A cooling system includes an evaporator, connected through fluid lines to a first condenser, a second condenser, a compressor, and a thermal expansion valve. One or more valves are arranged in the fluid lines. The one or more valves operated to, in a first mode, circulate fluid between the evaporator the first condenser; in a second mode, circulate the fluid between a) the evaporator and the first condenser, and b) the evaporator, the second condenser, and the thermal expansion valve, and; in a third mode, circulate the fluid between a) the evaporator and the first condenser, and c) the evaporator, the compressor, the second condenser, and the thermal expansion valve.

In order to improve a method for operating status determination of a refrigerant compressor/expander comprising a compressor unit and a drive unit such that information on the operating status of a refrigerant compressor/expander which is as reliable as possible can be obtained, it is proposed that, for at least one bearing of the refrigerant compressor/expander, a load value resulting from an operation of said refrigerant compressor/expander and a speed value are determined and in that, on the basis of the speed value and the load value and also at least one operating parameter, there is determined for the at least one bearing an operating prediction value for a future maintenance-free operation of the refrigerant compressor/expander.

An improved cryogenic cooling system is disclosed. The cryogenic cooling system comprises a pressure sensing system disposed at or near the cryocooler to provide a more accurate representation of the pressure of the working gas within the cryocooler. By utilizing pressure measurements at the cryocooler, the thermal performance and net cooling capacity of the system may be improved. This may also improve the life of the cryocooler. Further, in some embodiments, pressure sensing systems are disposed at both the compressor and the cryocooler. In these embodiments, performance issues and potential failures may be monitored.

Systems and methods are provided for controlling compressor systems to ensure sufficient pressure differentials to provide cooling. A compressor system includes a compressor, a suction pressure sensor at a suction of the compressor, a discharge pressure sensor, a condenser, an expansion device, a liquid line, a liquid line pressure sensor, an evaporator, a condenser blower and a controller. The method includes determining a pressure target based on an intermediate pressure within the compressor and a threshold cooling differential pressure value, determining a pressure ratio setpoint based on the pressure target and a liquid line pressure measured by the liquid line pressure sensor, controlling the condenser blower to operate based on the determined pressure ratio setpoint, determining a subcooling setpoint based on the pressure target and the liquid line pressure in the compressor system, and controlling the expansion device to operate based on the subcooling setpoint.

A screw compressor includes a compressor housing defining a working chamber, the housing including a plurality of bores; a first rotor having helical threads, the first rotor being housed in a first of the plurality of bores; a second rotor having helical threads intermeshing with the helical threads of the first rotor, the second rotor being housed in a second of the plurality of bores; an inlet port that receives a fluid to be compressed; an outlet port that receives a compressed fluid; and an intermediate discharge port disposed between the compression chamber and the outlet port, the intermediate discharge port including a sealing member and a biasing mechanism, fluid flow being prevented between the compression chamber and the intermediate discharge port when in a flow-blocked state, and fluid flow being enabled from the compression chamber through the intermediate discharge port when in a flow-permitted state.

A turbo compressor that has a pressure equalizing tube that circulates a gas from a gear unit accommodation space toward an IGV accommodation space, and an oil separation device that is provided in the gear unit accommodation space to separate lubricating oil that is contained in the gas, in which the oil separating device has a suction duct that communicates with the pressure equalizing tube, and the suction duct has a centrifugal separation portion provided with a first demister, a second demister provided on the downstream side of the first demister in relation to the suction direction, and a curved passage provided between the first demister and the second demister.

A cooling and heating control method of a multi type air conditioner in which a target pressure of a compressor is adjusted based on conditions of respective indoor units so as to reduce power consumption is provided. The cooling control method includes determining the indoor unit desired to execute power saving control, judging whether or not a difference between a temperature of a space in which the indoor unit desired to execute power saving control is located and a set temperature of the indoor unit is less than a reference value, raising a target evaporation temperature of the indoor unit upon judging that the difference is less than the reference value, comparing an evaporation temperature of the indoor unit with the raised target evaporation temperature, and raising an evaporation pressure of a compressor, when the evaporation temperature of the indoor unit is lower than the raised target evaporation temperature.

A control method and control device for a heat pump-type double-circulation hot-air drying system, relating to a device for supplying or controlling air or gas for drying solid materials or products, and in particular to a control method and control device for a heat pump-type hot-air drying system. The method comprises: configuring a temperature control parameter, and saving a preset temperature control curve parameter; detecting and monitoring an outlet air temperature, and the temperature and humidity of a drying room; dynamically adjusting a set temperature according to a preset temperature control curve; and selecting, according to a current set temperature, a double-circulation dynamic operation mode of a system. The control device uses a micro-processor to realize program control. By building an inner circulation loop for large-volume air circulation, the latent heat of condensation in a refrigerant is fully absorbed, to improve the basic air temperature.

A cooling system including a vaporizer configured to absorb heat due to a liquid-phase refrigerant being vaporized, a condenser configured to discharge heat due to a refrigerant in a gaseous phase state being liquefied, a resistance body provided in a middle of a pipe passage ranging from the vaporizer to the condenser and applying a resistance to the refrigerant, state detection sensors provided in the pipe passage on an upstream and downstream sides of the resistance body and detecting a state of the refrigerant flowing through each side inside the pipe passage, and a flow rate controller configured to detect droplets in the refrigerant flowing through the pipe passage on the basis of a difference between detection values of the state detection sensors which are detected on the upstream and downstream sides of the resistance body, and controls a flow rate of the refrigerant on the basis of detection results.

The present disclosure concerns a device and a method for chiller station management for providing chilled water to a load (30), a computer storage medium and a chiller station. The method for chiller station management includes: determining whether a chiller (10) with a low load exists in a chiller station and determining whether to allow to shut down one chiller (10) in the chiller station, when a certain chiller (10) in the chiller station transmits a surge risk signal; if yes, shutting down one chiller (10) in the chiller station to increase loads of other chillers (10); and if no, raising a chiller (10) outlet water temperature in the chiller station and/or lowering a cooling tower (20) outlet water temperature in the chiller station. The device and method for chiller station management according to the present disclosure provide a surge protection at a chiller station level, thereby effectively avoiding occurrence of surge in the chiller, and improving the efficiency and operation stability of the chiller station.