U.S. patent application number 13/702699 was filed with the patent office on 2013-04-04 for method for setting the volumetric flow rate of a heating and/or cooling medium by means of room heat exchangers of a heating or cooling system.
This patent application is currently assigned to Loeblich & Huebner Energie-Effizienz und Haustechnik GmbH. The applicant listed for this patent is Bertram Hubner, Maximilian Loblich. Invention is credited to Bertram Hubner, Maximilian Loblich.
Application Number | 20130081799 13/702699 |
Document ID | / |
Family ID | 44533244 |
Filed Date | 2013-04-04 |
United States Patent
Application |
20130081799 |
Kind Code |
A1 |
Loblich; Maximilian ; et
al. |
April 4, 2013 |
METHOD FOR SETTING THE VOLUMETRIC FLOW RATE OF A HEATING AND/OR
COOLING MEDIUM BY MEANS OF ROOM HEAT EXCHANGERS OF A HEATING OR
COOLING SYSTEM
Abstract
Room heat exchangers of varying priority are provided by setting
the volumetric flow rate of a medium by means of the room heat
exchangers of a heating or cooling system. A target spread of the
flow and return temperatures for each individual room heat
exchanger(s) is set by fixably or adjustably limiting the
respective room heat exchanger valve(s). A system-specific target
spread for high-priority room heat exchangers is a basis to allow a
lower target spread and a higher target spread is ensured given
low-priority room heat exchangers. When operating in a
high-priority room heat exchanger with a lower spread, the
volumetric flow through at least one low-priority room heat
exchanger with a higher spread is changed in such a way that a
return temperature optimized for the heating device of the heating
system is set by mixing the return medium from all room heat
exchangers of the heating system.
Inventors: |
Loblich; Maximilian;
(Vienna, AT) ; Hubner; Bertram; (Vienna,
AT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Loblich; Maximilian
Hubner; Bertram |
Vienna
Vienna |
|
AT
AT |
|
|
Assignee: |
Loeblich & Huebner
Energie-Effizienz und Haustechnik GmbH
Vienna
AT
|
Family ID: |
44533244 |
Appl. No.: |
13/702699 |
Filed: |
June 9, 2011 |
PCT Filed: |
June 9, 2011 |
PCT NO: |
PCT/AT11/00258 |
371 Date: |
December 7, 2012 |
Current U.S.
Class: |
165/200 |
Current CPC
Class: |
G05D 23/1934 20130101;
F24D 19/1018 20130101; F28F 13/00 20130101; Y02B 30/745 20130101;
F24D 19/1012 20130101; Y02B 30/762 20130101; Y02B 30/70
20130101 |
Class at
Publication: |
165/200 |
International
Class: |
F28F 13/00 20060101
F28F013/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 9, 2010 |
AT |
A 944/2010 |
Claims
1. A method for setting the volumetric flow rate of a heating
and/or cooling medium by means of room heat exchangers of a heating
or cooling system, in which the target spread of the flow and
return temperatures for the individual room heat exchangers is in
each case set by limiting the respective room heat exchanger valve
in an adjustable and/or fixable manner, characterized in that room
heat exchangers of varying priority are defined, wherein a
system-specific target spread for high-priority room heat
exchangers is used as the basis to allow a lower target spread, and
a higher target spread is ensured given low-priority room heat
exchangers, and that, during the operation of a high-priority room
heat exchanger with a lower spread, the volumetric flow through at
least one low-priority room heat exchanger with a higher spread is
changed in such a way that a return temperature optimized for the
heating device of the heating system is set by mixing the return
medium from all room heat exchangers of the heating system.
2. The method according to claim 1, characterized in that the
return temperature is set in such a way as to achieve the
system-specific target spread.
3. The method according to claim 1, characterized in that the
supply and return temperatures of the individual room heat
exchangers are acquired and transmitted to a central processing
unit, which determines control values for the adjustable and/or
fixable limitation of all room heat exchanger valves, and transmits
them as a control signal to in particular removable actuators on
the room heat exchanger valves.
4. The method according to claim 1, characterized in that the
amounts of heat released by the respective room heat exchangers
into the return flow are determined to calculate the control
values, and the elevated amounts of heat arising on high-priority
room heat exchangers due to a low spread are balanced out by
setting at least one low-priority room heat exchanger to a high
spread.
