U.S. patent application number 13/127170 was filed with the patent office on 2011-09-01 for climate control in a radio network node.
This patent application is currently assigned to TELEFONAKTIEBOLAGET LM ERICSSON (PUBL). Invention is credited to Klas Hedberg, Fredrik Jonsson.
Application Number | 20110209863 13/127170 |
Document ID | / |
Family ID | 40873257 |
Filed Date | 2011-09-01 |
United States Patent
Application |
20110209863 |
Kind Code |
A1 |
Jonsson; Fredrik ; et
al. |
September 1, 2011 |
Climate Control in a Radio Network Node
Abstract
The present invention relates to an arrangement (100) and a
method in a radio network node (400) for cooling electronic
equipment (102) within the arrangement (100). The arrangement (100)
comprises a closed space (104) for housing the electronic equipment
(102) and a heat exchanger (106) for transporting heat from the
closed space. A first flow regulating device (202) is arranged for
circulating a cooling fluid (204) within the closed space (104) and
a second flow regulating device (206) is arranged for circulating
an outer cooling fluid (208) outside (112) the closed space. The
arrangement (100) further comprises at least one sensor (301, 302,
303, 304, 305, 306) for measuring temperature in the arrangement
and a controller (210) for controlling at least one of the first
and second flow regulating devices (202, 206) based on at least one
temperature measurement from a fixed member (102, 104, 106, 112,
308) within the arrangement (100).
Inventors: |
Jonsson; Fredrik; (Bro,
SE) ; Hedberg; Klas; (Huddinge, SE) |
Assignee: |
TELEFONAKTIEBOLAGET LM ERICSSON
(PUBL)
Stockholm
SE
|
Family ID: |
40873257 |
Appl. No.: |
13/127170 |
Filed: |
November 3, 2008 |
PCT Filed: |
November 3, 2008 |
PCT NO: |
PCT/SE2008/051250 |
371 Date: |
May 2, 2011 |
Current U.S.
Class: |
165/287 ;
165/104.11 |
Current CPC
Class: |
H05K 7/206 20130101;
H05K 7/20609 20130101; H05K 7/207 20130101 |
Class at
Publication: |
165/287 ;
165/104.11 |
International
Class: |
F28F 27/00 20060101
F28F027/00; F28D 15/00 20060101 F28D015/00 |
Claims
1-13. (canceled)
14. An arrangement in a radio network node for cooling electronic
equipment within the arrangement, the arrangement comprising: wall
members defining a closed space within which the electronic
equipment is housed, a first flow regulating device configured to
circulate an inner cooling fluid within the closed space, a second
flow regulating device configured to circulate an outer cooling
fluid outside the closed space, a heat exchanger configured to
transport heat from the inner cooling fluid within the closed space
to the outer cooling fluid outside the closed space, at least one
sensor located on a fixed member within the arrangement and
configured to measure the temperature of that fixed member, and a
controller configured to control at least one of the first and
second flow regulating devices based on at least one temperature
measurement of said at least one sensor.
15. The arrangement according to claim 14, wherein the fixed member
comprises either: a measuring piece located within the arrangement,
any part of the electronic equipment, any part of the heat
exchanger, any of said wall members, or a combination thereof.
16. The arrangement according to claim 15, wherein the measuring
piece protrudes from the electronic equipment into the inner
cooling fluid in the closed space.
17. The arrangement according to claim 15, wherein the measuring
piece protrudes from an outside wall member into the outer cooling
fluid outside the closed space.
18. The arrangement according to claim 15, wherein the fixed member
comprises a heat sensitive part or by a heat sink on the electronic
equipment.
19. The arrangement according to claim 15, wherein the fixed member
comprises a first portion of the heat exchanger located in the
closed space.
20. The arrangement according to claim 15, wherein the fixed member
comprises a second portion of the heat exchanger located outside
the closed space.
21. The arrangement according to claim 20, wherein the second
portion of the heat exchanger and the second flow regulating device
are in contact with the ambient air.
22. The arrangement according to claim 15, wherein the fixed member
comprises a refrigerant fluid circulating in the heat
exchanger.
23. The arrangement according to claim 22, wherein the at least one
sensor is a pressure sensor configured to indirectly measure the
temperature of the fixed member.
24. The arrangement according to claim 14, wherein the at least one
sensor is a temperature sensor.
25. The arrangement according to claim 14, wherein the radio
network node is a radio base station.
