A method to detect the charge level of a refrigerant within a refrigeration circuit, where the refrigeration circuit has a compressor, a sensor to detect a pressure, and a sensor to detect a temperature. The method has a key cycle that has a first part and a second part.

A system and method are provided including a system controller for a refrigeration or HVAC system having a compressor rack with a compressor and a condensing unit with a condenser fan. The system controller monitors and controls operation of the refrigeration or HVAC system. A rack controller monitors and controls operation of the compressor rack and determines compressor rack power consumption data. A condensing unit controller monitors and controls operation of the condensing unit and determines condensing unit power consumption data. The system controller receives the compressor rack power consumption data and the condensing unit power consumption data, determines a total power consumption of the refrigeration or HVAC system, determines a predicted power consumption or a benchmark power consumption for the refrigeration system, compares the total power consumption with the predicted power consumption or the benchmark power consumption, and generates an alert based on the comparison.

A system for and method of monitoring cooling system parameters where the system identifies characteristic behaviors of the cooling system and establishes limits that identify when a parameter or parameters indicate that the cooling system is experiencing a failure or is predicted to experience a failure in the future. The system includes a processor, memory and instruction that when executed by the processor, perform steps to detect actual failures or predict future failures of the cooling system being monitored.

A system includes a dynamic compressor and a controller having a processor and a memory. The compressor includes a first compressor stage having a first variable inlet guide vane (VIGV) and a second compressor stage having a second VIGV. The memory stores instructions that program the processor to operate the compressor at a current speed, a first position of the first VIGV, and a second position of the second VIGV to compress the working fluid, and to determine if a condition is satisfied. If the condition is not satisfied, the processor is programmed to continue to operate the compressor at the current speed, the first position of the first VIGV, and the second position of the second VIGV. If the condition is satisfied, the processor is programmed to change the second position of the second VIGV to a third position and maintain the first position of the first VIGV.

This chiller control device (74) is provided with: a storage unit (18) which stores operation data detected at each site in a turbo chiller; a compression unit (34) which, when the size of the operation data accumulated over time in the storage unit (18) becomes too large, converts the operation data each time a condition depending on the type of operation data is met, thereby compressing the data size; and a diagnostic unit (36) which evaluates the state of the turbo chiller on the basis of the operation data converted by the compression unit (34). By this means, the state of the chiller can be diagnosed without increasing the storage capacity of the storage medium that stores operation data of the turbo chiller.

An air conditioner is provided. The air conditioner includes an indoor unit including an expansion valve and an indoor heat exchanger, a compressor configured to supply a refrigerant to the indoor unit, a compressor inlet pressure sensor configured to detect a compressor inlet pressure corresponding to a pressure of the refrigerant flowing into the compressor from an accumulator, memory storing one or more computer programs, and one or more processors communicatively coupled to the compressor inlet pressure sensor and the memory, wherein the one or more computer programs include computer-executable instructions that, when executed by the one or more processors individually or collectively, cause the air conditioner to adjust an opening degree of the expansion valve of the indoor unit based on the compressor inlet pressure during a defrosting operation.

A heat exchange apparatus includes a heat exchange circuit which is provided with an evaporator which is connected in output to a condenser, which is connected, in output, by way of the interposition of expansion elements to the evaporator and in which there is at least one regenerative exchanger between the evaporator and the condenser. The apparatus includes adjustment valve elements between the outlet of the condenser and the inlet of the evaporator. Sensor elements are further provided which are adapted to measure at least one thermodynamic parameter of the exchange fluid at preset points of the circuit and control elements are further provided which are connected to the sensor elements and are configured to calculate, using measurements supplied by the sensor elements, the instantaneous efficiency and a reference efficiency of the regenerative exchanger.

A method and system that describe collecting digital representation of observed variables of the operation of the vapor compression cycle over multiple instances of time and executing a constrained ensemble Kalman smoother for each instance of time to estimate the state variables of the vapor compression cycle for each instance of time. The constrained ensemble Kalman smoother updates the state variables over a sequence of time instances within a smoothing window by solving a series of constrained optimization problems in a range of a covariance, for which constraints are enforced for every variable in the smoothing window for every instance of the constrained optimization problems. The method and system further involve outputting, based on the estimates of the state variables, estimates of variables of the vapor compression cycle at each instance of time.

A vapor injection heat pump system and an operation method is disclosed. The operation method includes a compressor, an indoor heat exchanger, a vapor injection module, an outdoor heat exchanger, and an evaporator includes an operation of performing control in one of a first heating mode which is a non-vapor injection heating mode in which a refrigerant introduced into the module is introduced into the outdoor heat exchanger and a second heating mode which is a vapor injection heating mode in which some of the refrigerant introduced into the vapor module is introduced into the compressor and the remaining refrigerant is introduced into the outdoor exchanger, wherein, in the operation of performing control, a flow of the refrigerant is maintained in the vapor injection module when the first heating mode is switched to the second heating mode or the second heating mode is switched to the first heating mode.

A rotation speed control method and system, a device, and a storage medium is provided, which is applied to a heat pump system. The heat pump system includes a throttling short tube and a compressor, both sides of the throttling short tube are provided with a temperature sensor and a pressure sensor. The rotation speed control method includes: collecting actual data of the temperature sensors and the pressure sensors, processing to obtain temperature ratio data and pressure ratio data, and obtaining a corresponding oil content prediction model through matching; obtaining predicted oil content data according to the temperature ratio data and the pressure ratio data; and controlling a rotation speed of the compressor according to the predicted oil content data.