator or it climbs vi~ith rising actual moisture value over a
predetermined
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moisture range of the room moisture; at a room moisture content below this
moisture range, the heating performance has in each case a certain constant
magnitude and at a room moisture above the moisture range, the heating
performance has in each case a further determined constant magnitude.
It is hereby achieved that a dehumidifying is brought about over a rising room
temperature insofar as the actual value of the room temperature remains under
the limit value from which the cooling process is initiated. Cooling-starts
only
when the actual value of the room temperature is greater than the desired
value of
1 o the room temperature plus the temperature displacement dependent on the
outside temperature. By the heating-up, and therewith, the dehumidifying of
the
room over the rising temperature, the room is rapidly dehumidified with a
relatively
low expenditure of energy.
The channel pressure of the supply air is not raised during the dehumidifying
process.
In order to guarantee a minimum amount of fresh air in the room or the rooms,
the
regulation of the fresh air control valve and of the discharge air control
valve
2 0 occurs in dependence on the opening position of the mixed air control
valve.
The following drawings, which are included to provide further understanding of
the
present invention and are incorporated in and constitute a part of this
specification, illustrate the preferred embodiments of the invention and
together
with the description serve to explain the principles of the invention.
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In the simplest case, a single room is tempered and ventilated with the air-
conditioning apparatus. The regulation of a multi-room air-conditioning is
described in the example of execution with the aid of the drawings, in which:
s Fig. 1 shows a schematic representation of the air circulation in an air-
conditioning apparatus according to the invention.
Fig. 2 is a block circuit diagram with the most important elements of the
regulating and control arrangements in an example of execution.
Fig. 3 is a block circuit diagram with important elements of the temperature
regulating circuit from Fig. 2.
Fig. 4 is a block circuit diagram of a conveyance volume regulating circuit of
the
supply air from Fig. 2.
Fig. 5 is a block circuit diagram of an individual temperature regulating
circuit for
each room from Fig. 2.
2 0 Fig. 6a shows the relation between the supply air temperature and the
supply air
pressure for the example of execution when the room actual temperature is less
than the desired room temperature value.
Fig. 6b shows the relation between the room temperature and the supply air
pressure for the example of execution when the actual room temperature is
greater than or equal to the desired room temperature value.
CA 02225768 2002-04-29
Fig. 7 is a block circuit diagram of the temperature regulator of the example
of
execution.
Fig. 8a is a block circuit diagram of the regulator of the exhaust air motor
of the
5 example of execution.
Fig. 8b is a block circuit diagram with the most important elements from Fig.
8a.
Fig. 8c shows the relation between the desired value of the room difference
1 o pressure for the regulator of the exhaust air motor.
Fig. 9 shows the relation between the room exhaust air moisture and the
setting
value for the after-heater.
15 Fig. 10 is a run-off diagram with the most important block circuit diagram
elements
participating in the heating-up process,
In Fig. 1 there is schematically represented the air circulation of a mufti-
room air-
conditioning system. From the rooms 1 to be air-conditioned there lead, on the
one hand, supply air lines 5 to a supply air channel 10 and, on the other
hand,
exhaust air lines 6 to an exhaust air channel 11.
In the supply air line 5 there is arranged in each case a throttle control
valve 60
and in the exhaust air line 6 in each case a throttle control valve 61.
i
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16
The supply air channel 10 and the exhaust air channel 11 are connected. with
one
another through a return air channel 12.
On inlet side of the supply air channel 10 there is engaged a fresh air
channel 20
and on the outlet side of the exhaust air channel 11 there is engaged an
exhaust
air channel 21.
In the fresh air channel 20 there is provided a fresh air throttle control
valve 70, in
the return air channel 12 a mixed air throttle control valve 72 and in the
exhaust
1 o air channel 21 an exhaust air throttle control valve 71.
In the supply air channel 10 there are arranged successively in flow direction
of
the air a first heating device 30, a cooling device 40, a second heating
device 33,
a supply air motor 15 and a humidifying device 50.
In the supply air channel there is generated by the supply air motor 15 an air
pressure Pn, which provides that the supply air is blown with sufficient
conveyance volume into the rooms 1 to be air-conditioned.