26. A method in a radio network node arrangement for cooling
electronic equipment within the arrangement, the arrangement
comprising wall members defining a closed space within which the
electronic equipment is housed, a first flow regulating device
configured to circulate an inner cooling fluid within the closed
space, a second flow regulating device configured to circulate an
outer cooling fluid outside the closed space, and a heat exchanger
configured to transport heat from the inner cooling fluid within
the closed space to the outer cooling fluid outside the closed
space, and wherein the method comprises: measuring the temperature
of a fixed member within the arrangement with at least one sensor,
and controlling at least one of the first and second flow
regulating devices based on at least one temperature measurement of
the at least one sensor.
27. The method according to claim 26, wherein the fixed member
comprises either: a measuring piece located within the arrangement,
any part of the electronic equipment, any part of the heat
exchanger, any of said wall members, or a combination thereof.
28. The method according to claim 27, wherein the measuring piece
protrudes from the electronic equipment into the inner cooling
fluid in the closed space.
29. The method according to claim 27, wherein the measuring piece
protrudes from an outside wall member into the outer cooling fluid
outside the closed space.
30. The method according to claim 27, wherein the fixed member
comprises a heat sensitive part or by a heat sink on the electronic
equipment.
31. The method according to claim 27, wherein the fixed member
comprises a first portion of the heat exchanger located in the
closed space.
32. The method according to claim 27, wherein the fixed member
comprises a second portion of the heat exchanger located outside
the closed space.
33. The method according to claim 26, wherein the at least one
sensor is a temperature sensor.
Description
TECHNICAL FIELD
[0001] The present invention relates to an arrangement and a method
in a radio network node for cooling electronic equipment within the
radio network node.
BACKGROUND
[0002] Generally, a radio communication system of today comprises
an access network and a number of communication devices. The access
network is built up of several nodes, in particular, radio base
stations. The primary task of a radio base station is to send and
receive information to/from the communication devices within reach
of the radio base station. In many cases, the base station is run
24 hours a day. Therefore, it is of particular interest and
importance to ensure that the base station is operable predictably
and reliably. The radio base station further comprises a cabinet,
which comprises an enclosure for housing circuitry, or electronic
equipment, for performing different tasks of the radio base
station. For example, the circuitry may comprise a power control
unit, a radio unit and a filtering unit for performing
corresponding tasks.
[0003] Due to extensive operation of the radio base station, heat
generated in the circuitry of the base station, in particular the
radio unit, may not always dissipate naturally to a sufficiently
high degree. Instead, heat is accumulated in the circuitry and
temperature of the circuitry increases. The increased temperature
of the circuitry may decrease the performance of circuitry within
the radio base station, e.g. the circuitry within the radio base
station may fail. Consequently, unpredicted interruptions in
operation of the base station may occur. This is clearly not
desired.
[0004] Hence, as is known in the art, systems for cooling of heat
generating equipment within a radio base station have been
developed. These systems are sometimes referred to as climate
systems or climate control systems for radio base stations.
[0005] According to a known technique for cooling heat generating
equipment in radio base stations, fans are used to circulate air
through or over the heat generating equipment and through or over
one side of a heat exchanger (i.e. an internal side within the
enclosure). Moreover, further fans are used to force ambient air
through or over the other side of the heat exchanger (i.e. an
external side within the cabinet). The heat exchanger comprises a
refrigerant that absorbs heat from the air, heated by the
electronic equipment, at the internal side within the enclosure. As
a result, a transition from liquid phase to gas phase of the
refrigerant occurs. The portion of the heat exchanger that is
located at the internal side within the enclosure is called
evaporator. The gas is, by evaporation, forced to the external side
of the heat exchanger, where it dissipates heat to ambient air. As
a result, a transition from gas phase to liquid phase of the
refrigerant occurs in the external side of the heat exchanger. The
portion of the heat exchanger that is located on the external side
is called condenser. At this stage, gravity forces the liquid to
flow towards the evaporator.
[0006] An example of the known technique for cooling is disclosed
in U.S. Pat. No. 6,026,891, which document relates to a cooling
device for use in a radio base station and which comprises means
for cooling an interior of a housing for accommodating a heat
generating member such as an electronic component part. In the
prior art, heat transfer from the heat generating electronic
equipment inside the housing is performed by using a heat exchanger
including a boiling and condensing refrigerant. To improve the
cooling capacity, air regulating devices, e.g. fans, are used to
force the air on both or either sides of the heat exchanger.
[0007] The device further comprises a controller for controlling
the entire operation of the cooling device and a sensor for
detecting an air temperature in the housing and transmitting a
signal of the detected air temperature to the controller. The
normal control mode is to regulate the speed of each air regulating
device as a function of the air temperature inside the housing.
