DE2602582C2 - Liquid separator for refrigeration systems - Google Patents

Description

The invention relates to a liquid separator of vertical or horizontal design for refrigeration systems, in particular compression refrigeration systems for separating liquids (refrigerants, refrigeration machine oil and their mixtures) from the suction gas volume flow into the free container space and their proportional suction and recirculation through the suction gas volume flow, consisting of at least one container with an inlet nozzle, an outlet nozzle and a straight suction tube, the lower end of which is from The container bottom protrudes and the upper end of which opens into the flow channel of the outlet nozzle, as well as a heat exchanger designed as a!.> coiled tubing, its turns to a part of the separated liquid and on the other hand to the suction gas in the container are exposed.

Such a liquid separator is known from US Pat. No. 2,121,253.
This liquid separator is of the horizontal type.

Inlet nozzle and outlet nozzle are arranged horizontally opposite in the container lids. The outlet nozzle protrudes into the container as a thin-walled piece of pipe the size of the connecting line. A straight one The suction tube ends in an inclined position at the

♦ o Strönwngwall this pipe section. The lower end The suction tube extends to the bottom of the container with a free inlet opening. This liquid separator has a heat exchanger designed as a smooth tube coil, the turns of which in the longitudinal direction of the Run the container and rest against the inner wall of the container.

Such a liquid separator can only be used to a limited extent for the following reasons:

Due to the type of flow channel formation in the outlet nozzle as well as the position and arrangement of the Suction tube is only a small and conditionally protective suction. Because of the low Only the horizontal design has to be selected. Because of the low suction it is

Overfilling with the consequence of liquid hammers, which a liquid separator should avoid, is possible. The position of the outlet nozzle near the liquid level results in a slight overfilling already extremely unfavorable.

Liquid separators are also known which are divided into 5 groups with regard to their suction system permit:

1. Separator with float drain valve

The separated liquid is fed into the suction gas line via a float valve drained. Such separators have the disadvantage, in addition to the larger equipment costs, that also when

Interruption of the suction gas volume flow (e.g. compressor shutdown) During the float opening phase, liquid enters the suction gas line to the refrigeration compressor This can cause problems (e.g. liquid hammer).

2. Separator with U-shaped * suction pipe
for gas and liquid flow

Here the outlet nozzle is U-shaped Connected pipe that extends into the container area with the separated liquid. Because of this The suction gas volume flow flows through the suction pipe. The pipe bend has at least one small hole for the flow of the separated liquid on. Such liquid separators are also available Heat exchanger, designed as a coiled tubing or as a double-jacket container. Separator with U-shaped Suction tubes have the disadvantage that after a short period of standstill the separated liquid the The suction tube is filled up to the level of the liquid. The amount of liquid flowing in is not insignificant, since the suction pipe almost corresponds to the suction gas line in order to avoid high pressure losses The problems mentioned can also arise here when the liquid is sucked in from the U-tube.

3. Separator with vertical suction pipe
for gas and liquid flow

In this case, a partial suction gas flow through the liquid is used to suck off the separated liquid through into the vertical suction tube open at the bottom Outlet nozzle out. The suction tube only protrudes slightly from the bottom of the container and has an inflow hole at the top on. In the case of such liquid separators, the entrainment of larger amounts of liquid is particularly important cannot be avoided at the start of suction, which can lead to the problems mentioned.

4. Separator with peripheral suction tube for
the liquid flow

A suction tube for sucking off the separated liquid is attached to the outlet nozzle provided perpendicular to the direction of the exiting suction gas volume flow. The flow channel in the The outlet nozzle corresponds to the size of the suction gas line and points in the area of the suction tube inlet even an extension. Inevitably, at least the outlet nozzle is arranged horizontally here

Such liquid separators thus have the disadvantage that only the static speed level is used for the suction effect, and on the other hand this effect is still due to the flow channel widening in the mixing zone (liquid / suction gas) is reduced by the back pressure effect. Because of the low Only the lying type of suction has to be selected. Overcrowding and consequent Breakdowns are possible.

