A header includes a plurality of branch tubes and a header manifold. If refrigerant flowing into the header manifold forms a pattern of annular flow or churn flow, tips of the branch tubes inserted into the header manifold pass through a liquid-phase portion having a thickness δ [m] and reach a gas-phase portion. The thickness δ [m] of the liquid-phase portion is defined as δ=G×(1−x)×D/(4ρ.sub.L×U.sub.LS), where G is a flow speed [kg/(m.sup.2 s)] of the refrigerant, x is a quality of the refrigerant, D is an inside diameter [m] of the header manifold, ρ.sub.L is a liquid density [kg/m.sup.3] of the refrigerant, U.sub.LS is a reference apparent liquid speed [m/s] that is a maximum value within a range of variation in an apparent gas speed of the refrigerant flowing into a flow space of the header manifold. The reference apparent liquid speed U.sub.LS [m/s] is defined as G(1−x)/ρ.sub.L.

A cooling system and a related method is presented. The cooling system includes a reservoir configured to selectively supply a cooling fluid; a circulation loop fluidly coupled to the reservoir, and configured to circulate the cooling fluid to and from the reservoir, and a heat exchanger thermally coupled to the circulation loop and configured to exchange heat with the cooling fluid. The reservoir includes a refrigerant and an anti-freeze additive. The anti-freeze additive is characterized by a lower critical solution temperature (LCST) such that when an operating temperature of the reservoir is greater than the LCST, the reservoir is configured to supply a cooling fluid including the refrigerant to the circulation loop; and when the operating temperature of the reservoir is lower than the LCST, the reservoir is configured to supply a cooling fluid including the refrigerant and the anti-freeze additive to the circulation loop.

An apparatus includes a captured carbon dioxide input. The captured carbon dioxide input is coupled to receive captured carbon dioxide from a direct air capture system. The apparatus uses the captured carbon dioxide as a low global warming refrigerant to provide cooling functionality in automotive, commercial, and industrial applications, or other operations involving low global warming refrigerants. In various embodiments, the apparatus is a refrigeration apparatus or a heat pump apparatus. Low global warming carbon dioxide refrigerant is natural, non-toxic, non-flammable, and abundant when obtained from a direct air capture system. Moreover, carbon dioxide refrigerant has a high heat transfer coefficient and has a global warming potential (GWP) of one. Carbon dioxide refrigerant is a more sustainable and efficient coolant option than common refrigerants, such as R22, R152, R404a, and R1234yf refrigerants.

A heat transfer apparatus includes a plurality of “n” number of control valves, each of the plurality of “n” number of control valves including a control valve inlet and a control valve outlet; a like plurality of “n” number of evaporator sections, each of the like plurality of “n” number of evaporator sections including an evaporator section inlet and an evaporator section outlet, each evaporator section inlet fluidly coupled to a corresponding one of the plurality of “n” number of control valve outlets, each evaporator section configured to extract heat from at least one heat load that is in thermal conductive or convective contact or proximate to the evaporator section; a refrigerant fluid inlet fluidly coupled to the like plurality of evaporator sections; and a refrigerant fluid outlet fluidly coupled to the like plurality of evaporator sections.

Air-cooled module for an air-cooled refrigeration cycle apparatus, comprising a desuperheater and condenser heat exchanger configured for being fluidly connected to compressor means of the air-cooled refrigeration cycle apparatus and a subcooler configured for being fluidly connected to expansion means of the air-cooled refrigeration cycle apparatus, both the desuperheater and condenser heat exchanger and the subcooler being configured to allow the passage of a refrigerant fluid inside themselves for cooling the refrigerant fluid thanks to an air flow directed to pass through these latter, the subcooler being fluidically in series downstream and physically separated with respect to the desuperheater and condenser heat exchanger, these latter elements being positioned relatively so the air flow passes before in the subcooler and then in the desuperheater and condenser heat exchanger.

