Note: Descriptions are shown in the official language in which they were submitted.
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Multifunctional sandwich frame for installation
superstructures containing thermally influenced media
The invention relates to a multifunctional sandwich
frame for installation superstructures containing
thermally influenced media, said sandwich frame
performing an insulating function and being used as
assembly frame for the corresponding installation
superstructure.
Solutions are provided that are in particular based
on that, e.g., distributor installations, compact
district-heating installations and control
installations are mounted on adequate gratings and/or
steel structures, said steel structures being also
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helpful for fixed assembly at the location, depending
on their design. All medium lines to be insulated are
subsequently and separately covered in, e.g., PUR
foam as insulating material.
The essential disadvantage of the large variety of
known technical solutions is that a separate,
structural configuration in the form of gratings,
steel structures, etc. is required and simultaneously
insulating material is installed at said installation
superstructures. Prior art involves in particular use
of a PUR insulating body consisting of thermostable,
CFC-free, closed-cell hard cellular material. All
pre-forms are built up of two semi-shells that fully
enclose valves and pipework to be insulated. The
semi-shells are fixed during assembly by means of
self-locking stainless steel spring-type clasps as
separable junction.
Said superstructure insulation is in particular
documented in a company brochure of Petrick & Wolf
Energietechnik GmbH & Co. KG wherein furthermore a
structural steel frame is provided to which
installation superstructures, such as pipes, heat
exchangers, valves, control valves, shut-off valves
etc., are mounted and separately fitted with the
already mentioned pipe insulating body as insulation
material. The specific manufacture of the assembly
rack or the respective insulating body entails in the
described technical solution considerable
manufacturing costs, which costs being in a
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relatively unfavourable relation to other cost
components, such as pumps, valves and pipe material.
The present invention bases on the task of finding a
multifunctional sandwich frame for installation
superstructures containing thermally influenced media
and overcoming prior art disadvantages to establish a
frame functionality that realises the opportunity of
thermal insulation and contains further advantageous,
functional properties, such as assembly capacity,
modular system and mechanical strength.
Aim of this invention is to enable a multifunctional
sandwich frame for installation superstructures
containing thermally influenced media, according to
patent claim 1 and its sub-claims.
To this end a sandwich frame was developed that
consists of several sandwich slabs made of plastics,
in particular of hard polyurethane (PUR) cellular
material. Thermally influenced and/or installation
superstructures are enclosed by said sandwich frame.
The respective sandwich slab is a pre-fabricated
shape, adapted to the size of a given installation
superstructure, such as a pipe. Said pre-fabricated
shapes shall achieve that enclosure by the sandwich
frame provides adequate insulation of enclosed
installation modules through said sandwich slabs.
The given sandwich frame is in particular composed of
two sandwich slabs that enclose the respective sub-
assemblies by said pre-fabricated shapes. Furthermore
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it is possible to arrange further interior sandwich
slabs between the outer sandwich slabs to achieve
that lateral junctions or other types of mounting of
superstructures or installation components are
thermally enclose and thus provide stability of the
entire installation. The given sandwich slabs, such
as the top and bottom sandwich slabs, are fitted with
embedded stabilisation sheets at an outer edge, such
are preferably cast in at the exterior surface. Said
stabilisation sheets are provided with specified bore
holes or holding slots, thus pre-defining a sandwich
slab for assembly of an installation superstructure
or for final assembly at a defined position.
Stabilisation sheets are arranged at the respective
outer edge of a sandwich slab laterally to the
assembly direction of interior installation
superstructures, such as pipes, slabs or other sub-
assemblies. Said lateral assembly of stabilisation
sheets thus provides a structural configuration that
ensures stability of the sandwich frame because the
interior installations components in longitudinal
direction already establish a stability factor. A
given sandwich slab is already provided with passage
openings which allow for arrangement of
constructional superstructure elements outside of the
sandwich slab so as to attain the forms and sizes of
the given sandwich slab remain in the smallest
possible dimension to achieve assembly capacity. In
addition it is advantageous that the installation
superstructures are arranged outside of the sandwich
slab to ensure access to any sub-assemblies.
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Essential advantages of the sandwich frame,
consisting of two sandwich slabs or further interior
sandwich slabs within said two sandwich slabs to
enclose sub-assemblies, respectively, are given by
provision of optimal insulation and stability
capacity to the sandwich slabs by cellular PUR
material and its properties. The used cellular PUR
material is absolutely water-repellent and thus has
proven very well as insulating material in practice.
