FI123371B - Arrangement and method for separating droplets from evaporated refrigerant - Google Patents

Description

ARRANGEMANG OCH METOD FÖR SEPARERING AV DROPPAR FRÄN ETT FÖRÄNGAT REFRIGERATION SYSTEM AND METHOD FOR Separation of Drops from Steamed Cold

TECHNICAL FIELD OF THE INVENTION

The invention relates to an arrangement and a method for separating droplets from a vaporized refrigerant as disclosed in the preamble of the independent claims below. The invention relates in particular to the refrigerant vaporizer and the associated droplet separator, which ensures that refrigerant droplets do not pass to the compressor used in the refrigeration machinery.

BACKGROUND OF THE INVENTION

An important application of plate heat exchangers is the so-called "cold" used in large refrigeration machinery. wet evaporator and associated droplet separator. Typically, the wet vaporizer of a cold machine and the associated droplet separator are two functionally connected but separate devices. The function of the droplet separator is to ensure that no refrigerant droplets pass to the refrigerator compressor. Drops are extremely harmful because they easily cause the compressor to break. The droplet separator must be dimensioned sufficiently large and the inlet and outlet openings sufficient to allow the droplets to drop to the bottom of the separator before being introduced into the compressor by the inlet gas. On the other hand, the large size of the separator increases the manufacturing cost and the mass of the system and requires a large space.

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δ, EP 1466133 A1 discloses a device in which a vaporizing heat exchanger is disposed within the lower portion of the mantle which substantially fills the undersurface of the liquid to be vaporized ™. A cooling * heat exchanger and a device for separating droplets of gas from the jacket are located inside the top of the jacket.

r5 WO2008046951 discloses an embodiment in which the separation vessel is divided by a spacer g into two parts. At the right end of the baffle plate, part of the baffle plate has been replaced by an S-baffle plate. The refrigerant supply and the vapor / liquid droplet mixture generated by the evaporator are directed to the lower left side of the tank from where it spreads to the lower tank. The largest droplets drop directly to the bottom of the tank and only 2 small portions of the droplets pass with the suction gas through the hole plate to the top of the tank. At the top, a mixture of steam and small droplets of liquid is led toward the left edge outlet. The rest of the droplets thus have the entire length of the container to fall on the baffle and further to the bottom. Only very small droplets have the ability to enter the outlet.

Prior art devices are often complex in structure and their droplet separation capacity is not always satisfactory. On the other hand, in prior art solutions, the volume of the devices will not always be optimally utilized, but the devices will have to be made larger than is necessary for their operation.

OBJECTIVE AND BRIEF DESCRIPTION OF THE INVENTION

The object of the present invention is to reduce or even eliminate the above-mentioned problems in the prior art.

In particular, it is an object of the present invention to provide a solution that provides an efficient, reliable and compact combination of evaporator and droplet separator, especially for refrigerators.

Among other things, to accomplish the above purposes, the arrangement of the invention and the method for separating droplets from the evaporated refrigerant are characterized by what is set forth in the characterizing parts of the appended independent claims.

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The application examples and advantages mentioned herein apply, mutatis mutandis, to the arrangement and method of the invention, although not always specifically mentioned.

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Refrigerant as used herein refers to the working fluid used in the g evaporation processes used in refrigeration machinery. Such refrigerants include

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for example, ammonia, carbon dioxide and CFCs.

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A typical arrangement for separating the droplets from the evaporated refrigerant comprises a heat exchanger acting as a wet evaporator, and a droplet separator operably connected thereto. The heat exchanger and the droplet separator are typically arranged in the same diaper such that the heat exchanger is at the bottom of the diaper and the droplet separator is at the top of the diaper. Typically, the liquid refrigerant inlet is configured to open at the bottom of the jacket and the evaporated refrigerant outlet is provided at the top of the jacket. A typical droplet separator according to the invention comprises at the top of the diaper one or more autopilot baffles arranged at least substantially at all edges to be attached to the diaper. The vaporized refrigerant and any droplets that may accompany it are arranged to travel along a restricted path between the baffles and the sheath from the lower portion of the sheath to the outlet.

The droplet separator typically operates under gravity.

The major advantage of the arrangement over a system with a separate tank is its compact design. In refrigerators, the limiting factor is often the height required by the construction, which here is substantially smaller than before. On the other hand, one container is simpler to manufacture than two.

It is possible that the arrangement also comprises a refrigeration unit and the necessary connections for supplying the evaporated refrigerant from the refrigerant outlet to the refrigerant compressor and / or at least partially for supplying the liquid refrigerant from the high pressure portion of the refrigerant to the casing.

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One arrangement comprises means for at least partially introducing liquid refrigerant from the cold engine into the lower portion of the jacket.