Correspondingly in the exhaust air channel 11 there is generated by the
exhaust
air motor 16 a subpressure P"~, which draws off the room air.
In the simplest case, the pure airing case (office operation), the drawn off
room
air(i.e. the exhaust air) is taken off through the exhaust air channel 11 and
the
2 5 exhaust air channel 21 to the outer atmosphere, and through the fresh air
channel
20, the required supply air is drawn as fresh air into the supply air channel
10. For
this, the fresh air throttle control valve 70 and the exhaust air throttle
control valve
71 are opened and the mixed air throttle control valve 72 is closed. The fresh
air
CA 02225768 2002-04-29
17
throttle control valve 70 and the exhaust air throttle control valve 71,
always have
equal opening settings.
In order to make possible a warming-up of the air-conditioned rooms 1, the
drawn-
in fresh air flows through the first heating device 30 (preheater) through
which
drawn-in air is brought according to a heating requirement to the requisite
supply
air temperature Tn,. After passing the disengaged cooling device 40 and the
second heating device 33 (aftefieater), it is fed to the humidifying device
50,
which supplies the necessary moisture to the air.
to
Instead of the first heating device 30, in a required cooling of the rooms to
be air
conditioned, the cooling device 40 is in operation. In the case of excessive
humidity, instead of the humidifying device 50, the afterheater 33 is in
operation
for the dehumidifying. In order to ensure a more rapid heating-up, both the
first
heating device 30 and also the second heating device 33 can be in operation.
This, however is possible for the heating case, not for the dehumidifying
case.
The air worked-up in this way is fed to the individual rooms to be air-
conditioned,
through the supply air motor 15, the supply air channel 10 and the supply air
lines
2 0 5, with the throttle control valves 60. The volume of the air blown-in and
drawn off
from each individual room can be regulated by the throttle control valves 60,
61
arranged in the supply air lines 5 and in the exhaust air lines 6
individually.
In the case of increased heat requirement, for example in the morning warm-up
2 5 phase, it is advantageous to supply the rooms not only with drawn-in fresh
air, but
to use a part of the drawn-off room air repeatedly, for in the simultaneous
warming-up and ventilation the required supply air volume lies far above the
fresh
air minimum volume. 'For this reason, in dependence on the supply air
CA 02225768 2002-04-29
18
temperature Tz" through a control arrangement (controller) 500 in Fig. 2, a
setting
value Yv is calculated and supplied to the air throttle control valves 550 in
Fig. 2,
or 70, 71, 72 in Fig.1.
While the fresh air throttle control valve 70 and the exhaust air throttle
control
valve 71 receive the same control signal, the mixed air throttle control valve
72 in
the return air channel 12, is supplied the exactly opposite control signal.
The open
position of the mixed air throttle control valve 72 is.always the difference
between
the open position of the fresh air control valve 70 or of the exhaust air
control
1 o valve 71 and 100°~. For example, the open position of the fresh air
control valve
70 and of the exhaust air control valve 71 amounts in each case to
70°~, then the
open position of the mixed air control valve 30 amounts to 30°~. If the
mixed air
control valve has an open position of 70%, then the open position of the fresh
air
control valve 70 and of'the exhaust air control valve 71 is in each case 30%.
fn this manner it is possible again to feed a certain proportion of the drawn-
off
room air through the return air channel 12 to the supply air. Simultaneously
through the fresh air channel 20 and the fresh air control valve 70, a
corresponding fresh air component is supplied to the supply air. This fresh
air
2 0 component amounts in the example of execution in the airing case (during
the
office hours) to up to 100°~6. During office hours, therefore, the
mixed air control
valve 72 as a rule is not opened, and the fresh air control valve 70 and the
exhaust air control valve 71 are normally opened to 100% each. With increased
heating requirement and a maximal supply air pressure PZ~ M,e"~ the fresh air
component falls to approximately 10% warming-up phase in the morning.
4 i
CA 02225768 2002-04-29
19
1n the air-conditioning, from the measured room temperatures T ,~,uM IsTh
TRnuM IsT2
or T,~uMISTN in the minimal selection controller 400 in Fig. 2, the lowest
value
TRAUM IST MIN rS determined and used for the calculation of the heating
requirement.
