221 results about "Cascade refrigeration" patented technology

The present invention relates to a cascade refrigeration system which circulates a refrigerant comprising a fluoroolefin therethrough. The cascade refrigeration system includes a low temperature refrigeration loop and a medium temperature refrigeration loop. The fluoroolefin circulates through either loop, or both. In a particular embodiment, the fluoroolefin circulates through the medium temperature loop. In a particular embodiment, where the cascade refrigeration system includes a first and a second cascade heat exchanger, and a secondary heat transfer loop which extends between the first and second cascade heat exchangers, either the first and / or second refrigerant may be, but need not necessarily be, a fluoroolefin.

A two-stage cascade refrigeration system is provided having a first refrigeration stage and a second refrigeration stage. The first refrigeration stage defines a first fluid circuit for circulating a first refrigerant, and has a first compressor, a condenser, and a first expansion device that is in fluid communication with the first fluid circuit. The second refrigeration stage defines a second fluid circuit for circulating a second refrigerant, with the second refrigeration stage having a second compressor, a second expansion device, and an evaporator that is in fluid communication with the second fluid circuit. A heat exchanger is in fluid communication with the first and second fluid circuits to exchange heat between the first and second refrigerants. At least one of the first or second compressors is a variable speed compressor.

The invention discloses a double-stage cascade refrigeration method used for oil-gas recovery. The method adopts a double-stage cascade refrigeration system to provide cold energy for an oil-gas condenser step by step, wherein the cascade refrigeration system consists of two double-stage compression refrigeration cycles; and an oil-gas condenser with a higher level evaporating temperature is arranged on the cascade refrigeration system under an intermediate pressure of the double-stage compression refrigeration cycles to ensure that the oil gas is condensed step by step according to the temperature level. The double-stage cascade refrigeration method used for the oil-gas recovery has the advantages of not only being beneficial for reducing the manufacturing cost of equipment and the system energy consumption, but also providing convenience for adjusting condensation loads at each different temperature segment according to the different component distribution of the oil gas.

The utility model relates to a controlling device used to regulate the discharge pressure of an automatic cascaded refrigeration system, wherein a buffer is positioned between the outlet of a compressor and the inlet of a condenser, the buffer vessel is connected with a by-pass valve, an expanding vessel and a capillary tube in sequence, and the capillary tube is connected with the return duct to form a by-pass branch; the upper outlet of each gas-liquid separator in the middle of and downstream the automatic cascaded system is connected with a pressure control valve, the press control valves are connected with each other in parallel and connected with the expanding vessel by the pipeline. The utility model redesigns the arrangement of the tube so that the low temperature refrigerator based on automatic cascaded circulation can reduce operation pressure and equalizing pressure effectively and protect the compressor and pipeline of the system well; meanwhile, the air branch designed at the upper part of the gas-liquid separator increases the cooling speed of the system and shortens the cooling time of the refrigerator considerably.

A cascade refrigeration system using a first refrigerant or a high stage and a second, R-744, refrigerant for low stage refrigeration has a defrost system including a defrost compressor, a defrost inlet heat exchanger and defrost outlet heat exchanger. The defrost inlet heat exchanger receives a defrost portion of second refrigerant and adds an additional defrost heat load thereto from first refrigerant, thus evaporating defrost portion. Defrost portion is then compressed into high pressure defrost vapor potion in the defrost compressor. The defrost vapor portion is then circulated through a selected evaporator, where a defrost heat, augmented by additional defrost heat load, defrosts selected evaporator, defrost vapor being at least partially condensed into defrost condensed portion which is liquefied in defrost outlet heat exchanger.

The invention provides an intermediate fractional-condensation type auto-cascade refrigeration cycle system and refrigeration equipment. The intermediate fractional-condensation type auto-cascade refrigeration cycle system comprises a compressor, a first condenser, a gas-liquid separator, a first regenerator, a second condenser, a first throttle device and an evaporator. The first regenerator is provided with a first heat exchange channel and a second heat exchange channel. An outlet of the compressor is connected with an inlet of the first condenser. An outlet of the first condenser is connected with an inlet of the gas-liquid separator. A gas outlet of the gas-liquid separator is connected with an inlet of the second condenser, and an outlet of the second condenser is connected with an inlet of the evaporator sequentially through the first heat exchange channel and the first throttling device. A saturated liquid outlet of the gas-liquid separator is connected with an inlet of the compressor through the second heat exchange channel. An outlet of the evaporator is further connected with the inlet of the compressor. By the adoption of the intermediate fractional-condensation type auto-cascade refrigeration cycle system and the refrigeration equipment, the uniformity of temperature distribution in the refrigeration space is improved, the temperature variation is reduced, and thus the refrigeration effect is improved.

