EP2935823A1

EP2935823A1 - Modular system for forming an expansion tank

Info

Publication number: EP2935823A1
Application number: EP13865365.4A
Authority: EP
Inventors: Zoltan Kardos; Thomas HÄLLQVIST
Original assignee: Scania CV AB
Current assignee: Scania CV AB
Priority date: 2012-12-20
Filing date: 2013-11-27
Publication date: 2015-10-28
Also published as: KR20150091174A; BR112015014812A2; RU2015129491A; WO2014098713A1; CN104870771A; SE1251471A1; EP2935823A4; SE536829C2

Abstract

Modular system for forming an expansion tank (1) com prising a base module (10), a first superstructure module (30) interconnectible with the base module, and a second superstructure module (40) interconnectible with the first superstructure module, such that each one of these modules have a housing (11, 31, 41) and an expansion chamber (1 2, 32, 42) arranged inside the housing. One or several fluid passages are arranged in a wall (22) of the base module's housing to allow fluid exchange between the base module's expansion chamber (12) and the first superstructure module's expansion chamber (32). One or several fluid passages are also arranged inside a wall (35) of the first superstructure module's housing to allow fluid exchange between the first superstructure module's expansion chamber (32) and the second superstructure module's expansion chamber (42).

Description

Modular system for forming an expansion tank

FIELD OF TH E I NVENTION AN D PR IOR ART The present invention relates to a modular system according to the preamble of patent claim 1 , for forming an expansion tank intended to be included in a cooling system of a motor vehicle.

A combustion engine in a vehicle is cooled with coolant that circulates in a cooling system . When the combustion engine is in operation , it emits heat to the coolant which is thus heated and expands. The total increase in volume that arises in the coolant in the vehicle's cooling system may amount to several litres and depends on the original coolant volume and the current temperature increase. In order to avoid a too heavy surge in pressure in the cooling system , the cooling system is equipped with an expansion tank that may receive the surplus of coolant arising when the coolant expands. The coolant's boiling point increases with the increased pressure and it is therefore desirable to maintain a certain overpressure in the cooling system when the combustion engine is in operation , thus to avoid boiling . In order to facilitate this and simultaneously prevent a dangerously high coolant pressure, the expansion tank is equipped with an overpressure vent, which ensures that the pressure i n the expansion tank may not exceed a predetermined pressure level . When the coolant, as a consequence of heating , expands, the existing air in the expansion tank is com pressed , increasing the pressure in the expansion tank and in the rest of the cooling system . When the combustion engine starts, it is desirable with a relatively quick pressure increase in the cooling system , so that the boiling point for the coolant may quickly achieve a suitably high level and boiling may be avoided . If the expansion tank contains a large air volume which must be compressed before the desired pressure increase is achieved , the desired boiling point increase in the coolant is delayed . For this reason, it is therefore suitable to use as small an expansion tank as possible. The expansion tank must, however, be sufficiently big to be able to receive the expanded coolant so that an undesirable coolant leakage into the environment via the overpressure valve of the expansion tank is avoided. Since the volume of the coolant in the vehicle's cooling system varies significantly depending on the vehicle type and depending on the equipment which is connected to the cooling system , different vehicles need expansion tanks of different sizes.

A modular system for forming an expansion tank is previously known through SE 469 849 B. This prior art modular system is specifically designed for the formation of an expansion tank of dual-chamber type and consists of two modules which are mutually interconnectible, with one module placed above the other module.

OBJ ECTIVE OF TH E INVENTION The objective of the present invention is to achieve a further development of a modular system of the type described above, providing a modular system with a design which, in at least some aspect, offers an advantage compared to this one. SU MMARY OF TH E I NVENTION

According to the present invention, the above-mentioned objective is achieved with the help of a modular system having the characteristics defined in patent claim 1 .