It is an object of the present invention to provide a fluid stirring and liquefaction promoting apparatus which enables uniform mixture of refrigerator oil with refrigerant, thereby improving the heat exchange efficiency of heat pump systems and reducing the energy consumption.

There is provided a liquefaction promoting apparatus to be disposed on a pipeline of a heat pump system for the purpose of stirring and uniformly mixing the fluid containing refrigerant and refrigerator oil circulating therein. The apparatus comprises a cylindrical casing, one or more channelizing units each composed of a pair of large-diameter disks on its outer side and a pair of small-diameter disks on its inner side disposed in axial alignment inside the cylindrical casing. Each of the large-diameter disks is on its inner surface with a honeycomb panel having polygonal cells and each of the small-diameter disks is formed on its outer surface with a honeycomb panel having polygonal cells such that the honeycomb panels of the large-diameter disks and of the small-diameter disks are arranged to face each other and each polygonal cell communicates with more than one opposing polygonal cells. The fluid containing refrigerant and refrigerator oil is circulated in the heat pump system with a pressure of 0.2 to 10 MPa.

Some embodiments of the present disclosure provide a heat exchanger, including: at least three heat exchange tube groups, herein the heat exchange tube groups are communicated in sequence, and at least two heat exchange tube groups are superposed mutually along a direction in which a heat exchange airflow flows, a medium sequentially flows through each heat exchange tube group and forms a U-shaped trajectory; an intermediate adapter portion, herein at least two heat exchange tube groups are communicated with each other by means of the intermediate adapter portion, the intermediate adapter portion includes at least two adapters and an adapter tube communicated with the two adjacent adapters, herein the adapter is composed of a first plate and a second plate, the adapter tube is an extrusion-formed flat tube, and a width direction of the adapter tube is perpendicular to a width direction of the heat exchange tube groups.

A heat pump is provided that includes a first pipe in which a first refrigerant flows; a second pipe disposed at a side of the first pipe and in which a second refrigerant flows; a first heat exchanger connected with the first pipe and the second pipe and in which the first refrigerant exchanges heat with the second refrigerant; a boiler connected with the first pipe and in which the first refrigerant flows; a compressor connected with the second pipe and that compresses the second refrigerant; a second heat exchanger connected with the second pipe and in which the second refrigerant exchanges heat with outdoor air; a bypass pipe branched from first pipe and configured to exchange heat with the second heat exchanger; and a three-way valve that directs the first refrigerant to pass through the bypass pipe. When the outdoor heat exchanger operates as an evaporator, frost formation thereon may be prevented.

An energy efficient heat pump for a heating, ventilation, and air conditioning (HVAC) system includes a vapor compression circuit, a heat exchanger of the vapor compression circuit configured to place a working fluid in a heat exchange relationship with an air flow directed across the heat exchanger, and a conduit system of the vapor compression circuit. The conduit system of the vapor compression circuit is configured to direct the working fluid into the heat exchanger and to receive the working fluid from the heat exchanger, wherein the conduit system is configured to direct the working fluid into the heat exchanger to place the working fluid in a counterflow arrangement with the air flow directed across the heat exchanger in a cooling mode of the heat pump and in a heating mode of the heat pump.

An economizer module for increasing energy efficiency of a pumped refrigerant cooling system is connected to a refrigerant pumping unit including a primary pump connected with heat extractor(s) via a primary circuit and a primary heat exchanger connected with a condensing unit via a secondary circuit. The economizer module includes a control panel with control software, a secondary heat exchanger connected with the heat extractor(s) via the primary circuit and with the primary heat exchanger, a cooler connected with the secondary heat exchanger via an economizer circuit, and a secondary pump connected between the cooler and the secondary heat exchanger. The control panel executes the control software to control fluid flow in the economizer circuit via the secondary pump so as to use ambient air to reject heat from working fluid being used to collect heat from refrigerant in said primary circuit before said heat travels to said secondary circuit.