U.S. patent application number 13/318840 was filed with the patent office on 2012-03-01 for plate heat exchanger.
This patent application is currently assigned to ALFA LAVAL CORPORATE AB. Invention is credited to Johan Gardmo, Perola Magnus Helin.
Application Number | 20120048526 13/318840 |
Document ID | / |
Family ID | 42617525 |
Filed Date | 2012-03-01 |
United States Patent
Application |
20120048526 |
Kind Code |
A1 |
Helin; Perola Magnus ; et
al. |
March 1, 2012 |
Plate Heat Exchanger
Abstract
A plate heat exchanger comprises a plate package (1) with heat
exchanger plates (2) forming primary plate interspaces (3) for a
primary medium and secondary plate interspaces (4) for a secondary
medium. A primary inlet (11) transports the primary medium to the
primary plate interspaces. A primary outlet (12) transports the
primary medium from the primary plate interspaces. A secondary
inlet (21) transports the secondary medium to the secondary plate
interspaces. A secondary outlet (22) transports the secondary
medium from the secondary plate interspaces. A sensor device (30)
comprises a space (31) containing a sensor medium influenced by the
temperature of the secondary medium. A throttle member (35)
connected to the sensor device controls the flow of the primary
medium in response to the sensor medium. The space comprises a
first part space (31') delimited by one of the heat exchanger
plates (2), which adjoins and is in heat transfer contact with the
outermost secondary plate interspace (4'), and a second part space
(31''), which adjoins and is in heat transfer contact with the
secondary outlet located downstream the secondary plate
interspaces.
Inventors: |
Helin; Perola Magnus;
(Ronneby, SE) ; Gardmo; Johan; (Karlskrona,
SE) |
Assignee: |
ALFA LAVAL CORPORATE AB
Lund
SE
|
Family ID: |
42617525 |
Appl. No.: |
13/318840 |
Filed: |
April 21, 2010 |
PCT Filed: |
April 21, 2010 |
PCT NO: |
PCT/SE10/50436 |
371 Date: |
November 4, 2011 |
Current U.S.
Class: |
165/166 |
Current CPC
Class: |
F28F 27/02 20130101;
Y02E 20/14 20130101; F28D 9/005 20130101 |
Class at
Publication: |
165/166 |
International
Class: |
F28D 9/00 20060101
F28D009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 4, 2009 |
SE |
0950405-1 |
Claims
1. A plate heat exchanger comprising: a plate package having a
plurality of heat exchanger plates, the heat exchanger plates being
provided beside each other in the plate package in such a way that
they form primary plate interspaces for a primary medium and
secondary plate interspaces for a secondary medium, the primary and
the secondary plate interspaces being provided in an alternating
order in the plate package, wherein the plate package has a first
end and a second opposite end, and a front side and an opposite
rear side, and wherein one of the secondary plate interspaces forms
an outermost secondary plate interspace; a primary inlet, arranged
to transport the primary medium into the plate package to the
primary plate interspaces and comprising a primary inlet port
channel; a primary outlet, arranged to transport the primary medium
out from the plate package from the primary plate interspaces and
comprising a primary outlet port channel; a secondary inlet,
arranged to transport the secondary medium into the plate package
to the secondary plate interspaces and comprising at least one
secondary inlet port channel; a secondary outlet, arranged to
transport the secondary medium from the plate package from the
secondary plate interspaces; a sensor device, the sensor device
comprising a space closed in relation to the primary plate
interspaces and the secondary plate interspaces, wherein the space
contains a sensor medium, the sensor medium being provided to be
influenced by the temperature of the secondary medium; and a
throttle member, the throttle member being connected to the sensor
device and being arranged to control the flow of one of the primary
medium and the secondary medium in response to the sensor medium,
wherein the space comprises a first part space, which is delimited
by one of said heat exchanger plates that adjoins and is in heat
transfer contact with the outermost secondary plate interspace, and
a second part space, which adjoins and is in heat transfer contact
with the secondary outlet that is located downstream of the
secondary plate interspaces.