The modular system according to the invention comprises:

- a base module, with a housing and an expansion chamber delimited by the housing ,

- a first superstructure module, with a housing and an expansion chamber inside the housing and which is interconnectible with the base module via a first coupling , comprising a first coupling part arranged on the base module and a corresponding second coupling part arranged on the first superstructure module, wherein one or several fluid passages are arranged in a wall of the base module's housing, providing for fluid exchange between the base module's expansion chamber and the first superstructure module's expansion chamber via this fl uid passage or these fluid passages, when the first superstructure module is connected with the base module, and

- a second superstructure module, with a housing and an expansion chamber arranged i nside the housing and which is interconnectible with the first superstructure module via a second coupling, comprising a first coupling part arranged on the first superstructure module and a corresponding second coupling part arranged on the second superstructure module, wherein one or several fluid passages are arranged in a wall in the first superstructure module's housing in order to provide for fluid exchange between the first superstructure module's expansion chamber and the second superstructure module's expansion chamber via this fluid passage or these fluid passages ,when the second superstructure module is connected with the first superstructure module. The base module may be used independently, i.e. without any superstructure module connected to the base module, as an expansion tank in cases where only one expansion tank with a small expansion volume is needed. Where an expansion tank with a larger expansion volume is needed , the base module may be expanded with the desired number of superstructure modules dependi ng on the required expansion volume. Thus, possibilities are created , in a simple and cost effective manner, to adapt the size of the expansion tank to the volume of the coolant in the cooling system to which the expansion tank is to be connected , so that one and the same set of modules may be used to achieve expansion tanks of very different sizes.

According to one embodiment of the invention , an overpressure vent and a return valve are arranged on the said wall of the base module, wherein fluid transfer from the base module's expansion chamber to the first superstructure module's expansion chamber is allowed via this overpressure vent and fluid transfer from the first superstructure module's expansion chamber to the base module's expansion chamber is allowed via this return valve, when the first superstructure module is connected with the base module. Since the fluid exchange between the base module and the superstructure module is via an overpressure vent and a return valve, it is only the air volume in the base module that needs to be compressed by the expanding coolant in order for the desired overpressure i n the cooling system to be achieved , also in cases where the base module is enlarged with one or several superstructure modules. Thus it is possible to quickly achieve the desired pressure increase in the cooling system, independently of the total size of the expansion tank. When the volume increase of the coolant has become so extensive that the entire expansion chamber of the base module is filled with coolant, the coolant wil l, via said overpressure vent, flow from the base module to the first superstructure module. When the coolant in the cooling system eventually cools down , the volume of the coolant is reduced, which in turn gives rise to an underpressure in the base module's expansion chamber, which may be used to such back coolant from the first superstructure module to the base module, via said return valve.

According to another embodiment of the i nvention , said return valve in the base module is connected via a pipe to the lower part of the first superstructure module's expansion chamber, when the first superstructure module is connected with the base module. Thus, the coolant which has flowed out from the base module to the first superstructure module may be sucked back to the base module via said return valve, also when the modular system has such a design that the first superstructure module is connected with the base module in a horizontal direction , i .e. when the base module is expanded sideways by the first superstructure module.

According to another embodiment of the invention the side of the first superstructure module's housing , which is intended to be turned toward the base module, is open. In this case the wall of the base module's housing , which is facing the first superstructure module, operates as a partition wall between the base module's expansion chamber and the first superstructure module's expansion chamber, whereby the first superstructure module may be given a very simple and cost effective design.

According to another embodiment of the invention, the side of the second superstructure module's housing, which is intended to be facing the first superstructure, module is open. In this case, the wal l of the first superstructure module's housing , which is facing the second superstructure module, operates as a partition wall between the first superstructure module's expansion chamber and the second superstructure module's expansion chamber, whereby the second superstructure module may be given a very simple and cost effective design .

Other favourable features of the modular system according to the invention are set out in the non-independent patent claims and the description below. BR IEF DESCR IPTION OF DRAW I NGS

The invention is described below with the help of exam ple em bodiments, with reference to the enclosed drawings. Shown in :

Fig 1 is a perspective view obliquely from above, of a base module and two superstructure modules comprised in a modular system according to one embodiment of the present invention , is a perspective view obliquely from below, of the base module and the superstructure modules according to Fig 1 , Fig 3 is a side view of the base module and the superstructure modules according to Fig 1 , is a perspective view of an expansion tank formed by the base module and the superstructure modules according to Fig 1 -3,

Fig 5 is a longitudinal section through the expansion tank according to Fig 4, and Fig 6 is a perspective view of an expansion tank formed by the base module illustrated in Fig 1 -3.

DETAILED DESC R I PTION OF EM BODI M ENTS ACCO RD I NG TO TH E INVENTION

Fig 1 -3 illustrate a base module 1 0, a first superstructure module 30 and a second superstructure module 40 comprised in a modular system according to one embodiment of the present invention, for form ing an expansion tank intended to be included in a cooling system in a motor vehicle.

