US20140216681A1

US20140216681A1 - Cooling assembly

Info

Publication number: US20140216681A1
Application number: US14/172,280
Authority: US
Inventors: Jorma MANNINEN; Timo Koivuluoma; Jaakko Lehto
Original assignee: ABB Oy
Current assignee: ABB Schweiz AG
Priority date: 2013-02-04
Filing date: 2014-02-04
Publication date: 2014-08-07
Also published as: EP2762796A1; CN103974602A; CN103974602B

Abstract

A cooling assembly includes a device chamber, a cooling chamber separated from the device chamber, a heat exchanger, a device chamber fan arrangement and a control unit. The heat exchanger includes a first portion located in the device chamber and a second portion located in the cooling chamber for transferring heat from the device chamber to the cooling chamber. The device chamber fan arrangement is configured to generate a device chamber cooling medium flow including a first partial flow interacting with the first portion of the heat exchanger. The cooling assembly also includes a first throttle arrangement for regulating the first partial flow. The control unit is configured to reduce a cooling power of the heat exchanger as a response to predetermined operating conditions by decreasing the first partial flow with the first throttle arrangement.

Description

RELATED APPLICATION

This application claims priority under 35 U.S.C. §119 to European Patent Application No. 13153787.0 filed in Europe on February 4, 2013, the entire content of which is hereby incorporated by reference in its entirety.

FIELD

The present disclosure relates to a cooling assembly including a heat exchanger for transferring heat from a device chamber.

BACKGROUND INFORMATION

Humidity is harmful to many electronic components. Humidity is an issue, for example, in solar power plants and wind power plants. Challenging environments such as tropical or arctic climates increase problems caused by humidity.
In a known cooling assembly, heating of a device chamber is used to prevent excessive humidity. It is also known to use water absorbing materials such as silica gel to remove humidity from a device chamber.
Preventing humidity by means of heating induces extra cost. Water absorbing materials are also expensive and their useful life is limited thereby further increasing cost.

SUMMARY

An exemplary embodiment of the present disclosure provides a cooling assembly which includes a device chamber, a cooling chamber separated from the device chamber, a heat exchanger, device chamber fan means, and control means. The heat exchanger includes a first portion located in the device chamber and a second portion located in the cooling chamber for transferring heat from the device chamber to the cooling chamber. The device chamber fan means are configured to generate a device chamber cooling medium flow including a first partial flow interacting with the first portion of the heat exchanger. The exemplary cooling assembly also includes first throttle means for regulating the first partial flow. The control means are configured to reduce a cooling power of the heat exchanger as a response to predetermined operating conditions by decreasing the first partial flow with the first throttle means.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional refinements, advantages and features of the present disclosure are described in more detail below with reference to exemplary embodiments illustrated in the drawings, in which:

FIG. 1 shows a cooling assembly according to an exemplary embodiment of the present disclosure;

FIG. 2 shows a cooling assembly according to an exemplary embodiment of the present disclosure; and

FIG. 3 shows a cooling assembly according to an exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION

