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.

An apparatus includes a captured carbon dioxide input. The captured carbon dioxide input is coupled to receive captured carbon dioxide from a direct air capture system. The apparatus uses the captured carbon dioxide as a low global warming refrigerant to provide cooling functionality in automotive, commercial, and industrial applications, or other operations involving low global warming refrigerants. In various embodiments, the apparatus is a refrigeration apparatus or a heat pump apparatus. Low global warming carbon dioxide refrigerant is natural, non-toxic, non-flammable, and abundant when obtained from a direct air capture system. Moreover, carbon dioxide refrigerant has a high heat transfer coefficient and has a global warming potential (GWP) of one. Carbon dioxide refrigerant is a more sustainable and efficient coolant option than common refrigerants, such as R22, R152, R404a, and R1234yf refrigerants.

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.

A chilled water distribution system includes a chilled water loop in fluid communication with a plurality of buildings and also in fluid communication with a plurality of chiller stations. A monitoring and control system communicates with one of the chiller stations, hereinafter referred to as a “controlled” chiller station because it is configured with one or more variable frequency drives that are controlled by the monitoring and control system to modulate the speed of at least one chiller station component such as, but not limited to, a pump or a fan. By way of this modulation process, a differential pressure of the chilled water loop may be maintained in a “sweet spot” so as to optimize chiller station output while minimizing chiller station energy consumption.

A flow path switch is provided with a first opening to a fourth opening. A discharge side of a compressor is connected to the first opening. A first end of a first heat exchange unit is connected to the fourth opening. A first end of the second inner flow path is connected to the second opening. A first branching portion is connected to a first end of the second valve and the third opening. When an operation mode of an air conditioning apparatus is a first mode, the second valve is open, the first opening is connected to the fourth opening, and the second opening is connected to the third opening. When the operation mode of the air conditioning apparatus is a second mode, the second valve is closed, the first opening is connected to the third opening, and the second opening is connected to the fourth opening.

A HVAC system having an indoor heat exchanger having a first refrigerant passage extending in a first direction and a second refrigerant extending in a second direction opposite from the first direction, a first refrigerant circuit comprising a first compressor, a first expansion valve, a first outdoor heat exchanger, the first refrigerant passage, and a first reversing valve operable to control a direction of first refrigerant in the first refrigerant circuit, and a second refrigerant circuit comprising a second compressor, a second expansion valve, a second outdoor heat exchanger, the second refrigerant passage, and a second reversing valve operable to control a direction of second refrigerant in the second refrigerant circuit.

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.

A refrigeration cycle apparatus includes a first refrigerant circuit including a first compressor, a first heat exchanger, a first refrigerant flow path of a second heat exchanger, a first expansion device, a third heat exchanger, and a second refrigerant flow path of a fourth heat exchanger, and a second refrigerant circuit including a second compressor, a fifth heat exchanger, a second expansion device, a third refrigerant flow path of the second heat exchanger, and a fourth refrigerant flow path of the fourth heat exchanger, a first refrigerant flows through, in order, the first compressor, the first heat exchanger, the first refrigerant flow path, the first expansion device, the third heat exchanger, and the second refrigerant flow path, the second refrigerant flows through, in order, the second compressor, the fifth heat exchanger, the second expansion device, the third refrigerant flow path, and the fourth refrigerant flow path.

A sub-fab area installation apparatus includes: a vacuum pump configured to evacuate a processing gas from a processing chamber of the semiconductor manufacturing equipment; a cooling unit configured to cool a first circulation liquid used in the processing chamber; a heating unit configured to heat a second circulation liquid used in the processing chamber; and a cooling-liquid line configured to pass a cooling liquid therethrough. The cooling liquid is supplied from a cooling source. The cooling-liquid line includes: a distribution line configured to supply the cooling liquid to the vacuum pump and the cooling unit; and a merging return line configured to merge the cooling liquid that has passed through the vacuum pump and the cooling unit and return the cooling liquid to the cooling source.

A multiple-circuit heating and cooling system includes a first refrigeration circuit having a first condenser and a first evaporator and a second refrigeration circuit having a second condenser and a second evaporator. The first condenser and the second condenser are arranged in a first row split configuration, and the second condenser is downstream of the first condenser relative to a first air flow directed across the second condenser and the first condenser. Additionally, the first evaporator and the second evaporator are arranged in a second row split configuration, and the first evaporator is downstream of the second evaporator relative to a second air flow directed across the first evaporator and the second evaporator.