2. The plate heat exchanger according to claim 1, wherein the first
part space adjoins substantially the whole of said one of the heat
exchanger plates delimiting the outermost secondary plate
interspace.
3. The plate heat exchanger according to anyone of claims 1 and 2,
wherein the secondary outlet comprises a secondary outlet port
channel extending through the plate package.
4. The plate heat exchanger according to claim 3, wherein the
secondary outlet comprises a first outlet channel extending
outwardly in line with the secondary outlet port channel through
the front side.
5. The plate heat exchanger according to claim 3, wherein the
second part space is provided in the secondary outlet port
channel.
6. The plate heat exchanger according to claim 5, wherein the
second part space is surrounded by the secondary medium in the
secondary outlet port channel.
7. The plate heat exchanger according to anyone of claims 1 and 2,
wherein the second part space is delimited by one of said heat
exchanger plates which adjoins an outlet plate interspace forming a
part of the secondary outlet.
8. The plate heat exchanger according to claim 7, wherein the
secondary outlet comprises a second outlet channel extending from
the outlet plate interspace outwardly from the rear side.
9. The plate heat exchanger according to claim 3, wherein the
secondary outlet port channel is located in the proximity of the
first end, and a second outlet channel is located in the proximity
of the second end.
10. The plate heat exchanger according to claim 8, wherein the
outlet plate interspace communicates with the secondary plate
interspaces merely via the secondary outlet port channel.
11. The plate heat exchanger according to claim 7, wherein the
outlet plate interspace has a thickness which is significantly
thicker than the thickness of the secondary plate interspaces.
12. The plate heat exchanger according to claim 3, wherein the
secondary outlet port channel does not extend through the front
side.
13. The plate heat exchanger according to claim 1, wherein the
primary inlet port channel, the primary outlet port channel and the
secondary inlet port channel extend through the front side.
14. The plate heat exchanger according to claim 3, wherein the
throttle member comprises an influencing member which is connected
to the first part space and the second part space and arranged to
influence the throttle member by sensing a pressure change of the
sensor medium in the space.
15. The plate heat exchanger according to claim 3, wherein the
throttle member is arranged to control the flow of the primary
medium through the primary plate interspaces in response to the
sensor medium.
Description
THE BACKGROUND OF THE INVENTION AND PRIOR ART
[0001] The present invention refers to a plate heat exchanger
according to the preamble of claim 1.
[0002] EP-B-608 195 discloses such a plate heat exchanger with a
sensor device comprising a temperature sensor with an elongated
shape. The temperature sensor extends in one of the port channels
of the plate heat exchanger, which communicates with some of the
heat transfer passages of the plate package. The temperature sensor
communicates with a valve for controlling a flow of for instance
district heat water through the plate heat exchanger.
[0003] DK-U-9600205 discloses a similar plate heat exchanger
provided with a space arranged outside the plate heat exchanger and
extending at an outer surface of the plate hear exchanger. An
elongated temperature sensor is provided in the space. The space
communicates with passages for one of the fluids in the plate heat
exchanger. The space is provided in the proximity of an inlet or
outlet opening of the heat exchanger. The temperature sensor is
arranged to co-operate with equipment for controlling a flow of one
of the fluids through the plate heat exchanger.
[0004] These documents thus suggest the provision of a separate
sensor outside the plate heat exchanger or in any of the port
channels of the plate heat exchanger. The provision of such a
separate sensor is difficult from a manufacturing point of view.
Furthermore, a sensor in any of the port channels results in an
increased flow resistance, not only due to the sensor itself but
also due to the components required for attaching sensor in the
port channel. The known arrangements also have the disadvantage
that the time constant is long, i.e. it takes a relatively long
time before a temperature change of one or both fluids results in a
sufficient influence on said medium, and thus in for instance a
desired change of a valve position.
