An outer finned tube includes a tube body, an outer wall of the tube body is provided with outer fins spirally arranged in an extension direction of the tube body; grid fins are arranged between two adjacent spiral parts of the outer fins correspondingly; two ends of each grid fin are connected to the two adjacent spiral parts of the corresponding outer fin respectively; a gap is kept between each grid fin and the outer wall of the tube body; and the plurality of grid fins are spaced in the extension direction of the tube body. An enhancing cavity is formed in an area defined by the outer wall of the tube body, inner walls of the grid fins and the outer fins in an encircling way, which can form a larger degree of superheat, provides a nucleation point for a boiling/condensation process and improves a heat exchange performance.

A heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a heat exchanger with a shell having a first pass configured to place a fluid in a heat exchange relationship with a first refrigerant and a second pass configured to place the fluid in a heat exchange relationship with a second refrigerant. The heat exchanger also includes a water box coupled to the shell and configured to direct the fluid from the first pass to the second pass. The HVAC&R system also includes a fluid mixing manifold disposed within the water box, where the fluid mixing manifold is configured to collect and mix a plurality of flows of the fluid from within the water box to generate a mixed fluid, and a sensor coupled to the fluid mixing manifold, where the sensor is configured to measure a parameter of the mixed fluid.

A heat exchanger satisfies Expression (1) below, where the number of the main heat transfer tubes is represented as N.sub.1, and the number of the sub-heat transfer tubes is represented as N.sub.2. In this heat exchanger, the main heat exchanger satisfies Expressions (2) and (3) below, while the sub-heat exchanger satisfies Expressions (4) and (5) below.

0.1<N.sub.2(N.sub.1+N.sub.2)<0.4  (1)

0.03<Ta.sub.1/Ha.sub.1<0.3  (2)

0.03<Ta.sub.2/Ha.sub.2<0.3  (3)

AT.sub.1<Gr.sub.1/(G×D.sub.1(ρL.sub.1−ρG.sub.1)).sup.(1/2)×(X.sub.1.sup.(1/2)×ρG.sub.1.sup.(−1/4)+(1−X.sub.1).sup.(1/2)×ρL.sub.1.sup.(−1/4)).sup.2  (4)

AT.sub.2<Gr.sub.2/(G×D.sub.2(ρL.sub.2−ρG.sub.2)).sup.(1/2)×(X.sub.2.sup.(1/2)×ρG.sub.2.sup.(−1/4)+(1−X.sub.2).sup.(1/2)×ρL.sub.2.sup.(−1/4)).sup.2  (5)

A heat exchanger satisfies Expression (1) below, where the number of the main heat transfer tubes is represented as N.sub.1, and the number of the sub-heat transfer tubes is represented as N.sub.2. In this heat exchanger, the main heat exchanger satisfies Expressions (2) and (3) below, while the sub-heat exchanger satisfies Expressions (4) and (5) below.

0.1<N.sub.2(N.sub.1+N.sub.2)<0.4  (1)

0.03<Ta.sub.1/Ha.sub.1<0.3  (2)

0.03<Ta.sub.2/Ha.sub.2<0.3  (3)

AT.sub.1<Gr.sub.1/(G×D.sub.1(ρL.sub.1−ρG.sub.1)).sup.(1/2)×(X.sub.1.sup.(1/2)×ρG.sub.1.sup.(−1/4)+(1−X.sub.1).sup.(1/2)×ρL.sub.1.sup.(−1/4)).sup.2  (4)

AT.sub.2<Gr.sub.2/(G×D.sub.2(ρL.sub.2−ρG.sub.2)).sup.(1/2)×(X.sub.2.sup.(1/2)×ρG.sub.2.sup.(−1/4)+(1−X.sub.2).sup.(1/2)×ρL.sub.2.sup.(−1/4)).sup.2  (5)

A heat exchanger includes a plurality of heat exchange units each including a plurality of flat tubes, a plurality of fins, an upper header, and a lower header. In the plurality of heat exchange units, the upper headers are connected such that the upper headers communicate with each other, and the lower headers are connected such that the lower headers communicate with each other through an opening-closing valve. The heat exchanger has a configuration in which when the heat exchanger serves as a condenser, the opening-closing valve is controlled such that refrigerant in at least one of the plurality of heat exchange units flows in an upward direction, and refrigerant in the other one or the other ones of the plurality of heat exchange units flows in a downward direction.

A heat exchanger includes a plurality of flat heat transfer tubes and a header, wherein the header includes an inflow plate that divides an interior portion of the header into an inflow portion and a circulation portion located on an upper side of the inflow portion, a first partition member that divides the circulation portion into ascending path to which the flat heat transfer tubes are connected and a descending path, that forms an upper communication path that communicates the ascending path and the descending path on an upper side of the circulation portion, and a lower communication path that communicates the ascending path and the descending path on a lower side of the circulation portion, and the inflow plate includes a first ejection hole that ejects, on the ascending path side and a downwind side, a refrigerant from the inflow portion to the ascending path.

An end cover structure and a water chiller. The end cover structure includes: an end cover body; a water inlet pipe, provided on the end cover body; a water outlet pipe, provided on the end cover body, the water outlet pipe and the water inlet pipe being provided independent of each other; a bypass pipeline in which two cavities are formed, one of the two cavities being communicated with the water inlet pipe, and the other being communicated with the water outlet pipe; and an adjusting member, movably provided in the bypass pipeline. The adjusting member is movable to adjust the communication between the two cavities.

An example refrigeration system includes an indoor fluid loop, an outdoor fluid loop, and a heat exchanger assembly. The indoor fluid loop circulates a first working fluid. The outdoor fluid loop circulates a second working fluid that is different from the first working fluid and is separated from the indoor fluid loop by a wall of a structure. The heat exchanger assembly is mounted within the wall of the structure. The heat exchanger assembly includes a heat exchanger and a housing, where the heat exchanger is disposed within an internal space defined by the housing. The housing supports the heat exchanger within the internal space and is mounted to a structure of the wall.

Disclosed is a CO.sub.2 based refrigeration system including a condenser for transferring heat from a CO.sub.2 refrigerant of the refrigeration system to an air stream. The system further includes a metering device downstream of the condenser and a bypass arrangement. The metering device is configured to create a pressure drop so that part of the refrigerant liquifies, when received in a supercritical state, from the condenser such that a liquid component and a flash gas component are generated. The bypass arrangement includes a valve and a bypass line to allow the refrigerant to bypass the metering device.

Disclosed is a CO.sub.2 based refrigeration system including a condenser for transferring heat from a CO.sub.2 refrigerant of the refrigeration system to an air stream. The system further includes a metering device downstream of the condenser and a bypass arrangement. The metering device is configured to create a pressure drop so that part of the refrigerant liquifies, when received in a supercritical state, from the condenser such that a liquid component and a flash gas component are generated. The bypass arrangement includes a valve and a bypass line to allow the refrigerant to bypass the metering device.