Patent Description:
A chiller is a machine that removes heat from a liquid via a vapor-compression or absorption refrigeration cycle. This liquid can then be circulated through a heat exchanger to cool equipment, or another process stream (such as air or process water). A typical chiller includes a compressor (e.g., a screw compressor), a condenser, an evaporator or cooler, an oil-refrigerant separator, an economizer and expansion devices. These components are connected to each other by tubing that carries a working fluid (e.g., refrigerant) through the chiller system. The evaporator typically includes a plurality of tubes that circulate water to be cooled. The condenser typically includes a plurality of tubes through which is circulated tower water to which heat is rejected. The compressor requires oil for lubrication which is typically entrained in the refrigerant. The combined oil and refrigerant mixture is carried through the compression cycle and then discharged into the oil separator where the oil must be removed from the refrigerant to allow for proper operation of the heat exchangers. The separated refrigerant is supplied to condenser and separated oil is returned to the compressor. From the oil separator, the clean refrigerant flows to the condenser.

In some chiller systems, the oil separator is integrated with a heat exchanger (e.g., a condenser) which provides for among other things, a manufacturing cost savings. Some integrated oil separators may include an off-centered refrigeration inlet, and a distributor for distributing the oil/refrigerant mixture into the body of the oil separator. Such oil separators may also include filtration devices such as wire mesh and demister pads for separating the incoming oil/refrigerant mixture. In general, separation occurs by the collision of the oil and refrigerant mixture on the walls of the oil separator. The oil is further separated from the mixture due to gravity and the filtration. When refrigerant enters the oil separator it may impinge on the side walls of the oil separator, and if the distribution of refrigerant is uneven, then oil separation efficiency may be reduced. In addition, if the flow within the oil separator body is non-uniform as it enters the filtration devices, then separation efficiency may be further reduced and permit oil particles to remain in the refrigerant as the refrigerant flows to the compressor. This in turn reduces the efficiency of the HVAC system and may lead to reliability and quality issues. What is needed then, is a system and method for improving the flow and distribution of refrigerant within an integrated oil separator, having off-centered refrigerant inlet. According to <CIT>, it is known to provide an oil separation device, a condenser and a refrigerating device, wherein the oil separation device comprises an oil separation casing and a baffle plate, an air inlet is arranged on the oil separation casing, and the baffle plate is arranged along with the oil separation plate. The air inlet direction of the casing is arranged in the oil separator casing in such a way that the air inlet direction intersects, and the oil separator casing comprises an oil baffle bottom groove arranged under the baffle plate, and the baffle plate is provided with a liquid drop hole, used to make the lubricating oil accumulated on the baffle plate fall into the oil retaining bottom groove.

According to <CIT>, it is known to provide an oil separator including an exterior shell defining a first interior and first and second openings fluidly communicative with the first interior, a distributor and first and second filter media cartridges. The distributor is integrated within the exterior shell to define a second interior within the first interior, has a length, which is slightly less than that of the exterior shell, being disposed to define opposite spaces between opposites ends thereof and opposite ends of the exterior shell and is sealed to the exterior shell along the length to form first and second passageways from the first opening to the opposite spaces. The first and second filter media cartridges are disposed within the first interior between the opposite spaces and the second opening.

According to <CIT>, it is known to provide an oil-air separator and an air-conditioning system with the same. The oil-air separator comprises a housing, an oil baffle plate, an air inlet pipe, at least one air homogenizing plate, and an oil filter assembly, wherein the housing comprises an upper chamber and a lower chamber; an oil drain outlet communicating with the lower chamber is formed in a bottom wall of the upper chamber, and an air outlet is formed in the upper chamber, while a collected oil outlet is formed in the lower chamber; the oil baffle plate is disposed on the bottom wall of the upper chamber; one end of the air inlet pipe extends into the upper chamber and is located above the oil baffle plate, and a gap is formed between a bottom end of the air inlet pipe and the oil baffle plate to define a circulation passage; each air homogenizing plate is disposed in the upper chamber, and a plurality of air vents are formed in each air homogenizing plate; the oil filter assembly is disposed in the upper chamber; and in an air circulation direction, each air homogenizing plate is located downstream of the circulation passage, and the oil filter assembly is located downstream of the air homogenizing plate.