[0005] U.S. Pat. No. 7,152,663 discloses a similar plate heat
exchanger where these problems at least partly have been solved. In
one of the disclosed embodiments, the closed space of the sensor
device is formed by two of the heat exchanger plates in the plate
package. In such a way, the closed space may be provided in very
close heat transferring contact with one or both of the media.
Consequently, possibilities are created for achieving a large
contact surface of the sensor device. With a large contact service,
a large drive force is achieved for, for instance, a control valve,
the valve position of which is controlled by means of the sensor
medium, and a short time constant at a short dead time, i.e. a very
quick reaction to changes of the temperature of any of the media is
obtained.
[0006] One problem which is not solved in an optimum manner with
the plate heat exchanger disclosed in U.S. Pat. No. 7,152,663 is
that the sensor device can result in a too large control deviation
on the secondary side when operation changes occur. The solution
disclosed in U.S. Pat. No. 7,152,663 ensures that the closed space
of the sensor device is only influenced by either one of the media
from only one adjacent plate interspace or possibly by both of the
media. In order to achieve a proper control it is necessary that
the sensor device may sense a temperature of the secondary media
which is representative for the desired temperature of the
secondary media.
[0007] A further problem in the context is that the temperature
profile along the plate interspaces may be such that it is
difficult to achieve a representative and proper temperature
sensing of the sensor device. If the sensor media comprises for
instance a gaseous phase and a liquid phase, the result of the
temperature influence on the sensor device will be different at the
different phases. Due to the fact that the border between the
gaseous phase and the liquid phase is not located at a constant
level, the control can be problematic. The temperature influence on
the gas phase results in a relatively smaller pressure increase of
the sensor medium than the temperature influence on the liquid
phase. If the gaseous phase to a substantial part is located in the
area where the secondary medium has a high temperature, this
temperature may rise without achieving a sufficient pressure
increase of the sensor medium, and thus also no sufficient
influence on the throttle member.
SUMMARY OF THE INVENTION
[0008] The object of the present invention is to remedy the
problems mentioned above and provide a plate heat exchanger with an
improved sensor device ensuring a proper and uniform control of the
temperature of the secondary medium.
[0009] This object is achieved by the plate heat exchanger
initially defined, which is characterised in that the space
comprises a first part space, which is delimited by one of said
heat exchanger plates that adjoins and is in heat transfer contract
with the outermost secondary plate interspace, and a second part
space, which adjoins and is in heat transfer contact with the
secondary outlet that is located downstream the secondary plate
interspaces.
[0010] In such a way, the sensor device, i.e. the sensor medium
contained in the close space, will be influenced by the temperature
of the secondary medium from two sides or positions. Consequently,
a quick control and a control based on a correct, or at least
substantially correct, temperature is achieved. The secondary
medium in the secondary outlet, which adjoins the second part
space, has a uniform, or substantially uniform, temperature
corresponding to the outlet temperature of the secondary medium.
Since the second part space of the sensor device adjoins the
secondary outlet, the sensor media will in a substantial way be
influenced by the temperature to be achieved by means of
controlling.
[0011] According to an embodiment of the invention, the first part
space adjoins substantially the whole, or the whole, of said heat
exchanger plate delimiting the outermost secondary plate
interspace. In such a way, a large contact surface, ensuring that a
large and sufficient drive force is generated by the sensor media
for the influencing of the throttle member, is achieved.
[0012] According to an embodiment of the invention, the secondary
outlet comprises a secondary outlet port channel extending through
the plate package. The secondary outlet may advantageously also
comprise a first outlet channel extending outwardly in line with
the secondary outlet port channel through the front side for
discharge of at least a part of the secondary medium with achieved
outlet temperature.
[0013] According to an embodiment of the invention, the second part
space is provided in the secondary outlet port channel.
