CH664623A5 - HORIZONTAL suction manifold FOR HEAT PUMP FOR PHASE SEPARATION AND KAELTEANLAGEN WORK MEANS AND / OR SEPARATION OF OELS. - Google Patents

Description

664 623

2nd

PATENT CLAIM Horizontal suction manifold for refrigeration systems and heat pumps for separating the liquid phase of the working fluid and / or oil emerging from at least one evaporator and for passing the volatile phase to at least one vertical standpipe, which begins in its upper interior and in which a suction flow temporarily leads to the volatile phase a compressor can be produced, with a tube of small inner diameter running between the bottom of the suction collecting tube and the standpipe and containing a siphon, characterized in that at an opening (18) in the upper end of the standpipe (10) close to the bottom (20 ) of the suction manifold (16) is connected to the siphon (26), the curvature (22) of which reaches a level which is substantially above the bottom (20) of the suction manifold (16), and that the siphon (26) is in a downward venturi -Distribution nozzle (24) with an enlarged outlet cross-section below the bottom (20) of the suction manifold it ends (16).

DESCRIPTION

The invention relates to a horizontal suction manifold for refrigeration systems and heat pumps for separating the liquid phase of the working fluid and / or oil emerging from at least one evaporator and for passing the volatile phase to at least one vertical standpipe which begins in its upper interior and in which a suction stream is temporarily discharged volatile phase to a compressor can be generated, with a tube running between the bottom of the suction manifold and the standpipe and having a small inner diameter and containing a siphon.

As is known from US Pat. No. 4,068,493, the volatile phase of the working medium, which is the refrigerant in connection with a refrigeration system, enters the evaporator as steam, to which the liquid phase and normally also oil is sometimes added the horizontal suction manifold, the task of which is to separate the oil and / or the liquid phase of the refrigerant from its volatile phase, which is sucked off by the compressor via a standpipe that ends just under the ceiling of the suction manifold. A tube runs beneath the suction manifold, in which the separated oil is returned from the bottom of the suction manifold to the standpipe so that it can get into the compressor and thus back into the volatile refrigerant circuit. If, however, liquid refrigerant is added to the settled oil at the bottom of the suction manifold, the oil floats on the liquid phase of the refrigerant and is partially mixed with it.

Even if only small amounts of the liquid refrigerant get into the compressor, they try to dissolve the oil required there for the bearing lubrication, i.e. to dilute it and render it ineffective, so that the compressor is damaged.

In order to prevent damage to the compressor, in the arrangement according to the US Pat. No. 4,068,493, a valve is inserted into the returning tube, which is bridged by a siphon, the upward curvature of which, however, does not reach the level of the bottom of the suction manifold . The valve is switched depending on whether only the viscous oil is to be returned through the tube or whether low-viscosity refrigerant is trying to run back into the standpipe. In the latter case, the valve shuts off the return pipe, so that the low-viscosity refrigerant bridges the valve.

must flow through the siphon. The inside diameter of the siphon is so small that only insufficient oil is able to pass through the siphon to the compressor. The thin-bodied refrigerant, on the other hand, can absorb heat from the environment on its relatively long path through the wall of the siphon and at least partially transition into the volatile phase. Small residual quantities of the thin-bodied refrigerant reaching the compressor are evaporated under normal conditions on the relatively warm parts of the compressor, that is, they evaporate. In winter conditions, however, even the smallest amounts can no longer be volatilized in this way, so that the use of the siphon seems inappropriate. Consequently, the liquid components at the bottom of the suction manifold must be heated by a heating rod under such conditions so that they are sucked off in their volatile phase through the standpipe towards the compressor. Oil heated by the heating element is much more liquid than cold oil and can also run through the return pipe to the standpipe.

According to the information in US Pat. No. 4,068,493, the use of a siphon in a cold environment between the suction manifold and the standpipe is therefore omitted.

U.S. Patent No. 4,068,493 also mentions the use of so-called "venturi devices" to return sufficient viscous oil and excess amounts of the low-viscosity refrigerant to the compressor, especially when the suction manifold is partially filled with liquid refrigerant. In these devices, the drive for the return of the liquid phase increases with the flow rate of the volatile phase. In addition, they cannot differentiate between the viscous oil and the low-viscosity refrigerant.

