674 results about "Compression system" patented technology

The invention provides a water working medium quasi-saturated compression high-temperature heat pump system based on an ejector, and belongs to the field of compression heat pumps. The problems that after an existing compression system flows through a throttling valve, the superheat degree of steam exhaust is large due to high-temperature lift compression, and the loss of available energy in the throttling process from condensate to a two-phase region is too large are solved. A multi-stage spraying atomization structure is adopted, a micro-nano liquid drop mist flow with the particle size controllable to be 50-200 nm and the liquid mass fraction adjustable to be 5%-10% is formed before compression, the airflow humidity regulation and control precision is remarkably improved, the quasi-saturation compression process is matched, and the thermal matching performance and the energy efficiency level of a system are effectively improved; a main flow inlet of the jet atomizer is changed into a compressor outlet from a condenser outlet, so that the response speed is increased, and meanwhile the jet atomizer is suitable for a complex variable-working-condition system; or single-stage compression is optimized into a two-stage compression form, so that higher heating temperature and more stable system operation are realized; or liquid from a lower-pressure position is injected, so that the injection capacity is improved.

The invention relates to the technical field of transformers, in particular to an anti-interference phase-shifting rectification dry-type high-capacity transformer which comprises a cooling channel, an air inlet system, an air outlet system and a compression system. The cooling channel is arranged between the high-voltage coil and the low-voltage coil; the air inlet system is connected with the mounting frame, and when the air inlet system works, low-temperature gas outside the anti-interference shell is sucked in, forms rotational flow and is fed into the cooling channel; the air outlet system is connected with the top of the anti-interference shell, and the compression system is connected with the air outlet system; low-temperature air is extracted from the outside and fed into the space between the high-voltage coil and the low-voltage coil in a rotational flow mode, dead-corner-free heat dissipation is guaranteed, the heat dissipation efficiency can be improved by changing the included angle between the low-temperature air and the horizontal plane during rotational flow along with heat change, heat is recycled for refrigeration, and the heat dissipation efficiency is further improved; the problem that due to heat accumulation in the anti-interference shell, air blown into the position between the high-voltage coil and the low-voltage coil by the draught fan is hot air and is not evenly distributed is solved.

The invention provides a combustion drive circulating gas-lift pressurizing all-in-one machine, and belongs to the technical field of natural gas production. Comprising a pressurization exhaust system, a gas lift pressurization system, a sewage discharge system, a pressure stabilizing system, a combustion drive multi-stage compression system and a base, and the pressurization exhaust system, the gas lift pressurization system, the sewage discharge system, the pressure stabilizing system and the combustion drive multi-stage compression system are all installed on the base. By arranging the pressurization exhaust system and the gas lift pressurization system, the device can perform gas lift and pressurization operation in an oil field, one machine has two purposes, by arranging the combustion drive multi-stage compression system, efficient dispatching of an oil and gas field circulation gas lift pressurization site is achieved, powerful guarantee is provided for development of the dual-carbon industry, and meanwhile, the device has good application prospects. By arranging the purification assembly, the natural gas in the well rises, so that the purity of the extracted natural gas is improved, and the problems that an existing gas lifting and pressurizing all-in-one machine is high in use cost and poor in effect are solved.

The invention relates to a hydrogen refueling station system which comprises a gas filling column, a compression system, a hydrogen storage system and a hydrogen filling machine which are sequentially connected in series, the compression system comprises a first compressor and a second compressor, the first compressor is connected with a first hydrogen storage bottle set, and the second compressor is connected with a second hydrogen storage bottle set. The sequence control panel arranged in the hydrogen refueling station system obtains the pressure in the equipment to be subjected to hydrogen refueling in real time according to the set control logic and judges the relation between the pressure and the hydrogen storage containers of different grades so as to adjust opening and closing of the corresponding valves and the opening degrees of the valves, hydrogen refueling of two refueling pressures is achieved in one hydrogen refueling station, and the safety of hydrogen refueling is improved. The device can be applied to equipment to be subjected to hydrogenation in different scenes, so that the filling pressure is controlled within a safe range, the hydrogenation safety is improved, meanwhile, hydrogenation is carried out at proper filling pressure, and the hydrogenation speed and efficiency are improved.