Advantageously, the second part space may be provided in such a way
that it is surrounded by the secondary medium in the secondary
outlet port channel. In such a way, it is ensured that sensor
medium in the second part space will be in heat transfer contact
with the secondary medium and influenced by the outlet temperature
of the secondary medium.
[0014] According to an embodiment of the invention, the second part
space is delimited by one of said heat exchanger plates which
adjoins an outlet plate interspace forming a part of the secondary
outlet. In such a way, the sensor medium in the second part space
may also adjoin and be influenced by the outlet temperature of the
secondary medium over a large surface so that a substantial
temperature influence is achieved. Advantageously, the secondary
outlet then comprise a second outlet channel extending from the
outlet plate interspace outwardly from the rear side.
[0015] According to an embodiment of the invention, the secondary
outlet port channel is located in the proximity of the first end
and the second outlet channel in the proximity of the second end.
In such a way a long and thus large contact surface between the
second part space and the outlet plate interspace is ensured.
Advantageously, the outlet plate interspace communicates with the
secondary plate interspaces merely via the secondary outlet port
channel. In such a way, a uniform, or substantially uniform,
distribution of the temperature of the secondary medium is ensured
in the whole outlet plate interspace.
[0016] According to an embodiment of the invention, the outlet
plate interspace has a thickness of which is significantly thicker
than the thickness of the secondary plate interspaces. The
secondary outlet port channel does then not need to extend through
the front side. The whole flow of the secondary medium may thus be
discharged via the second outlet channel.
[0017] According to an embodiment of the invention, the primary
inlet port channel, the primary outlet port channel and the
secondary inlet port channel extend through front side.
[0018] According to an embodiment of the invention, the throttle
member comprises an influencing member which is connected to the
first part space and the second part space, and arranged to
influence the throttle member by sensing a pressure change of the
sensor medium in the first part space and the second part space.
The throttle member may advantageously be arranged to control the
flow of the primary medium through the primary plate interspaces in
response to the sensor medium.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The present invention is now to be explained more closely
through a description of various embodiments and with reference to
the drawings attached hereto.
[0020] FIG. 1 discloses schematically a front view of a plate heat
exchanger according to a first embodiment of the invention.
[0021] FIG. 2 discloses schematically a side view through the plate
heat exchanger along line II-II in FIG. 1.
[0022] FIG. 3 discloses schematically a side view through the plate
heat exchanger along line III-III in FIG. 1.
[0023] FIG. 4 discloses schematically a front view of a plate heat
exchanger according to a second embodiment of the invention.
[0024] FIG. 5 discloses schematically a side view through the plate
heat exchanger along the line V-V in FIG. 4.
[0025] FIG. 6 discloses schematically a side view through the plate
heat exchanger along the line VI-VI in FIG. 4.
[0026] FIG. 7 discloses schematically a front view of a plate heat
exchanger according to a third embodiment of the invention.
[0027] FIG. 8 discloses schematically a side view through the plate
heat exchanger along the line VII-VII in FIG. 7.
[0028] FIG. 9 discloses schematically a side view through the plate
heat exchanger along the line IX-IX in FIG. 7.
DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS OF THE INVENTION
[0029] FIGS. 1-3 disclose a plate heat exchanger according to a
first embodiment of the invention. The plate heat exchanger
comprises a plate package 1, with a plurality of heat exchanger
plates 2 which are compression-moulded in a manner known per se and
comprise a heat transfer surface 2' with a compression-moulded
corrugation 2'' of ridges and valleys, schematically disclosed in
FIG. 1. The heat exchanger plates 2 are provided beside each other
in the plate package 1 in such a way that they form primary plate
interspaces 3 for a primary medium and secondary plate interspaces
4' for a secondary medium, see FIGS. 2 and 3. A first of the
secondary plate interspaces forms an outermost secondary plate
interspace 4'. The primary and secondary plate interspaces 3 and 4,
4' are provided in an alternating order in the plate package, i.e.
every second plate interspace is a primary plate interspace 3 and
every second a secondary plate interspace 4, 4'.