According to a first aspect of the invention, there is provided an oil separator including: an exterior shell having opposite end walls defining a first interior, and a first and second opening fluidly communicative with the first interior; a plurality of baffles operably coupled to and extending from at least a first opposite end wall, each baffle comprising: a first support member generally parallel to a second support member, each operably coupled, and in an orientation that is generally perpendicular, to at least the first opposite end wall, and a crossmember operably coupled between the first support member and the second support member, the crossmember having a width dimension that is less than the width dimension of the first support member and the second support member, forming an orifice between the crossmember and the at least first opposite end wall; and a distributor integrated within the exterior shell to define a second interior within the first interior.

Optionally, at least one of the crossmember, the first support member and the second support member comprises a concave surface for deflecting the flow of a fluid.

Optionally, the internal width of the orifice between the support members comprises a dimension of less than or equal to about <NUM> millimeters.

Optionally, the internal depth of the orifice between the crossmember and the at least first opposite end wall comprises a dimension of less than or equal to about <NUM> millimeters.

Optionally, the width of the baffle across the support members and the crossmember comprise a dimension of less than or equal to about <NUM> millimeters.

Optionally, the length of a support member comprises a dimension of less than or equal to about <NUM> millimeters.

Optionally, the distributor has a length, which is slightly less than that of the exterior shell, being disposed to define opposite spaces between a first opposite end and a second opposite end thereof and the opposite end walls and being sealed to the exterior shell along the length to form first and second passageways from the first opening to the opposite spaces.

Optionally, a first filter media cartridge and a second filter media cartridge are disposed within the first interior between the opposite spaces and the second opening.

There is a flow component for an oil separator including: an end wall defining an exterior shell of an oil separator having an integrated distributor disposed within the oil separator; and a plurality of baffles operably coupled to and extending from the end wall, each baffle comprising a first support member generally parallel to a second support member, each operably coupled, and in an orientation that is generally perpendicular, to the at least the first opposite end wall, and a crossmember operably coupled between the first support member and the second support member, the crossmember having a width dimension that is less than the width dimension of the first support member and the second support member, forming an orifice between the crossmember and the at least first opposite end wall.

According to an embodiment of the present invention, there is provided a chiller assembly, including: a compressor; an oil separator including, an exterior shell having opposite end walls defining a first interior, and a first and second opening fluidly communicative with the first interior, a plurality of baffles operably coupled to and extending from at least a first opposite end wall, each baffle comprising: a first support member generally parallel to a second support member, each operably coupled, and in an orientation that is generally perpendicular, to the at least the first opposite end wall, and a crossmember operably coupled between the first support member and the second support member, the crossmember having a width dimension that is less than the width dimension of the first support member and the second support member, forming an orifice between the crossmember and the at least first opposite end wall; and a distributor integrated within the exterior shell to define a second interior within the first interior.

Optionally, the chiller assembly includes a single discharge pipe sub-assembly fluidly interposed between the compressor and the oil separator.

Optionally, the distributor comprises a cross-sectional area which is substantially similar to that of the single discharge pipe sub-assembly.

Optionally, the internal depth of the orifice between the crossmember and the opposite end wall comprises a dimension of less than or equal to about <NUM> millimeters.

The foregoing and other features and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:.

As will be described below, an integrated oil separator is provided with a distributor such that fluid (e.g., an oil/refrigerant mixture) distribution occurs within the elongated body of the oil separator interior. The oil separator is defined by opposing end walls in fluid communication with the distributor. In general, fluid will flow from a discharge pipe of a compressor into an inlet port of the oil separator, which is integrated with a heat exchanger shell, such as a condenser. In some embodiments, the inlet port may be in an off-centered position (e.g., on either side from center of the oil separator). As fluid flows into the oil separator, the distributor will distribute the fluid into one or both ends of the oil separator in the flow direction of the opposing end walls.

Typically, the end walls of an oil separator have a generally flat surface; however when combined with the off-centered positioning of the inlet port, this may result in a non-uniform flow pattern and the creation of unwanted flow vortices within the body of the oil separator. By operably coupling a plurality of baffles to at least one opposing end wall to deflect the flow of fluid as it flows from the distributor into the oil separator body, the fluid flow velocity into the oil separator, before entering the filtration devices (e.g., mesh and demister pads) may be reduced, resulting in improved flow, a reduced occurrence of flow vortices, and with a negligible impact on total pressure drop within the oil separator. The benefits of deflecting flow within the oil separator body using a plurality of baffles will be described below.