5. Separator with suction tube for the

Liquid flow in the direction of the

Suction gas outlet

With regard to the suction system, a distinction must be made between the following configurations, with these Liquid separators are exclusively of upright design and no Rohrwendef as heat exchangers exhibit:

a) Separator in which a straight suction tube opens directly into the outlet nozzle Suction gas volume flow occurs laterally into the outlet nozzle, the flow channel of which is the The size of the suction gas line corresponds to the insufficient speed in the mixing zone Functional and protective suction of the separated liquid limited disadvantage There are also deflection and transition joint losses in the outlet nozzle.

ίο b) separator with a suction tube in a U-shaped suction tube opens in the area of the bend The suction tube has the size here the suction gas line. Accordingly, under certain operating conditions, liquid can enter the The suction pipe, which can cause the problems already mentioned at the start of suction, c) Separator, in which a double bent longer suction tube into a horizontally arranged one Outlet nozzle with convexoid nozzle in the narrowest cross-section opens into the suction area The suction tube is also provided with a screen body. This is the suction effect the nozzle is adversely affected by a flow back pressure from the immediate nozzle widening behind the suction tube opening results in the higher pressure loss in the suction tube due to the great length, the bends and the screen body in front of it, this also reduces the Suction effect.

In addition to the liquid separators described so far, systems are known for increasing capacity of 2 liquid separators of the same design by connecting one behind the other by means of pipelines be put together. The disadvantage here is the additive pressure loss.

Systems are also known in which a twin design is achieved in that 2 separators of the same component are connected to one another with a small pressure equalization line above and a pipe below the size of the suction gas line. This modified separator system has the disadvantage that the separated liquid and suction gas are routed together through the large connecting pipe below and a vertical suction pipe. This unfavorably causes foaming and entrainment of larger amounts of liquid.
Liquid separators with heat exchangers in twin or multi-tank design, lying or standing, are not known.

In contrast, the invention is based on the object of providing a liquid separator of the initially mentioned mentioned genus so that the suction of the separated liquid, especially in low evaporation temperatures, and the extracted liquid as finely divided droplets in Fog form the suction gas flow in a wide area of application in an operationally appropriate and protective manner Way is fed.

According to the invention, this object is achieved in that the one arranged vertically at the top of the container Outlet nozzle a suction nozzle with an inlet cone, a cylindrical flow channel and a Has outlet cone, the vertical suction tube in the direction of the exiting suction gas volume flow opens into the cylindrical flow channel, and designed as a finned tube helix

Has heat exchanger hairpin shape with turns transverse to the longitudinal axis of the container and about Fasteners is brought into thermal contact with the suction tube.

The features of the invention ensure that the separated liquid is continuous and in certain proportions as finely divided droplets in the form of a mist from the suction gas volume flow and thus system-compatible and is extracted over a wide area of application in accordance with protection regulations (UVV).

This improved suction is achieved through the interaction of the individual features as follows achieved.

1. Maximum, operationally efficient suction effect: the geometric shape and their size relationships the suction nozzle and the position, shape and size of the suction tube determine this effect. It is the smaller, cylinder-sized, assigned to the connection diameter of the outlet nozzle The nozzle channel is just as important as the formation of the inlet cone and outlet cone. The flush opening of the suction tube into the "flow back pressure" is also very important avoiding and »flow smoothing« causing nozzle channel, because this becomes a Functionally favorable full utilization of the entire speed level (dyn. and stat.) and thus an expansion of the area of application and use of devices as well as greater operational reliability achieved.

2. Protective suction: Under the aforementioned geometric conditions and the resulting resulting flow conditions is in Together with the ideal suction tube, the cylindrical nozzle channel for a functionally favorable Mixing zone for the extracted liquid with the suction gas. This is decisive for them Protective suction of the liquid as finely divided droplets with a proportional share on the suction gas volume flow.