[0030] The plate heat exchanger disclosed is especially configured
for an application in a local heating network or a district heating
network, for instance for heating of tap water, wherein the primary
medium is district heating water from a central district heating
plant and the secondary medium is tapwater to be heated by the
district heating water in the plate heat exchanger. In the heating
network, any heating source can be used, for instance a heating
plant, an oil heater, a sun energy plant etc. It is to be noted,
however, that the plate heat exchanger according to the invention
may also be used in other applications, for instance for cooling,
in heat pump plants, in industrial process for cooling, in heat
pump plants in industrial process, for cooling and/or heating in
vehicles etc.
[0031] The plate package has a first end 1' and a second opposite
end 1'', and a front side 5 and an opposite rear side 6. A front
side plate 7 is provided outermost at the front side 5 and can be
formed by an outermost heat exchanger plate 2 or by a plane plate
provided outside but preferably against the outermost heat
exchanger plate 2. The plate heat exchanger may also comprise a
corresponding rear side plate 8 provided outermost at the rear side
6 and which may be formed by the outermost heat exchanger plate 2
or by a plane plate provided outside but preferably against the
outermost heat exchanger plate 2.
[0032] In the embodiments disclosed, the heat exchanger plates 2
are permanently connected to each other by for instance brazing,
gluing or welding. Preferably, also the front side plate 7, and
possibly the rear side plate 8, are permanently connected to the
heat exchanger plates 2 by for instance brazing, gluing or welding.
The front side plate 7 and the rear side plate 8 may then form a
part of the plate package 1. However, it is to be noted that the
invention also is applicable to plate heat exchangers which are
kept together in any other way, such as by means of tie bolts.
[0033] The plate heat exchanger comprises a primary inlet 11 and a
primary outlet 12 for the primary medium, and a secondary inlet 21
and a secondary outlet 22 for the secondary medium, se FIGS. 1 and
3.
[0034] The primary inlet 11 is arranged to transport the primary
medium into the plate package 1 to the primary plate interspaces 3.
The primary inlet 11 comprises a primary inlet port channel 13
extending through at least a part of the plate package 1. The
primary inlet port channel 13 is formed by a porthole through each
of the heat exchanger plates 2 except for some of the heat
exchanger plates 2 as will be seen more closely below.
[0035] The primary outlet 12 is arranged to transport the primary
medium out from the plate package 1 from the primary plate
interspaces 3. The primary outlet 12 comprises a primary outlet
port channel 14 extending through at least a part of the plate
package 1. The primary outlet port channel 14 is formed by a
porthole through each of the heat exchanger plates 2 except for
some of the heat exchanger plates 2 as can be seen more closely
below.
[0036] The secondary inlet 21 is arranged to transport the
secondary medium into the plate package 1 to the secondary plate
interspaces 4. The secondary inlet 21 comprises a secondary inlet
port channel 23 extending through at least a part of the plate
package 1. The secondary inlet port channel 23 is formed by a
porthole through each of the heat exchanger plates 2 except for
some of the heat exchanger plates 2, as can be seen more closely
below. It is to be noted that the secondary inlet 21 may comprise
more than one, for instance two, secondary inlet port channels.
[0037] The secondary outlet 22 is arranged to transport the
secondary medium out from the plate package 1 from the secondary
plate interspace 4, 4'. The secondary outlet 22 comprises a
secondary outlet port channel 24 extending through at least a part
of the plate package 1. The secondary outlet port channel 24 is
formed by a porthole through each of the heat exchanger plates
2.