Examples of a plasma compression system are disclosed. The system includes a metallic vessel configured to receive and contain a plasma. The system further includes a metallic liquid liner in the vessel and at least partially bounding a plasma compression region having a longitudinal axis, and means for moving the liquid liner inwardly towards the longitudinal axis to compress the plasma in the plasma compression region. The system further includes a plurality of electrically conductive coils outside the plasma compression region and configured to generate a poloidal magnetic field in the liquid liner and the plasma compression region. At least some of the poloidal magnetic field within the plasma compression region extends along the longitudinal axis, and at least some of the poloidal magnetic field in the liquid liner moves inwardly towards the longitudinal axis with the liquid liner as the liquid liner moves towards the longitudinal axis.

The invention discloses a turbine for testing, an engine testing device and a method for determining a pneumatic instability boundary of a compression system, which can determine the pneumatic instability boundary of the compression system in a complete machine environment, do not cause extra burden to the turbine and compression system components, and do not need to modify a tester and surrounding equipment on a large scale. The turbine for testing is used for replacing an original turbine in a complete machine surge test of an engine, and the engine testing device is used for the complete machine surge test of the engine. Stator blades of the test turbine are arranged to be rotatable blades, so that the circulation sectional area of the test turbine is reduced by rotating the stator blades, and the compression system can enter a surge state.

The invention discloses a gas fuel compression control system, method, device and equipment and a storage medium. The gas fuel compression control system comprises an oil supply control valve, a sensor unit and a controller, and the signal output end of the sensor unit is connected with the signal input end of the controller; the oil supply control valve is used for controlling the on-off of an oil path of the final-stage compression cylinder according to a control instruction output by the controller; the sensor unit is used for collecting working state signals of the compression system in real time. And the controller is used for outputting a corresponding control instruction according to the working state signal so as to control the opening and closing state of the oil supply control valve based on the control instruction, so that the final-stage compression cylinder is put into compression work or quits compression work. The compression efficiency of the gas fuel compression system with the fixed displacement can be effectively improved.

The invention provides a triangular circulation heat management system and method for an automobile air conditioner. The system comprises a host system, a condensation system and a compression system. The main machine system comprises an air conditioner main machine with an evaporator, and the evaporator evaporates condensate water in the main machine system into water vapor. The condensing system comprises a condenser, one end of the condensing system is communicated with the host system through a pipeline, and the condensing system condenses water vapor into liquid water; the compression system comprises a compressor, the compression system communicates with the main machine system and the condensation system through pipelines, and the compressor provides heat for the evaporator. A first electronic expansion valve is arranged between the main machine system and the condensation system, a second electronic expansion valve is arranged between the main machine system and the compression system, the two ends of the compression system are connected through a third electronic expansion valve, and when the third electronic expansion valve is opened, the two ends of the compression system are directly communicated. The triangular circulation heat management system of the automobile air conditioner can solve the problem that peculiar smell is generated when the air conditioner is started in the prior art.

The invention discloses a compressor system and a method for realizing stable boundary control of a gas compressor thereof, which can actively adjust parameters B of the system and realize switching of an instability mode of the gas compressor between surging and rotating stall by only depending on an independent, small and adjustable switching section on the premise of not modifying large basic hardware (such as a volute and a pipeline). According to the principle of the compressor system provided by the embodiment of the invention, the effective flow area is changed by adjusting the angle of the turbine guider, so that the stability boundary of an upstream gas compressor or a fan is actively expanded, low-cost and rapid adjustment of the stability of the gas compressor is realized, the research and development efficiency is improved, and the test period is effectively shortened. The compressor system provided by the embodiment of the invention has the characteristic of wide applicability, can be applied to an independent compression system part test environment, and can also be applied to a complex complete machine environment comprising a compression system.

The invention discloses a vehicle moving track data compression method, which comprises the following steps of: acquiring vehicle driving data which comprises vehicle original track data; performing first analysis processing on the vehicle driving data to obtain vehicle travel information; performing first impurity removal processing on the vehicle original trajectory data to obtain first trajectory impurity removal data; performing track redundant point merging processing on the first track impurity-removed data to obtain first track compressed data; and performing similar track merging processing on the first track compressed data to output second track compressed data. According to the technical scheme, compared with the prior art, the compression rate of the vehicle form track can be increased, and the pressure of data processing and transmission can be reduced. In addition, the invention also relates to a vehicle movement track data compression system and electronic equipment, which also have the above beneficial effects.