With reference to <FIG>, a chiller assembly <NUM> is provided. The chiller assembly <NUM> includes a compressor <NUM>, an oil separator <NUM> and a single discharge pipe sub-assembly <NUM>. The compressor <NUM> is configured to compress refrigerant and to discharge the compressed refrigerant at an initial pressure to the single discharge pipe sub-assembly <NUM>. The single discharge pipe sub-assembly <NUM> is fluidly interposed between the compressor <NUM> and the oil separator <NUM> and conveys the compressed refrigerant at the initial pressure from the compressor <NUM> to the oil separator <NUM>. The single discharge pipe sub-assembly <NUM> may be formed of steel or other similar or suitable materials and includes a weld joint <NUM> at an interface between an end <NUM> thereof and the oil separator <NUM>.

As shown in <FIG> and with additional reference to <FIG>, the oil separator <NUM> includes an exterior shell <NUM>, a distributor <NUM> and first and second filter media cartridges <NUM> and <NUM>. The distributor <NUM> is integrated within the exterior shell <NUM> and has a cross-sectional area which is substantially similar to the cross-sectional area of the single discharge pipe sub-assembly <NUM>. In some embodiments, the distributor internal cross-section size will be equal to the discharge pipe size so that the integrated oil separator <NUM> will induce no additional pressure drop or change in thermal properties of the refrigerant. The integrated oil separator assembly with the compressor <NUM> will also be characterized in that copper pipes of conventional chillers will be replaced with a steel pipe. Similarly, silver brazing process that are used with conventional assemblies may be replaced with welding.

With continued reference to <FIG> and with additional reference to <FIG>, the exterior shell <NUM> is formed to define a first interior <NUM>, a first opening <NUM>, which is fluidly communicative with the first interior <NUM> and a second opening <NUM>, which is also fluidly communicative with the first interior <NUM>. In addition to the second opening <NUM>, which may be an oil outlet, the exterior shell <NUM> also includes a separate refrigerant outlet configured to allow oil and the refrigerant to separately flow from the oil separator.

The distributor <NUM> is integrated within the exterior shell <NUM> to define a second interior <NUM> within the first interior <NUM>. The distributor <NUM> has a longitudinal length L1, which is slightly less than a longitudinal length L2 of the exterior shell <NUM>. The distributor <NUM> is disposed within the exterior shell <NUM> to thus define opposite spaces <NUM>, <NUM> between opposite ends <NUM>, <NUM> of the distributor <NUM> and corresponding distributor opposite ends <NUM>, <NUM> of the exterior shell <NUM>. The distributor <NUM> is also sealed to the exterior shell <NUM> by seals (not shown) that extend along the edges of the distributor <NUM> along an entirety of the length L1. The distributor <NUM> thus forms first and second passageways P1 and P2 from the first opening <NUM> to the opposite spaces <NUM>, <NUM>. First and second filter media cartridges <NUM>, <NUM> are respectively disposed within the first interior <NUM> between corresponding ones of the opposite spaces <NUM>, <NUM> and the second opening <NUM>.

With continued reference to <FIG> and with additional reference to <FIG>, the exterior shell <NUM> may have a substantially semi-circular cross-sectional shape and may include a flat side <NUM>, a curved side <NUM> that protrudes away from the flat side <NUM> and opposite end walls <NUM>. The opposite end walls <NUM> are provided at respective opposite ends of the flat side <NUM> and the curved side <NUM>. The flat side <NUM>, the curved side <NUM> and the opposite end walls <NUM> cooperatively define the first interior <NUM>. At least one of the opposite end walls <NUM> has a plurality of baffles <NUM> as further described below in reference to <FIG>. In some embodiments, the cross-sectional area of the distributor <NUM> is substantially similar to the cross-sectional area of the single discharge pipe sub-assembly <NUM>, such that fluid moving through the single discharge pipe sub-assembly <NUM> at the initial pressure moves through the distributor <NUM>, the opposite spaces <NUM>, <NUM> and into the first interior <NUM> after interacting with baffles <NUM>, without experiencing a pressure drop. That is, the fluid passes through the opposite spaces <NUM>, <NUM> at substantially a same pressure as the initial pressure.