[0038] The plate heat exchanger comprises a sensor device 30, which
comprises a space 31 which is closed in relation to the primary
plate interspaces 3 and in relation to the secondary plate
interspaces 4, 4'. The space 31 contains a sensor medium which is
provided to be influenced by the temperature of the secondary
medium. The sensor medium may advantageously comprise or consist of
a substance which is in gaseous phase and a liquid phase at the
temperature and the pressure prevailing in the space 31. The sensor
medium may for instance comprise or consist of carbon dioxide and
active carbon or a gas-liquid mixture.
[0039] The space 31 comprises a first part space 31' and a second
part space 31''. The first part space 31' is delimited by one of
the heat exchanger plates 2, which adjoins and is in heat transfer
contact with the outermost secondary plate interspace 4'. The
second part space 31' adjoins and is in heat transfer contact with
the secondary outlet 22 which is located downstream the secondary
plate interspace 4, 4''. The first part space 31' adjoins
substantially the whole of said adjoining heat exchanger plate 2
which delimits the outermost secondary plate interspace 4'.
[0040] In the first embodiment disclosed in FIGS. 1-3, the space
31, i.e. both the first part space 31' and the second part space
41'', is defined by two of the heat exchanger plates 2. The border
between the first part space 31' and the second part space 31'' is
marked with a dashed line in FIGS. 2 and 3. The space 31 is formed
by a closed plate interspace adjoining the first outermost
secondary plate interspace 4' and an outlet plate interspace 28.
The outlet plate interspace 28 forms a part of the secondary outlet
22 and is also defined by two heat exchanger plates 2. The space 31
is thus divided into a first part space 31', which adjoins the
first outermost secondary plate interspace 4', and a second part
space 31'' which adjoins the outlet plate interspace 28.
[0041] The secondary outlet 22 comprises a first outlet channel 26
which extends in line with the secondary outlet port channel 24
through the front side 5 and through the front side plate 7.
Consequently, the primary inlet port channel 13, the primary outlet
port channel 14, the secondary inlet channel 23 and the secondary
outlet port channel 24 extend through the front side plate 7, i.e.
outwardly from the front side 5.
[0042] In the first embodiment, the secondary outlet 22 also
comprises a second outlet channel 27 extending from the outlet
plate interspace 28 outwardly from the rear side 6 and through the
rear side plate 8.
[0043] The second outlet channel 27 is located at or in the
proximity of the second end 1'' whereas the secondary outlet port
channel 24 is located at or in the proximity of the first end 1'.
Since the outlet plate interspace 28 communicates with the first
outermost secondary plate interspace 4' and the remaining secondary
plate interspace 4 merely via the secondary outlet port channel 24,
the secondary medium in the outlet port channel 28 will not be
influenced by the primary medium. The space 31, and in particular
the second part space 31'', will therefore not be influenced by the
outlet temperature, or the final temperature, of the secondary
medium before it leaves the plate heat exchanger along the whole,
or substantially the whole, surface of the heat exchanger plate
located between the space 31, i.e. the second part space 31'', and
the outlet plate interspace 28.
[0044] The plate heat exchanger is connected to or comprises a
throttle member 35 connected to the sensor device 30. The throttle
member 35 is in the embodiments disclosed arranged to control the
flow of the primary medium through the primary plate interspaces 3
in response to the sensor medium. However, it is to be noted that
the throttle member 35 may be arranged to control the flow of the
secondary medium through the secondary plate interspaces 4 in
response to sensor medium. The throttle member 35 may be realized
in the form of a valve of suitable design. In the embodiments
disclosed, the throttle member 35 is provided on a connection pipe
16 from the primary outlet 12, but it may also be provided on a
connection pipe 15 to the primary inlet 11.