The invention discloses a steam compression system and a control method thereof. The steam compression system comprises a flash tank, at least one stage of steam compressor and a first water circulation pipe. The flash tank is used for enabling the steam generation water heated to the specified flash temperature to be subjected to flash evaporation under the negative pressure condition in the tank to become low-pressure steam; the steam compressor is used for compressing the low-pressure steam into superheated steam of which the saturation pressure is target condensing pressure; and the first water circulating pipe is used for guiding water of a target water source to motors of the steam compressors at all levels and exchanging heat with heat dissipation mechanisms of all the motors, and the water subjected to heat exchange returns to the target water source. Compared with the prior art, heat at the motor is recycled through water circulation, so that the enthalpy value of water for steam generation is increased, energy consumption needed by steam generation is reduced, and the comprehensive energy efficiency of the system is improved.

The invention discloses a gas TPSA compression interstage purification integrated device control system and method. The system comprises a gas compression unit, an adsorption purification unit, a regeneration gas treatment unit and a control unit. The gas compression unit comprises a gas inlet pressure stabilizing valve, a gas compressor preceding stage, an interstage gas-gas heat exchanger, a compressor backward stage, an interstage pressure control valve and a backflow control valve, wherein the gas compressor preceding stage is used for pressurizing low-pressure raw gas and backflow regenerated gas to the pressure required by purification; compression heat of the interstage gas heat exchanger is used for preheating regenerated gas; the rear stage of the gas compressor is used for pressurizing the purified raw material gas to the pressure required by the downstream; the technical problems that a traditional TPSA gas purification device needs at least two compressors for staged compression, purification and compression systems are high in energy consumption, and loads are not easy to adjust are solved.

The invention discloses an acoustic monitoring method, system, medium and equipment for the near stall condition of an aircraft compressor, and the method comprises the steps: carrying out the synchronous collection of sound pressure time domain signals of multiple channels of an aviation compression system; adding a rectangular window to the multi-channel sound pressure time-domain signal, and constructing an acoustic time-domain signal segment to monitor the current operation state of the aviation compression system; performing fast Fourier transform on the multichannel acoustic time domain signal segment in the current time domain window to form a plurality of sound pressure frequency spectrums, judging whether a plurality of single-tone characteristic frequencies which are non-integer multiples of the current rotation frequency exist in the sound pressure frequency spectrums or not, and constructing an orthogonal Fourier transfer matrix based on the installation position and the highest circumferential modal order, and judging whether the order difference of the characteristic acoustic mode under each characteristic frequency is the rotation frequency multiple difference of the corresponding characteristic frequency, calculating the acoustic mode amplitude corresponding to each broadband frequency component, drawing an acoustic mode spectrogram, and judging whether a mode bright band exists at the cut-off frequency boundary in the acoustic mode spectrogram.

This application relates to a performance test system and method for a self-circulating steam compressor. Specifically, the system includes a steam input system, a steam compression system, a buffer and storage system, a steam recovery system, and an intelligent control system, as well as an optional steam compressor makeup water system, a condensate recovery system, and an internal oil cooling system. The self-circulating steam compressor performance test system described herein only requires a small amount of external steam to be input at the initial startup stage. After reaching a stable state, it can achieve full self-circulation operation. This reduces steam consumption, improves the overall economy and energy utilization rate of the system, and has strong operating reliability.

The utility model discloses a device for separating LNG (Liquefied Natural Gas) and CO (Carbonic Oxide) through dual-circulation refrigeration and cryogenic separation of mixed refrigerants and nitrogen. Comprising a main heat exchanger, a heavy hydrocarbon separator, an MRC low-temperature separator, a low-temperature separator, a hydrogen stripping tower, a hydrogen stripping tower reboiler, an LNG separation tower, an LNG separation tower reboiler, an LNG separation tower return tank, an LNG separation tower condenser, an N2 / CO separation tower, an N2 / CO separation tower reboiler, an N2 / CO separation tower return tank, an N2 / CO separation tower condenser, a mixed refrigerant compressor system and a nitrogen compression system. In addition, due to the fact that a low-temperature separator, a hydrogen stripping tower, an LNG separation tower and an N2 / CO separation tower are arranged in the process, the purity of CO is larger than 98.5% mol, and cold energy is provided for condensation and liquefaction of raw material gas and nitrogen and liquefaction and supercooling of LNG through a mixed refrigerant refrigeration cycle.

