CONDENSER HAVING A SUB-COOLING UNIT

Condensers are known and widely used in cooling devices of any kind. Within said condensers gaseous refrigerant h- condensed to liquid refrigerant and then supplied to the expansion device and the evaporator downstream of the condenser. Sometimes a condenser is followed by a sub cooling unit in order to cool the liquid refrigerant even further before feeding it to the expansion device and the evaporator. This increases the efficiency of the vapor compression cycle.

A condenser as shown by the European patent application EP 1 406 050 A2 further comprises a gas compensation unit. The condenser according to the EP 1 406 050 A2 comprises three collectors, a gas inlet collector, a gas outlet collector, and a gas compensation collector.

Accordingly, it would be beneficial to reduce the complexity of such a condenser comprising a gas compensation unit in order to minimize the costs for production and installation.

Furthermore, it would be beneficial to provide the capability to better adjust the temperature of the liquid refrigerant entering the expansion device and the evaporator.

Exemplary embodiments of the invention include a condenser having a sub cooling unit, comprising a gas inlet collector; a sub cooler collector connected to the gas inlet collector by at least one condensing conduit having a condensing surface, said condensing surface condensing the gaseous refrigerant to liquid refrige- rant, said sub cooler collector collecting the liquid refrigerant; and a liquid refrigerant collector connected to the sub cooler collector by at least one cooling conduit having a cooling surface, said cooling surface cooling down the liquid refrigerant; the at least one condensing conduit discharging into the top of the sub cooler col-

lector and the at least one cooling conduit joining at the bottom of the sub cooler collector so that the sub cooler collector allows for compensation of the gaseous refrigerant.

Exemplary embodiments of the invention further comprise a method for regulating a condenser according to the invention by regulating the airflow passing the cooling conduit in order to adjust the temperature of the liquid refrigerant output by the •,•<, condenser.

Embodiments of the invention will be described in greater detail below with reference to the Figures, wherein:

Figure 1 shows a schematic front view of a condenser in accordance with an embodiment of the present invention;

Figure 2 shows a sectional side view of the condenser of Figure 1 in accordance with an embodiment of the present invention.

Figure 1 shows a schematic front view of a condenser 1 according 1o a embodiment of the present invention. Two fans 24 are arranged on top of the condenser 1 in order to draw a cooling air flow F from the bottom to the top of the condenser 1. These fans can be of conventional kind.

Below the fans 24 the condenser 1 comprises at its top a gas inlet collector 2 which is supplied with gaseous refrigerant by a refrigerant conduit 8 which opens to the top of the gas inlet collector 2.

A plurality of condensing conduits 12 are connected to the gas inlet collector 2. Said condensing conduits 12 form a condensing surface in order to condense the gaseous refrigerant to liquid refrigerant. The condensing conduits 12 run in vertical direction from the gas inlet collector 2 to a sub cooler collector 4 which is arranged below the gas inlet collector 2. The condensing conduits 12 open to the top of said sub cooler collector 4.

A plurality of cooling conduits 14 join at the bottom of the sub cooler collector 4 so that liquid refrigerant 10b flows out of said sub cooler collector 4 through said cooling conduits 14.

The cooling conduits 14 run vertically down from the sub cooler collector 4 to a liquid refrigerant collector 6 and open to its top. The liquid refrigerant collector 6 is arranged in parallel below the sub cooler collector 4. The cooling conduits 14 have

a cooling surface for further cooling down the liquid refrigerant 10b. The cooled liquid refrigerant is collected in the liquid refrigerant collector 4 and delivered to an expansion device and an evaporator (not shown) by a liquid conduit 16 which joins at the bottom of the liquid collector 6.

In operation, the sub cooler collector 4 is filled approximately up to the half of its height with liquid refrigerant 10b, while its upper half is filled with gaseous refrigerant 10a.

Figure 2 shows a sectional view ,pf the condenser 1 according to an embodiment of the present invention, taken along the line A-A in Figure 1.

