Mufflers for Refrigerant Compressors

This application is a 371 application of International Application No. PCT/US2023/023194, filed May 23, 2023, which claims priority to U.S. Provisional Application No. 63/356,020, which was filed on Jun. 27, 2022.

Refrigerant compressors are used to circulate refrigerant in a chiller via a refrigerant loop. Refrigerant loops are known to include a condenser, an expansion device, and an evaporator. The compressor compresses the fluid, which then travels to a condenser, which in turn cools and condenses the fluid. The refrigerant then goes to an expansion device, which decreases the pressure of the fluid, and to the evaporator, where the fluid is vaporized, completing a refrigeration cycle.

A refrigerant compressor according to an example of this disclosure includes a discharge portion and a muffler disposed at the discharge portion. The muffler includes an outer cylinder having a center axis, and a sleeve concentric with and radially inward of the outer cylinder relative to the center axis. The sleeve includes a plurality of radially extending through holes and provides a resonance cavity radially between the sleeve and the outer cylinder.

In a further example of the foregoing, the muffler is attached to the discharge portion.

In a further example of any of the foregoing, the resonance cavity is sealed at its axial ends.

In a further example of any of the foregoing, a plurality of axially spaced annular plates are located within the resonance cavity.

In a further example of any of the foregoing, each of the plurality of annular plates include a plurality of axially extending through holes.

In a further example of any of the foregoing, the plurality of axially extending through holes are equally circumferentially spaced from one another.

In a further example of any of the foregoing, the radially extending through holes form axially spaced circumferential rows of radially extending through holes.

In a further example of any of the foregoing, the plates are positioned axially between, and radially outward of, immediately adjacent of the circumferential rows.

In a further example of any of the foregoing, the axially extending through holes are circumferentially aligned across two or more of the plates.

In a further example of any of the foregoing, the radii of the axially extending through holes are greater than the radii of the radially extending through holes.

In a further example of any of the foregoing, the radially extending through holes are equally circumferentially spaced from one another.

In a further example of any of the foregoing, the sleeve is welded to the cylinder.

In a further example of any of the foregoing, the muffler is configured to receive fluid from the discharge portion into the sleeve.

A method according to an example of this disclosure includes providing a muffler fluidly between a discharge portion of a compressor and a condenser. The muffler includes an outer cylinder including an inner diameter surface and a center axis, and a sleeve concentric with the outer cylinder. The sleeve includes a plurality of radially extending through holes and provides a resonance cavity radially between the outer cylinder and the sleeve.

In a further example of the foregoing, a plurality of axially spaced annular plates are located within the resonance cavity, each of the plurality of annular plates include a plurality of axially extending through holes.

In a further example of any of the foregoing, the radially extending through holes form axially spaced circumferential rows of radially extending through holes, and provide the plurality of axially spaced annular plates step, which includes positioning the plurality of annular plates axially between, and radially outward of, immediately adjacent of the circumferential rows.

In a further example of any of the foregoing, the resonance cavity is sealed at its axial ends.

In a further example of any of the foregoing, the sleeve is welded to the outer cylinder.

In a further example of any of the foregoing, the muffler is attached to the discharge portion.

In a further example of any of the foregoing, the muffler is configured to receive fluid from the discharge portion into the sleeve.

These and other features may be best understood from the following specification and drawings, the following of which is a brief description.

This disclosure relates generally to refrigerant compressors, and more particularly to mufflers at a discharge portion of a refrigerant compressor. The systems and methods disclosed herein have been found to decrease the noise output of refrigerant compressors. The term “muffler” as used herein is intended to refer to all types of noise reduction devices and is not intended to be limited to any size or shape.

schematically illustrates a refrigerant cooling system. The refrigerant systemincludes a main refrigerant loop, or circuit,in communication with a compressor or multiple compressors, a condenser, an evaporator, and an expansion device. This refrigerant systemmay be used in a chiller or heat pump, for example. While a particular example of the refrigerant systemis shown, this disclosure extends to other refrigerant system configurations. For instance, the main refrigerant loopcan include an economizer downstream of the condenserand upstream of the expansion device. The refrigerant cooling systemmay be an air conditioning system, for example.

illustrates an example compressorincluding a discharge portionwhere refrigerant exits the compressorbefore flowing to the condenser(see). The example discharge portionis where refrigerant exits the compressor, as opposed to a location between compressor stages. Although an example compressoris shown, other types of compressors may benefit from this disclosure.