[0008] However, to measure the relevant and correct air temperature
is difficult since an air temperature sensor normally measures the
temperature in a point, and the air temperature can be uneven.
Further, the air temperature sensor can also be influenced by
radiation and local heat sources, e.g. a heater, which is an
increasing problem with future very compact climate systems.
SUMMARY
[0009] It is an object of the present invention to alleviate at
least some of the above disadvantages and provide an improved
arrangement and method for cooling in a radio network node.
[0010] According to a first aspect of the invention the object is
achieved by an arrangement for controlling the cooling of
electronic equipment in a radio network node. The arrangement
comprises a closed space for housing the electronic equipment and a
heat exchanger for transporting heat from the closed space. A first
flow regulating device is arranged for circulating a cooling fluid
within the closed space and a second flow regulating device is
arranged for circulating a cooling fluid outside the closed space.
The arrangement further comprises at least one sensor for measuring
temperature in the arrangement and a controller for controlling at
least one of the first and second flow regulating devices based on
at least one temperature measurement, wherein the at least one
sensor is located on a fixed member within the arrangement.
[0011] According to a second aspect of the invention the object is
achieved by a method in a radio network node arrangement for
cooling electronic equipment within the arrangement. The
arrangement comprises a closed space for housing the electronic
equipment and a heat exchanger for transporting heat from the
closed space. The arrangement further comprises a first flow
regulating device for circulating a cooling fluid within the closed
space and a second flow regulating device for circulating a cooling
fluid outside the closed space. At least one sensor measures at
least one temperature on a fixed member within the arrangement. A
controller receives the at least one measured temperature and
controls at least one of the first and second flow regulating
devices based on that temperature(s).
[0012] An advantage of the present invention is that the
temperature used in accordance with the present invention for
controlling the at least one of the first and second flow
regulating devices is a stable temperature safe from influences
such as radiation and/or local heat sources, e.g. heaters. By
measuring a temperature on a fixed member within the arrangement, a
reliable and stable value is provided to the controller used for
controlling the flow regulating devices. This results in an
efficient, reliable and improved cooling of electronic equipment
within a radio network node in accordance with the object of the
present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The various aspects of the invention, including its
particular features and advantages, will be readily understood from
the following detailed description and the accompanying drawings,
in which
[0014] FIG. 1 illustrates a schematic block diagram of parts within
the arrangement within a network node according to the invention,
and
[0015] FIG. 2 is a flow chart showing the methods according to the
invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0016] FIG. 1 shows an arrangement 100 in a radio network node 400
for cooling electronic equipment 102 within the arrangement 100.
The arrangement comprises a closed space 104, defined by wall
members 104 of the closed space for housing the electronic
equipment 102. The arrangement 100 further comprises a heat
exchanger 106 for transporting heat from the closed space 104 to
outside 112 of the closed space. The heat exchanger 106 may
comprise of one or several heat exchangers in series or in
parallel.
[0017] A first flow regulating device 202 is arranged for
circulating a cooling fluid 204 within the closed space 104. The
heat exchanger 106 takes up heat from the cooling fluid 204 within
the closed space and dissipates it outside 112 the closed space. A
second flow regulating device 206 is arranged for circulating an
outer cooling fluid 208 outside 112 the closed space. The flow
regulating devices 202, 206 may be for example fans. The fluid
regulating devices 202, 206 are regulated by a controller 210
connected to the first and second flow regulating devices
respectively. The controller 210 is preferably located within the
closed space in the vicinity of the first flow regulating device
202. The arrangement 100 further comprises at least one sensor 301,
302, 303, 304, 305, 306 for measuring temperature within the closed
space 104 or outside 112 the closed space.
[0018] In the embodiment shown in FIG. 1, the heat exchanger 106
includes a boiling and condensing refrigerant i.e. a refrigerant
fluid, referred to as arrow 109. The heat exchanger 106 has a first
portion 107 located within the closed space 104. This first portion
107 of the heat exchanger 106 is an evaporator. In the first
portion 107 the refrigerant fluid 109 evaporates and takes up heat
energy from the cooling fluid 204 that has been warmed up by the
electronic equipment 102 inside the closed space 104. The heat
exchanger 106 also has a second portion 108 located outside 112 the
closed space 104. The second portion 108 of the heat exchanger is a
condenser. In the second portion 108 the refrigerant fluid 109 is
condensed and heat is dissipated to the outer cooling fluid 208
outside 112 of the closed space. The refrigerant flow 109 between
the first portion 107 and the second portion 108 is generated
either by gravitation from the density difference between liquid
and gas phases of the refrigerant, as in a thermosiphon or by
gravitation and capillary forces, as in a heat pipe. The first and
second fluid regulating devices 202, 206 are used to force the
cooling fluids in directions indicated by arrows 204, 208 on both
or either sides of the heat exchanger 106 to improve the cooling
capacity.