Exemplary embodiments of the present disclosure provide a cooling assembly which is capable of alleviating disadvantages caused by humidity.
Exemplary embodiments of the present disclosure are based on the idea of decreasing in predetermined operating conditions a relative humidity level in a device chamber by reducing a cooling power of a heat exchanger configured to transfer heat from the device chamber. The cooling power is reduced by a first throttle means capable of regulating a first partial flow of a cooling medium interacting with a first portion of the heat exchanger located in the device chamber. Exemplary embodiments of the present disclosure improve controllability of a heat exchanger by lowering a minimum cooling power of the heat exchanger. Decreasing cooling power of the heat exchanger raises the temperature in a device chamber thereby reducing relative humidity.
An advantage of the cooling assembly of the present disclosure is that a relative humidity level inside a device chamber can be decreased with a very small operating cost.
FIG. 1 shows a cooling assembly including a device chamber 2, a cooling chamber 4, a heat exchanger 3, device chamber fan means, control means 6 (e.g., a computer processor configured to execute a computer program and/or computer-readable instructions tangibly recorded on a non-transitory computer-readable recording medium, such as a non-volatile memory), a humidity sensor 61, a temperature sensor 62, first throttle means 81, and an electrical apparatus 102. The cooling chamber 4 is separated from the device chamber 2. The heat exchanger 3 includes a first portion 31 located in the device chamber 2 and a second portion 32 located in the cooling chamber 4 for transferring heat from the device chamber 2 to the cooling chamber 4. The first portion 31 of the heat exchanger is in an operating situation located lower than the second portion 32 of the heat exchanger.
The device chamber fan means are configured to generate a device chamber cooling medium flow including a first partial flow interacting with the first portion 31 of the heat exchanger 3. As used herein, interaction between a cooling medium flow and a heat exchanger means heat transfer between the cooling medium flow and the heat exchanger. The first throttle means 81 are configured for regulating the first partial flow. The humidity sensor 61 is configured to detect a humidity level in the device chamber 2. The temperature sensor 62 is configured to detect a temperature in the device chamber 2.
The control means 6 are configured to reduce a cooling power of the heat exchanger 3 as a response to predetermined operating conditions by decreasing the first partial flow with the first throttle means 81. The first throttle means 81 are configured to regulate the first partial flow by adjusting a bypass flow of the cooling medium. The bypass flow is a portion of the device chamber cooling medium flow that bypasses the first portion 31 of the heat exchanger 3 without interaction. The predetermined operating conditions including a situation where the humidity sensor 61 detects a humidity level exceeding a predetermined threshold value in the device chamber 2, and a situation where the temperature sensor 62 detects a temperature below a predetermined threshold value in the device chamber 2. In accordance with an exemplary embodiment, a predetermined condition is defined as a function of humidity and temperature.
A wall 22 separates a first flow channel 71 from a second flow channel 72. The first portion 31 of the heat exchanger 3 is located in the first flow channel 71. The second flow channel 72 extends between the electrical apparatus 102 and the wall 22 bypassing the first portion 31 of the heat exchanger 3. There is an opening 24 in the wall 22 providing a passage between the first flow channel 71 and the second flow channel 72. According to an exemplary embodiment, the first throttle means 81 include a generally planar first valve plate 812 configured to pivot about a pivoting axis extending substantially parallel to a plane defined by the first valve plate 812. The pivoting axis passes through a lower edge of the first valve plate 812. The first valve plate 812 has a closed position and an open position. In the closed position, the first valve plate 812 closes the opening 24 in the wall 22. In FIG. 1, the closed position of the first valve plate 812 is depicted with a dashed line. In the open position, the first valve plate 812 allows a bypass flow of the cooling medium from the first flow channel 71 to the second flow channel 72 through the opening 24. In FIG. 1, the first valve plate 812 is in the open position.
In accordance with an exemplary embodiment, the first valve plate 812 only has two positions, the open position and the closed position. In other exemplary embodiments, the first throttle means may have more than two positions including at least one intermediate position between an open position and a closed position. Alternatively, the control means may be configured to alternate the position of the first throttle means between an open position and a closed position in order to provide an average bypass flow of the cooling medium smaller than the bypass flow corresponding to the open position of the first throttle means.
According to an exemplary embodiment, the heat exchanger 3 is a cothex type heat exchanger. A cothex is a thermosyphon heat exchanger where a cooling medium circulates by means of natural convection without a mechanical pump. In another exemplary embodiment, a heat exchanger configured to transfer heat from the device chamber to the cooling chamber may include another type of passive heat exchanger, or an active heat exchanger.
The electrical apparatus 102 is provided with apparatus cooling fan means 51 (e.g., at least one fan) located inside a housing of the electrical apparatus 102 and configured for cooling the electrical apparatus 102. In the embodiment of FIG. 1, the device chamber fan means includes the apparatus cooling fan means 51.
One skilled in the art understands that relative humidity in the device chamber 2 could be slightly decreased by reducing power of apparatus cooling fan means 51. However, reducing a power of the apparatus cooling fan means 51 could lead to unfavourable heat distribution inside the electrical apparatus 102. Further, reducing a power of apparatus cooling fan means 51 could in fact increase relative humidity in some parts of the device chamber 2.
In another exemplary embodiment, the device chamber fan means can include at least one fan not belonging to the apparatus cooling fan means but specifically configured to generate a device chamber cooling medium flow. Such at least one fan may be located separately from the electrical apparatus.
In accordance with an exemplary embodiment, the electrical apparatus 102 includes a frequency converter. In another exemplary embodiment, an electrical apparatus located in the device chamber may include an inverter or some other heat generating apparatus that requires cooling.
In the exemplary embodiment of FIG. 1, the device chamber cooling medium flow always includes some bypass flow of the cooling medium irrespective of operation of the first throttle means 81. In the closed position of the first valve plate 812, a bypass flow passes through the second flow channel 72 and a third flow channel 73 extending between the electrical apparatus 102 and an inner wall of the device chamber 2.
