A temperature adjusting device includes a heat radiation portion and a refrigeration cycle device. The heat radiation portion radiates heat of a target object to outside air. The refrigeration cycle device has a condenser and an evaporator. The condenser condenses a high-pressure refrigerant discharged from a compressor that compresses and discharges a refrigerant. The evaporator evaporates a low-pressure refrigerant pressure-reduced in a pressure reducing portion that reduces a pressure of the high-pressure refrigerant. The condenser radiates heat of the high-pressure refrigerant to at least part of the outside air that has passed through the heat radiation portion. The heat radiation portion radiates the heat of the target object to the outside air before heat of the outside air is absorbed in the condenser.

A method of operating an HVAC system using a controller includes predicting a first predicted temperature of an enclosed space during an unoccupied time with the HVAC system off. The controller determines if the first predicted temperature is less than a set-point temperature. Responsive to a determination that the first predicted temperature is less than the set-point temperature, the controller predicts a second predicted temperature of the enclosed space if the HVAC system is operated for a first runtime. The controller determines if the second predicted temperature is less than the set-point temperature and, responsive to a determination that the second predicted temperature is not less than the set-point temperature, the controller operates the HVAC system for the first runtime.

The purpose of the invention is to provide a control device that can calculate the lower limit of cooling water inlet temperature according to the operation status of a chiller. A control device comprises: a lower limit calculation unit that calculates the lower limit of cooling water outlet temperature, where a prescribed required temperature difference is added to the cooling water outlet temperature of a chiller, and an inlet-outlet required temperature difference, which is the difference between the cooling water outlet temperature and the cooling water inlet temperature in the chiller and which is generated according to the operation status of the chiller, and that calculates a cooling water inlet temperature lower limit calculated value for the chiller by subtracting the inlet-outlet required temperature difference from the cooling water outlet temperature lower limit value; and a lower limit value determination unit that fixes the cooling water inlet temperature lower limit calculated value as the cooling water inlet temperature lower limit value.

No studies have been made regarding what kinds of refrigerants should be used in a refrigeration cycle device for a vehicle. An air conditioner (1) for a vehicle includes a refrigerant circuit (10) and a refrigerant that is sealed in the refrigerant circuit (10). The refrigerant circuit (10) includes a compressor (80), a first heat exchanger (85), which serves as a heat dissipater in a dehumidifying heating mode, an outside-air heat exchanger (82), a cooling control valve (87), and a second heat exchanger (86), which serves as an evaporator in the dehumidifying heating mode. The refrigerant is a refrigerant having a low GWP.

The present invention provides a system and method for an improved multistage, cascade refrigeration system using hot gas defrost to rid the evaporator of ice build-up which accumulates over time, while the air in the evaporator enclosure remains below the freezing point of water. The present invention thus provides greater defrost flexibility with increased ease of design and implementation than current refrigeration systems, which allows for more robust hot gas defrost function for multistage refrigeration systems, such that it is unaffected by temperature changes of the condensing fluid (ambient air temperature for air cooled condensers, water temperature for water cooled condensers), and can be readily adapted to any refrigerant suitable for a selected temperature range.

A multi-stage refrigeration system (100) includes: a refrigeration loop (110), which includes a gas suction port of a multi-stage compressor (111), a condenser (112), a first throttling element (113), an evaporator (114) and an exhaust port of the multi-stage compressor which are sequentially connected through pipelines; an economizer branch (120), which includes an economizer (121), a second throttling element (122) and a first control valve (123), the economizer having an economizer liquid inlet connected to the condenser via the first throttling element, an economizer liquid outlet connected to the evaporator via the second throttling element, and an economizer exhaust port connected to an intermediate stage of the multi-stage compressor via a control valve; and a bypass branch (130), which is joined to the evaporator from the downstream of the second throttling element and connected to the condenser via the first throttling element, and on which a second control valve (131) is arranged.

The present application discloses a cooling system and a control method thereof; the cooling system includes a compressor unit, a condenser, a first solenoid valve, a second solenoid valve, a first throttle valve and a frequency converter; the second solenoid valve and the first throttle valve are connected with the first solenoid valve in parallel after being connected in series with each other; the compressor unit, the condenser, the first solenoid valve and the frequency converter are connected in series to form a first cooling loop; the compressor unit, the condenser, the second solenoid valve, the first throttle valve and the frequency converter are connected in series to form a second cooling loop; and the frequency converter is internally provided with a temperature detection module and a heat exchange module.

A refrigerant circuit is disclosed. The refrigerant circuit includes a compressor, a condenser, a first expansion device, an economizer, a second expansion device, and an evaporator fluidly connected. A working fluid flows through the refrigerant circuit. A bypass segment is fluidly connected to the refrigerant circuit. A portion of the working fluid is provided from the refrigerant circuit to the bypass segment from a location in the refrigerant circuit disposed between the condenser and the evaporator with respect to flow of the working fluid. The portion of the working fluid flows through the bypass segment in a flow enabled state and is provided to a location in the refrigerant circuit disposed between the economizer and the evaporator with respect to flow of the working fluid. A vortical flow is induced at the location in the refrigerant circuit disposed between the economizer and the evaporator.

A refrigeration cycle apparatus includes a main circuit through which refrigerant circulates and in which a compressor, a condenser, a first expansion device, a centrifugal gas-liquid separator that separates refrigerant into gas refrigerant and liquid refrigerant by using centrifugal force, and an evaporator are connected by refrigerant pipes; and a bypass that returns the gas refrigerant obtained through the separation by the gas-liquid separator to a suction side of the compressor. The gas-liquid separator includes a cylindrical container, an inflow pipe, a gas outflow pipe, and a liquid outflow pipe. The main circuit includes a second expansion device provided between the liquid outflow pipe of the gas-liquid separator and the evaporator. The gas refrigerant discharged from the gas outflow pipe of the gas-liquid separator flows into the bypass, and the bypass is provided with a third expansion device.

A temperature control device for controlling a temperature of a temperature adjustment target part is provided. A communication module of the temperature control device is configured to store target temperature information of each of the temperature adjustment target parts included in a communication frame periodically received via a field network in a predetermined position of a memory, and an arithmetic operation module of the temperature control device receives the target temperature information of each of the temperature adjustment target parts, receives refrigerant temperature information from each of temperature sensors corresponding to each of the temperature adjustment target parts, and calculates each of control parameter for adjusting an opening degree of each corresponding control valve so that each temperature of the temperature adjustment target parts becomes a target temperature indicated by the received target temperature information based on the received target temperature information and the received refrigerant temperature information.