For this, the actual temperature TRpuM IST MIN rn the block circuit diagram
element
100 is subtracted from the predetermined (maximal) desired temperature T~"uM
SOLL (of all the rooms). On the basis of the temperature difference T
(regulating
difference), by the temperature regulation system 130, there is determined a
suitable desired value y' for the heating valve 170 of the heating device 30
in Fig.
1.
to
The setting value Yr calculated in Fig. 3 for the temperature regulation is
monitored by the switching controller 125 arranged on an outlet side in order
largely to prevent an overswinging of the temperature usual with conventional
regulators. In the normal case, as long as TRpuM IS MIN lies below
TRpUM SOLL, the switching controller 125 forwards the setting value YR
unaltered as
y' onward to the heating valve 170. If, however, T,~,uMIST MIN exceeds the
desired
temperature T~~M SOLL then, instead of YR a much smaller setting value y' will
be
forwarded on to the heating valve 170. The value of the setting magnitude y'
assures in this case the.minimally required supply air temperature TZUMIN~
rich is
2o dependent on the outside temperature TA. In this manner with the example of
execution, there is achieved a maximal overswinging of the desired temperature
by only 0.3°C; a falling below this virtually does not take place.
The monitoring of the setting signal YR of the regulator 120 is executed in
the
example of execution by a switching controller 127 in Fig. 7 and a minimum
selection controller 128. The control arrangement simultaneously generates,
for
the regulator 120, a setting signal YS which takes on a maximally great value
as
CA 02225768 2002-04-29
long as the desired temperature T,~,~MS~ ties above the actual temperature
T,~,~M
,sT and moves down .to the very low setting Y s MAN as soon as the actual
temperature exceeds the desired value.
5 The setting value Ys MAN of the controller 128 is adjusted by the computing
system
129 for the cutting-off of the otherwise occurring underswinging of the
temperature regulation in dependence on the outside temperature TA with which
the fresh air is drawn in.
10 The minimum selection controller 128 in each case selects, from the two
setting
value signals YR and Ys at its disposal, the smaller one and forvvards this
onward
as y' to the heating valve 170. In this manner there is prevented, insofar as
possible, an overswinging of the temperature to be regulated.
In dependence on the temperature of the supply air, the conveyance of the
supply
air motor 15 is adjusted over the generated supply air pressure Pn,. For this
first
of all, in a Pn, s~ value calculating controller 200 shown in Fig. 2, there is
determined a desired value P~ s~ for the supply air pressure. The relation
2 o between the supply air temperature Tn, and the supply air pressure PZ"
so,~ is
given in Fig. 6a, for the case in which the room temperature T,~,~M,sr is less
than
the desired value of the room temperature T~"",~, ~~
Only when the supply air temperature lies clearly above the desired
temperature
value, in the example of execution by 5°C, is the desired pressure of
the supply
air. increased. When this supply air temperature is below this threshold, only
the
volume of air necessary for the ventilation of the rooms is blown into the air-
oonditioned rooms.
n
CA 02225768 2002-04-29
21
The relation between the room temperature T~uM ~T and the desired value of the
supply air pressure Pzu so~~. is represented in Fig. 6b, for the case in which
the
room temperature T~uM IST is greater than the desired value of the room
temperature T~"uMS~~, or is equal to the desired value for the supply air
temperature T,~uM sm.
With increasing actual room temperature T,~,uM ~sT, when the room-temperature
is
higher than the desired room temperature value T,~,uMSOU~ the air supply
1 o temperature TZU falls and the supply air pressure PZU falls from its
maximal
pressure Pzusou..nea~c to its minimal pressure PZUS~M,~,.
The desired supply air pressure PZU sou. determined by the PZU sou value
calculating controller 200 in Fig. 2 is compared in the block circuit diagram
element 230 with supply air actual pressure Pn"sT. The pressure difference P
is
supplied to the pressure regulator 250.
The complete pressure regulating circuit is represented in Fig. 4. The
regulating
difference DP is fed to -the regulator 240, which sets-in the setting value
YP. A limit
2o value switch 245 monitors the setting value YP, so that a'predetermined
minimum
pressure PZU MAN which corresponds to a predetermined minimum ventilation
volume is not gone below. The setting value YP of the limit value switch 245
controls the air supply motor 285 in Fig. 4 or 15 in Fig. 1, which generates
the
pressure of the process regulating controller 286.