At the top of Figure 2, again two fans 24 are shown which draw an air flow F from the bottom to the top of the condenser 1.

Said air flow F is laterally confined by two sidewalls 3a, 3b which are arranged at the left and the right side of the fans 24 and extend over the whole height of the condenser 1.

The gas inlet collector 2 is shown at the right side of the right sidewall 3b. The gas inlet collector 2 is formed as a circular pipe which is viewed in axial direction in Fig. 2. The gas inlet conduit 8 opens to the top of the gas inlet collector 2 delivering gaseous refrigerant 10a. A gas condensing conduit 12 joins at the left side of the gas inlet collector 2. Said condensing conduit 12 passes the right sidewall 3 from right to left and meanders over the width of the condenser 1 between the left sidewall 3a and the right sidewall 3b in the form of a winding line, down to approximately the middle of the condenser 1. There, there condensing conduit 12 passes the right sidewall 3b from left to right, bends down from a horizontal to a vertical direction and opens to the top of the sub cooler collector 4.

The sub cooler collector 4 is formed as a pipe running parallel to the gas inlet collector 2.

In operation the sub cooler collector 4 is filled with liquid refrigerant 10b approximately up to half of its height. The upper half of the sub cooler collector 4 is filled with gaseous refrigerant 10a.

A cooling conduit 14 joins at the bottom of the sub cooler collector 4. Due to this assembly the sub cooler collector 4 allows for compensation of the gaseous refrigerant without the need of an additional gas compensating collector.

The cooling conduit 14 extending from the bottom of the sub cooler collector 4 bends from the vertical to the horizontal direction and again passes the right side-,, wall 3b from right to left. At the left side of the right sidewall 3b the cooler conduit 14 meanders in the form of a winding line downwards, but uses only half of the width between the left sidewall 3a and the right sidewall 3b. The cooling conduit 14 then passes again the right sidewall 3b horizontally from left to right and opens to the side of liquid refrigerant collector 6. The liquid refrigerant collector 6 is formed as a pipe running parallel to the gas inlet collector 2 and to the sub cooler collector 4. A liquid conduit 16 joins at the bottom of liquid refrigerant collector 6 discharging the liquid refrigerant 10b from the liquid collector 6 and delivering the liquid refrigerant to the expansion device and the evaporator (not shown).

An air flow regulation means 22 in form of an air flap is arranged above the cooling conduit 14 but below the condensing conduit 12 at the left side of the right sidewall 3b. This air flap 22 is only represented schematically. As a matter of course, a plurality of air flaps 22 can be present, and they can also be arranged before the cooling conduit 14. The air flow passing the cooling conduit 14 can be regulated by operating said air flap 22. In doing so the temperature of the liquid refrigerant leaving the cooling conduit 14 and entering the liquid refrigerant collector 6 can be adjusted conveniently.

Only the part of the air flow passing the cooling conduit 14 is affected by the air flap 22, while the part of the air flow F shown on the left side of Figure 2, which does not pass the cooling conduit 14, is not affected by the air flap 22. Therefore

only the sub cooling performance but not the condensing performance is affected by the air flap 22.

In a further embodiment, which is not shown here, the air flow passing only the condensing conduit 12 can be separated from the air flow passing both the cooling conduit 14 and the condensing conduit 12 by means of a wall, that extends for example vertically to the left from the cooling conduit 14.

A condenser according to exemplary embodiments of the invention, as described above, allows to reduce the number of components and thus the complexity of the condenser and it therefore facilitates the assembly and minimizes the time needed for the assembly, which results in the reduction of the production costs. It also allows to easily regulate the temperature of the liquid refrigerant output by the condenser.

In an exemplary embodiment of the invention, as described above, at least one of the gas inlet collector, the sub cooler collector and the liquid collector is formed as a pipe. Pipes can be purchased very easily from the shelf in any desired diameter and do not comprise any edges which could provide a point of mechanical weak- ness.

