A heat exchanger includes: a plurality of flat tubes arranged in a height direction of the heat exchanger; a connection portion in which a plurality of connection spaces are provided as spaces with which ends of the plurality of flat tubes are connected; and a refrigerant distributor connected to each of the plurality of connection spaces. The flat tubes each have a first side end portion located on a windward side, a second side end portion located on a leeward side, and a plurality of refrigerant passages arranged between the first and second side end portions. Each flat tube is inclined such that in the height direction, the position of the first side end portion is lower than the position of the second side end portion. The connection spaces are spaced from each other in the height direction, and a lower side of each of the connection spaces has a first region located on the windward side and a second region located on the leeward side, and is inclined such that in the height direction, the position of the first region is lower than a position of the second region.

A cooling system for a motor vehicle may include a first circuit, a second circuit, a first heat exchanger incorporated in the first circuit, and a second heat exchanger incorporated in the second circuit. The first heat exchanger and the second heat exchanger may be flowed through by ambient air and a coolant. The first heat exchanger may be arranged, relative to an airflow direction, in front of and directly adjacent to the second heat exchanger. The first circuit and the second circuit may be fluidically connected to one another at an upstream distribution point and at a downstream collection point such that a part mass flow of the coolant is flowable from the second circuit into the first circuit at the distribution point, from the first circuit into the first heat exchanger, and out of the first heat exchanger back into the second circuit at the collection point.

A layered diffuser-channel heat exchanger may comprise a plurality of fluid channel layers and a plurality of diffuser fin layers interleaved with the plurality of fluid channel layers. Each fluid channel layer of the plurality of fluid channel layers may have a first surface, a second surface opposite the first surface, and a fluid channel located between the first surface and the second surface.

A compact, lightweight multilayer heat exchanger for an electric vehicle, including a first heat exchanger configured to enable cooling of a first heat conducting fluid medium traversing therethrough, and a second heat exchanger configured to enable cooling of a second heat conducting fluid medium traversing therethrough, wherein at least portions of the first heat exchanger are in contact with the second heat exchanger enabling heat transfer between the first heat exchanger and second heat exchanger.

A multi-step method is disclosed for exchanging heat in a vapor compression heat transfer system having a working fluid circulating therethrough. The method includes the step of circulating a working fluid comprising a fluoroolefin to an inlet of a first tube of an internal heat exchanger, through the internal heat exchanger and to an outlet thereof. Also disclosed are vapor compression heat transfer systems for exchanging heat. The systems include an evaporator, a compressor, a dual-row condenser and an intermediate heat exchanger having a first tube and a second tube. A disclosed system involves a dual-row condenser connected to the first and second intermediate heat exchanger tubes. Another disclosed system involves a dual-row evaporator connected to the first and second intermediate heat exchanger tubes.

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)

Embodiments of the present invention disclose a heat exchanger and an air-conditioning system. The heat exchanger includes heat exchange tubes. The heat exchange tubes have first heat exchange tubes configured to form a first circuit, and second heat exchange tubes configured to form a second circuit. With the heat exchanger and the air-conditioning system according to the embodiments of the present invention, for example, a heat exchange capacity of the heat exchanger in a part load condition is improved.

Provided is a process for reducing the size of ethylcellulose polymer particles comprising (a) providing a slurry comprising (i) water (ii) said ethylcellulose particles, wherein said ethylcellulose polymer particles have D50 of 100 μm or less; (iii) surfactant comprising 1.2% or more anionic surfactants by weight based on the solid weight of said slurry, with the proviso that if the amount of anionic surfactant is 2.5% or less by weight based on the solid weight of said slurry, then said surfactant further comprises 5% or more stabilizers by weight based on the solid weight of said slurry, wherein said stabilizer is selected from the group consisting of water-soluble polymers, water-soluble fatty alcohols, and mixtures thereof. (b) grinding said slurry in an agitated media mill having a collection of media particles having a median particle size of 550 μm or smaller.

Also provided is a dispersion made by such a process.

A combined heat exchanger is provided. The combined heat exchanger includes at least two heat exchanger cores, a first communicating member and a second communicating member. Each of the at least two heat exchanger cores includes at least a first collecting pipe, a second collecting pipe and multiple flat pipes. The flat pipes are vertically disposed between the first collecting pipe and the second collecting pipe. Both ends of the first communicating member are in communication with the first collecting pipes of two adjacent heat exchanger cores, respectively; both ends of the second communicating member are in communication with the second collecting pipes of the two adjacent heat exchanger cores, respectively; and the two adjacent heat exchanger cores are disposed on different planes.

A method of operating a heat exchanger is disclosed in which an electric field is applied to a hydrophobic surface having condensed water droplets thereon to reduce a contact angle between the individual droplet surfaces and the hydrophobic surface, and to increase droplet surface energy to a second surface energy level. The electric field is removed to increase the contact angle between the individual droplet surfaces and the hydrophobic surface, and to reduce droplet surface energy to a third surface energy level. The third surface energy level is greater than the first surface energy level and greater than a surface energy level for a free droplet. A portion of the droplet surface energy is converted to kinetic energy to detach droplets from the hydrophobic surface. The detached droplets are removed from the heat rejection side fluid flow path.