To make such a distinction, however, does not appear to be necessary if measures are taken in connection with the use of “Venturi devices”, through which both the liquid phase of the refrigerant and the viscous oil are atomized into the finest mist particles. In this fog phase, there is neither the disadvantageous dilution of the oil used for bearing lubrication nor mechanical damage to the compressor due to liquid refrigerant hitting solid.

A typical example of the use of a “Venturi device” is given in German Offenlegungsschrift No. 3 119 440. Oil and low-viscosity refrigerant accumulate on the bottom of an upright, cylindrical container. A suction pipe connected to the compressor ends in a venturi nozzle in the middle of the container lid. A straight tube is arranged along the central axis of the container, one end of which is immersed in the liquid at the bottom, while the other end is arranged within the venturi nozzle of the suction tube. With this “Venturi device”, the “Venturi effect” can only be used once.

The invention has for its object to provide an arrangement for a suction manifold of the type mentioned, of which the connection between the suction manifold and the standpipe leading to the compressor is to be effectively interrupted during the downtimes of the compressor and for easier emptying of the suction manifold when the compressor is running Suction power is increased, which can be exerted on the liquid deposited on the bottom of the suction manifold.

This object is achieved according to the invention in that at an opening in the upper end of the standpipe close to s

10th

IS

20th

25th

30th

35

40

45

50

55

60

65

664623

the siphon is connected to the bottom of the suction manifold, the curvature of which reaches a level which is substantially above the bottom of the suction manifold, and that the siphon ends in a downward-facing venturi distributor nozzle with an enlarged outlet cross section below the bottom of the suction manifold.

An embodiment of the invention is shown in the drawing and is explained in more detail below. Show it:

1 and 2 a longitudinal section and a cross section through the suction manifold. and the arrangement according to the invention and

Fig. 3 shows a cross section through the Venturi distributor nozzle.

A standpipe 10 runs vertically upward from a compressor (not shown), and its upper end 12 projects into the interior of a suction manifold 16. Close to the bottom 20 of the suction manifold 16 there is an opening 18 passing through the wall of the standpipe 10, through which refrigerant and / or oil deposited or collected on the bottom 20 can be sucked into the interior 28 of the standpipe 10 and through it to the compressor .

In order to prevent a substantial, self-contained amount of liquid from reaching the compressor directly and causing shocks there, a siphon 26 is arranged in the interior 28 of the standpipe 10, which creates a connection between the opening 18 and a Venturi distributor nozzle 24, of which the liquid drawn in through the siphon 26 is broken up into the interior 28 of the standpipe 10 until it is atomized. The siphon 26 used here has only one curvature 22, the position of which above the bottom 20 of the suction manifold 16 is determined by the level which can practically no longer be reached when the liquid collecting on the bottom 20 rises.

At the top of the suction manifold 16 there is a connection 30 to the evaporator (not shown). Of course s further compressors can be connected in parallel to the suction manifold 16 by a similar arrangement to that shown; the compressors can deliver different outputs.

FIG. 3 shows the cross section through the Venturi distributor nozzle 24. At the end of the long leg of the siphon 26, the cross section available to the flow decreases and, viewed in the direction of flow, finally reaches a bottleneck 34, behind which the cross section widens abruptly. This extension 36 15 is followed by an approximately uniformly increasing cross-section 32 up to the edge 38 of the Venturi distributor nozzle 24, at which the liquid emerges in a finely atomized form.

The atomization of the liquid flow is already initiated in 2 # of the curvature of the siphon 26, in which vortices are generated as a result of the strong change in direction. These fluid vortices are then carried along by the long leg to the evenly narrowing cross section of the Venturi distributor nozzle 24 and, upon reaching the abrupt transition from the bottleneck 34 to the expansion 36, cause the previously connected fluid flow to be broken up to the finest, mist-like droplets, the mutual spacing of which at Passage through the increasing cross-section 32 is further enlarged.

30th

As is well known, a refrigeration system can be converted into a heat pump by fairly simple measures. However, this does not result in any significant changes to the described embodiment of the invention.

25th

B

1 sheet of drawings