The base module includes a housing 1 1 and an expansion chamber 1 2 delimited by the housing (see Fig 5). The housing 1 1 of the base module is equipped with an outlet opening 1 3 (see Fig 5), intended to be connected to a coolant pipe in a cooling system to provide for exchange of coolant between the base module's expansion chamber 12 and other parts of the cooling system via this outlet opening 13. The outlet opening 13 is arranged at the bottom of the base module's expansion chamber 12. A pipe socket 14 connected with the outlet opening 13 protrudes from the bottom of the housing. Said coolant pipe is intended to be connected to this pipe socket 14.

The base module's housing 11 is equipped with two inlet openings 15, which are intended to be connected to a vent each in said cooling system, to provide for an inflow of coolant and air from the vent pipes to the base modules' expansion chamber 12 via these inlet openings. The inlet openings 15 are arranged in a side wall 16 of the housing 11. Each inlet opening 15 is connected to a pipe socket 17 protruding from the side wall 16 of the housing. Said vent pipes are intended to be connected to these pipe sockets 17. The base module's housing 11 may alternatively be equipped with only one inlet opening 15 for connection to a vent pipe in the cooling system.

The base module's housing 11 is also equipped with a sealable refill opening, through which coolant may be introduced into the base module's expansion chamber 12 in order thus to provide for refill of coolant to said cooling system. This refilling opening is sealed with the help of a releasable lid 18.

An overpressure valve 20 and a return valve 21 are arranged on a wall 22 of the base module's housing 11. In the illustrated embodiment, this wall 22 is a side wall of the housing 11. In the illustrated example, said valves 20, 21 are arranged at a distance from each other in one opening each in said wall 22, but they may alternatively be placed next to each other in a joint vent unit, is arranged in a larger opening in said wall 22. Via the overpressure valve 20, air and coolant are allowed to flow out from the upper part of the base module's expansion chamber 1 2 when, in connection with the increase in volume of the coolant, an overpressure arises in the expansion chamber 1 2 which is higher than a level given by the overpressure valve. Via the return valve 21 air, and in applicable cases coolant, is allowed to flow into the upper part of the base module's expansion chamber 1 2 when , in connection with a decrease in the coolant's volume, an under pressure arises in the expansion chamber 1 2 which is lower than a level given by the return valve. The first superstructure module 30 has a housing 31 and an expansion chamber 32 arranged inside the housing. The first superstructure module 30 is interconnectible with the base module 1 0 via a coupling comprising a fist coupling part 2a arranged on the base module 1 0 and a corresponding second coupling part 2b arranged on the first superstructure module 30, which is arranged to connect with the first coupling part 2a. The first coupling part 2a is frame shaped and extends around the above mentioned wall 22 of the base module's housing 1 1 , wherein the overpressure valve 20 and the return valve 21 are arranged inside the first coupling part 2a. The first coupling part 2a is fixedly connected with the base module's housing 1 1 and protrudes from the housi ng 1 1 at a right angle i n relation to said wal l 22. The second coupling part 2b is frame shaped and arranged to be inserted into the first coupling part 2a. The second coupling part 2b is fixedly connected with the superstructure module's housing 31 and designed to fit into the first coupling part 2a with a close fit. A sealing element 3 is arranged between the two coupling parts 2a, 2b, creating a fl uid tight connection between the base module 1 0 and the superstructure module 30 when these are connected with each other. In the illustrated example, this sealing element 3 is arranged in a groove on the outside of the second coupling part 2b. The base module 1 0 and the first superstructure module 30 are equipped with lock elements 4a, 4b, 5a, 5b which may be brought into interlocking engagement with one another in order to thus lock the first superstructure module 30 to the base module 1 0, when these are connected with each other via the coupling parts 2a, 2b.

In the illustrated embodiment, the fi rst superstructure module 30 is equipped with a hook shaped lock element 4b, arranged on the bottom of the superstructure module's housing 31 . This hook shaped lock element 4b is designed to engage with a rod shaped lock element 4a, arranged on the bottom of the base module's housing 1 1 .