[0045] The throttle member 35 comprises an influencing member 35
which is connected to the space 31 via a conduit 37, for instance
and electric conduit or a capillary tube configured to transfer a
pressure change in the space 31 to the influencing member 36. The
influencing member 36 is arranged to influence the throttle member
35 by sensing a pressure change of the sensor medium in the space
31. The pressure of the sensor medium is depending on the
temperature. An increase of the temperature of the secondary medium
leads to an increase of the pressure of the sensor medium which via
the influencing member 36 increases the throttling of the throttle
member 35 so that the flow of the primary medium is reduced. In a
corresponding way, a decrease of the temperature of the secondary
medium leads to a decrease of the pressure of the sensor medium
which via the influencing member 36 reduces the throttling of the
throttle member 35 so that the flow of the primary medium is
increased. In a cooling application, the influencing member 36 is
inverted so that an increase of the temperature of the secondary
medium leads to an increase of the pressure of the sensor medium
which via the influencing member 36 decreases the throttling of the
throttle member 35 so that the flow of the primary medium
increases.
[0046] FIGS. 4-6 disclose a second embodiment of the plate heat
exchanger according to the invention. It is to be noted that the
same or similar elements have been provided with the same reference
signs in the embodiments disclosed. The second embodiment differs
from the first embodiment in that the secondary outlet port channel
24 does not extend through the front side 5 and the front side
plate 7. The secondary outlet 22 thus comprises only one second
outlet channel 27 which extends from the outlet plate interspace
28. In the second embodiment, this second outlet channel 27 extends
from the rear side 6 through the rear side plate 8. It is to be
noted that the plate heat exchanger according to the second
embodiment may comprise several such second outlet channels 27
extending from the outlet plate interspace 28.
[0047] As can be seen in FIG. 6, the heat exchanger plate 2, which
separates the first outermost secondary plate interspace 4' and the
outermost primary plate interspace 3, lacks portholes along the
primary inlet port channel 13 and the primary outlet port channel
14.
[0048] As also can be seen in FIG. 6, the outlet plate interspace
28 has a thickness which is significantly thicker than the
thickness of the secondary plate interspaces 4, 4'. For instance,
the outlet plate interspace 28 may have a thickness which is twice
as thick, or substantially twice as thick, as the thickness of the
secondary plate interspaces 4, 4'.
[0049] FIGS. 7-9 discloses a third embodiment of the invention,
which differs from the first and second embodiments in that the
plate heat exchanger lacks the outlet plate interspace 28 and in
that the second part space 31'' is provided separately from the
first part space 31, but connected to the latter and to the
influencing member 36 via the conduit 37'. Consequently one and the
same sensor medium is distributed in and between the two part space
31' and 31''.
[0050] In the third embodiment, the second part space 31'' is
provided in the second outlet port channel 24 which is a part of
the secondary outlet 22 and which is located downstream the
secondary plate interspaces 4, 4'. The second part space 31'' is
formed by a hollow closed element, for instance a tubular element,
which is provided in the secondary outlet port channel 24 in such a
way that the second part space 31'' adjoins and is surrounded by
the secondary medium. The second part space 31'' in the closed
element communicates with the first part space 31' via the conduit
37'. The sensor medium in the second part space 31'' will therefore
be in heat transfer contact with the secondary medium and
influenced by the outlet temperature of the secondary medium before
it leaves the plate heat exchanger along the whole, or
substantially the whole surface of the second part space 31'' or of
the tubular element forming and inclosing the second part space
31''.
[0051] In the third embodiment, the first part space 31' of the
space 31 will thus adjoin directly the rear side 6 and possibly the
rear side plate 8.
[0052] The invention is not limited to the embodiments disclosed
but may be varied and modified within the scope of the following
claims.
[0053] In the embodiments disclosed, the plate heat exchanger is
configured for counter flow flowing of the primary medium and the
secondary medium. It is possible to configure the plate heat
exchanger according to other flowing principles, such as parallel
flowing or flowing in the same direction. Furthermore, the primary
inlet port channel 13 and the primary outlet port channel 14 may be
located diagonally, and not straight above each other as disclosed
in the figures. The same apply also to the secondary inlet port
channel 23 and the secondary outlet port channel 24.
* * * * *