5. The method according to claim 1, characterized in that a
measured value for the outside temperature is drawn upon to
calculate the control value for at least one high or low-priority
room heat exchanger.
6. The method according to claim 1, characterized in that, given a
temporary operational requirement on a room heat exchanger that
leads to a decrease in the spread on the room heat exchanger in
question, this room heat exchanger is subjected to prioritization,
whereupon the volumetric flow rate of heating medium through at
least one low-priority room heat exchanger is lowered to balance
the return temperature of the heating system.
7. The method according to claim 1, characterized in that, given a
temporary operational requirement on a room heat exchanger that
leads to a decrease in the spread on the room heat exchanger in
question, this room heat exchanger is subjected to prioritization,
whereupon the volumetric flow rate of heating medium through at
least one low-priority room heat exchanger is raised to balance the
return temperature of the heating system.
8. The method according to claim 1, characterized in that a
temporary user requirement is issued by inputting a desired value
for the ambient temperature, the desired value is sent to the
central processing unit, and control values for the room heat
exchanger(s) situated in the respective room are calculated in the
central processing unit and transmitted as a control signal to the
actuators on the room heat exchanger valves.
Description
[0001] The invention relates to a method for setting the volumetric
flow rate of a heating and/or cooling medium by means of room heat
exchangers of a heating or cooling system, in which the target
spread of the flow and return temperatures for the individual room
heat exchangers is in each case set by limiting the respective room
heat exchanger valve in an adjustable and/or fixable manner.
[0002] As a rule, such methods are used in heating systems to limit
the maximum flow through the individual room heat exchangers that
the user can set with the room heat exchanger valve, so that, when
the valves have been completely opened, all room heat exchangers
are supplied with heating medium in such a way that the identical
spread arises at all room heat exchangers (hydraulic balancing).
The differences in heating medium supply are rooted in the
relatively strong variability of the hydraulic resistances of the
pump that stem from the differing tube dimensions and lengths, as
well as from changes in direction.
[0003] In conjunction with the present invention, room heat
exchangers are understood to be heating elements or radiators as
well as cooling elements, for example air conditioning systems, in
which the indoor air is heated or cooled. In the technical field in
question, the spread is understood as the difference between the
flow and return temperature of the heating medium, which arises
when the heating medium flows through the room heat exchanger, and
releases heat to the room to be heated or cooled in the process.
For the sake of simplicity, reference is most often made to heating
in the present specification, although instances of cooling a room
are also always conceivable and intended.
[0004] Among other things, the spread on the one hand depends on
the ambient temperature of the room heat exchanger, but on the
other hand also depends primarily on how fast the heating medium
flows through the room heat exchanger on the other, since obviously
the medium cools to a relatively little extent given a high flow
rate, i.e., a short retention time in the room heat exchanger,
while a relatively rapid cooling takes place in the room heat
exchanger given low flow rate, i.e., given a long retention time.
Given a high flow rate through a room heat exchanger, which is
tantamount to a low spread, the room heat exchanger is operated at
a high heat output, since the entire heating surface of the room
heat exchanger is used, so that a lot of heat is released into the
environment.
[0005] In order to operate a heating system in an energy-efficient
manner, the goal is to achieve both a specific return temperature
for the heating medium to the heater, and in general the lowest
possible temperature level, depending on the heating unit. Only in
the case of steel boilers is a return temperature of under
35.degree. C. disadvantageous, since the condensation of water
vapor from the exhaust gas can then lead to corrosion problems. In
modern condensing boilers, however, a low return temperature is in
turn required so the moisture contained in the exhaust gas can be
condensed on corresponding heat exchangers, and the condensation
heat obtained in the process can be utilized for warming up the
heating medium.
