Systems and methods for lubricant management of a compressor in an HVACR system are disclosed. A heat transfer circuit can utilize a working fluid to provide heating or cooling includes a compressor for compressing the working fluid and a heat source configured to increase a suction temperature of the working fluid entering the compressor. One or more lubricant rheological properties in a compressor system based on measurements taken at or near a bearing cavity of the compressor are determinable. A lubricant reservoir can be in thermal communication with a discharge flow path of the compressor. An internal heat exchanger can be disposed within a compressor for improving viscosity of the lubricant to be cycled back into the compressor. A heater can be located on a fluid line between a lubricant separator and a lubricant inlet. Condenser fans can be controlled.

Compositions and methods are configured to reduce flammability in a heating, ventilation, and air conditioning (HVAC) system having R32 refrigerant included in the refrigerant composition. Refrigerant compositions and methods can be used for retrofitting, servicing, controlling flammability, improving performance, lubricant solubility and miscibility, and improving the safety of an HVAC system.

Secondary loop air conditioning and heat pump systems include a reservoir with a capsule holding a phase change material.

Method for retrofitting an existing heat transfer system comprising adding to said existing system a refrigerant consisting essentially of: (i) from about 25% to about 45% by weight of 1,1,1,2-tetrafluoroethane (HFC-134a); (ii) from 25% to about 35% by weight of trans-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)) and/or 2,3,3,3-tetrafluoropropene (HFO-1234yf); and (iii) from about 37% to about 46% by weight of a combination of difluoromethane (HFC-32) and pentafluoroethane (HFC-125), provided that the weight ratio of HFO-32:HFC-125 is from about 1.21:1 to about 0.8:1, wherein the refrigerant preferably is a non-flammable refrigerant having a GWP of 1350 or less.

A non-combustible mixed refrigerant having a low greenhouse effect and an application thereof, the mixed refrigerant comprises the following components in mass fractions: 4-31.5% of R125, 50-80% of R1234ze (E) and 12-22% of R1234yf. Under the cooperation of each component dosage range, the mixed refrigerant becomes non-combustible, the ODP is 0, and the GWP is not greater than 1000. The present invention may be used in a refrigeration system, does not destruct ozone, reduces the greenhouse effect, and has a low slip temperature, relating to ternary azeotropic or near-azeotropic refrigerants, and being beneficial for the stable operation of a refrigeration system. The mixed refrigerant may also be used as a foaming agent or an aerosol propellant, and has the advantages of being non-combustible, having a low ozone destruction index, and being environmentally friendly, safe and reliable.

An object is to provide a novel low-GWP mixed refrigerant. A solution to the problem is to provide a composition containing a refrigerant that contains trans-1,2-difluoroethylene (HFO-1132(E)), difluoromethane (R32), and 1,3,3,3-tetrafluoropropene (R1234ze).

This refrigeration apparatus (1) includes a main refrigerant circuit (2) including a positive displacement compressor (4), a condenser (6), an expansion valve (8), and an evaporator (10), through which a refrigerant circulates successively in a closed loop circulation, and a lubrication refrigerant line (18) connected to the main refrigerant circuit (2) between the condenser (6) and the expansion valve (8) or to the condenser (6), in which circulates a portion of the refrigerant of the main refrigerant circuit (2) and connected to the compressor (4) for lubrication of said compressor (4) with the refrigerant. The refrigeration apparatus includes a lubrication refrigerant tank (20) connected to the lubrication refrigerant line (18) upstream the compressor (4), the lubrication tank (20) being configured to store liquid refrigerant for lubrication of the compressor (4) and the lubrication refrigerant tank (20) comprises means (32, 34; 38, 40) to cool down the refrigerant.

Methods for forming an improved, centralized refrigeration systems comprising: (a) providing an existing refrigeration circuit with an existing high GWP refrigerant; (b) disconnecting the fluid connection between the existing liquid refrigerant from the condenser and the evaporators; (c) disconnecting the fluid connection between the existing refrigerant vapor from the evaporators and the compressor suction; (d) establishing a new first refrigeration circuit comprising the compressor and the condenser; (e) establishing a new second refrigeration circuit comprising the evaporators by removing existing refrigerant from the evaporators and the disconnected conduits and replacing the removed refrigerant with a second refrigerant comprising at least 50% of R1234ze(E) and being Class A1 and having an OEL greater than 400 and a GWP of about 150 or less; and thermally interconnecting the new first refrigeration circuit and the new second refrigeration circuit with an inter-circuit heat exchanger.

A refrigeration system is disclosed. The refrigeration system includes a refrigeration circuit including a compressor, a condenser, an expansion valve, and an evaporator fluidly connected. A purge circuit is fluidly connected to the condenser. The purge circuit is configured to receive a purge stream from the condenser. The purge stream is a mixture including a refrigerant and non-condensables. The purge circuit includes a plurality of heat exchangers for condensing the purge stream such that the non-condensables and the refrigerant in the purge stream are separated.

An object of the present disclosure is to provide a composition in which a disproportionation reaction of a refrigerant is suppressed, and in which the refrigerant has excellent stability. Another object of the present disclosure is to provide a composition comprising a refrigerant useful for air-conditioning systems. The composition comprises a refrigerant, wherein the refrigerant comprises a refrigerant that undergoes disproportionation and a refrigerant that does not undergo disproportionation.