The invention discloses an auto-cascade vapor compression type refrigeration cycle system with an evaporation subcooler. The auto-cascade vapor compression type refrigeration cycle system comprises a compressor, a condenser and a gas-liquid separator which are sequentially connected, wherein the outlet of the gas-liquid separator is divided into two channels; in one channel, a liquid outlet of a saturated refrigerant is connected with an inlet of a first throttle mechanism and an outlet of the first throttle mechanism is connected with an evaporation side inlet of an evaporative condenser; in the other channel, a gas outlet of the saturated refrigerant is connected with an condensation side inlet of the evaporative condenser, an condensation side outlet of the evaporative condenser is connected with a high temperature side inlet of the evaporation subcooler, a high temperature side outlet of the evaporation subcooler is connected with an inlet of a second throttle mechanism, an outlet of the second throttle mechanism is connected with an inlet of an evaporator, an outlet of the evaporator is connected with an evaporation side inlet of the evaporation subcooler, an evaporation side outlet of the evaporation subcooler and an evaporation side outlet of the evaporative condenser are converged, and then connected with a gas suction opening of the compressor to complete the cycle. According to the auto-cascade vapor compression type refrigeration cycle system disclosed by the invention, the evaporation subcooler is used in the auto-cascade refrigeration cycle system, so that the performance of the auto-cascade vapor compression type refrigeration cycle system is effectively improved.

The invention discloses an ejector expansion auto-cascade refrigeration circulation system and a work process. The system comprises a compressor, a condenser, an ejector, a gas and liquid separator, athrottling valve, an evaporator, a backpressure valve and an evaporation cooler which are connected on a pipeline; the ejector takes condenser outlet high-pressure non-azeotropy mixture refrigerationagent gas and liquid two-phase fluid as work fluid, an evaporator outlet low-pressure refrigeration agent is ejected, a two-phase refrigerant obtained after mixed pressure rise enters the gas and liquid separator through an ejector outlet to be separated into the liquid state and the gas state, a gas outlet of the gas and liquid separator is divided into two paths, one path is connected with an air suction pipeline of the compressor, and the other path is connected with a condensation channel inlet of the evaporation condenser; a liquid outlet of the gas and liquid separator is connected withthe backpressure valve, and the backpressure valve adjusts the flow and the pressure of the refrigeration agent of the evaporation condenser by sensing the liquid outlet pressure of the gas and liquid separator. The ejector and the backpressure valve are effectively arranged in the auto-cascade refrigeration circulation system, the ejector expansion power recycling effect and the system dynamic adjusting effect can be sufficiently improved, and the refrigeration efficiency of the auto-cascade refrigeration circulation system can be efficiently improved.

The invention discloses a self-cascade refrigeration system with a double-stage compression function. The self-cascade refrigeration system is characterized in that a compressor (1) is provided with an intermediate air supplement port, refrigerants adopt two non-azeotropic refrigerants, an exhaust port of the compressor is sequentially connected with a condenser (3) and a gas-liquid separator (4),the high-boiling-point refrigerant discharged from the lower part of the gas-liquid separator sequentially flows through a heat regenerator (6), a first throttling component (7), a condensation evaporator (8) to a port A of a three-way valve (9), the low-boiling-point refrigerant discharged from the upper part of the gas-liquid separator sequentially flows through the condensation evaporator (8),a second throttling component (10), an evaporator (2), a rectifying pipe (11) arranged in the gas-liquid separator and the heat regenerator (6) and then is mixed with the refrigerant discharged froma port B of the three-way valve and then is returned to an air suction port of the compressor, and a port C of the three-way valve is connected with the air supplement port of the compressor. According to the system, the structure is simple, the power consumption can be effectively reduced, the refrigerating capacity can be improved, the lower temperature can be prepared, and the efficiency can beimproved.

The invention provides a mixed refrigerant suitable for the freezing zone at 105 to 125 DEG C below zero. The carbon tetrafluoride (R14) is mixed with one or two of the ethane (R170) and the ethylene (R1150) and then the mixed refrigerant can be obtained after physically mixing. The above components are physically mixed according to a set matching at normal temperature and the corresponding mixedworking substance can be obtained. The ODP is zero, greenly and environment-friendlily, and the mineral lubricating oil of compressor can be well inter-dissolved with the mixed refrigerant. The mixedrefrigerant suitable for the freezing zone at 90 to 100 below zero DEG C can flow the capillary and the expansion valve throttling gear well without oil solidification and wax plugging, and is suitable for the low temperature third grade of three-grade cascade refrigeration system and can form 105 to 125 DEG Cbelow zero low temperature.

The invention discloses a condensed explosion-proof oil gas reclaiming device, which comprises an oil gas heat exchange separator, a first condensation evaporator, a second condensation evaporator and three-stage refrigerating parts, wherein the cold energy of the first-stage refrigerating part is divided into two paths, one path of cold energy enters the first condensation evaporator, and the other path of cold energy enters the oil gas heat exchange separator; the cold energy of the second-stage refrigerating part is divided into two paths, one path of cold energy enters the second condensation evaporator, and the other path of cold energy enters the oil gas heat exchange separator; and the cold energy of the third-stage refrigerating part directly enters the oil gas heat exchange separator. The condensed explosion-proof oil gas reclaiming device reclaims oil gas by adopting a pure condensation method, and the oil gas after condensation and liquefaction directly becomes gasoline for recycle; meanwhile, fractional condensation is performed at a higher evaporation temperature by adopting compressor double-parallel cascade refrigeration technology, and the preceding stage refrigerating part provides a heat displacement low-temperature environment for the refrigeration and oil gas cooling fractional condensation of the post stage, so the energy efficiency ratio can be improved; and the device has the advantages of energy conservation, environmental protection, low cost and convenient operation and maintenance.