In the illustrated embodiment, the fi rst superstructure module 30 is also equipped with a lock element 5b, arranged on the upper side of the superstructure module's housing 31 . This lock element 5b is designed to abut against a lock element 5a, arranged on the upper side of the base module's housing 1 1 . The two most recently mentioned lock elements 5a, 5b are intended to be secured together by means of a screw (not displayed) which may be inserted into a through-hole 6 in the superstructure module's lock element 5b, and may be screwed into a threaded hole 7 of the base module's lock element 5a. When the base module 1 0 and the first superstructure module 30 are connected with each other, a fluid exchange is al lowed between the base module's expansion chamber 1 2 and the first superstructure module's expansion chamber 32 via fl uid passages formed by the overpressure valve 20 and the return valve 21 in the wall 22 of the base module's housing 1 1 . Via the overpressure valve 20, air and coolant are allowed to flow from the base module's expansion chamber 1 2 to the first superstructure module's expansion chamber 32, and via the return valve 21 air and coolant are allowed to flow from the first superstructure module's expansion chamber 32 to the base module's expansion chamber 1 2. In order to allow coolant which has gathered on the bottom of the first superstructure module's expansion chamber 32 to be sucked back to the base module's expansion chamber 1 2, the return valve 21 is connected via a pipe 23 to the lower part of the first superstructure module's expansion chamber 32.

An overpressure valve 33 and a return valve 34 are arranged on a wall 35 of the first superstructure module's housing 31 . In the illustrated embodiment, this wall 35 is a side wall of the housing 31 . In the illustrated example, said valves 33, 34 are arranged at a distance from each other in one opening each in said wall 35, but they may alternatively be placed next to each other in a joint vent unit which is arranged in a larger opening in the said wall 35. Via the overpressure valve 33, air and coolant are allowed to flow out from the upper part of the first superstructure module's expansion chamber 32 when , in connection with the volume increase of the coolant, an overpressure arises in the expansion chamber 32 which is higher than a level given by the overpressure valve 33. Via the return valve 34 air, and in applicable cases coolant, is allowed to flow into the upper part of the fi rst superstructure module's expansion chamber 32 when , in connection with a decrease in the coolant's volume, an under pressure which is lower than a level given by the return valve 34 arises in the expansion cham ber 32.

The side of the first superstructure module's housing 31 , intended to face the base module 1 0, is advantageously open , as illustrated in Fig 2. In this case, the coupling part 2b extends around the edge of the opening 36 in the first superstructure module's housing 31 on the open side of the housing. When the base module 1 0 and the superstructure module 30 are connected with each other, the above mentioned wall 22 of the base module's housing 1 1 forms a partition wall between the first superstructure module's expansion chamber 32 and the base module's expansion chamber 1 2.

The second superstructure module 40 has a housing 41 and an expansion chamber 42 arranged inside the housing . The second superstructure module 40 is interconnectible with the first superstructure module 30 via a coupling comprising a first coupling part 2a arranged on the first superstructure module 30, and a corresponding second coupling part 2b arranged on the second superstructure module 40, which is arranged to engage with the first coupling part 2a. The first coupli ng part 2a is frame shaped and extends around the above mentioned wall 35 of the first superstructure module's housing 31 , so that the overpressure valve 33 and the return valve 34 are arranged inside the first coupling part 2a. The first coupling part 2a is fixedly connected with the first superstructure module's housing 31 and protrudes from the housing 31 at a right angle in relation to said wall 35. The second coupli ng part 2b is frame shaped and arranged to be inserted into the first coupling part 2a. The second coupling part 2b is fixedly connected with the second superstructure module's housing 41 and designed to fit into the first coupling part 2a with a close fit. A sealing element 3 is arranged between the two coupling parts 2a, 2b in order to create a fluid tight connection between the first superstructure module 30 and the second superstructure module 40, when these are connected with each other. In the illustrated example, this sealing element 3 is arranged in a groove on the outside of the second coupling part 2b.

The first superstructure module 30 and the second superstructure module 40 are equipped with lock elements 4a, 4b, 5a, 5b which may be brought into interlocking engagement with one another in order to thus lock the second superstructure module 40 to the first superstructure module 30, when these are connected with each other.

In the illustrated embodiment, the second superstructure module 40 is equipped with a hook shaped lock element 4b, arranged on the bottom of the second superstructure module's housing 41 . This hook shaped lock element 4b is designed to engage with a rod shaped lock element 4a, arranged on the bottom of the first superstructure module's housing 31 .

In the illustrated embodiment, the second superstructure module 40 is also equipped with a lock element 5b, arranged on the upper side of the superstructure module's housing 41 . This lock element 5b is designed to abut against a lock element 5a, arranged on the upper side of the first superstructure module's housing 31 . The two most recently mentioned lock elements 5a, 5b are intended to be secured together by means of a screw (not displayed) which may be inserted into a through-hole 6 in the second superstructure module's lock element 5b, and may be screwed into a threaded hole 7 of the first superstructure module's lock element 5a.

