A control system for controlling the flow of refrigerant includes: an inlet valve configured to selectively isolate or couple a supply path for supplying refrigerant from a refrigeration system with an inlet of a cooling loop; an outlet valve configured to selectively isolate or couple a return path for returning refrigerant to the refrigeration system with an outlet of the cooling loop; a refrigerant collection valve configured to selectively isolate or couple a refrigerant collection path for collecting refrigerant for the refrigeration system with the cooling loop; a pressure sensor for determining a pressure of refrigerant in the cooling loop; an input for receiving cooling loop disconnect and connect commands; and control circuitry configured to receive signals from the pressure sensor and the commands from the input and to generate control signals for controlling the opening and closing of the inlet, outlet and refrigerant collection valves in response thereto.

A liquid level detector includes: a vertically-mounted accumulator that stores refrigerant; a heater that heats the accumulator; a temperature detector that detects a surface temperature of the accumulator; a pressure detector that detects a pressure of the refrigerant in the accumulator; and a controller. The controller detects a position of a liquid surface of the refrigerant in the accumulator based on a surface temperature of the accumulator detected by the temperature detector when the accumulator is heated by the heater, and a pressure of the refrigerant in the accumulator detected by the pressure detector.

A hoseless sensor system for a refrigerant unit includes a plurality of hoseless sensors for sensing system parameters of the refrigerant unit, and a portable electronic device configured to receive the system parameters from the hoseless sensors and to calculate system conditions for the refrigerant based on the system parameters. The plurality of hoseless sensors includes a hoseless first pressure sensor and a hoseless second pressure sensor, and a hoseless first temperature sensor and a hoseless second temperature sensor. The temperature sensors are temperature sensor clamps. Each temperature sensor clamp includes a clamping portion configured to clamp on a tube of the refrigerant unit, the clamping portion including a sensor element to measure temperature about the tube. The clamping portion further includes a plurality of clamping teeth, and adjacent clamping teeth interlock in an overlapping configuration when the clamp closes inward beyond a threshold point.

HVAC-R sensor probes include a visual indicator switch that is built on to the tool itself. The switch can be toggled between 2 selections indicated by the colors red and blue. If the switch is on red, the color signifies high side pressure for a pressure gauge, high side temperature for a pipe clamp thermocouple, and return side for a psychrometer. If the switch is on blue, the color signifies low side pressure for a pressure gauge, low side temperature for a pipe clamp thermocouple, and supply side for a psychrometer. Once the switch has been set to the appropriate side, the probe will relay this information via wireless transmission to the smart device. The smart device reads this data in real time and will instantly set the tools to the selected side in the app, changing sides if the tool switch is once again toggled. This switch allows a direct correlation in the real world as well as in the virtual world.

The invention relates to a method for the pressure-based determining of a product parameter in a freeze dryer, in particular a product temperature. In a method of this type at a point in time t.sub.START a closing element as an intermediate valve between an ice chamber and a drying chamber of the freeze dryer is closed. Then, during a pressure rise occurring due to the sublimation pressure values (P.sub.1, P.sub.2, . . . ) are measured in the drying chamber. At a point in time t.sub.END then the closing element is opened. From the measured pressure values (P.sub.1, P.sub.2, . . . ) an approximation of a product parameter, in particular a product temperature T.sub.APPROX, is determined.

According to the invention the point in time t.sub.END is determined specifically for the measured pressure values (P.sub.1, P.sub.2, . . . ) such that the time span for which the closing element is closed and the pressure rising occurs depends on the determined pressure values and such that the time span is variable during a drying process.

By use of the inventive method it is in particular possible to avoid an undesired start of thawing of the drying product.

A refrigerating system according to the invention includes a refrigerant circuit having at least one compressor, a condenser/gascooler, an intermediate pressure container, at least one evaporator and a respective expansion device before said at least one evaporator, and refrigerant pipes connecting said elements and circulating a refrigerant therethrough; a high pressure regulating device between the condenser/gascooler and the intermediate pressure container, expanding the refrigerant from a high pressure level to an intermediate pressure level; an intermediate pressure sensor sensing the intermediate pressure level; and a control unit controlling the high pressure regulating device. The control unit in operation limits the maximum refrigerant flow through the high pressure regulating device to a maximum flow value F.sub.Max, if the sensed intermediate pressure level exceeds a predetermined threshold value P.sub.IntTh.

A non-condensable gas purge system is configured to be used in a chiller system that uses a low pressure refrigerant in a loop refrigeration circuit. The non-condensable gas purge system includes a purge tank and a purge heat exchanger coil arranged inside the purge tank. The purge tank has a tank inlet for receiving the low pressure refrigerant from a condenser of the refrigeration circuit, a tank outlet for returning the low pressure refrigerant to an evaporator of the refrigeration circuit, and a purge outlet for purging non-condensable gas from the purge tank to the ambient atmosphere. The purge heat exchanger coil is fluidly connected to the loop refrigeration circuit such that the low pressure refrigerant contained in the loop of the chiller system can pass through the purge heat exchanger coil. Refrigerant in the purge tank is condensed by the heat exchanger coil while non-condensable gases remain gaseous.

A subcooling controller includes a sensor and a processor. The sensor measures one or more of a temperature external to a first heat exchanger that removes heat from carbon dioxide refrigerant, a temperature of the carbon dioxide refrigerant, and a pressure of the carbon dioxide refrigerant. The processor determines that one or more of the measured temperature external to the first heat exchanger, the temperature of the carbon dioxide refrigerant, and the pressure of the carbon dioxide refrigerant is above a threshold and in response to that determination, activates a subcooling system. The subcooling system includes a condenser, a second heat exchanger, and a compressor. The condenser removes heat from a second refrigerant. The second heat removes heat from the carbon dioxide refrigerant stored in a flash tank. The compressor compresses the second refrigerant from the second heat exchanger and sends the second refrigerant to the condenser.

In an air conditioner, during an operation, a gas-liquid two-phase non-azeotropic mixture refrigerant enters a receiver and accumulates in the receiver in a state where a gas phase and a liquid phase are separated. For example, when the non-azeotropic mixture refrigerant includes two components, i.e., a high-boiling refrigerant and a low-boiling refrigerant, the controller may estimate the ratio (composition ratio) between the low-boiling refrigerant and the high-boiling refrigerant in each of the gas phase and the liquid phase based on the temperature and the pressure of the non-azeotropic mixture refrigerant in the receiver. Thus, the controller may estimate the composition ratio of the liquid-phase non-azeotropic mixture refrigerant flowing out of the receiver as the composition ratio of the non-azeotropic mixture refrigerant circulating in the refrigerant circuit.

A device for separation of oil particles by a coolant for air conditioning systems comprises a hollow container body and an inlet arranged to make enter the hollow container body a coolant, with oil particles, mainly in liquid phase and have a temperature T.sub.1. The device also comprises a outlet located upper part of the hollow container body and arranged to cause protrude coolant regenerated in vapour phase by the hollow container body. is also provided a heating coil arranged in the hollow container body and containing fluid at a temperature T.sub.2>>T.sub.1, in such a way that the coolant evaporates when comes in contact with the heating coil and the oil particles rimangano instead on the bottom of the hollow container body. The device also comprises a first oil barrier arranged above with respect to the heating coil and arranged to avoid that the oil particles schizino towards the outlet. is also provided a second oil barrier 114 located in the hollow container body at the outlet, said second oil barrier comprising holes having a diameter of a predetermined value D configured for preventing to oil particles of larger diameter to the predetermined value D of crossing the outlet.