The invention discloses a transcritical carbon dioxide hot water system. The system comprises a first-stage compressor, a first heat exchanger used for exchanging heat with user side cooling water, a second-stage compressor, a second heat exchanger used for exchanging heat with user side cooling water, a third heat exchanger used for exchanging heat with a liquid-phase refrigerant and a gas-phase refrigerant, an expansion valve, a fourth heat exchanger used for exchanging heat with ambient air, a buffer water tank and a first proportional valve. A first proportional valve, a second proportional valve, a third proportional valve, a fourth proportional valve, a defrosting valve, a refrigerant path bypass valve and the like; according to the system, single-stage and double-stage compression switching in high-temperature weather and low-temperature weather can be achieved, it is guaranteed that the unit has good heating capacity and energy efficiency ratio when high-temperature water is discharged in the high-temperature weather and the low-temperature weather, and meanwhile the water outlet temperature control problem and the defrosting problem of the transcritical carbon dioxide single-double-unit compression system are solved.

The invention belongs to the technical field of compressors, and provides a compressor and a compression system. The compressor comprises a machine shell assembly, wherein a containing part is formed in the machine shell assembly; the rotor assembly comprises a female rotor and a male rotor which are meshed with each other, and the rotor assembly is positioned in the accommodating part; and the sliding block assembly is arranged in the containing part, and the sliding block assembly can move in the radial direction of the rotor assembly so as to adjust the opening degree of an axial exhaust port of the compressor and the opening degree of a radial exhaust channel. According to the compressor, the compression ratio of the compressor can be flexibly adjusted, meanwhile, the flowing loss of the axial exhaust port with the fixed size in a medium-low pressure mode is avoided, the working efficiency of the compressor is improved, the exhaust pressure is guaranteed, and meanwhile the gas flow is also guaranteed.

The invention discloses a power grid primary frequency modulation control model based on large-scale compressed air energy storage power generation, which is used for carrying out key technical research by adopting a research method combining current situation investigation, theoretical analysis, simulation calculation, database establishment, numerical simulation, test verification, development of process parameters and summarization and induction. And finally, an own compressed air energy storage technology is formed and popularized to practical engineering application. Through the complex heat exchange system, the turbine system, the heat storage system, the compression system and the like which are complex in characteristics and mutually coupled, the influence on the power grid in different operation modes of energy storage and energy release is studied and mastered, through theoretical research and numerical simulation, the response time of the energy storage power station is shortened as much as possible, the fastest load response speed is achieved, and the energy storage and energy release efficiency is improved. And requirements of power grid frequency modulation and peak regulation are satisfied.

A compression system comprising a compressor, the compressor comprising a sealing arrangement including at least one gas seal. A gas leakage recovery line is adapted to recover process gas leakages from the at least one gas seal. A fuel cell arrangement is fluidly coupled to the gas leakage recovery line. The fuel cell arrangement is adapted to process gas leakages and generate electric power therefrom.

The utility model discloses a multi-stage compression gas compression system which comprises a hydraulic driving unit with fixed displacement, a multi-stage compression cylinder, a gas storage device, a gas pressure detection unit and a control unit, the multi-stage compression cylinder comprises a plurality of compression cylinders which are sequentially connected in series from the first stage to the last stage through gas conveying pipelines. The signal output end of the air pressure detection unit is connected with the signal input end of the control unit. The air pressure detection unit is used for detecting air pressure signals of the multi-stage compression cylinder and sending the air pressure signals to the control unit. And the control unit is used for controlling the working states of the other stages of compression cylinders except the first-stage compression cylinder in the multi-stage compression cylinders according to the air pressure signal, so that the other stages of compression cylinders except the first-stage compression cylinder in the multi-stage compression cylinders are put into compression work or quit compression work. According to the utility model, the cost and the control complexity of the gas compression system can be reduced, and the efficiency improvement and consumption reduction of the gas compression system can be realized.