3.Improved suction even at low evaporation temperatures: The heat exchanger, which is designed as a finned tube coil, has the effect of its hairpin shape with turns transverse to the longitudinal axis of the container and through the thermal contact via fastenings with the suction tube for better, system-compatible Extraction also in the application area with evaporation temperatures below -10 ° C.

The following ilici rnodynäuiischen effects of this Features according to the invention form the basis for this:

The separated liquid is heated to the appropriate viscosity values. Preservation of these viscosity values also for the flow of liquid in the suction tube through thermal contact and essential supported by the structural and thermal shielding effect of the finned tube helix the cold suction gas flow. System-compatible heat transfer to the suction gas flow and thus also Support of the suction process.

These effects of the feature make the use of the device more extensive.

Advantageous further developments of the subject matter of the main claim according to the invention are provided in the features specified in the subclaims.

So achieve the U- and T-shaped baffle plates and baffles mentioned in the dependent claims 2 to 4 the tubular body with baffle plate cause operationally efficient pulsation and flow shock damping Forced flow and thereby a better separation effect and at the same time serve as a foam breaker and therefore result in a still safe suction.

The features of a further embodiment of the invention specified in the subclaims 5 to 7, in particular, the connecting pipes in the appropriate size, position and separated according to flow paths for the suction gas volume flow and the separated liquid, achieve an advantageous suction gas flow in the device and a reliable suction system even when large amounts of liquid flow in.

The invention is explained in more detail below with reference to the exemplary embodiments shown in the drawings explained. It shows

1 shows a liquid separator of the vertical type with a heat exchanger in the form of a finned tube helix (6) in the shape of a hairpin with turns transverse to the longitudinal axis of the container. The vaporous (") refrigerant flow (V '\) coming from the evaporator, called the suction gas volume flow, is sucked in by the refrigeration compressor via the inlet connection (1), container space (2) and suction nozzle (5) in the outlet connection (3). In the suction gas volume flow (V". 11 ) a small proportion of dissolved refrigeration machine oil (II) is carried along. During operational downtimes, it is possible that liquid refrigerant (V \) and oil (V ₁₁ ) flows out of the circuit to the suction gas side. These liquid volumes (V \ 11) then reach the container space (2) via the inlet nozzle (1) and are collected there. Particularly in the compressor start-up and when the system switches with contact with liquid areas entrainment of liquid (V ,. _M) by the Sauggasvolumstrom (V "i μ) is often unavoidable. The entrained liquid volumes (V \ .n) are then in the container space (2) Also precipitated and collected to protect the refrigeration compressor. Differences in density, changes in speed and direction of the inflowing media as well as the shielding and atomizing effect of the finned coiled tubing (6) due to their shape, size and position are decisive for this.

The protective and system-compatible suction of the accumulated liquids (V \, V'n) or liquid mixtures (V '\, 11) takes place proportionally to the suction gas volume flow (V ". 11) via the suction tube (4) in the suction nozzle (5) through the suction gas volume flow (V " _UI ). The negative pressure required for this in relation to the container space (2) is achieved by the greater speed prevailing in the suction nozzle (5). Almost the entire (dynamic and static) velocity level is used for the suction through the suction tube outlet in the direction of the exiting suction gas volume flow. This is a prerequisite for a wide use of the device. The flow conditions in the suction nozzle (5), caused by the geometric shape and size of the suction nozzle (5) and suction tube (4), play a key role in this, whereby the inlet cone, the cylindrical nozzle channel, the outlet cone and the confluence position of the suction tube are important. All of this means that the suctioned liquid (V \ π) in the nozzle area is ideally mixed with the suction gas (V "i, ii) and in accordance with protection, namely as finely divided droplets in the form of a mist, and operationally, i.e. continuously and in the necessary quantity, from the suction gas (V "\, 11) is recorded.

The heat exchanger (6) is another prerequisite for the wide range of applications, as it ensures that the system-compatible extraction of the accumulated fluid occurs.