Cellular PUR insulating material is a thermostable,
CFC-free, closed-cell hard cellular material.
Further technical parameters of the hard cellular
material are as follows:
Specific volume weight 90 kg/m3
Compression strength 0.43 N/mm3
Application temperature up to 130 C
Thermal conductivity 0.031 W/mK
Building material class B 2
Further, said sandwich frame has best insulating
properties, and high stability is achieved by
installation of stabilisation sheets at the outer
edges of the respective sandwich slab. Another
advantage is that use of said sandwich frame provides
sound and vibration damping at the given
installations. The structural configuration of said
sandwich frame also enables realisation of several
installation components by means of a so-called
modular system. In particular sizes, forms and scopes
of the sandwich frame and the content of several
other slabs can be constructively executed and
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adapted to a respective installation component. The
modular principle also allows for combining, beside
said installations, also additional installations by
means of another sandwich frame and thus realise the
essential advantages of the inventive solution also
for additional devices and modules.
The embedded stabilisation sheets, in particular in
the rear wall of the sandwich frame, in the sandwich
slab, are advantageously provided with bore holes or
slots that enable realisation of an installation
without much technical, e.g., by wall mounting.
A practical example demonstrates the superstructure
and application of said sandwich slab in practice,
illustrated in the following figures:
Figure 1: Configuration of sandwich slab
Figure 2: Application of sandwich slab
Figure 3: Application of sandwich slab
Figure 4: Application of sandwich slab
Figure 5: Additional sandwich slab
Figure 6: Assembly of sandwich slabs
Figure 7: 3D view of Sandwich slab
Figure 7a: Top view of sandwich slab
Figure 7b: Side view of sandwich slab
Figure 7c: Side view of sandwich slab
Figure 8: Circuit diagram of installation
superstructure as compact district-heating
station
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Application and configuration of said sandwich slab,
especially for a specific installation superstructure
are described below for a compact district-heating
station for indirect connection to a
district-heating system.
Installation superstructures 13 as compact district-
heating stations are fabricated as compact units and
contain all necessary sub-assemblies for connection
of building systems to the local district-heating
network. Design and fabrication of installation
superstructures as compact district-heating stations
comply with all valid regulations and codes for
district-heating connections, in particular:
- applicable DIN and VDE regulations;
- heating Installation Ordinance;
- Pressure Vessel Ordinance;
- AGFW codes, and
- Technical connection conditions of the
district-heating utility company.
Depending on their throughput capacities, the
stations are fabricated as wall-mounting or wall
erection models as described in the inventive
solution of sandwich frame 11. Both mounting variants
provide for front accessibility of all components and
controls, since sandwich slab 2 is fitted with
passage openings 8 and 8' onto which the components
and controls are built outside of sandwich frame 11.
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As a standard a compact district-heating station
essentially contains the following functional groups:
- District-heating transfer section
- Heat exchanger with pilot control and
safety devices
- One or more secondary heating circuits
- Water heating
- Control equipment.
Control of the compact district-heating station that
is installed as installation superstructure 13 on the
sandwich frame 11 is performed by several control
circuits that operate differently depending on the
equipment level of the station. Control of the
secondary -side outlet temperature of heating medium
from the heat exchanger 48 is carried out in the
pilot control circuit by means of a control valve 68.
For controlling the heating circuit, the heating
circuit feed flow temperature is controlled demand-
dependant as a function of outside temperature, room
temperature or a constant specified value. Control of
water heating allows for controlling several water
heating systems (e.g. types: BS / BTL / BTD / BTLRA /
BTLDR). The transfer section with pilot control
circuit is the interface between district-heating
network and domestic system. The hydraulic
configuration depends on the technical connection
conditions of the district-heating utility company
and technical requirements due to existing district-
heating network parameters. Sub-assemblies of the
pilot control circuit are arranged downstream of the
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transfer section. Figure 8 shows the schematic
configuration of this sub-assembly. Control of
secondary feed flow temperature is performed by
targeted control of volume flow in the primary
circuit (opening or shutting of motor control valve
91/72) . The pilot control valve 91/72 is controlled
through the temperature sensor in secondary feed flow
75.2 according to the value of secondary feed flow
temperature. Depending on the actuating drive used,
there is either continuous selection or selection
with three-level action. The DDC controller 70
continually compares the secondary feed flow actual
value with the setpoint value and calculates the
required manipulated variable for driving valve
91/72. The setpoint value is calculated by the
controller from `Temperature requirements of
secondary control circuits' and further parameters.