The invention relates to a vehicle-mounted screw air compressor oil emulsification prevention method and system, a medium and a program product, and in the method, the running state parameters of a screw air compressor are monitored in real time, and a water vapor saturation pressure formula and a temperature and pressure coupling mathematical model are used for calculating saturation water vapor pressure and actual water vapor partial pressure respectively. When the actual water vapor partial pressure is larger than the saturated water vapor pressure force corrected by the safety coefficient, the system adjusts the oil way temperature control valve to reduce the lubricating oil flow of the oil cooler so as to increase the exhaust temperature. If the condensation risk still exists and the exhaust temperature does not reach the shutdown protection threshold value, the oil way temperature control valve continues to be adjusted; if the exhaust temperature reaches the shutdown protection threshold value, the actual water vapor partial pressure is reduced by reducing the rotating speed of the frequency converter. And after the condensation risk is eliminated, the current operation parameters are maintained. The method is used for reducing the possibility that water vapor reaches saturation in the compression system and liquid water is separated out, and the accuracy and stability of lubricating oil emulsification risk control of the air compressor under the variable load working condition are improved.

The invention discloses a rapid calculation method for flow field prediction of a compression system of a variable cycle engine, and the method comprises the steps: building a parameterized mapping model of valve opening and total pressure distribution based on a wall attachment turbulent jet theory; the fan state conversion process is dispersed into a plurality of quasi-steady-state working conditions according to the actuation angle range of a mode selection valve; constructing a total pressure distribution and recovery coefficient prediction module under each working condition by using the parameterized model; the prediction module is embedded into a fluid mechanics solver in the form of boundary conditions, numerical simulation of the state transition process is completed, and performance change data are obtained. According to the scheme, full-three-dimensional complex calculation is replaced by parameterized mapping, the efficiency and precision of variable circulating fan mode conversion performance analysis are remarkably improved, meanwhile, the calculation cost is reduced, and quick-response technical support is provided for compression system optimization design.

A method and apparatus for controlling compressors in a cascade vapor compression system. The process may include controlling the operation of a first compressor based on a constant band control, and controlling the operation of a second compressor based on a proportional band control. Controlling the first compressor based on the constant band control may include operating the compressor at a constant setting if first measurements are within a range associated with a first setpoint. It may also include proportionally adjusting the operation of the first compressor if the first measurements are outside the range. Further, controlling the second compressor based on the proportional band control may include operating the compressor based on one of a plurality of proportional bands, each proportional band having a different proportional factor. Controlling the second compressor operation may further include switching between these proportional bands based on a second measured parameter.

The invention discloses a gas and heat combined supply compression system operation optimization method based on energy efficiency evaluation, and relates to the technical field of heat supply system operation optimizing.Distributed sensors are deployed at equipment and pipeline nodes of a gas and heat combined supply compression system, and operation data of equipment and pipelines of the gas and heat combined supply compression system are collected in real time through the sensors; the operation data comprises equipment and pipeline node inlet and outlet temperature, pressure, flow, power consumption and operation state parameters of the gas and heat combined supply compression system. The operation data of the gas and heat combined supply compression system is collected in real time, a multi-dimensional dynamic energy efficiency evaluation model is constructed by using the operation data, core indexes such as waste heat recovery efficiency and waste heat utilization matching degree are accurately quantified, and accurate mastering of waste heat supply and demand states is achieved. The problem that waste heat supply is wrongly matched with actual heat requirements is effectively solved, and the effectiveness of waste heat recovery is improved.

The utility model relates to the technical field of cleaning equipment, in particular to an MVR evaporator which is provided with an evaporator body, the evaporator body is provided with a stock solution inlet pipe, a condensate water outlet pipe and a water vapor compression system, the stock solution inlet pipe is provided with a heat exchanger, the condensate water outlet pipe is provided with a condensate water tank, and the condensate water tank is provided with a heating jacket. The heat exchanger is used for recovering the heat of the condensed water in the condensed liquid outlet pipe and preheating the stock solution, so that the effective utilization of energy sources and the improvement of the evaporation efficiency are realized; through recycling of the water vapor compression system, the MVR evaporator remarkably reduces the requirement for external steam, and therefore energy is saved; by arranging the condensate water tank and the heating jacket of the condensate water tank, a necessary initial steam environment is provided for the evaporator in the starting stage, the starting process of the evaporator is accelerated, and the overall operation efficiency is improved.