For this purpose, the warmer, liquid refrigerant flow (V) coming from the condenser is passed through the heat exchanger designed as a hairpin-shaped finned tube coil (6). (At very low evaporation temperatures below - 40 ° C, it is advantageous under certain operating conditions to even pass hot compressed gas through.) The separated liquid (V'i.u) is heated so that viscosity values that are favorable for the suction can be achieved. In addition, due to its shape, size and position in the container (2) and through thermal contact with the suction tube (4), the finned tube helix (fi) not only maintains the favorable viscosity values for the liquid flow (V '\, _n ) in the suction tube , but also the suction is improved by thermal buoyancy. Fasteners (10) provide the necessary structural connection between the suction tube (4) and the appropriately designed finned tube helix (6). The suction is also favorably influenced by the structural and thermal shielding effect of the finned tube helix against the cold suction gas and by the system-specific heating of the suction gas volume flow (V ", n).

F i g. 2 shows a section of a liquid separator according to FIG. 1, but with a T-shaped baffle baffle (7). The suction tube (4) is fastened in the deflector plate and in the outlet nozzle (3) centrally arranged.

The design with a T-shaped deflector plate produces the following advantageous effects achieved:

a) Liquids (V'i, n) carried along or separately entering by the suction gas volume flow (V ", n) are braked by the baffle plate and then directed downwards Entering with force Liquids then do not lead to excessive foaming and impaired suction.

b) Through the baffle baffle (7), the suction gas volume flow (V '\, \\ ) experiences several deflections on the flow path in the container (2) between the inlet nozzle (1) and the outlet nozzle (3). This improves the separation of liquids.

c) The deflector plate also acts as a foam breaker during the suction process. (When the compressor starts up, a negative pressure arises in the container space (2), which causes the gas (V "\) dissolved in the liquid (V \\) to be expelled and therefore causes foaming)

F i g. 3 shows a section of a liquid separator according to FIG. 1, but with a perforated tubular body (la,) and baffle plate on the inlet side and U-shaped deflector plate (8) on the outlet nozzle (3). That The suction tube (4) is fastened in the deflector plate and arranged centrally in the outlet nozzle

This refinement achieves in addition to the under F i g. 2 effects a complete deceleration from liquid surges in the perforated pipe body (IaJt (This is an important protection for refrigeration systems with suction gas side riser.) In addition, a damping of pulsation noises and a causes even better liquid separation in the container (2).

4 shows a horizontal type of liquid separator with a heat exchanger in the form of a finned tube helix (6) in the shape of a hairpin with turns transverse to the longitudinal axis of the container (2a). Inlet nozzle (\ b) and outlet nozzle (3) are each provided with a U-shaped deflector plate (8, 9). The suction tube (Aa) is centrically converging into the outlet nozzle (3) in the deflector plate (8)

ίο arranged and by means of fastenings (10) with the Finned coiled tubing brought into thermal contact.

From the arrangement of the suction system (3, 4a, 8) with the suction nozzle (5) designed according to the invention there is the advantage of maximum absorption capacity of liquid for the horizontal design. Compared to the upright design, suction is cheaper because of the lower suction height. For the further The description of Figs. 1, 2 and 3 apply to the mode of operation of the liquid separator.

FIG. 5 shows a liquid separator of the vertical design in twin container design with a heat exchanger in the outlet container (2c) designed as a finned tube helix (6a). The finned tube coil has a hairpin shape with turns transverse to the longitudinal axis of the container.

Inlet nozzle (1) and outlet nozzle (3) are each arranged centrally in one of the twin containers (2b, 2c).
Fasteners (10) ensure thermal contact between the suction tube (4) and the finned tube helix.

The suction gas volume flow (V ", n) reaches the inlet container (2b ) via the inlet connector (1) and into the outlet container (2c) via the upper connecting pipe (11) and on to the outlet connector (3). V'in) is separated out in the inlet container. The liquid level is equalized in both containers (2b, 2c) via the lower, smaller connecting pipe (12) Suction gas volume flow sucked off in the suction nozzle.

