A multi-connected heat recovery air conditioning system and a control method thereof. The multi-connected heat recovery air conditioning system includes an indoor unit, an outdoor unit and a hydraulic module, wherein the outdoor unit comprises a compressor, an outdoor heat exchanger, a first four-way valve and a second four-way valve. The multi-connected heat recovery air conditioning system further comprises an indoor unit temperature unit, a water temperature unit, a high-pressure sensor and a low-pressure sensor. The indoor unit temperature unit is arranged in the indoor unit for detecting and obtaining the outlet temperature value of the indoor unit, the water temperature unit is arranged at a heat exchange water tank for detecting and obtaining water temperature, and the high-pressure sensor and the low-pressure sensor are arranged at the output end and the air return end of the compressor respectively.

A thermal management system includes a refrigerant system, which includes a compressor, a flow control device, a valve member, a first heat exchanger, a second heat exchanger, and a third heat exchanger. The flow control device includes a first throttle unit, a second throttle unit, and a valve assembly; the flow control device includes a first port, a second port, and a third port; a first connection port of the first heat exchanger is in communication with the second port, and a first connection port of the second heat exchanger is in communication with the third port, while a first connection port of the third heat exchanger is in communication with the first port. The thermal management system includes a first operating state and a second operating state.

Multi-compressor chiller systems can be efficiently operated by determining real time efficiency curves for the compressors currently in operation, along with any compressors that may be added to address demand, and using these efficiency curves to determine changes to compressor operation to improve efficiency in meeting chiller demand. The efficiency curves can be parabolic curves. The data used to determine the efficiency curves can be obtained through operation at a variety of lift points and a variety of load points within those lift points. The efficiency curves can be solved to find intersections where there may be staging points for adding or subtracting compressors from operation to efficiently meet demand. This operation can be automated through a controller of a control system for the multi-compressor chiller system.

A device for storing refrigerant of a refrigeration circuit and a method of operating the device, in particular for an air conditioning system of a motor vehicle. The device has a housing having a volume-enclosing wall with an inlet for introducing a refrigerant-oil mixture, and an outlet, a refrigerant discharge line arranged in the interior of the housing with an inlet opening arranged above a liquid level of the refrigerant for receiving gaseous refrigerant, and a system for returning oil to a compressor having at least one through hole formed below the liquid level of the refrigerant, in particular below a filling level of the oil, in the refrigerant discharge line. In addition, at least one through hole formed in the refrigerant discharge line is formed with an adjustable through-flow cross section, which can be varied by means of a closing apparatus.

According to one embodiment, there is provided a refrigeration system including detectors, each of which detects a phase indicative of a displacement of a displacer of each of cryogenic refrigerators; a processor that calculates an operation frequency of a motor of each of the cryogenic refrigerators, which is a frequency that suppresses oscillations or noises generated by reciprocating motions of the displacer of each of the cryogenic refrigerators, based on a detection result obtained by each of the detectors; and drivers, each of which drives the motor of each of the cryogenic refrigerators based on a calculation result obtained by the processor.

An evaporator header can include a header body having one or more walls that define an inner cavity configured to receive a first flow of refrigerant from a plurality of evaporator flow paths. A liquid line portion can extend through the inner cavity, can define a liquid line flow path that is fluidly separated from the inner cavity, and can be configured to receive a second flow of refrigerant. A plurality of apertures can extend through the one or more walls of the header body. The evaporator head can include a plurality of flow path connectors, and each can be configured to facilitate at least some of the first flow of refrigerant from a corresponding evaporator flow path of the plurality of evaporator flow paths, into the inner cavity via a corresponding aperture of the plurality of apertures, and across at least some of the liquid line portion.

An electrochemical heat transfer device utilizes an electrochemical hydrogen compressor to pump hydrogen into and out of a reservoir having a metal hydride forming alloy therein. The absorption of hydrogen by the metal hydride forming alloy is exothermic, produces heat, and the desorption of the hydrogen from the metal hydride forming alloy is endothermic and draws heat in. An electrochemical hydrogen compressor may be configured between to reservoirs and pump hydrogen back and forth to form a heat transfer device. A heat exchange device may be coupled with the reservoir or may comprise the outer surface of the reservoir to transfer heat to an object or to the surroundings. A closed loop may be configured having two reservoirs and one or two electrochemical hydrogen compressors to pump the hydrogen in a loop around the system.

A solar distillation system for producing a distillate and providing cooling for a structure or appliance, and a method of using the system to produce a distillate and cool a structure or appliance. The system includes a distillate cooling coil, a secondary cooling coil, an expansion valve which is capable of controlling an amount of a coolant that flows through each of the coils. The system also includes a compressor, a plurality of sensors including a temperature sensor and a distillate flow sensor, and a controller which receives input from the sensors and controls the activity of the compressor and expansion valve. The system is capable of producing distillate at night in the absence of solar radiation.

A system for controlling or optimizing the performance of a vapor compression system by modifying the actuator commands via an output interface, that realizes thermofluid property functions and their derivatives as spline functions which are represented in a coordinate system that is aligned with a fluid saturation curve. The system includes an interface configured to receive measurement data from sensors, a memory configured to store thermofluid property data and computer-executable programs including a B-spline method, and a processor for performing the computer-implemented method. The processor is configured to take as input two thermofluid property variables, and compute a coordinate transformation in which one axis of the coordinates is aligned with the liquid and vapor saturation curves. In the saturation-curve aligned coordinates, a spline function represents the thermofluid property function, with coefficients and knots stored in memory. The spline function is constructed in a manner such that derivatives of the thermofluid property function may be discontinuous across the saturation curve.

A gas refrigerating machine having: an input for gas to be cooled; a recuperator; a compressor having a compressor input, the compressor input being coupled to a first recuperator output; a heat exchanger; a turbine; and a gas output, wherein the recuperator is rotationally symmetrical, wherein an axis of symmetry of the recuperator coincides with an axis of the compressor, or an axis of the turbine, or an axis of a rotor of a drive motor, or an axis of the gas output, or an axis of the input, or an axis of a suction region basically or within manufacturing tolerances.