[0006] The hydraulic balancing to a spread identical for all room
heat exchangers of a heating system mentioned at the outset is only
beneficial in terms of energy if each room or area of the building
to be heated is actually equipped with respective optimally
dimensioned room heat exchangers. However, this is virtually never
the case in practice, since not only is suitability in terms of
energy engineering taken into account during the installation of
room heat exchangers; aesthetic aspects and their actual
availability at the desired time of installation also play a role,
in particular in the concluding phase of a construction project. In
addition, room heat exchangers are not continuously available for
each operating level. As a result, the room heat exchangers are in
practical terms only very rarely optimally dimensioned in a room or
area, so that a hydraulic balancing according to prior art to an
identical spread for all room heat exchangers will not satisfy the
actual energy requirements. Beyond that, heating systems are as a
rule not operated with a focus on energy engineering above all in
the private areas, with the user instead briefly regulating the
room heat exchanger valves or thermostatic heads based on a
subjective sensitivity to cold, so that an unfavorably high heat
output is often demanded of individual room heat exchangers, while
very low temperatures are selected in other areas as a presumed
cost-cutting measure. However, especially low temperatures in rooms
next to rooms with a high temperature result in a loss of heat in
the high-temperature rooms (in particular when doors are left
open), so that the room heat exchangers must in turn be operated at
a very high heat output level in order to maintain the temperature
required in these rooms, which increases the return temperature of
the system overall, and hence lowers the efficiency of the heating
system.
[0007] Therefore, the object of the present invention is to set or
hydraulically balance the room heat exchangers of a heating system
in such a way as to take stock of undersizing or oversizing, or
user requirements that are unfavorable from an energy standpoint,
while at the same time keeping the return temperature of the entire
system at a favorable level.
[0008] This object is achieved by further developing a method of
the kind mentioned at the outset according to the invention in such
a way that room heat exchangers of varying priority are defined,
wherein a system-specific target spread for high-priority room heat
exchangers is used as the basis to allow a lower target spread, and
a higher target spread is ensured given low-priority room heat
exchangers, and that, during the operation of a high-priority room
heat exchanger with a lower spread, the volumetric flow through at
least one low-priority room heat exchanger with a higher spread is
changed in such a way that a return temperature optimized for the
heating device of the heating system is set by mixing the return
medium from all room heat exchangers of the heating system.
[0009] As a consequence, the method according to the invention
defines high-priority room heat exchangers as room heat exchangers
which are constantly or temporarily required to exhibit a heat
output lying above the heat output that can be achieved when
complying with the system-specific target spread. For example, this
is the case when the room heat exchangers in a room or area are
themselves undersized in terms of providing the thermal output
necessary there, or if a user wants to quickly heat up the
environment for a brief time, and therefore widely opens the room
heat exchanger valve. In order to compensate for the excess amount
of heat fed into the return flow from room heat exchangers operated
in this manner so as to achieve an optimized return temperature for
the heating system, the method according to the invention provides
that certain room heat exchangers be defined as low-priority room
heat exchangers, wherein a very high spread intended to exceed the
system-specific target spread is ensured for such room heat
exchangers. For example, such room heat exchangers are room heat
exchangers in rooms or areas that are oversized for the heat needed
there, or room heat exchangers in areas where high heat-up dynamics
are not required or only a certain basic supply of heat is to be
ensured. Meant in this conjunction are basements and dens, heated
garages, workout rooms, secondary rooms and similar areas in
buildings. In such areas, very high spreads can be accommodated,
since no rapid heating is normally required there, and it is
sufficient to supply a certain amount of heat at a specific time of
day, so as to prevent the area from cooling down completely.
Operating low-priority room heat exchangers at a high spread, i.e.,
with very low return temperatures, makes a relatively cool return
medium available, which mixes with the hot heating medium from the
high-priority room heat exchangers in the return flow of the
heating system, so that a temperature balancing takes place, an
acceptably low return temperature is achieved overall, and the
system can be efficiently operated despite the individual room heat
exchangers being oversized and undersized. As a consequence, the
invention deviates from the concept of hydraulic balancing
described at the outset in that different spreads are deliberately
set, and can also be fixed by suitable limiters, so that the
portrayed deviations from the system-specific target spread in the
room heat exchangers of the heating system are balanced out using
all heating surfaces of the heating system, as a result of which
even heating systems without an optimal design, for example those
often encountered in old buildings, can be enhanced to exhibit a
satisfactory energy efficiency level.
[0010] The respective actually achieved target spread clearly
depends on how many heating elements of a system are even operated
after adjustment, since when a user closes room heat exchanger
valves, the volumetric flow rate, and hence the flow pressure in
the still operating room heat exchangers, rises, so that the target
spread can in turn be dipped below. This effect can be countered by
variably controlling the feed pump of the heating system. However,
in the simplest case, the balancing desired according to the
invention is also achieved by ensuring the target spread in the
respective heating elements for a case in which all room heat
exchanger valves are opened.