When the first superstructure module 30 and the second superstructure module 40 are connected with each other, a fluid exchange is allowed between the first superstructure module's expansion chamber 32 and the second superstructure module's expansion chamber 42 via fluid passages formed by the overpressure valve 33 and he return valve 34 in the wall 35 of the first superstructure module's housing 31 . Via the overpressure valve 33 air and coolant are allowed to flow from the first superstructure module's expansion chamber 32 to the second superstructure module's expansion chamber 42 and via the return valve 34 air and coolant are allowed to flow from the second superstructure module's expansion chamber 42 to the first superstructure module's expansion chamber 32. In order to allow coolant which has gathered at the bottom of the second superstructure module's expansion chamber 42 to be sucked back to the first superstructure module's expansion chamber 32, the return valve 34 is connected via a pipe 37 to the lower part of the second superstructure module's expansion chamber 42. An overpressure valve 43 and a return valve 44 are arranged on a wall 45 of the second superstructure module's housing 41 . In the illustrated embodiment, this wall 45 is a side wall of the housing 41 . In the illustrated example, said valves 43, 44 are arranged at a distance from each other in one opening each in said wall 45, but they may alternatively be placed next to each other in a joint vent unit, arranged in a larger opening in the said wal l 45. Via the overpressure valve 43, air and coolant are allowed to flow out from the upper part of the second superstructure module's expansion chamber 42 when , in connection with the volume increase of the coolant, an overpressure arises in the expansion chamber 42 which is higher than a level given by the overpressure valve 43. Via the return valve 44 air, and in applicable cases coolant, is allowed to flow into the upper part of the second superstructure module's expansion chamber 42 when, in connection with a decrease in the coolant's volume, an under pressure arises in the expansion chamber 42 which is lower than a level given by the return valve 44. The side in the second superstructure module's housing 41 which is intended to face the first superstructure module 30 is advantageously open, as illustrated in Fig 2. In this case, the coupling part 2b extends around the edge of the opening 46 in the second superstructure module's housing 41 on the open side of the housing. When the superstructure modules 30, 40 are connected with each other, the above mentioned wall 35 in the first superstructure module's housing 31 forms a partition wall between the second superstructure module's expansion chamber 42 and the first superstructure module's expansion chamber 32.

In the illustrated embodiment, the second superstructure module 40 has the same design as the first superstructure module 30. The modular system may also comprise one or several further superstructure modules with the same design as the first and second superstructure modules 30, 40 in order to facilitate connection of a greater number of superstructure modules for the forming of a larger expansion tank.

Fig 6 illustrates an expansion tank 1 formed by the base module 1 0, shown in Fig 1 -3. In this case, the pi pe 23 connected to the return valve 21 may potentially be removed .

Fig 4 and 5 ill ustrate an expansion tank 1 formed by the base module 1 0 and the two superstructure modules 30, 40 shown in Fig 1 -3. In this case, the pipe 47 connected to the return valve 44 may potentially be removed .

In order to facilitate fixing an expansion tank 1 formed by a modular system in a motor vehicle, the base module 1 0 is advantageously equipped with one or several brackets 24 arranged on the outside of the base module's housing 1 1 .

In the illustrated embodiment, the base module 1 0 and the superstructure modules 30, 40 have a rectangular cross sectional form . They could, however, naturally be designed in a different manner.

In the illustrated embodiment, the coupling parts 2a, 2b of the base module 1 0 and the superstructure modules 30, 40 are rectangular. The base module 1 0 could , however, as an alternative be interconnectible with the first superstructure module 30 via a coupling consisting of two circular coupling parts, which could for example be threaded in order to form a screw coupling or designed to form a bayonet coupling . Si milarly, the two superstructure modules 30, 40 could be interconnecti ble with each other via a coupling consisting of two circular coupling parts, which could for example be threaded in order to form a screw coupl ing or designed to form a bayonet coupling . In the event that the coupling parts form a screw or bayonet coupling , the modules 1 0, 30, 40 need not be equipped with separate lock elements 4a, 4b, 5a, 5b.

In the illustrated embodiment, the base module 1 0 and superstructure modules 30, 40 are designed to be connected to each other sideways, i .e. in a horizontal direction . As an alternative, however, the base module and the superstructure modules could be designed to be connected with each other one over the other, i .e. in a vertical direction . In the latter case the overpressure valves and the return valves m ust be arranged on the upper side of the base module's and the superstructure modules' housings.