With the corresponding regulating circuit by an exhaust air motor 16 in the
exhaust air channel 11, a subpressure PA8 is generated which, for the
maintaining
CA 02225768 2002-04-29
22
of a predetermined excess pressure in the rooms, draws off a corresponding
volume of air. The regulation of the exhaust air motor 16 will still be
further
described below.
The tempered supply air in the supply air channel 10 is available through the
supply air lines 5 for the ventilating and heating-up of all the rooms 1. With
the aid
of the throttle valves 60, 61, the volume of the air blown in or drawn off in
each
room is adapted to the particular actual heating requirement. For this in each
case
there are used the desired temperature, the actual temperature, the supply air
temperature and the minimum ventilation volume for the setting of the throttle
valves. This regulating circuit, represented in Fig. 2 as a block circuit
forming
element 300, is reproduced in Fig. 5.
In the block circuit element 310, the individual desired temperature Tso~N is
compared with the corresponding actual temperature T,sT N; the regulating
difference TN ascertained there is supplied to the regulator 320. On the basis
of
the temperature difference, STN, of the supply air temperature Tn, and of the
supply air pressure PZU, this generates a setting signal YT which must not
fall
below a minimal value which is yielded from the actual supply air pressure PZu
2 o and from the minimal pressure PZU Mn~~ The setting signal YT N is fed to
the throttle
control valves 330 in Fig. 5, and 60, 61 in Fig. 1. The regulating controller
of this
individual temperature regulating circuit is represented by the block circuit
element 340.
The throttle valves 60, 61 are regulated, therefore, in dependence on the
desired
temperature value T~"uMSOm in each room individually, on the actual
temperature
value T,~,uM,sT measured in each individual room, of the temperature value of
the
supply air temperature Tzu, as well as in dependence on the supply air
pressure
CA 02225768 2002-04-29
23
P~" andlor the speed of the supply air motor.
As stated above, the regulating circuit ensures, for the adjustment of the
opening
cross section of the throttle valves 60, 61, a certain minimum opening cross
section yielded in dependence on the supply air pressure, which cross section
is
not gone below in the adjustment of the throttle valves 60, 61. This minimum
opening cross section is adjusted there in such manner that each room receives
a
predetermined absolute minimum fresh air volume.
1 o The minimum opening cross section of the throttle valves 60, 61 is
likewise
adjusted in dependence on the opening of the fresh air valve 70, of the
exhaust
air valve 71 and of the mixed air valve 72.
With regulated conveyance volume of the supply air and of the exhaust air, the
opening settings of the throttle valves 60, 61 allocated to one another in a
room 1
are equal.
In the regulating of the exhaust air motor 785 according to Fig. Sb, or 16
according to Fig. 1, the desired value for the exhaust air motor is calculated
in
2 o dependence on the outside temperature in the P~,~ $~ value calculating
controller 710, in which operation this desired value forms a room excess
pressure Pp~~Sp~,L established in respect to the outside pressure PA in
dependence on the outside temperature. The desired value P,s,BSO,.,~ can also
be
determined in dependence on the supply air temperature andlor on the supply
air
2 5 pressure.
The relation between the outside temperature TA and the desired value for the
exhaust air motor gives the desired value for the room excess pressure P~,~
So,,~,
CA 02225768 2002-04-29
24
which is yielded from the difference between the desired value of the exhaust
air
pressure P"~SOm and the outside pressure PA, is represented in Fig. 8c. If the
outside temperature TA exceeds a certain limit value, for example an outside
temperature of -10°C, the desired value P~,~SO~~of the exhaust air
motor fails with
rising outside temperature from its maximum Pp,FF Sou Mnx to its minimum Po,~
So,~
MIN With a further limit value, for example with an outside temperature of
+15°C. At
an outside temperature before or after this temperature range established by
the
two limit values, the desired value of the exhaust air motor
Pp,~ Sou corresponds either to the maximal room difference pressure Dp,FF SOLL
Max
or to the minimal room difference pressure Pp,pF SOLL MIN'
The desired value of the exhaust air motor Pp~FFS~LI determined by the value
calculating controller 710 in Fig. 8a is compared in the block circuit diagram
element 700 with the actual room pressure difference value P~,~,~T in one room
Z 5 and in several rooms with the supply air and exhaust air channel pressure
differential. The pressure difference DP is fed to the pressure regulation
system
730.
