In various implementations, an air conditioner may include one or more compressors, more than one expansion device, and/or a microchannel condenser. High pressure events may occur during operation of the air conditioner and may be identified. When a high pressure event is identified a bypass operation may be allowed.

A refrigeration cycle apparatus includes a refrigerant circuit, a high-side pressure sensor, an outside air temperature sensor, an outdoor fan, a fan driving unit, and a controller. The controller includes a pressure prediction unit that predicts, based on a high-side pressure detected by the high-side pressure sensor, a predicted value of high-side pressure at the elapse of a set time, a fan rotation speed control unit that, during cooling operation in which an indoor heat exchanger acts as an evaporator, adjusts the rotation speed of the fan driving unit based on the outside air temperature detected by the outside air temperature sensor and the operating capacity of an indoor unit, and an intermittent fan control unit that, if the fan driving unit is running at a set lower limit rotation speed, and if the high-side pressure is below a target value, controls the fan driving unit to perform intermittent operation, the intermittent operation being performed by setting an ON time and an OFF time such that the predicted value predicted by the pressure prediction unit approaches the target value.

An electric-power control device including a substrate of an annular shape in which a through hole is formed and a connector is arranged in a peripheral part, the electric-power control device driving an electric motor. On the substrate, a power semiconductor module is mounted on a first region on one side relative to a straight line connecting the center of the through hole to the center of the connector, and a microcomputer is mounted on a second region on the other side. Furthermore, a first ground pattern part that is formed extending from the power semiconductor module toward the connector in the first region and a second ground pattern part that is formed extending from the microcomputer toward the connecter in the second region are provided on the substrate.

The present utility model relates to a deflector for a condenser. The condenser has an inlet in communication with a compressor, and a deflector for guiding a refrigerant gas flow from the compressor is arranged in the condenser and at a position close to the inlet. The deflector is provided with a deflecting structure projecting toward the inlet, and the deflecting structure is configured as impermeable to the refrigerant gas flow. The present utility model further provides a condenser having the deflector for a condenser and a refrigeration system equipped with the condenser. The deflector for a condenser according to the present utility model not only can alleviate the impact of high-temperature high-pressure gas from the compressor but also can reduce noise and vibration.

A heating, ventilation, and air conditioning (HVAC) system includes an expansion device disposed between a condenser and an evaporator of a vapor compression system and a control panel communicatively coupled to the expansion device. The control panel is configured to: determine a liquid refrigerant level set point of the condenser based on parameters of the vapor compression system, provide a first control signal to increase an opening of the expansion device in response determining that the current liquid refrigerant level in the condenser is greater than a determined liquid refrigerant level set point of the condenser, and provide a second control signal to decrease the opening of the expansion device in response to determining that the current liquid refrigerant level in the condenser is less than the determined liquid refrigerant level set point of the condenser.

The present disclosure relates to efficient condensing operations and apparatuses. Methods of fabricating condensers and specifically condenser surfaces are also disclosed. A condensing apparatus can include a condenser surface having a substrate and one or more layers of graphene. The substrate can be formed of nickel and a nickel-graphene surface composite layer can be formed. The substrate-graphene composite can be highly durable, hydrophobic, and resistant to fouling. Dropwise condensation can be induced.

A transportation refrigeration system includes an enclosure, and at least two compartments within the enclosure to be conditioned to two distinct temperatures. A refrigeration is circuit associated with each of the at least two compartments. A first refrigeration circuit includes a first compressor, a first evaporator, and a first expansion valve. A second refrigeration circuit includes a second compressor, a second evaporator, and a second expansion valve. The first and second refrigeration circuits utilize a common condenser, with first inlets into the condenser from the first circuit connected to a first flow passage and second inlets from the second circuit connected to second flow passages. First and second outlets are connected to the first and second flow passages. The first and second flow passages are staggered in a direction perpendicular to a flow passage across the condenser. A heat exchanger is also disclosed.

A condenser having passages of varying geometry for cooling of fluid. The condenser apparatus includes substantially parallel tubes each defining a channel and having an inlet at a first end and an outlet at a second end, the first end having a greater hydraulic diameter than the second end. Inlet and outlet manifolds are provided. The tubes may be oriented substantially vertically with the inlets above the respective outlets. A heat exchanger core comprises the tubes and substantially horizontally oriented fin material connecting the tubes. The tubes may receive a relatively higher temperature vapor or vapor and liquid mixture into the inlets of the tubes, around the tubes coolant flows substantially horizontally to remove heat from the tubes, and relatively cooler saturated liquid is discharged from the outlets. In one embodiment, the tube's channel splits into multiple channels to reduce the hydraulic diameter and increase the surface area ratio.

A microchannel heat exchanger includes at least one manifold and at least one a microchannel tube. The microchannel tube includes a plurality of ports, and the microchannel tube extends from the at least one manifold. The plurality of ports each have a width and a height. The microchannel heat exchanger further includes at least one fin extending from the at least one manifold. The fins are arranged between the at least one microchannel tube and a second microchannel tube. The microchannel heat exchanger further includes a refrigerant arranged to flow through the microchannel tube. At least one port of the plurality of ports has a cross-section area less than 0.35 millimeters squared.

A refrigeration cycle apparatus includes a refrigerant circuit in which a compressor, a first heat exchanger, an expansion mechanism, and a second heat exchanger are connected by pipes. The first heat exchanger includes a first refrigerant passage and a second refrigerant passage that share a plurality of fins with each other and provided in parallel in the refrigerant circuit. The apparatus further includes a high-and-low-pressure switching mechanism which is located on an inlet side of the second refrigerant passage of the first heat exchanger in flowing of refrigerant in an operation in which the first heat exchanger functions as a condenser, and which performs switching between flow directions of the refrigerant. The apparatus further includes a refrigerant blocking mechanism located on an outlet side of the second refrigerant passage of the first heat exchanger in the flowing of the refrigerant in the operation, and which blocks the flowing of the refrigerant.