An air conditioning device has: a refrigerant circuit that includes a compressor, a switching valve, a cascade heat exchanger, an expansion valve and an outdoor heat exchanger connected to one another by a first pipe through which a refrigerant flows, and that performs a defrosting operation in which the refrigerant discharged from the compressor is introduced into the outdoor heat exchanger; a heat-transfer medium circuit that includes a pump, the cascade heat exchanger, and the indoor heat exchanger connected to one another by a second pipe through which a heat-transfer medium flows; and a control device that controls the compressor and the pump. When an amount of heat storage of the heat-transfer medium is less than a threshold, the control device reduces the heating capability of the indoor heat exchanger when the air conditioning device transitions from a heating operation to the defrosting operation.

In one embodiment, an apparatus includes an insert for an evaporator coil. The insert is a curved wire located within the evaporator coil. The insert for the evaporator coil reduces refrigerant charge in the evaporator coil and causes refrigerant flowing through the evaporator coil to change direction.

The present application provides an evaporator, comprising: a housing, a first heat exchange tube set, a second heat exchange tube set, a first side heat exchange tube baffle device, a second side heat exchange tube baffle device, and a redistribution device. The first heat exchange tube set is located above the second heat exchange tube set, and the number of columns of the first heat exchange tube set is greater than that of the second heat exchange tube set. The first side heat exchange tube baffle device and the second side heat exchange tube baffle device are respectively disposed on two opposite sides of the first heat exchange tube set and the second heat exchange tube set, and are arranged along the outer contours of the first heat exchange tube set and the second heat exchange tube set, so as to guide a refrigerant to flow from the first heat exchange tube set to the second heat exchange tube set. The redistribution device is disposed between the first heat exchange tube set and the second heat exchange tube set to evenly distribute the refrigerant to the second heat exchange tube set. The evaporator in the present application has higher heat exchange efficiency.

A heating, ventilation, and air conditioning (HVAC) system and controller therefor to operate with thermal energy reservoirs are provided to set a four-way valve to route a refrigerant through a refrigerant circuit in a first direction when the HVAC system is set to a cooling mode or in a second direction, opposite to the first direction, when the HVAC system is set to a heating mode; and set bypass valves in the refrigerant circuit based on a temperature of a temperature holding material in a thermal energy reservoir and which of the heating mode and the cooling mode the four-way valve is set to, wherein the bypass valves route the refrigerant through the thermal energy reservoir to transfer thermal energy between the refrigerant and the temperature holding material.

The present disclosure discloses a MgAl based magnesium alloy, and a preparation method of a tube and an application of the same, and belongs to the technical field of alloy materials. The magnesium alloy includes, by weight percentage, 7.0-8.6% Al, 0.8-2.0% RE, 0.2-0.8% Mn, and a balance of Mg, and the magnesium alloy has an elongation of 15-22%. The preparation method of a tube of the MgAl based magnesium alloy includes: mixing and smelting an Al source, a RE source, a Mn source, and a Mg source to give a liquid mixed metal; casting the liquid mixed metal into a bar through semi-continuous casting; performing homogenization heat treatment on the bar at 360-400 C. for 6-10 h; and performing extrusion-forming on the heat-treated bar to obtain a magnesium alloy tube. The MgAl based magnesium alloy of the present disclosure has high elongation, and the elongation of the tube formed using the same can reach 15-22%, so that it can withstand large plastic deformation. Meanwhile, the MgAl based magnesium alloy has excellent welding performance and a welding loss rate of less than 6%, which greatly reduces the strength loss of magnesium alloy profiles after welding, and ensures the strength of magnesium alloy profiles after welding. The MgAl based magnesium alloy can be used in the fields of vehicle equipment and medical equipment.

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 refrigeration system includes a refrigeration circuit and a coolant circuit separate from the refrigeration circuit. The refrigerant circuit includes a gas cooler/condenser, a receiver, and an evaporator. The coolant circuit includes a heat exchanger configured to transfer heat from a refrigerant circulating within the refrigeration circuit into a coolant circulating within the coolant circuit, a heat sink configured to remove heat from the coolant circulating within the coolant circuit, and a magnetocaloric conditioning unit configured to transfer heat from the coolant within a first fluid conduit of the coolant circuit into the coolant within a second fluid conduit of the coolant circuit. The first fluid conduit connects an outlet of the heat exchanger to an inlet of the heat sink, whereas the second fluid conduit connects an outlet of the heat sink to an inlet of the heat exchanger.

A heat exchanger includes a plurality of fins and a plurality of tubes that are inserted into the fins and that allow refrigerant to flow in the tubes. The tubes include first heat transfer tubes and second heat transfer tubes. Each of the first heat transfer tubes includes grooves formed in an inner surface of the first heat transfer tube, and has an inside diameter Da and a groove depth Ta. Each of the second heat transfer tubes has an inner surface smoothed, has an inside diameter Db, and is connected to an associated one of the first heat transfer tubes. Da?2?Ta?Db is satisfied.

A one-piece part based on magnetocaloric material comprising an alloy comprising iron and silicon and a lanthanide, comprises a base in a first plane defined by a first and second direction and N unitary blades secured to the base; the blades having a first and second dimension in the first and second direction, respectively, and a third dimension in a third direction at right angles to the first and second dimensions; an ith blade being separated from an (i+1)th blade by an ith distance; the ratio between the second dimension and first dimension being at least 10; the ratio between the third dimension and first dimension being at least 6; the first dimension being the same order of magnitude as the distance separating an ith blade from an (i+1)th blade. The magnetocaloric material can be rare-earth alloy or a composite material based on polymer binder and rare-earth alloy.

An apparatus includes a first compressor, a first load, a second compressor, a second load, and a heat exchanger. The first compressor compresses a first refrigerant. The first load uses the first refrigerant to remove heat from a space proximate the first load. The first load sends the first refrigerant to the first compressor. The second compressor compresses a second refrigerant. The second load uses the second refrigerant to remove heat from a space proximate the second load. The second load sends the second refrigerant to the second compressor. The heat exchanger receives the first refrigerant from the first compressor and receives the second refrigerant from the second compressor. The heat exchanger transfers heat from the first refrigerant to the second refrigerant. The heat exchanger discharges the first refrigerant to the first load and discharges the second refrigerant to the second compressor.