In a further embodiment according to the invention at least one of the condensing conduit and the cooling conduit is a core pipe. Core pipes are usually and conveniently used as condensing and/or cooling conduits in condensers, as they enable a very efficient condensing and/or cooling of a refrigerant.

In another exemplary embodiment of the invention a cooling air flow is effected. Such an air flow improves the efficiency of the condensing conduit and the cooling conduit, respectively.

In a further embodiment at least part of the air flow passes only the condensing surface of the condensing conduit while another part passes the condensing sur-

face of the condensing conduit as well as the cooling surface of the sub cooling conduit. This further improves the efficiency of the condensing conduit.

In a further embodiment the condensing surface of the condensing conduit is ar- ranged in the air flow downstream of the sub cooling surface of the cooling conduit. This further improves the efficiency of the condenser, since the cooling conduit having a lower temperature than the condensing coruUit is cooled first by the air flow.

in a further embodiment the condensing surface is arranged above the sub cooling surface. This enhances the efficiency even further since in this configuration the air flow is supported by the thermodynamic properties of warm air raising upwards.

In another embodiment the condensing surface and the sub cooling surface are connected by a flange connection. This also improves the air flow from the condensing surface to the sub cooling surface.

In another embodiment the surface area of the condensing surface is larger than the surface area of the sub cooling surface. This also increases the efficiency as usually a larger surface area is needed for condensing than for sub cooling.

In another embodiment the condenser comprises at least one air flow regulation means which is configured to regulate the air flow passing the sub cooling surface. This enables regulating the temperature of the liquid refrigerant leaving the cooling conduit and thereby enhancing the efficiency of the vapor compression cycle.

In a further embodiment the condenser comprises at least one air flow regulation means configured to regulate the air flow passing the condenser surface. This enables regulating the performance of the condensing conduit in order to increase the efficiency of the condenser.

In a further embodiment the at least one air flow regulation means comprises a throttle valve. A throttle valve is a very convenient and inexpensive means for regulating the air flow.

In another embodiment the air flow regulation means is arranged in the air flow between a condensing conduit and the cooling conduit. This arrangement enables a particular effective regulation of the air flow passing the cooling conduit.

In another embodiment a condenser further comprises a fan for enhancing the air flow. By enhancing the air flow the efficiency of.,ihe condenser can be enhanced even further.

In a further embodiment the at least one fan is arranged on top of the condenser in order to draw the air from the bottom to the top of the condenser. This enables a particularly efficient air flow through the condenser.

In another embodiment the gas inlet collector comprises a gas inlet conduit feeding a gaseous refrigerant thereto. This enables a particular effective operation of the condenser.

In a further embodiment the liquid collector comprises a liquid conduit in order to discharge the liquid refrigerant from the liquid collector. This also enables a particular effective operation of the condenser.

In another embodiment a condenser according to the present invention is comprised in a vapor compression cycle. This provides a vapor compression cycle which can be operated very efficiently and which can be assembled at low cost.

In another embodiment such a vapor compression cycle comprising a condenser according to the present invention is comprised in a refrigerating furniture. This provides a very efficient refrigerating furniture which can be produced at low cost.

The features, embodiments and advantages as described with respect to the condenser having a sub cooling unit can also be realized, in terms of method steps, with the method for regulating a condenser according to the invention.

While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition many modifications may be made to adopt a particular situation or material to the teachings of the invention without departing from th£ essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention include all embodiments falling within the scope of the dependent claims.

List of Reference Numerals:

1 condenser

2 gas inlet collector 3a left side wall

3b right side wall 4 sub cooler collector

6 liquid collector

8 gas inlet conduit

10a gaseous refrigerant

10b liquid refrigerant 12 condensing conduit

14 cooling conduit

16 liquid conduit

22 air flow regulation means 4 fan