This configuration of the liquid separator includes, in addition to the operationally favorable capacity increase the following special features:

a) Separate inlet and outlet zones with central flow confluences.

b) Separate connection paths (11, 12) assigned to the function and assigned to the position for the suction gas volume flow (V "i ii) and for the liquid (V \, n).

c) Favorable influence on the separation and the pressure drop through the size and position of the connecting pipe: (11) for the suction gas volume flow.

d) Flow-efficient design of all components in the area of the flow paths through the formation of inflow and outflow zones. Functionally favorable position of the finned tube helix (6a).

The description of FIG. 1 applies to the further mode of operation of the liquid separator. 1.

Fig.6 shows a liquid separator with basic Structure according to FIG. 5, but in a multi-tank design with an additional 4 connected in parallel Containers.

F i g. 7 shows a liquid separator of the horizontal type in a twin-container construction with basic principles Structure according to FIG. 4, however

Pipelines (13, 13 ') and traverse (14) connect two containers (2c /, 2e) to form a simple structural unit with a larger capacity.

FIG. 8 shows a liquid separator according to FIG. 7, but in a multi-tank design.

For this purpose 4 sheets of drawings

Claims (7)

Patent claims: 1.Liquid separators of vertical or horizontal design for refrigeration systems, in particular compression refrigeration systems, for separating liquids (refrigerants, refrigeration machine oil and their mixtures) from the suction gas volume flow into the free »container space and its proportional suction and recirculation through the suction gas volume flow, consisting of at least one container with a Inlet nozzle, an outlet nozzle arranged at a distance from it and a straight suction tube, the lower open end of which protrudes from the bottom of the container and its upper open end End opens at the flow channel of the outlet nozzle, as well as one designed as a coiled tubing Heat exchanger, the windings of which rait their part in which the separated liquid containing container area and with its other part in the container area containing the suction gas are, characterized in that the outlet nozzle (3) arranged vertically at the top of the container has a suction nozzle (5) with a Has inlet cone, a cylindrical flow channel and an outlet cone that is perpendicular upright suction tube (4) in the direction of the exiting suction gas volume flow into the cylindrical Flow channel opens, and the heat exchanger designed as a finned tube helix (6) hairpin shape with turns transverse to the longitudinal axis of the container (2) and via fastenings (10) in thermal contact with the suction tube is brought (Fig. 1,4). 2. Liquid separator according to claim 1, characterized in that the inlet nozzle (\ b) and outlet nozzle (3) each have a U-shaped baffle baffle (8, 9) with openings transverse to the flow direction in the container, the baffle baffle (8 ) at the outlet connection at the same time for receiving the suction tube (4a ^ serves (Fig. 4). 3. Liquid separator standing type according to claim 1, characterized in that it is a T-shaped, narrow and limited in length by the container diameter, with the web has baffle deflector plate (7) arranged transversely between inlet nozzle (1) and outlet nozzle (3), in which the suction tube (4) is attached (Fig. 2). 4. Liquid separator according to claim 1, characterized in that it is a little after has inside elongated inlet nozzle (la,), the with several holes across the direction of flow in the container and at the end of the pipe with a baffle plate is provided (Fig. 3). 5. Liquid separator in twin construction of standing type according to claim 1 or 2, characterized in that the inlet container (2b) has a central inlet nozzle (1) and the outlet container (2c ^ a central outlet nozzle (3), and that Both containers are connected to form a unit by an upper, horizontal pipe (11) with a diameter larger than the connecting pieces and by a lower horizontal pipe (12) with a diameter smaller than the connecting pieces (FIG. 5). 6. Liquid separator in twin construction of horizontal design according to one of claims 1, 2 or 4, characterized in that a container (2d) has an inlet nozzle {ib) and an outlet nozzle. zen (3), and this container with at least one further container (2e ^ by two horizontal Pipes (13, 13 ') above and below, supported by a cross member (14), connected to form a structural unit (Fig. 7,8). 7. Liquid separator according to claim 5, characterized in that the twin design at least one further container is added, connected by corresponding horizontal ones Pairs of pipes for a multi-container unit (Fig. 6).