[0011] In a preferred embodiment of the present invention, the
spread selected for low-priority room heat exchangers is so high
that the return temperature is set in such a way as to achieve the
system-specific target spread. At the system-specific target
spread, the respective heating devices, e.g., gas and oil burners,
wood chip heaters, but also other thermal sources like district
heating, can be operated at their energy optimum, enabling the best
possible utilization of the employed energy source.
[0012] Implementation of the method according to the invention is
facilitated when taking into account operating parameters for all
room heat exchangers or heating surfaces of a building, wherein, in
order to achieve the effect desired according to the invention,
specifically to obtain a return temperature optimized for the
respectively used heat generator, the amounts of heat can be
acquired or determined, and the thermal loads, i.e., the excess
amounts of heat from high-priority room heat exchangers, can be
economized accordingly in low-priority room heat exchangers, for
example. So as to be able to quickly and controllably implement
this approach in practice, the method according to the invention is
preferably developed further so as to acquire the supply and return
temperatures of the individual room heat exchanger and transmit
them to a central processing unit, which determines control values
for the adjustable and/or fixable limitation of all room heat
exchanger valves, and transmits them as a control signal to in
particular removable actuators on the room heat exchanger valves.
For this purpose, temperature sensors are secured to the room heat
exchangers at the supply and return points of the room heat
exchanger, which relay the measured values to the central
processing unit in a wireless or tethered manner. The values are
there compared with the desired values, and the commands for the
next switching step are sent after a corresponding waiting period.
As an alternative, the amounts of heat released by individual room
heat exchangers into the return flow are calculated in the central
processing unit in a known manner, wherein a corresponding
adjustment of the adjustable and/or fixable limitation is
introduced on the room heat exchanger valves or thermostatic heads
by means of actuators or motor units. After the system has been
balanced using the method according to the invention, the control
values can either be fixed manually via mechanical stops, or the
control values can be stored in the actuator units. Once the
control values that limit the flow through the room heat exchanger
valves have been set, the motor units can either be removed, or be
left on the room heat exchangers. The data can be stored in the
central processing unit, and be used to calculate heating costs,
for example. The data can here be read remotely in an especially
advantageous way.
[0013] As already mentioned, a room heat exchanger can be
categorized as a high or low-priority room heat exchanger, based on
the consideration of whether the respective room heat exchanger is
oversized or undersized for the respective area. However,
prioritization can also take place dynamically, wherein the
preferred procedure is to use a measured value for the outside
temperature to calculate the control value of at least one high or
low-priority room heat exchanger.
[0014] If the aforementioned actuators or motor units remain on the
room heat exchangers, an especially favorable adaptive mode of
operation can be achieved for the heating system, which makes it
possible to also respond to temporary user requirements placed on
individual room heat exchangers in individual rooms or areas. For
example, the method can preferably be implemented in such a way
that, given a temporary operational requirement on a room heat
exchanger that leads to a decrease in the spread on the room heat
exchanger in question, this room heat exchanger is subjected to
prioritization, whereupon the volumetric flow rate of heating
medium through at least one low-priority room heat exchanger is
lowered to balance the return temperature of the heating system. As
a consequence, this dynamic change in priorities of the individual
room heat exchangers makes it possible to diminish the volumetric
flow rate through the room heat exchangers in certain areas of a
building, so that the resultantly increasing spread on these room
heat exchangers yields a cool return medium. Since the return flow
amounts of room heat exchangers operated with a high spread, i.e.,
at a low flow rate, are clearly comparatively slight, balancing the
excess amounts of heat fed into the return flow from a room heat
exchanger operated with too low a spread as a rule requires that
several room heat exchangers be operated with a high spread, so as
to provide for a sufficiently cool return flow medium.
[0015] For example, given an unexpected heating requirement on the
part of a user in a phase where a building is not being heated all
that much, for example to quickly heat up a workroom in the night
hours, a very low spread in turn results on the corresponding room
heat exchanger. In this case, the method according to the invention
can preferably be implemented in such a way that, given a temporary
operating requirement on a room heat exchanger that results in a
diminished spread on the room heat exchanger in question, this room
heat exchanger is subjected to a prioritization, whereupon the
return temperature of the heating system is balanced by increasing
the flow rate of heating medium through at least one low-priority
room heat exchanger. While this measure clearly leads to a
resultantly decreased spread in these low-priority room heat
exchangers, increasing the flow rate makes it possible to obtain a
cool return flow medium from these room heat exchangers, which
benefits the overall efficiency of the heating system. Therefore,
at least one room heat exchanger is again operated with a high
spread in such a way as to yield an optimized return temperature.