The modular system according to the i nvention is intended to be used for the formation of an expansion tank for a cooling system in a heavy goods vehicle, such as a bus, a towing vehicle or a truck.

The invention is not limited in any way to the embodiments described above, but numerous possible modifications thereof should be obvious to a person skilled in the art, without such person departing from the spirit of the invention as defined by the appended patent claims.

Claims

PATENT CLAIMS

1 . Modular system for the formation of an expansion tank (1 ) intended to be comprised in a cooling system in a motor vehicle, which modular system comprises:

- a base module (1 0), with a housing ( 1 1 ) and an expansion chamber (1 2) delimited by the housing , and

- a first superstructure module (30), with a housing (31 ) and an expansion chamber (32) arranged inside the housing and which is interconnectible with the base module (1 0) via a first coupling comprising a first coupling part (2a) arranged on the base module (1 0) and a corresponding second coupling part (2b) arranged on the first superstructure module (30), wherein one or several fluid passages are arranged inside a wall (22) of the base module's housing (1 1 ) in order to allow fluid exchange between the base module's expansion chamber ( 1 2) and the first superstructure module's expansion chamber (32) via this fluid passage or these fluid passages, when the first superstructure module (30) is connected with the base module (1 0),

characterised by:

- the modular system comprising a second superstructure module (40) with a housing (41 ) and an expansion chamber (42) arranged inside the housing , and which is interconnectible with the first superstructure module (30) via a second coupling which comprises a first coupling part (2a) arranged on the first superstructure module (30) and a corresponding second coupling part (2b) arranged on the second superstructure module (40), and - one or several fluid passages being arranged in a wall (35) of the first superstructure module's housing (31 ) to allow fluid exchange between the first superstructure module's expansion chamber (32) and the second superstructure module's expansion cham ber (42) via this fluid passage or these fl uid passages, when the second superstructure module (40) is connected with the first superstructure module (30) .

Modular system according to claim 1 , characterised by an overpressure valve (20) and a return valve (21 ) being arranged on the said wall (22) of the base module's housing ( 1 1 ), so that fluid transfer from the base module's expansion chamber (1 2) to the first superstructure module's expansion chamber (32) is allowed via this overpressure valve (20) and fluid transfer from the first superstructure module's expansion chamber (32) to the base module's expansion chamber (1 2) is allowed via this return valve (21 ), when the first superstructure module (30) is connected with the base module ( 1 0).

Modular system according to claim 2, characterised by said return valve (21 ) of the base module (1 0) being connected to the lower part of the first superstructure module's expansion chamber (32) via a pipe (23), when the first superstructure module (30) is connected with the base module ( 1 0).

Modular system according to any of claims 1 -3, characterised by an overpressure valve (33) and a return valve (34) being arranged on said wall (35) of the first superstructure module's housing (31 ), wherein fluid transfer from the first superstructure module's expansion chamber (32) to the second superstructure module's expansion chamber (42) is allowed via this overpressure valve (33) and fl uid transfer from the second superstructure module's expansion chamber (42) to the first superstructure module's expansion chamber (32) is allowed via this return valve (34), when the second superstructure module (40) is connected to the first superstructure module (30).

Modular system according to claim 4, characterised by said return valve (34) of the first superstructure module (30) being connected to the lower part of the second superstructure module's expansion chamber (42) via a pipe (37), when the second superstructure module (40) is connected with the first superstructure module (30).

Modular system according to any of claims 1 -5, characterised by the side of the first superstructure module's housing (31 ) , intended to face the base module (1 0), being open .

Modular system according to any of claims 1 -6, characterised by the side of the second superstructure module's housing (41 ), intended to face the first superstructure module (30), bei ng open.

Modular system according to any of claims 1 -7, characterised by the base module's housing (1 1 ) being equipped with an outlet opening (1 3) intended to be connected to a coolant pipe in said cooling system , to allow exchange of coolant between the base module's expansion chamber (1 2) and other parts of the cooling system via this outlet opening (1 3).

9. Modular system according to any of claims 1 -8, characterised by the base module's housing (1 1 ) being equipped with an inlet opening (1 5) intended to be connected to a vent pipe in said cooling system, to allow in-flow of coolant and air from this vent pipe to the base module's expansion chamber (1 2) via this inlet opening (1 5).