Compression system for monitoring and controlling fluid pressure during compression therapy has inflatable or deflatable compression garment, an air pump for regulating air pressure to the compression garment when connected to the air pump, an indicator unit, and controller operatively connected to the air pump for monitoring usage of the compression garment. The indicator unit has a first display indicator associated with the time of the monitored usage of the compression garment in a first operation state of the compression system when the compression garment is delivering compression to a patient, and a second display indicator associated with the time of the monitored usage of the compression garment in a second operation state of the compression system when the compression garment is not delivering compression to a patient. The indicator unit automatically swaps between the first and second display indicators associated with the states of operation of the compression system.

The invention provides a cooling device, a control method, a compression system and an air conditioner, the cooling device comprises a cooling unit and a vacuum pump, the cooling unit comprises an oil storage tank and an oil conveying tank, an oil inlet and an exhaust port are formed in the upper end of the oil conveying tank, and an oil outlet is formed in the lower end of the oil conveying tank; the oil inlet pipeline communicates with the oil storage tank and the oil inlet. The exhaust pipeline communicates with the vacuum pump and the exhaust port. Under the action of the vacuum pump, air in the oil conveying tank is exhausted, so that negative pressure is formed in the oil conveying tank; under the action of negative pressure, cooling oil in the oil storage tank enters the oil conveying tank through the oil inlet pipeline, and then the cooling oil in the oil conveying tank is output through the oil outlet pipeline; the scheme that the vacuum pump replaces a traditional oil pump is adopted, cooling oil in the oil storage tank is input into the oil conveying tank through negative pressure, then the cooling oil is output through gravity, and conveying of one or more kinds of cooling oil is achieved; due to the characteristic of negative pressure driving, the device is not influenced by the viscosity of cooling oil and can be compatible with cooling oil with different rheological characteristics; when cooling oil is replaced, only the oil conveying tank and the corresponding pipeline need to be cleaned.

The invention provides a double-shaft compression system supporting structure suitable for a large-mass long shaft system, and belongs to the technical field of aero-engines, the double-shaft compression system supporting structure comprises a main support, a rear auxiliary support and a front auxiliary support, the main support is connected with an exhaust force bearing casing of a double-shaft compression system and used for transmitting part of weight of the double-shaft compression system to the main support, and the rear auxiliary support is connected with the front auxiliary support; the rear auxiliary support is connected with an intermediate force-bearing casing of the double-shaft compression system and used for transmitting the weight of the intermediate force-bearing casing of the double-shaft compression system to the rear auxiliary support, and the front auxiliary support is connected with an air inlet force-bearing casing of the double-shaft compression system and used for transmitting the weight of the air inlet force-bearing casing of the double-shaft compression system to the front auxiliary support. The technical problem that a traditional single-fulcrum supporting structure cannot stably position and absorb thermal expansion deformation is solved, and long-time stable supporting of a large-mass long-shafting biaxial compression system in a biaxial compressor tester in a high-temperature working environment is achieved through the three-fulcrum supporting structure.

The invention provides an automobile damping spring compression rigidity detection device which comprises a spring feeding control system, a spring compression system, a spring deformation detection system, a spring discharging screening system, a digital control system and a rack. The spring feeding control system comprises a spring, a spring supporting plate, a side plate adjusting mechanism, a first blocking mechanism and a second blocking mechanism, the spring compression system comprises a rotary base mechanism, a spring radial positioning mechanism and a main pressing mechanism, and the spring deformation detection system comprises a push rod motor mechanism, a detection supporting plate mechanism, a deformation detection mechanism and a discharging port. The discharging screening system comprises a discharging supporting plate, a first discharging mechanism, a second discharging mechanism and a qualified product box, compression strength ultimate pressure detection and fatigue durability detection can be carried out on springs of different sizes at the same time, and screening is carried out on the deformation of the compressed springs in different interval ranges.

A vapor compression system includes a primary loop and a secondary loop. The primary loop includes a dynamic compressor operable to compress a refrigerant, a condenser fluidly connected to the dynamic compressor, a first expansion device fluidly connected to the condenser, and an evaporator fluidly connected to the first expansion device and the dynamic compressor. The dynamic compressor includes a housing, a shaft supported in the housing by a bearing, an impeller connected to the shaft, a motor operably connected to the shaft to drive rotation thereof, and a drive operable to control the motor. The secondary loop includes a second expansion device fluidly connected to the condenser, a heat exchanger fluidly connected to the second expansion device, the condenser, and the dynamic compressor, and a supply duct fluidly connected between the heat exchanger and the dynamic compressor to provide a flow of refrigerant to the bearing.