This also represents a dynamic definition of priorities, and is
introduced by the central processing unit. As a consequence, the
central processing unit assigns a high priority to the room heat
exchanger from which a high heat output is required, and
correspondingly activates the actuators to permit a low spread, and
hence a high heat output on the room heat exchanger in question.
This room heat exchanger subsequently supplies unfavorably hot
return medium in the return flow of the heating system, whereupon
an elevated flow through one or more low-priority room heat
exchangers takes place in the preferred method. A low-priority room
heat exchanger is here in turn a room heat exchanger in a room in
which a specific heat output is not directly required, but the flow
rate through such low-priority room heat exchangers is elevated to
increase the overall efficiency of the system, so that having the
return medium obtained from these areas cool the return point
raises the efficiency of the heat exchanger in the heat generator.
The preferred method can here even be implemented in such a way as
to not just increase an already existing flow rate in a
low-priority room heat exchanger, but to start up a room heat
exchanger that had itself not been operational at the time in
question, which in turn is accomplished by sending a corresponding
control signal from the central processing unit to the actuators or
motor units in question.
[0016] A preferred embodiment of the method according to the
invention here involves a process in which a temporary user
requirement is issued by inputting a desired value for the ambient
temperature, the desired value is sent to the central processing
unit, and control values for the room heat exchanger(s) situated in
the respective room are calculated in the central processing unit
and transmitted as a control signal to the actuators on the room
heat exchanger valves.
[0017] The invention will be explained in greater detail below
based on an exemplary embodiment shown on the drawing. In the
latter, FIG. 1 presents a schematic depiction of a heating system
for implementing the method according to the invention.
[0018] A heating system is denoted by 1 on FIG. 1. The heating
system 1 exhibits a heating device 2 and a series of room heat
exchangers 3 and 4. The room heat exchangers 3 and 4 are connected
in parallel between a supply line 5 and a return line 6. A pump for
conveying the heating medium is marked 7. The room heat exchanger
valves 8 of the room heat exchangers 3 and 4 are adjusted using
actuators or motor units 9, and can be limited in each position by
stops. The actuators 9 are wirelessly connected or tethered to the
central processing unit 10, which receives and processes the data
that are acquired by the temperature sensors 11 at the supply point
and the temperature sensors 12 at the return point of the
individual room heat exchangers, and measured by ambient
temperature sensors in the room. The central processor unit ideally
also has data relating to the supply temperature on the heating
device, the pumping rotation speed and outside temperature, as well
as the temperature in the respective rooms or areas to be
heated.
[0019] For example, room heat exchanger 3 is now defined as the
high-priority room heat exchanger, and room heat exchanger 4 is
defined as the low-priority room heat exchanger during
implementation of the method according to the invention. As already
described, this can be the result of oversizing or undersizing, or
caused by temporary heat requirements on the part of the user. If
the room heat exchangers 3 are for the reasons cited now operated
with a low spread, i.e., at a high return temperature, relatively
hot heating medium gets into the return line 6, and would lead to
an unfavorably high return temperature in the heating device 2. In
order to counter this, at least one of the room heat exchangers 4,
i.e., a low-priority room heat exchanger, is now operated with a
very high spread, so as to convey a certain quantity of cool
heating medium into the return line 6, thereby correspondingly
lowering the return temperature in the heating device 2.
[0020] The spread on the individual room heat exchangers is set by
controlling the flow rate, wherein this setting takes place based
on the control signals transmitted by the central processing unit
10 to the actuators or motor units 9.
[0021] If the user now additionally operates one or more of the
room heat exchangers 3 at an even greater heat output, i.e., with
an even lower spread, this can be balanced out with the system
according to the invention, for example by using the actuators to
reduce the flow rate through one or more of the room heat
exchangers 4, so that the return to the heating unit 2 can in turn
be kept at the desired temperature level.
[0022] In a less complicated approach, the removable actuators are
only used to set the maximum flow rate through the individual room
heat exchangers one time, whereupon the set positions calculated by
the central processing unit are limited with mechanical stops, the
actuators are again removed, and conventional thermostatic heads
are secured.
* * * * *