Noise Reduction Techniques in HVAC Compressors

Sealed compressor design to reduce vibration and noise by preventing gaps between the compressor container and base member during welding. The compressor has a cylindrical container with compressor and motor inside. The container bottom is welded to a base that supports it. The container bottom has an opening in the center that fits into an opening in the base. Welding spots are formed between the base and container at intervals around the opening. The welding spots extend a predetermined length in the circumferential direction and are positioned between the outer edge of the base opening and the container opening rim. This prevents deformation between the spots that could form gaps between the container and base during welding.

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A linear compressor with improved muffler design to reduce noise and improve rigidity. The compressor has a piston that linearly reciprocates in a cylinder to compress a fluid. It uses mufflers to suppress noise. The first muffler is attached to the piston. The second muffler is attached to the back cover spaced from the piston. The second muffler has a rib protruding from its inner or outer surface. This rib improves rigidity of the second muffler without affecting the refrigerant flow. The rib guides the muffler cover position relative to the muffler body. It also guides the muffler body position relative to the back cover. The ribbed muffler improves rigidity compared to a plain muffler. The ribbed muffler, in combination with the elastically supported back cover, reduces noise by amplifying the piston's

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Compressor device that improves energy efficiency and reduces vibrations compared to conventional compressors. The device has a compressor element to compress fluid. An adapter with expansion chambers at the outlet modifies the acoustic impedance to compensate for pressure pulsations. The adapter inlet has a smaller diameter than the outlet to create a step change. This causes the outgoing pressure pulsation to compensate the incoming pulsation, smoothing the fluid flow. The larger outlet area also improves evacuation and reduces pulsations.

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Rotary compressor and refrigeration cycle apparatus that reliably reduces pressure pulsation and vibration in the intermediate pipe connecting the low-stage and high-stage compressors, while downsizing the compressor overall. The compressor has a muffler connected to the intermediate pipe between the low-stage and high-stage compressors. The muffler outlet area is within a specific range relative to the flow path area. This optimized muffler size provides sufficient pulsation reduction without excessive muffler size. The compressor also has a fixation mechanism to secure the muffler. The muffler can be tangent or inside an imaginary circle centered on the compressor's axis, encompassing the accumulator, to minimize overall compressor size.

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Piston compressor with multiple gas discharge paths to reduce noise and vibration during operation compared to a single discharge path. The compressor has a cylinder head with a high-pressure chamber and a discharge hole. The crankcase has a high-pressure chamber, discharge channel, and discharge hole. The compressor has additional gas guide holes in components like the head gasket, valve plate, valve, and gasket. These paths allow gas to discharge via the crankcase channels instead of just the head hole, spreading out the discharge and reducing impact. This can significantly reduce vibration and noise compared to a single discharge path.

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Co-rotating scroll compressor for improved quietness. The scroll compressor has a driving scroll and a driven scroll that rotate around eccentric axes. To improve quietness, the scrolls have reduced thickness portions near the opposing scroll ends. These protrusions align the center of gravity of each scroll's spiral portion closer to its axis. This reduces dynamic imbalance during rotation compared to having thick scroll ends.

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Window-type air conditioner design to reduce noise transfer between the indoor and outdoor units. The air conditioner separates the compressor and outdoor heat exchanger from the indoor unit. It connects the two modules with a support that has soundproofing around the refrigerant pipe. This prevents noise from the compressor reaching the indoor space. The support also has features to improve connection strength considering the external forces applied to the window-mounted air conditioner.

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Reciprocating compressor design with reduced vibration transmission to the enclosure and improved discharge gas flow at high speeds. The compressor has multiple flexible discharge hoses connecting the discharge muffler and discharge pipe. This allows vibrations from the compressor body to be isolated from the enclosure since the flexible hoses can move independently. It also prevents clogging of the discharge gas during high-speed operation since the flexible hoses can accommodate any expansion/contraction of the discharge gas.

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Reducing noise in devices like compressors and ducted air movers by using a noise-damping resonator. It involves adding an acoustic resistive screen over an aperture between the air flow duct and a gas-filled cavity. The screen resists airflow between the duct and cavity, forming a resonator that attenuates noise in a target frequency band. The screen characteristics are optimized based on duct, cavity, and aperture geometry to maximize noise reduction.

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Heat pumps represent an essential component of the energy transition. While they are effective in generating heat, also generate sound, which has potential to cause annoyance. Therefore, it is enhance transparency sound behavior. Analyses were performed identify factors influencing levels at both and system levels. A total three refrigerant compressors examined with objective determining most acoustically efficient components currently available key acoustics. Two low-noise axial fans used illustrate differing characteristics when a heat pump application. Based on tests measurements level, speeds compressor fan confirmed as significant emissions air-to-water pumps. In addition, flow temperature operating point identified influencing. The results employed develop improved demonstrator. model could be developed that capable describing behavior for wide range conditions. This methodology allows increased Different behaviors can demonstrated basis model, discussions definition maximum specifications held data. Sound should not only linked output, this increases uncertainty comparability.... Read More

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Air-cooled compressor installation with improved fan housing for radial fans to reduce pressure drop, noise, and improve airflow. The fan housing has the fan inlet and outlet parallel planes. The fan axis at an angle between 0-45° to the inlet plane. The outlet edge doesn't intersect the fan axis extension to avoid bending airflow. This eliminates the need for the fan to bend airflow through a 90° turn at the outlet, reducing pressure drop and noise.

