The present invention discloses a refrigerator controlling method and system with a linear compressor. The method comprises: monitoring an environment temperature T of the refrigerator located in the environment comparing the environment temperature T with a preset environment temperature threshold T0; if T is larger than T0, controlling a refrigerating unit and/or a heating unit in the refrigerator such that the refrigerator runs under a first operation condition; and if T is smaller than or equal to T0, controlling the refrigerating unit and/or the heating unit in the refrigerator such that the refrigerator runs under a second operation condition. When the linear compressor runs within predetermined time, a refrigeration amount of the linear compressor under the second operation condition is controlled to be larger than a refrigeration amount of the linear compressor under the first operation condition, such that a compartment of the refrigerator reaches a target temperature.

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.

A method of making clear ice includes circulating a refrigerant through a refrigerant loop. A portion of the refrigerant loop is in contact with a mold body. Thus, the refrigerant chills the mold body. The method also includes spraying a first volume of liquid water into a mold cavity of the mold body. As a result, a first volume of ice is formed in the mold cavity. The method also includes spraying a second volume of liquid water into the mold cavity after the first volume of ice has formed. Thus, a portion of the first volume of ice is melted and a second volume of ice is formed in mold cavity. The clear ice includes an unmelted portion of the first volume of ice and the second volume of ice.

An HVAC system includes an evaporator. The evaporator includes a sensor configured to measure a property value (i.e., a saturated suction temperature or a saturated suction pressure) associated with saturated refrigerant flowing through the evaporator. The system includes a variable-speed compressor configured to receive the refrigerant and compress the received refrigerant. The system includes a controller communicatively coupled to the sensor and the variable-speed compressor. The controller monitors the property value measured by the sensor and detects a system fault, based on the monitored property value. In response to detecting the system fault, the controller operates the compressor in a freeze-prevention mode, which is configured to maintain the property value above a setpoint value by adjusting a speed of the variable-speed compressor. This prevents or delays freezing of the evaporator during operation of the system during the detected system fault.

A refrigerant compressor group for a refrigeration system, comprising at least two piston compressors that operate in parallel between a common low-pressure connector and a common high-pressure connector, wherein, for the purpose of adjusting it to different requirements, it is provided, in a refrigerant compressor group, for a variable overall mass flow throughput in the refrigerant compressor group to be adjustable in that, in the case of at least one of the piston compressors, its mass flow throughput is adjustable by speed selection with the aid of a frequency converter for the electric motor, and in that, in the case of at least one of the piston compressors, its mass flow throughput is adjustable by cylinder selection, and in that an operating condition controller for the refrigerant compressor group is provided which, on the basis of a performance request signal of the refrigeration system that is transmitted to the operating condition controller, controls the overall mass flow throughput by open or closed-loop control by predetermining the cylinder selection and the speed selection.

A heating, ventilation, air conditioning, and refrigeration (HVACR) system includes a compressor with a gas bearing supplied with compressed gas and a controller. The controller is configured to determine an inlet pressure and outlet pressure of the gas bearing, determine a maximum speed limit based on the inlet pressure and the outlet pressure, and prevent the compressor from operating at a speed that is greater than the maximum speed limit. A method of controlling a compressor includes calculating a maximum speed limit based on an inlet pressure and an outlet pressure of the gas bearing. The method also includes in response to determining that a speed setting is greater than the maximum speed limit, adjusting operation of the compressor such that a speed of the compressor is at or below the maximum speed limit.

A cooling system includes an ingress port to receive refrigerant in a vapor form from an evaporator, an egress port to return refrigerant in a liquid form back to the evaporator, a condenser coupled to the ingress port and the egress port, and a compressor coupled to the ingress port and the condenser. When the cooling system operates in a first mode, the condenser is configured to receive and condense the refrigerant from the vapor form into the liquid form and to return the refrigerant in the liquid form to the regress port. When the cooling system operates in a second mode, the compressor is configured to compress the refrigerant in the vapor form and to supply the compressed refrigerant to the condenser to be condensed therein.

A system includes a pressure exchanger (PX). The PX is coupled to a motor that controls an operating speed of the PX. The system further includes a first pressure gauge configured to generate first pressure data indicative of a pressure of a fluid of a condenser. A first controller is to generate a first control signal based on the first pressure data. The motor of the PX is configured to adjust the operating speed of the PX based on the first control signal. The system further includes a pump. The system further includes a fluid density sensor for generating fluid density data associated with a first output fluid of the PX. A second controller is to generate a second control signal based on at least the fluid density data. The pump is to adjust an operating speed of the pump based on the second control signal.

Disclosed are a carbon dioxide overlapping type heating system and a control method therefor. The heating system comprises a low-temperature stage loop, a high-temperature stage loop and a heat supply loop, wherein a low-temperature stage compressor (3) and a high-temperature stage compressor (7) are both variable-frequency compressors; and a water pump (10) is a variable-frequency water pump.

A method may include selecting a first set of values for a first set of parameters of one or more hardware components of an ice-making machine; identifying a water temperature at a water inlet of the ice-making machine; identifying an ambient air temperature surrounding the ice-making machine; calculating a second set of parameters of the ice-making machine based on at least a portion of the first set of values, the water temperature and the ambient temperature, the second set of parameters corresponding to operation of the ice-making machine in a freeze mode in which liquid water is cooled by an evaporator; and calculating a third set of parameters based on at least a portion of the first set of values, the water temperature and the ambient temperature, the third set of parameters corresponding to operation of the ice-making machine in a harvest mode.