The complete pressure regulating circuit is presented in Fig. 8b. The
regulating
2 o difference ~Po,~ is fed fo the regulator 740, which adjusts the setting
value YP a,~.
If in a large room, several windows are open, the exhaust fan can be shut off
entirely--only in this way is it possible to maintain a slight excess
pressure. With
the setting value YP p,FF of the regulator 740, the exhaust air motor 785 in
Fig. 8b,
or 16 in Fig. I which generates the pressure is controlled by the regulating
2 5 controller 786.
The actual value for the regulator 740 of the exhaust air motor 16 or 785 is
formed
by the actual room difference pressure Pp,pF IST~ which is Yielded from the
~ i
CA 02225768 2002-04-29
difference between the outside pressure PA and the room pressure P,~~M ~sr =
Pne
~sr~ The room difference pressure Pp,FF ~sT is measured there at a level above
0
(sea level).
5 The form of execution described can be used analogously for the cooling.
In an additional regulating circuit, the air humidity in the air-conditioned
rooms is
regulated. It is measured preferably as relative air moisture (in percent of
the
vapor pressure at full saturation) and expressed by a simplified designation F
in
1 o the following. It is entirely possible, however, to use instead of the
relative
humidity, the absolute humidity (g of water vapor per m3 of air), the vapor
pressure, the specific moisture (in g HZO per kg of moist air) or as mixture
ratio (in
g H20 per kg of dry air). With use of the relative humidity, the dependence on
the
saturation limit is advantageously integrated into the value. According to the
VDI
15 ventilation rules, air humidity should amount in winter, at 20°C
room temperature,
to 35°r6 to 70% relative air humidity, and, in summer, at 22°C
air temperature, to
70°r6, and at 25°C, to 60%.
In the block circuit element 600 in Fig. 1, there is determined the difference
2 o between the desired air moisture F,s,s so,_,, and actual air moisture
F"s,sT, in which
representationally for the air moisture in the individual rooms in the example
of
execution, the moisture of the exhaust air F,,,g is measured and adjusted. The
determined moisture difference ~F"~ is first introduced into a limit value
circuit
device 610, which on the basis of predetermined minimal and maximal moisture
2 5 F~ MAN and F,~ M,N in dependence on the supply and exhaust air
temperature,
prevents the saturation limit from being exceeded in any place in the air
circulation. From this limit value switching device 610, a corrected
regulating
difference 01=,,,8, is now fed to the regulator 620, which controls the air
moistener
r.
CA 02225768 2002-04-29
26
630 over the control signal Y~. Thereby, the moisture of the supply air Fn, is
adjusted. The regulating controller is represented by the block circuit
diagram
element 640.
The second heating device 33, in the heating case, may also contain the signal
Y'
of the first heating device 30. The second heating device (33) serves,
however, as
an after-heater essentially for the dehumidifying. This second heating device
(33)
is regulated in dependence on the actual moisture value F,sT for the desired
moisture value, in which with rising actual moisture value F,sT over the
desired
1 o moisture value Fsou the heating performance of the second heating device
(33)
rises. The rise of the heating performance of the second heating device (33)
moves over a predetermined moisture range of the room moisture F,sT. This
relation is represented in Fig. 9. At a room moisture F,sT before this
moisture
range, the second heating device (33) is not in operation.
At a room moisture value F,sT above this moisture range, the second heating
device (33)--the after-heater-is in operation with its maximal performance.
By a control arrangement (not represented here) it is made certain that the
conveyance volume of the supply air is not increased during the dehumidifying
process and that only a minimum amount of fresh air is blown in.