[0019] The cooling of the electronic equipment 102 within the
arrangement is controlled by controlling at least one of the first
and second flow regulating devices 202, 206 based on at least one
temperature measurement wherein the at least one sensor 301, 302,
303, 304, 305, 306 is located on a fixed member 102, 104, 106, 112,
308 within the arrangement 100.
[0020] The sensors 301, 302, 303, 304, 305, 306 shown in FIG. 1 are
shown for illustrative purpose and it is to be understood that
still further sensors may be positioned on further fixed members
within the arrangement 100.
[0021] The fixed member may be represented by [0022] a measuring
piece 308 located within the arrangement 100, [0023] any part of
the electronic equipment 102, [0024] any part of the heat exchanger
106, 107, 108 [0025] a wall member 104, 112 of the arrangement 100
or a combination thereof. By measuring a temperature on a fixed
member within the arrangement 100, a reliable and stable value is
provided to the controller 210 used for controlling the flow
regulating devices 202, 206. This results in an efficient, reliable
and improved cooling of electronic equipment 102 within the network
node 400.
[0026] In an embodiment of the invention, the measuring piece 308
protrudes from the electronic equipment 102 into the cooling fluid
204 in the closed space 104. An advantage with this embodiment is
that the change in temperature of the measuring piece involves a
certain inertia or delay, which means that measuring piece 308 will
have a similar temperature to that in the electronic equipment 102
during a cold start up.
[0027] In a further embodiment of the invention (not shown in FIG.
1), the measuring piece 308 protrudes from an outside 112 wall
member into the outer cooling fluid 208 outside the closed space.
By regulating the cooling performance with an external sensor in
combination with any of the other suggested sensors gives the
possibility to chose the most efficient and appropriate cooling
mode. For example, at lower ambient temperatures it is very
efficient to start the second flow regulating device 206 and take
the temperature inside the closed space 104 down, whereas at higher
ambient temperatures in a situation when the interior is already
close to the ambient it will be less noisy to speed up the first
flow regulating device 202. For arrangements in which the heat
dissipation can vary drastically, as is the case in the radio
network node 400 this controlling arrangement makes it possible to
optimize the cooling depending on heat dissipation and ambient
conditions.
[0028] In an embodiment of the invention, the fixed member is
represented by a heat sensitive part of the electronic equipment or
a heat sink of the electronic equipment. A sensor 303, 305 may be
positioned for example on or near a temperature sensitive part of
the electronic equipment 102 or in a heat sink on the electronic
equipment. The equipment temperature is often the limiting factor
for the life length or reliability of the arrangement. The
equipment temperature depends on both the cooling fluid 204
temperature inside the closed space 104, the heat transfer to the
cooling fluid 204 inside the closed space and the heat dissipation
of the electronic equipment 102. By measuring the temperature of
the electronic equipment 102 all these factors are taken into
account. Also, in case of a sudden increase in heat generation
within the system, for example in a starting up mode, a fast
response from the cooling system can be achieved.
[0029] In an embodiment of the invention the fixed member 102, 104,
106, 112, 308 is represented by a first portion 107 of the heat
exchanger 106 located in the closed space 104. For measuring a
temperature of the first portion 107 of the heat exchanger a sensor
302 may be positioned somewhere on the piping of the first portion
107, the evaporator, of the heat exchanger 106 within the closed
space 104. The temperature of the evaporator piping on the internal
parts of the heat exchanger depends on the temperature of the
cooling fluid 204 inside the closed space, the fluid 208 outside
112 the closed space and how the fluid regulating devices are
regulated. The most significant influence of this temperature and
the capacity of the heat exchanger 106 is the amount of fluid flow
208 over the second portion 108 of the heat exchanger 106, possibly
generated by a the second fluid regulating device 206 outside the
closed space. The evaporator piping temperature gives an even value
temperature as heat is distributed in the material of the
piping.