In accordance with another exemplary embodiment, a closed position of first throttle means substantially prevents a bypass flow of the cooling medium. The bypass flow is a portion of the device chamber cooling medium flow that bypasses the first portion of the heat exchanger without interaction. For example, blocking the second flow channel 72 and the third flow channel 73 in the cooling assembly of FIG. 1 would provide such an embodiment.
The cooling assembly further includes second throttle means 82 and cooling chamber fan means 52 (e.g., at least one fan and/or a ventilation arrangement) for regulating a cooling chamber cooling medium flow interacting with the second portion 32 of the heat exchanger 3. The control means 6 are configured to reduce a cooling power of the heat exchanger 3 as a response to predetermined operating conditions by decreasing the cooling chamber cooling medium flow by controlling the second throttle means 82 and the cooling chamber fan means 52.
The device chamber 2 is separated from the cooling chamber 4 such that there is substantially no cooling medium flow between the device chamber 2 and the cooling chamber 4. Therefore, substantially no contaminant particles can pass from the cooling chamber 4 into the device chamber 2. According to an exemplary embodiment, the cooling medium in the cooling chamber 4 as well as in the device chamber 2 is air.
A wall 42 separates a first portion 401 of the cooling chamber 4 from a second portion 402 of the cooling chamber 4. The first portion 401 of the cooling chamber 4 includes the second portion 32 of the heat exchanger 3. The second portion 402 of the cooling chamber 4 includes the cooling chamber fan means 52. The second portion 402 is in an operating situation located above the first portion 401. There is an opening 44 in the wall 42 providing a passage between the first portion 401 of the cooling chamber 4 and the second portion 402 of the cooling chamber 4.
According to an exemplary embodiment, the second throttle means 82 include a generally planar second valve plate 822 configured to pivot about a pivoting axis extending substantially parallel to a plane defined by the second valve plate 822. The pivoting axis passes through an upper edge of the second valve plate 822. The second valve plate 822 has a closed position and an open position. In the closed position, the second valve plate 822 closes the opening 44 in the wall 42. In FIG. 1, the closed position of the second valve plate 822 is depicted with a dashed line. In the open position depicted in FIG. 1, the second valve plate 822 allows a flow of cooling medium from the first portion 401 of the cooling chamber 4 to the second portion 402 of the cooling chamber 4 through the opening 44. The open position of the second valve plate 822 increases a cooling power of the heat exchanger 3 compared to the closed position of the second valve plate 822, because a lower part of the first portion 401 of the cooling chamber 4 and the second portion 402 of the cooling chamber 4 include openings allowing the cooling medium to flow between exterior of the cooling assembly and the cooling chamber 4. Consequently, the open position of the second valve plate 822 induces a draught in the cooling chamber 4 during operation of the cooling assembly.
When the control means 6 detect an operating condition that requires or allows reducing cooling power of the heat exchanger 3, the control means 6 turns off the cooling chamber fan means 52. If the turning off of the cooling chamber fan means 52 does not reduce a cooling power of the heat exchanger 3 enough the control means 6 opens the first valve plate 812 and/or closes the second valve plate 822.
In the embodiment of FIG. 1, the first throttle means 81 include only one valve member, namely the first valve plate 812. In another exemplary embodiment, first throttle means may include a plurality of valve members. For example, FIG. 2 shows a cooling assembly in which first throttle means 81′ include a first adjustable grill 816′ and a second adjustable grill 836′. The first adjustable grill 816′ includes a plurality of louvers 861′, and the second adjustable grill 836′ includes a plurality of louvers 862′.
The first adjustable grill 816′ is located in an opening 24′ in a wall 22′, and is configured to regulate a cooling medium flow through the opening 24′. The second adjustable grill 836′ is located adjacent to an upper surface of the first portion 31′ of the heat exchanger 3′. The control means 6′ are configured to control both the first adjustable grill 816′ and the second adjustable grill 836′. A first partial flow interacting with the first portion 31′ of the heat exchanger 3′ is minimized by an open position of the first adjustable grill 816′ and a closed position of the second adjustable grill 836′. The first partial flow is maximized by a closed position of the first adjustable grill 816′ and an open position of the second adjustable grill 836′.
The control means 6′ are configured to steplessly control the first adjustable grill 816′ and the second adjustable grill 836′. In FIG. 2, both the first adjustable grill 816′ and the second adjustable grill 836′ are in an intermediate position between an open and closed position.
A type of valve member of the first throttle means and second throttle means is not limited to a planar valve plate and an adjustable grill. FIG. 3 shows a cooling assembly in which first throttle means 81″ include a cylindrical valve 814″ whose valve surface has a general form of a cylindrical segment. The valve surface of the cylindrical valve 814″ is configured to pivot about a pivoting axis extending substantially parallel to an axis of the cylindrical segment. The control means 6″ are configured to steplessly control the cylindrical valve 814″.
It should be noticed that although both second throttle means 82′ of FIG. 2 and second throttle means 82″ of FIG. 3 include a generally planar second valve plate, the second throttle means may alternatively include an adjustable grill, a cylindrical valve, or any other suitable valve member.
Except for the first throttle means, the cooling assemblies of FIGS. 1 to 3 are quite similar. The only further significant difference relates to a wall separating a first flow channel from a second flow channel. For example, in the cooling assembly of FIG. 3, the segments of wall 22″ located adjacent the cylindrical valve 814″ are inclined towards the cylindrical valve 814″ in order to better co-operate with it. The wall segments have been inclined because of a relatively long radius of the cylindrical valve 814″ and a relatively short distance between a wall 22″ and an electrical apparatus 102″.
In accordance with an exemplary embodiment, a cooling assembly includes heating means (e.g., a heater) for heating the device chamber. In this embodiment, the control means are configured to decrease the first partial flow with the first throttle means when the heating means are in use. Such operation improves efficiency of the heating by reducing heat loss from the device chamber.
It will be appreciated by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restricted. The scope of the invention is indicated by the appended claims rather than the foregoing description and all changes that come within the meaning and range and equivalence thereof are intended to be embraced therein.