The highest heat demand is the dominating command
variable for the pilot control circuit. The operating
regimes of the pilot control circuit described below
are possible options. The pilot control circuit shall
be operated with a freely selectable excess
temperature, i.e. the pilot control circuit provides
a specified secondary excess temperature. Such is,
e.g., necessary where long line sections between heat
exchanger 48 and consumer cause heat losses. The
pilot control circuit can be optionally operated to a
freely selectable constant setpoint value or variably
as a function of outside temperature through the
outside temperature sensor 60. The temperature sensor
primary return flow 75.1 is provided to realise the
additional function `Temperature limiting of primary
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return flow'. Over-exceeding of the maximal
admissible return flow temperature upon reaching a
freely selectable return flow temperature is
prevented by shutting of pilot control valve 91/72.
This function should only be activated when the
heating system is well-balanced and the temperature
spread rated for dimensioning of the station is
achieved. Otherwise buildings may be undersupplied
due to insufficient secondary feed flow temperatures.
Figure 8 shows the connection diagram of a compact
district-heating station as a practical example of an
installation superstructure 13. The technical
functionality is illustrated in Figure 8. A DDC
controller 70 is used to control the compact
district-heating station. Input variables are
provided through the temperature sensor secondary
return flow 75.3 as well as the temperature sensor
secondary feed flow 75.2 and the temperature sensor
primary return flow 75.1 as well as through an
outside temperature sensor 60. An actuating signal on
the stop valve 91/72 is executed as output signal.
The primary feed flow is furthermore fitted with a
dirt filter 59, with another dirt filter 59 being
installed in the secondary feed flow. Thermometers 79
in the return flow and in the secondary-side feed
flow indicate feed and return flow temperatures on
the secondary side. A heat quantity counter 96 is
arranged in the primary-side return flow. The plate-
type heat exchanger 48 is a heat exchanger of a known
design. dirt filter s 59 in the primary-side feed
flow and the secondary-side feed flow are of a novel
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design for pipe systems. These dirt filters s 59 can
also be installed into individual heating circuits.
The distinguishing features of said novel filter is
that it consists of a filter housing that enforces a
filter flow of 90 , within which filter flow a filter
sieve is arranged that s fitted with a bolted union
in longitudinal direction for replacement of the
filter sieve. Thus it is possible to replace the
filter sieve in this installation superstructure 13
of the compact district-heating station from the
front (see also Reference character 59 - Figure 3). A
further advance of the insert in the novel dirt
filter is that the 90 execution of the filter system
allows for a considerable saving in piping because
known filters (dirt filter or dirt traps) do not have
said throughput flow of 90 . Thus it was achieved
that especially in this specific installation
superstructure 13 the arrangement of the two dirt
filters 59 permits an easy and clearly arranged
configuration of installation superstructures 13 in
the form of pipework with individual controls and
components according to Figure 8.
In particular Figure 3 illustrates why this insert in
dirt filters 59 can be deemed an essential advantage
because said dirt filters 59 and the angle of 90
from the sandwich frame 11 allow for an immediate
conveyance at a right angle via the installation
superstructures 13 in the form of pipes.
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Figure 1 shows the configuration of a sandwich frame
11 of sandwich slab 1 and sandwich slab 2. Said
sandwich slabs 1 and 2 are made of plastics, in
particular of cellular PUR material. The used
cellular PUR material is absolutely water-repellent
and hence best suited as insulating material. The
cellular PUR insulating material is made of
thermostable, CFC-free, closed-cell hard cellular
material. These properties ensure optimal insulating
and stabilising capacities of the sandwich slabs.
It is obvious that there are respective shapes 12 in
this practical example are given in particular for
pipework. The stabilisation sheets 3 and 3' are cast
into sandwich slab 1 at the outer edge laterally to
the assembly direction of installation
superstructures 13 at the top edge. The inserted bore
holes 6 or holding slots 7 in stabilisation sheet 3
and 3' are arranged so that a wall-mounting or wall
erection location can be fixed by these provided bore
holes 6 and holding slots 7. In addition, it is
possible to arrange further components via said bore
holes 6 and holding slots 7. Insertion of said
stabilisation sheets 3 and 3' enhances the stability
of sandwich slab 1 because in this practical example
pipes 9 or other pipes are arranged in the form of
installation superstructures 13 in the pre-fabricated
shapes 12. Stabilisation sheets 4 and 4' are also
cast in at the outer edge at sandwich slab 2.