For a better illustration of the regulating system, in the following there is
described, by way of example, a warming-up process such as ordinarily takes
place in the morning. The block circuit diagram elements participating in the
run-
off of the regulation are represented in Fig. 10. At the time point when the
switching-on of the air-conditioning apparatus takes place, the actual
temperatures of all the rooms 1 and the temperature of the drawn-in fresh air
lie
CA 02225768 2002-04-29
27
far above the desired temperature for the rooms 1. Since the temperature of
the
supply air is still very low, no more supply air is blown into the rooms. For
this, a
minimal air pressure PZU MAN, corresponding to the minimum of fresh air
volume, is
generated.
At a lower outside temperature below 16° C, the regulator is prior-
occupied at the
start with a value according to the outside temperature, so that the
installation will
show no frost disturbance when starting.
From the actual temperatures of all the rooms 1 to be air-conditioned, the
minimum-selection controller 400 selects the lowest value and conducts this to
the
block circuit diagram element 100. Here the regulating difference AT between
the
desired and actual value of the room air temperatures is formed and supplied
to
the regulator 120 and the controller 127. On the basis of the regulating
difference
DT, the regulator 120 determines a setting value YR, Simultaneously with the
controller 127, a setting value Ys is determined, which takes on a maximally
great
value as long as the desired temperature lies above the actual temperature. Of
the two setting values YS and YR, the selection controller 128 selects the
smaller
one, at this time point the setting value YR of the regulator 120, and
conducts it
onward to the heating device (30). This warms up the air flowing through the
air
supply channel (10). Therewith, the air supply temperature Tn, rises
continuously.
From a predetermined temperature threshold value of the air supply, for
example
T~~~ + 5°C, with further rising air supply temperature, the air supply
pressure
also is increased, since the regulation of the air supply pressure occurs in
2 5 dependence on the temperature of the air supply. The conveyance volume
increases and there takes place a maximally rapid heating-up of all the rooms.
CA 02225768 2002-04-29
28
The increased air volume consists not only of fresh air, but a part of the
exhaust
air again is conducted to the supply air through the environmental air channel
12
in Fig. 1. In this manner, the rooms 1 are sufficiently ventilated and,
simultaneously, it is not necessary to heat up much fresh air needlessly.
In the morning heating-up, the fresh air constituent is only--at least--such
that the
requisite excess pressure is achieved.
When the heating-up process is concluded, usual commercial regulators do not
lower the setting value rapidly enough to prevent a rise of the actual
temperatures
of the rooms I over the desired temperature. For this reason the setting value
YS
of the controller 127 on exceeding of the desired temperature falls to a
predetermined minimal value YS MIN~ Now the minimum selection controller 128
selects the value YS of the controller 127 and passes it onward as y' to the
heating
device 30. Thereupon the air supply temperature again falls, and after a short
time the rooms again receive only the minimum fresh air volume that is
sufficiently
tempered to prevent a lowering of the actual temperature of the air supply
below
the desired temperature of the air supply. The regulator can therefore slowly
reduce its output.
Now there is to be described in addition the case in which only one room has
to
be heated, while the other rooms have already reached the desired temperature.
The selection controller 400 selects the lowest actual temperature of the
unheated
rooms and passes it on to the block circuit diagram element 100. On the basis
of
2 5 the regulating difference now a setting value y' is set in and the supply
air
pressure rises correspondingly. So that the rooms will not be supplied with
very
warm supply air which have already reached the desired temperature, however,
the individual room temperature regulation systems 300 regulates the blov~in
air
i n ,..,
CA 02225768 2002-04-29
29
volume of the throttle valves 60, 61 for each room separately. In this manner
the
throttle valves 60, 61 of the rooms in which the actual temperature are closed
to
the minimum opening, which ensures that the rooms are sufficiently ventilated.
Simultaneously, the throttle valves 60, 61 of the room being heated rising TZ"
is
opened up by the Pp~FF, up to 100%, in order to make possible a rapid heating-
up.
Only when this room has reached its desired temperature does the air-
conditioning regulation again set in the minimum ventilation and desired
temperature holding state. _ -
1 o It will be apparent to those skilled in the art that various modifications
and
variations can be made in the air-conditioning apparatus of the present
invention
without deviating from the spirit or scope of the invention. Thus, it is
intended that
the present invention cover the modifications and variations of this
inventions
provided they come within the scope of the appended claims and their
equivalents.