illustrates an example muffler, which may be provided at the area A () fluidly between the compressorand the condenser. In some examples, the mufflermay be attached to, or otherwise positioned near, the discharge portion() of the compressor. The example mufflerincludes a hollow outer cylinderhaving a center axis. The outer cylinderis shown as transparent for ease of viewing the other components of the example muffler. A cylindrical sleeveis concentric with and radially inward of the outer cylinder. The sleeveincludes a plurality of radially extending through holes. An axially extending annular resonance cavityis provided radially between the radially inner surfaceof the outer cylinderand the radially outer surfaceof the sleeve. The example resonance cavityis sealed at axial ends of the cylinderand sleeve.

As shown schematically in, with continued reference to, the discharge flow from the discharge portionof the compressorenters the mufflerwith leftover swirl from the input rotational energy produced by the compressor impeller. The flow enters the mufflerinto the sleeve. As the flow enters and flows axially through the muffler, a portion of the fluid is directed radially outward through the radially extending through holes, being reoriented to the resonance cavityand creating pressure wave reflections in the flow that, in turn, generate reflective waves that cancels the naturally incoming pressure waves. The result is a decrease in overall noise generation from the compressor.

Refrigerant enters the mufflerat one axial endof the sleeveand exits the mufflerat an opposite axial endof the sleeve. Because the resonance cavityis sealed at the axial ends, refrigerant flows back radially inward of the radially inner surfaceof the sleevebefore exiting the mufflerat the axial end. In some examples, as shown, the resonance cavityis sealed at its axial ends by annular radially inwardly extending extensionsreceived against the sleeve. In the example, the resonance cavityreceives fluid through the through holesof the sleeverather than being fed fluid directly from the discharge portionat its axial end.

The mufflerdesign can be finely tuned to reflect specific wavelengths that exhibit the highest level of noise in the compressor operation, such as through sizing the holesand their spacing to generate noise at desired frequencies. In some examples, the radially extending through holesare equally circumferentially spaced from one another.

In some examples, the sleeveis manufactured separately, according to the desired application, and fixed to the cylinder, such as by mechanical connection or welding in some examples.

illustrate another example mufflersubstantially similar to the mufflerexcept that a plurality of axially spaced annular platesare provided within the resonance cavity. It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. One or more or each of the example platesincludes a plurality of circumferentially spaced axially extending through holes. In some examples, as shown, the radially extending through holesof the sleeveform axially spaced circumferential rows of through holes, and the platesare positioned axially between, and radially outward of, immediately adjacent rows. The example platesare disk-shaped, extending a full circumference.

The usage of additional platesallows for more frequencies to be resonated within the system, and the decrease of noise generation of multiple frequencies. The mufflerdesign can be finely tuned to reflect specific wavelengths that exhibit the highest level of noise in the compressor operation. This is done by sizing the holes and their spacing in both the sleeveand in the platesto generate noise at desired frequencies.

In some examples, the axially extending through holesare equally circumferentially spaced from one another. In some examples, as shown, the axially extending through holesare circumferentially aligned across two or more of the plates. In some examples, as shown, the axially extending through holesare circumferentially aligned with adjacent radially extending through holes. In some examples, as shown, the radii of the axially extending through holesare greater than the radii of the radially extending through holes. Applicant has found that the above examples can be utilized to resonate noise at certain frequencies.

schematically illustrates flow through the example mufflerof.

A method in view of the above examples may be said to include providing a muffler/fluidly between a discharge portion of a compressor and a condenser, the muffler including a hollow outer cylinder including an inner diameter surface and a center axis, and a hollow inner cylinder or sleeve concentric with the outer cylinder and including a plurality of radially extending through holes.

An example refrigerant compressor may be said to include a discharge portion and a muffler at the discharge portion. The muffler includes an outer cylinder having a center axis, and a sleeve concentric with, and radially inward of, the outer cylinder relative to the center axis. The sleeve includes a plurality of radially extending through holes, providing a resonance cavity radially between the sleeve and the outer cylinder.

The foregoing description shall be interpreted as illustrative. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. Various examples of the disclosure have been described. Any combination of the described systems, operations, or functions is contemplated. It is possible to use some of the components or features from any of the examples in combination with features or components from any of the other examples. These and other examples are within the scope of the following claims.