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A rotary compressor design for reducing noise, vibration and improving efficiency in air conditioners, refrigerators, and heaters using natural refrigerants like CO2. The compressor has a discharge space with 3-10 times the cylinder volume to mitigate pulsation when the gas exits the compression chamber. This reduces pressure fluctuations and noise compared to conventional compressors. The discharge space is formed by recessing one end plate and covering it with a separate plate.

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A piston rod mechanism for an air compressor that reduces noise during operation. The mechanism has an intake valve secured to the piston with pivot pins. It also has a receiving portion in the piston to house the closed intake valve. This allows the intake valve to oscillate relative to the piston as it moves. The receiving portion prevents the valve from contacting the piston and generating noise when the valve is closed. This improves the overall noise level of the air compressor. The valve can be made of silicone, the rod of plastic, the bearing of metal, and the piston ring of rubber to further reduce noise.

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Apparatus for damping pressure pulsation in a refrigerant compressor that reduces noise without significant pressure loss. It has a piston in a housing that can move to control flow area. The piston has seals to create chambers that expand the fluid as it flows. This dampens pressure pulsations when the compressor has low flow. The piston moves between closed and fully open positions. The chambers allow flow when the piston is not at the ends. The piston seals contact the housing seals. This simple, compact design with minimal components and materials reduces costs and space requirements compared to complex valves or silencers.

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A linear compressor for compressing a refrigerant using a piston that linearly reciprocates in a cylinder. The compressor has two muffler units to improve noise filtering, intake efficiency, and space efficiency. The first muffler is between the piston and back cover. The second muffler surrounds the first muffler and has a communication hole between the inner and outer mufflers. This allows fluid flow between the mufflers. The outer muffler also surrounds the cylinder opening. This dual muffler setup filters noise, improves intake efficiency by capturing and compressing more fluid, and saves space compared to a single muffler.

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Abstract In this paper, a systematic experimental study is carried out on the overclocking operation of chillers. Based platform under nominal refrigeration conditions, evolution key performance parameters such as evaporation pressure, condensation capacity, power, and noise different driving frequencies was tested. The results show that with increase frequency, capacity increases linearly, while coefficient chiller decreases significantly, sound pressure level shows nonlinear acceleration upward trend. This achievement can provide theoretical basis engineering decision support for selection design chillers, frequency conversion optimization, energy efficiency-noise collaborative control in industrial field.

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Motor-driven compressor with improved heat dissipation and noise reduction. The compressor has an inverter to convert DC power to AC for the motor. A noise reducing unit at the inverter input reduces common mode and normal mode noise in the DC power. The inverter case is thermally coupled to the compressor housing. A damping unit forms a magnetic path for the choke coil leakage flux and increases choke inductance. This damping unit covers part of the choke coil side surface and is thermally coupled to the inverter case and compressor housing for heat dissipation.

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Heat pump water heater with mufflers to reduce noise transmission from the compressor. The heat pump water heater has mufflers, an inlet muffler between the compressor and air inlet, and an outlet muffler between the compressor and air outlet. These mufflers prevent sound waves generated by the compressor from traveling through the air inlet and outlet and escaping the water heater, reducing exterior noise levels.

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Electric compressor for refrigeration applications that has reduced noise, vibration, and pulsation compared to prior art scroll-type electric compressors. The compressor has features like a modified fixed scroll floor, an isolation/constraint system, and a reed mechanism in the head. These reduce oscillations and pulsations during operation that can transmit to the housing and cause noise, vibration, and durability issues. The modified scroll floor reduces articulation and oscillations of the scroll. The isolation/constraint system isolates the housing from compressor oscillations. The reed mechanism in the head releases compressed refrigerant earlier from side ports before the central port to prevent strong pulsations in the refrigerant flow.

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Electric compressor for refrigeration systems that compresses refrigerant using a scroll compression device. The compressor has features to improve efficiency, reduce noise, and extend durability compared to prior scroll compressors. These include: 1. Swing-link mechanism with integrated limit pin to replace separate drive and eccentric pins. This simplifies and strengthens the connection between the drive shaft and swing-link. 2. Discharge head with an integrated oil separator to separate oil from refrigerant before exiting. 3. Scroll bearing with oil injection orifice to ensure adequate oil lubrication. 4. Bearing oil communication hole in the drive shaft to improve oil flow to bearings. 5. Dome-shaped inverter cover to reduce vibrations and noise.

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