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In addition to the evaporator and the droplet separator, the main components of a typical cold machine where the arrangement according to the invention can be used are a compressor, a condenser, an expansion or float valve, and piping connecting the parts. The evaporation process is divided into low pressure and high pressure parts. The low pressure section includes a vaporizer and droplet separator with piping, the high pressure section with a condenser and an expansion or 4 float valve with piping. Refrigeration machines are known per se and will not be discussed further here.

The heat exchanger is a plate heat exchanger. For example, the plate heat exchanger may be formed as a plate stack consisting of circular heat transfer plates. In this case, the heat exchanger is in the form of a main circular cylinder. In one embodiment of the invention, the diaper is in the form of a main circular cylinder. In one embodiment of the invention, the ratio of the outer diameter of the sheet pack to the inner diameter of the jacket is 40-80% or 60-70%.

In one embodiment of the invention, the cylindrical heat exchanger is eccentrically located in the circular cylindrical shell.

In one embodiment of the invention, the baffles are located above the heat exchanger. In one embodiment of the invention, the baffles are curved. In one embodiment of the invention, the baffles are curved in the same direction as the inner surface of the diaper and / or the outer surface of the heat exchanger. In one embodiment of the invention, the radii of curvature of the baffles are greater than the radius of curvature of the outer surface of the heat exchanger. In one embodiment of the invention, the radius of curvature of the baffles is greater than the radius of curvature of the inner surface of the diaper. In one embodiment of the invention, the longitudinal edges of the curved baffle are secured to the sheath below the top of the heat exchanger. In one embodiment of the invention, openings may be provided in the baffle or between the baffle and the inner walls of the diaper to direct fluid to the lower portion of the diaper. The spacers can be made curved so that droplets colliding with the surfaces flow to the edges and from there to the vaporizing liquid back along the inner surface of the diaper. Another advantage of the curvature is that it reduces the drop separation space when the spacers can be placed * closer to the round stack of plates.

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1 ^ m g In one embodiment of the invention, the baffles are intact at one end and

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c \ j with openings at one end. The autoplate may, for example, account for 10-40%, or 15-30%, or about 20% of the length and area of the spacer.

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In one embodiment of the invention, at one end, autopilot baffles are alternately arranged such that the evaporated refrigerant and any droplets that may accompany it are arranged to follow a meandering path bounded by the baffles from the lower end of the diaper to the outlet. This results in a long droplet separation distance, good flow distribution and effective droplet separation when colliding with the plate surfaces.

It is possible to implement the evaporator according to the invention with various heat exchangers, such as plate heat exchangers or tubular heat exchangers. In one embodiment, the heat exchanger refers to a plate heat exchanger consisting of a plate stack formed by heat transfer plates. The disc stack is formed of a plurality of disc pairs. Each pair of plates is formed by two heat transfer plates which are welded at least at their outer periphery to each other. Each heat transfer plate has at least two first openings for the flow of the first heat transfer medium. The adjacent pairs of plates are secured to one another by welding or otherwise joining the first openings of two adjacent pairs of plates. This allows the first heat transfer medium to flow from one pair of plates to the other through the first openings. Another heat transfer medium, the refrigerant to be evaporated, is arranged to flow between the pairs of plates.

In one embodiment, inlet and outlet connections for both the first and second heat transfer media are provided through the jacket. The inlet and outlet connection of the first heat transfer medium are arranged in communication with the inner portions of the plate stack, i.e. the inner portions of the pair of plates. The primary circuit of the plate heat exchanger is thus formed between the inlet and outlet of the first heat transfer medium, inside the pair of plates.

^ Typically, the primary and secondary circuits are separated, i.e., the first heat transfer fluid flowing inside the disc pack ™ cannot mix with the evaporative refrigerant flowing inside the envelope, i.e., outside the disc pack. Thus, a plate heat exchanger to the first heat transfer fluid flowing in the second plate between the primary and g of the second intermediate plate according to the invention,

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secondary side of the second heat transfer agent, a vaporized refrigerant.

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BRIEF DESCRIPTION OF THE FIGURES

The invention will now be described in more detail with reference to the accompanying schematic drawing in which

Figure 1 is a side view of an arrangement according to the invention,

Figure 2 is an end view of the arrangement of Figure 1,

Figure 3 is a sectional view A-A of Figure 1, or more precisely, a flow guide at the top of the jacket, illustrated at the end,

Figure 4 is a side view of the flow guide of Figure 3,

Figure 5 is a top view of the baffle according to the invention, and Figure 6 is an end view of the baffle of Figure 5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the construction of the figures, the evaporator of the refrigeration device is a plate pack 2 formed of circular heat transfer plates and a droplet separator 3 connected to the same circular cylinder shaped casing 4. The heat exchanger 2

Two inlet conduits 19 are provided through the lower portion of the diaper 1 through which at least partially liquid refrigerant is introduced into the diaper. Four inlet and outlet connections 6 are connected through the jacket 4 to the vaporizing heat exchanger, i.e. the plate package 2.