[0030] In an embodiment of the invention, the fixed member 102,
104, 106, 112, 308 is represented by a second portion 108 of the
heat exchanger 106 located outside 112 the closed space. For
measuring a temperature of the second portion 108, the condenser,
of the heat exchanger 106 a sensor 301 can be positioned somewhere
on the condenser piping outside 112 the closed space. The
temperature of the condenser piping on the external parts of the
heat exchanger depends on the fluid flow 208 outside the
arrangement, the heat transfer in the heat exchanger 106 and how
the fluid regulating devices 202, 206 are regulated. Normally, the
fluid flow 208 outside the arrangement 100 is the ambient air.
[0031] In an embodiment of the invention, the fixed member 102,
104, 106, 112, 308 is represented by a refrigerant fluid 109
circulating in the heat exchanger 106. For measuring a temperature
of the refrigerant fluid 109 within the heat exchanger 106 a sensor
304 may be positioned somewhere on the inside or on the outside of
the piping of the first portion 107 of the heat exchanger 106. The
refrigerant 109 temperature is slightly lower than the mean
temperature of the cooling fluid 204 that has passed through or
over the first portion 107 and slightly higher than the mean
temperature of the cooling fluid 208 surrounding or that has passed
through or over the second portion 108 of the heat exchanger 106.
The refrigerant 109 temperature is a stable temperature safe from
influences such as radiation and/or local heat sources (heaters).
It also gives a mean value of the cooling fluid 204 temperature
over the first portion 107 of the heat exchanger 106.
[0032] In an embodiment of the invention the sensor is a
temperature sensor.
[0033] In another embodiment of the invention the sensor is a
pressure sensor for indirectly measuring the temperature. For
example, for measuring the temperature of the refrigerant fluid a
pressure sensor may be used. By determining pressure in the
refrigerant fluid 109 circuit, the temperature of the refrigerant
fluid can be established. Since there is always a saturated
condition in the refrigerant circuit 109, the relation between
temperature and pressure for a chosen refrigerant can be
established through reference data for each refrigerant.
[0034] The dotted line having reference number 112 illustrates wall
members outside 112 the closed space. The second portion 108 of the
heat exchanger 106 and the second flow regulation device 206 are
located outside 112 the closed space and are in contact with the
ambient air.
[0035] The method steps in the arrangement 100 for controlling
cooling of electronic equipment 102 in a radio network node
arrangement 100 will now be described with reference to a flow
chart depicted in FIG. 2. As mentioned above, the arrangement 100
comprises a closed space 104 for housing the electronic equipment
102, a heat exchanger 106 for transporting heat from the closed
space and a first flow regulating device 202 for circulating a
cooling fluid 204 within the closed space 104 and a second flow
regulating device 206 for circulating an outer cooling fluid 208
outside 112 the closed space. [0036] 301. At least one sensor
measures a temperature on a fixed member within the arrangement.
[0037] 302. At least one of the first and second flow regulating
devices are controlled based on at least one temperature
measurement.
[0038] According to the method of the present invention, at least
one temperature is measured on a fixed member 102, 104, 106, 112,
308 in the arrangement 100 wherein a reliable and stable value is
provided to the controller 210 used for controlling the flow
regulating devices 202, 204. This results in an efficient and
reliable cooling of the electronic equipment 102 within the radio
network node 400.
[0039] Even though the invention has been described with reference
to specific exemplifying embodiments thereof, many different
alterations, modifications and the like will become apparent for
those skilled in the art. The described embodiments are therefore
not intended to limit the scope of the invention, which is defined
by the appended claims.
DEFINITIONS
[0040] In this application the term fixed member is used. The
expression fixed member shall be interpreted to mean any member of
a radio network node arrangement, inside the closed space or
outside the closed space that has a solid, semi-solid or liquid
phase, such as any part of the electronic equipment, any part of
the heat exchanger, the flow generating devices, any part of the
construction elements of the arrangement, for example wall members,
racks for holding equipment as well as batteries and battery
compartments within the arrangement.
[0041] Further, the fixed member may be a piece of material without
any practical or mechanical function but located within the
arrangement to act as a measuring piece, protruding slightly from
its fixing point and made of preferably a metallic, polymeric or
composite material.
[0042] It is to be understood that the heat exchanger may be an
air-to-air heat exchanger, for example a plate heat exchanger, or a
boiling and condensing heat exchanger comprising a refrigerant
fluid.
[0043] It is to be understood that the radio network node may be a
Radio Base Station (RBS) or any other kind of node in a radio
communication system, which node comprises heat generating
electronic equipment. Examples of other kinds of nodes are
transmission nodes, Remote Subscriber Switches (RSS) and nodes with
similar functionality.
[0044] When using the word "comprise" or "comprising" it shall be
interpreted as non-limiting, in the meaning of "consist at least
of".
* * * * *