Sandwich slab 2 is further equipped with passage
openings 8 and 8' to execute with the enclosed
installation superstructures 13 or thermally
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influenced pipes 9 a connection via said passage
openings 8 and 8' and arrange the necessary controls
and superstructure elements according to Figure 3 and
Figure 2, respectively.
Figure 2 is a drawing that illustrates the
application of a sandwich frame 11. A thermally
influenced pipe 9 is led within sandwich frame 11.
Passage openings 8 and 8' in sandwich slab 2 are used
to arrange respective components or pipes at the
thermally influenced pipes 9 through a given welded
connection. Sandwich slab 1 and sandwich slab 2 are
laterally clamped together by means of brackets 5 and
thus form a closed component. It is also possible t
join the two sandwich slabs 1 and 2 by means of a
bolted union, clamp or other detachable connections.
The novel sandwich frame 11 achieves simultaneously
stability and insulation of thermally influenced
pipes 9.
Figure 3 shows the complete combination of the
sandwich frame 11 with respective installation
superstructures 13 and instruments, controls and
components shown in Figure 8 for a compact district-
heating station.
Figure 4 is a side view of the sandwich frame 11 with
its sandwich slabs 1 and 2 on which the respective
installation superstructures 13 of the controls and
components are arranged.
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As shown in the last-mentioned figures, the sandwich
frame 11 provides a base rack that functions as
insulation, e.g. of thermally influenced pipes 9,
ensures the assembly capacity of the compact
district-heating station in several configuration
variants by means of the inserted stabilisation
sheets 3 in sandwich slab 1 and has the already
described advantages of sandwich frame 11.
Figure 6 shows a sandwich frame 11 without any
installation superstructures 13. As can be seen in
Figure 6, it is possible, depending on a given
application case and installation superstructure, to
fabricate a respective sandwich frame. The pre-
fabricated shapes 12 serve as bases for insertion of
components, etc. By tightening the brackets 5,
sandwich slabs 1 and 2 are forming a base rack base
rack onto which further installation components 13
can be mounted via provided passage openings 8 and 8'
in sandwich slab 2.
Figures 7, 7a, 7b and 7c show sandwich slab 1. Figure
7 is a three-dimensional view of sandwich slab 7
showing that the stabilisation sheets 3 and 3' are
cast in at the top edge of sandwich slab 1. Further,
there are bore holes 6 and holding slots 7 provided
over the entire length of stabilisation sheets 3 and
3' to allow for mounting of sandwich slab 1 over the
whole sandwich frame 11.
Figure 7a is a top view of said sandwich slab 1.
Figures 7b and 7c provide side views of sandwich slab
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1. Essential is always that stabilisation sheets 3
and 3' are arranged at the outer edge laterally the
pre-fabricated shapes lines 12. It is emphasized
again, that said stabilisation sheets 3 and 3' are
cast into cellular PUR material at the top edge.
Figure 5 shows another practical variant of the
sandwich frame 11. It is possible to arrange a
further sandwich slab 14 between sandwich slab 1 and
a pre-fabricated sandwich slab 2. Installation
superstructures 13 in the form of controls and
components can be mounted on top of said sandwich
slab 14, such as laterally to the pre-fabricated
shape 12 for thermally influenced pipes 9 as shown in
this practical example.
Hence, it is basically possible to execute several
sandwich slabs 1 and 2 on top of each other as one
structural unit rack. The underlying principle of
this application example and the inventive solution
is the execution of a sandwich frame 11 by embedding
respective installation superstructures 13 that is
preferably made of hard PUR material. This frame
allows as an advantage carrying out of a transport,
insulating proofing against sound and noise, enhanced
mechanical strength, low-cost construction of a base
frame and housing component for an installation
superstructure 13 and good stackability for
transport.
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Reference characters
1 Sandwich slab
2 Sandwich slab
3 Stabilisation sheet
3' Stabilisation sheet
4 Stabilisation sheet
4' Stabilisation sheet
Bracket
6 Bore hole
7 Holding slots
8 Passage opening
8' Passage opening
9 Thermally influenced pipe
11 Sandwich frame
12 Pre-fabricated shapes
13 Installation superstructures
14 Sandwich slab
48 Heat exchanger
59 Dirt filter
60 Outside temperature sensor
68 Control valve
70 DDC controller
75.1 Temperature sensor primary return flow
75.2 Temperature sensor secondary feed flow
75.3 Temperature sensor secondary return flow
79 Thermometer
91/72 Motor control valve (pilot control valve)
96 Heat quantity counter