Referring to <FIG>, a view of the oil separator12 and distributor <NUM> is provided, however omitting the plurality of baffles <NUM>, for clarity. The distributor may have a substantially trapezoidal shape (with the curved side <NUM>) serving as one of the trapezoidal sides or other similar shapes to be described in greater detail below. The distributor <NUM> may include a base <NUM>, sidewalls <NUM>, <NUM> that extend in a same direction from opposite edges of the base <NUM>. The distributor <NUM> is disposed within the first interior <NUM> at an offset position relative to a mid-line of the exterior shell <NUM> such that the sidewalls <NUM>, <NUM> extend in the same direction from the opposite edges of the base <NUM> toward an interior surface of the curved side <NUM> of the exterior shell <NUM>. Seals may be sealably interposed between distal edges of the sidewalls <NUM>, <NUM> and the interior surface of the curved side <NUM>. Respective widths of the sidewalls <NUM>, <NUM> dispose the base <NUM> at a depth from the interior surface of the curved side <NUM>. The base <NUM>, the sidewalls <NUM>, <NUM> and the curved side <NUM> thus define the second interior <NUM>.

As shown in <FIG>, fluid received by the oil separator <NUM> includes a mixture of refrigerant and oil that was compressed in the compressor <NUM> and conveyed to the oil separator <NUM> through the single discharge pipe sub-assembly <NUM>. The fluid enters the exterior shell <NUM> via first opening <NUM> and is contained within the sealed second interior <NUM>. The fluid thus moves through either the first or the second passageways P1 and P2 within the second interior <NUM> and along the length L1 of the distributor <NUM> as the seals prevent the fluid from flowing in any other direction. Once the fluid that has moved through either the first passageway P1 or the second passageway P2, the fluid reaches the opposite spaces <NUM>, <NUM>. The fluid then passes through the opposite spaces <NUM>, <NUM> and turns back into the first interior <NUM> due to interactions with the opposite end walls <NUM> and baffles <NUM>, and flows through the first and second filter media cartridges <NUM>, <NUM> toward the second opening <NUM>.

A baffle <NUM>, is shown in <FIG>. Deflecting the flow of fluid using a plurality of baffles <NUM> has the benefit of reducing the formation of flow vortices that can occur in the first interior <NUM>, and which will also cause a lack of fluid distribution uniformity in the first interior <NUM>. When distribution of fluid is non-uniform, the flow distribution of fluid across the filter media cartridges <NUM>, <NUM> is reduced. In some embodiments, the filter media cartridges <NUM>, <NUM> are wire mesh (e.g., demister). When flow distribution is reduced, the filter media cartridges <NUM>, <NUM>, which aid in oil/refrigerant separation, may be less efficient. The flow distribution index (FDI) may be used to obtain the deviation from the average flow velocity. If the flow is perfectly uniform, then FDI is close to <NUM>, otherwise it is less than <NUM>. In general, an oil separator with internal distributor, but without the disclosed baffles, may have an average FDI at the entrance to the wire mesh/demister pads equal to or greater than <NUM> and equal to or less than <NUM>. By including a plurality of baffles <NUM> as disclosed, the FDI may be improved, indicating better distribution of flow.

Each baffle <NUM> includes a pair of support members <NUM>, <NUM>, wherein a first support member <NUM> is generally parallel to a second support member <NUM>, each operably coupled, and in an orientation that is generally perpendicular, to at least the first opposite end wall, and a crossmember <NUM> operably coupled between the first support member <NUM> and the second support member <NUM>, the crossmember <NUM> having a width dimension that is less than the width dimension of the first support member <NUM> and the second support member <NUM>, forming an orifice between the crossmember <NUM> and the at least first opposite end wall <NUM>.

Baffle <NUM> may be constructed from, and is coupled to the at least one opposite end wall <NUM> by, any material, preferably metal or metal alloy, that may withstand the fluid forces of fluid acting upon the baffles <NUM>. A baffle <NUM>, not in accordance with the invention, may be of any shape that serves to interact with fluid so as to reduce the effect of flow vortices that may occur within the first interior <NUM>, as fluid flows from the distributor <NUM> through the opposite spaces <NUM>, <NUM> and into the first interior <NUM>. In addition, a baffle <NUM>, not in accordance with the invention, may have any dimension (length, width, depth) depending on a variety of factors, such as size of the oil separator <NUM> and/or the rate of fluid flow through the oil separator.

In one non-limiting embodiment, baffle <NUM> has a square U-shape, including two support members <NUM>, <NUM> extending from an operably coupled crossmember <NUM>. In one non-limiting embodiment, at least one of the crossmember <NUM> and the support members <NUM>, <NUM> have a concave surface for deflecting fluid flowing from the distributor <NUM> into the first interior <NUM>. For example, baffles <NUM> positioned in proximity to the first opening <NUM>, may deflect approximately <NUM>-<NUM>% of fluid flow from the distributor <NUM>, with the remaining portion flowing directly into the first interior <NUM>. For example, flow distribution of fluid in the first interior <NUM> may be measured (e.g., flow distribution index (FDI)) with higher values indicating improved (e.g., more uniform) flow distribution. For example, an oil separator <NUM> without deflecting baffles <NUM> may have a FDI of less than <NUM>, while an oil separator <NUM> with deflecting baffles <NUM> may have a higher FDI (e.g., equal to or greater than <NUM>).