Claims

What is claimed is:

1. A cooling assembly comprising: a device chamber;

a cooling chamber separated from the device chamber;

a heat exchanger;

device chamber fan means; and

control means, wherein:

the heat exchanger comprises a first portion located in the device chamber and a second portion located in the cooling chamber for transferring heat from the device chamber to the cooling chamber;

the device chamber fan means are configured to generate a device chamber cooling medium flow including a first partial flow interacting with the first portion of the heat exchanger;

the cooling assembly comprises first throttle means for regulating the first partial flow;

the control means are configured to reduce a cooling power of the heat exchanger as a response to predetermined operating conditions by decreasing the first partial flow with the first throttle means.

2. A cooling assembly according to claim 1, wherein the cooling assembly comprises a humidity sensor configured to detect a humidity level in the device chamber, and

wherein the predetermined operating conditions comprise a situation where the humidity sensor detects a humidity level exceeding a predetermined threshold value in the device chamber.

3. A cooling assembly according to claim 2, wherein the cooling assembly comprises a temperature sensor configured to detect a temperature in the device chamber, and

wherein the predetermined operating conditions comprise a situation where the temperature sensor detects a temperature below a predetermined threshold value in the device chamber.

4. A cooling assembly according to claim 1, wherein the cooling assembly comprises a temperature sensor configured to detect a temperature in the device chamber, and

5. A cooling assembly according to claim 1, wherein the first throttle means are configured to regulate the first partial flow by adjusting a bypass flow of the cooling medium, the bypass flow being a portion of the device chamber cooling medium flow that bypasses the first portion of the heat exchanger without interaction.

6. A cooling assembly according to claim 1, wherein the first throttle means comprise a generally planar first valve plate configured to pivot about a pivoting axis extending substantially parallel to a plane defined by the first valve plate.

7. A cooling assembly according to claim 1, wherein the first throttle means comprise a cylindrical valve whose valve surface has a general form of a cylindrical segment, the valve surface being configured to pivot about a pivoting axis extending substantially parallel to an axis of the cylindrical segment.

8. A cooling assembly according to claim 1, wherein the first throttle means comprise a first adjustable grill with a plurality of louvers.

9. A cooling assembly according to claim 1, wherein the first portion of the heat exchanger is in an operating situation located lower than the second portion of the heat exchanger.

10. A cooling assembly according to claim 9, wherein the heat exchanger comprises a passive heat exchanger.

11. A cooling assembly according to claim 10, wherein the heat exchanger comprises a thermosyphon heat exchanger.

12. A cooling assembly according to claim 1, comprising:

second throttle means for regulating a cooling chamber cooling medium flow interacting with the second portion of the heat exchanger,

wherein the control means are configured to reduce a cooling power of the heat exchanger as a response to predetermined operating conditions by decreasing the cooling chamber cooling medium flow with the second throttle means.

13. A cooling assembly according to claim 1, comprising:

an electrical apparatus in the device chamber, the electrical apparatus having apparatus cooling fan means configured for cooling the electrical apparatus, the apparatus cooling fan means constituting at least part of the device chamber fan means.

14. A cooling assembly according to claim 13, wherein the device chamber fan means consists of the apparatus cooling fan means.

15. A cooling assembly according to claim 13, wherein the electrical apparatus comprises one of a frequency converter and an inverter.