The liquid surface 5 of the evaporating liquid contained in the jacket 4 is adjusted to an end-6 level of the heat exchanger 2. The liquid surface 5 can also be adjusted to some other height.

The droplet separation is achieved by using one, two or even more baffles * 7, 8, which at one end are solid plates 9 and at the other end 10 are provided with openings 11 r5. The portion 10 of the spacer plate provided with the openings 11 may comprise openings 11 having a diameter g of, for example, 2 to 8 mm or 4 to 6 mm.

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The area of the end portion 10 of the apertured spacer plate 10 may be, for example, 25-50% or 30-40% or about 35%. Figure 6 shows how the baffle 7 is curved.

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Figure 1 illustrates the path of refrigerant vaporized by arrows. From the figure it is seen that the evaporated refrigerant in the lower part 12 of the jacket passes through the opening plate part 10, the so-called opening part 10 on the right side of the lower baffle 7. through the drip plate to the lower intermediate space 13 between the baffles 7 and 8, thence through the drip plate 10 on the left side of the upper baffle 8 to the upper intermediate space 14, thence between the upper baffle 8 and the outlet 4 through the outlet port 2 on the right side

Fig. 3 shows a vertical plate 16 located downstream of the jacket 4 in the upper intermediate space 14, which forces the flow to turn downward just before the outlet 15, preventing the flow from flowing and thereby enhancing droplet separation. At the bottom 17 of the main vertical vertical plate 16 is provided a main horizontal bar 18 which further prevents the flow from flowing.

The figures show only one preferred embodiment of the invention. It will be apparent to one skilled in the art that the invention is not limited to the examples set forth above, but that the invention may vary within the scope of the following claims. The dependent claims disclose some possible embodiments of the invention and are not to be construed as limiting the scope of the invention as such.

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Claims (9)

An arrangement (1) for separating droplets from an extended coolant comprising a heat exchanger (2) acting as a hydrogen exchanger, and a functionally associated drip separator (3), the heat exchanger and the droplet separator part being arranged in the same jacket ( 4), so that the heat exchanger is in the lower part (12) of the jacket and the drip separator in the upper part of the jacket (4), whereby a liquid coolant inlet (19) has been arranged to open in the lower part of the jacket and the outlet coolant (15) has been arranged being opened in the upper part of the jacket, characterized in that the drip separator (3) in the upper part of the jacket comprises two or more intermediate discs (7, 8) with apertures, which are arranged at least substantially at all their lateral edges in connection with the men (4), and which intermediate discs (7, 8) are whole at one end (9) and have an opening at their other end (10), the extended coolant and droplets possibly accompanying it being arranged to pass through ngs a tortuous route defined by the alternately arranged between the discs (7, 8) and mäntein (4) from the lower part of the jacket (12) Tili outlet (15). Arrangement according to claim 1, characterized in that the drip separator (3) is gravitational. 3. Arrangement according to claim 1 or 2, characterized in that the heat exchanger (2) is a plate heat exchanger. Arrangement according to any of the preceding claims, characterized in that the heat exchanger comprises a disk package (2) consisting of round heat transfer plates, the heat exchanger in its shape being essentially a circular cylinder. CVJ X 5. Arrangement according to claim 4, characterized in that the manifold (4) in its form is mainly a circular cylinder, and the heat exchanger (2) is eccentric in the section relating to the manifold. o o C \ J Arrangement according to any of the preceding claims, characterized in that the intermediate discs (7, 8) are located above the heat exchanger (2). Arrangement according to any of the preceding claims, characterized in that the intermediate discs (7, 8) are bent. 8. Method for separating droplets from an extended coolant, in which method: - liquid coolant is collected at the lower part (12) of the jacket (4), - the coolant is extended in the heat exchanger (2) in the lower part of the jacket, - droplets are separated from the extended the coolant in the casing (4) Upper part, - extended coolant is removed via an outlet (15) in the casing (4) Upper part, characterized in that - droplets are separated from the extended refrigerant by passing the refrigerant in the upper part of the casing through two or more intermediate discs (7, 8) with opening and along a winding route bounded by them and men (4) from the lower part (12) of the jacket to the outlet (15). Method according to claim 8, characterized in that the liquid surface (5) of the coolant to be extended is regulated to the level by the end coupling (6) of the heat exchanger (2). CO δ c \ j i δ i co CVJ X cc CL CD 1 ^ m o co o o CVJ