Each support member <NUM>, <NUM> has a proximal end (e.g., 502a) that operably couples the baffle <NUM> to the at least one opposite end wall <NUM>. In one non-limiting embodiment, the support members <NUM>, <NUM> and the crossmember <NUM> have a total length (l) dimension that is generally equal to or less than <NUM> millimeters (mm). In one non-limiting embodiment, each support member has a width (w) dimension measurable from a proximal end 502a to a distal end 502b that is generally equal to or less than <NUM>.

The crossmember <NUM> of baffle <NUM> is has a width dimension that is less than the width dimension of the two support members <NUM>, <NUM> such that when baffle <NUM> is operably coupled to at least one opposite end wall <NUM>, an orifice <NUM> is formed. In one non-limiting embodiment, the orifice <NUM> has a length (a) dimension as measured from the medial facing side of each support member <NUM>, <NUM> that is generally equal to or less than <NUM>. In one non-limiting embodiment, the orifice <NUM> has a depth (d) dimension measured from the proximal end 502a to an interior surface 504a of the crossmember <NUM> that is generally equal to or less than <NUM>. The orifice <NUM> permits a portion of the fluid from the distributor <NUM>, to flow through to the first interior <NUM>. The orifice <NUM> may have the further benefit of minimizing any potential pressure increase as fluid flows from the distributor <NUM> to the first interior <NUM>.

It should be appreciated that the length (l) & width (w) dimensions disclosed above, can be varied (increased or decreased) to control the flow deflection toward central portion depending on the desired result and design needs.

<FIG>, <FIG>, <FIG> show various views of a plurality of baffles <NUM> is in accordance with embodiments of the invention. According to the invention, a plurality of baffles <NUM> are operably coupled to at least one opposite end wall <NUM> as illustrated in <FIG>. In some embodiments, baffles <NUM> may be on both opposite end walls <NUM> as illustrated in the side view of <FIG> and the top view of <FIG>. In some embodiments, the baffles <NUM>, not in accordance with the invention, may be coupled to the internal portion of the shell <NUM>, for example, within the first interior <NUM> (not shown).

Referring to <FIG>, an axial view of the oil separator is provided to illustrate one non-limiting embodiment of the plurality of baffles <NUM> as coupled to at least one opposite end wall <NUM>, however omitting other details such as the distributor, for clarity. Referring to <FIG>, the vertical plane of the opposite end wall <NUM> may be described in terms of x, y coordinates, having an x-axis and a y-axis. In some embodiments, the position of a baffle <NUM> along the plane of the opposite end wall <NUM>, may be generally perpendicular to the y-axis, as illustrated by baffle 205a. In some embodiments, the position of a baffle may be at an angle (θ) generally less than forty-five degrees (<NUM>°) from the x-axis as illustrated by baffle 205b.

The number of baffles <NUM> coupled to at least one opposite end wall <NUM>, and the spacing between baffles <NUM>, may vary based on a variety factors, including size of the oil separator <NUM>, the rate of fluid flow through the oil separator, and the location of the first opening <NUM>.

Claim 1:
An oil separator, comprising:
an exterior shell (<NUM>) having opposite end walls (<NUM>) defining a first interior (<NUM>), and a first and second opening (<NUM>, <NUM>) fluidly communicative with the first interior (<NUM>), a distributor (<NUM>) integrated within the exterior shell (<NUM>) to define a second interior (<NUM>) within the first interior (<NUM>);
a plurality of baffles (<NUM>) operably coupled to and extending from at least a first opposite end wall (<NUM>), each baffle (<NUM>) comprising:
a first support member (<NUM>) generally parallel to a second support member (<NUM>), each operably coupled, and in an orientation that is generally perpendicular, to at least the first opposite end wall (<NUM>); and
a crossmember (<NUM>) operably coupled between the first support member (<NUM>) and the second support member (<NUM>), the crossmember (<NUM>) having a width dimension that is less than the width dimension of the first support member (<NUM>) and the second support member (<NUM>), forming an orifice (<NUM>) between the crossmember (<NUM>) and the at least first opposite end wall (<NUM>).