91 results about "Transcritical cycle" patented technology

A refrigerant system utilizes an expander that provides a more efficient expansion process and recovers at least a portion of energy from this expansion process. At least a portion of refrigerant that has been at least partially expanded in the expander is tapped and passed through an economizer heat exchanger. In the economizer heat exchanger, the tapped refrigerant cools a main circuit refrigerant increasing its thermodynamic potential. Further, a compression section is provided with at least two compressors operating in tandem and allowing for multiple stages of unloading. By selectively utilizing one or more of the tandem compressors, the economizer cycle, and the expander, the refrigerant system can achieve very efficient operation and provide enhanced control flexibility, in particular, for the CO2 refrigerant system operating in the transcritical cycle.

This invention relates to a refrigeration method and processes that employ a nontoxic and environmentally benign, oil-free refrigerant in a novel vapor-compression thermodynamic cycle that includes a means for enhancing cooling capacity and efficiency. A means of controlling of the process conditions and flow of the refrigerant are provided. The refrigerant in the invention in used in a transcritical cycle.

A phase separation apparatus is provided for separating a two-phase fluid flow into a liquid phase portion and a vapor phase portion. The phase separation apparatus may be applied to the separation of a two-phase refrigerant flow in a refrigerant vapor compression system operating in a transcritical cycle.

The invention discloses a trans-critical-compression / absorption composite refrigeration device utilizing low-grade heat, which comprises a high-pressure stage absorption refrigeration subsystem, a trans-critical circulation subsystem and a low-pressure stage absorption refrigeration subsystem. Through reasonable energy coupling among the systems, the utilization efficiency of electric energy as well as the utilization efficiency of low-grade heat of an input system is improved, and the low-grade heat at a very low temperature can be fully utilized, so that the trans-critical-compression / absorption composite refrigeration device has better economic performance; and the whole device has a simple structure, thereby facilitating steady operation and requiring low construction and maintenance costs.

A refrigerant vapor compression system using CO2 as the working fluid and operating in a transcritical cycle, compression of the refrigerant is accomplished by use of a digital scroll compressor adapted to a variable duty cycle in a pulse width modulation manner. The compression ratio is maintained at an acceptable level by selective control of various components within the system, depending on the mode of operation.

A vapour compression device including an internal heat exchanger, a low-pressure compressor and an associated gas cooler, a fluid distributor separating the fluid into a main circuit of the cycle and into an auxiliary cooling circuit of the cycle, an auxiliary expansion system placed on the auxiliary cooling circuit, and a main expansion system placed on the main circuit of the cycle. The device also includes a high-pressure compressor and an associated gas cooler placed on the main circuit of the cycle. A method for performing a transcritical fluid cycle including a substantially isentropic compression step of the fluid, on the main circuit of the cycle, to reach a maximum high pressure greater than a critical pressure of the fluid, and an isobaric cooling step of the fluid to substantially reach a cold source temperature.

The invention discloses a CO2 power cycle and absorption heat pump combined heat and power cogeneration system for high temperature flue gas waste heat recovery. The CO2 power cycle and absorption heat pump combined heat and power cogeneration system realizes combined heat and power cogeneration by integrating high and low temperature power cycle and absorption heat pump cycle. The power cycle uses CO2 as the working medium, the endothermic process is located at the supercritical pressure, the exothermic process to a cold source is located at the subcritical pressure, and a transcritical cycleform is achieved. The high-temperature power cycle uses high-temperature flue gas as a heat source, and the low-temperature power cycle absorbs heat from dead steam of the high-temperature power cycle. An absorption heat pump system uses low-temperature power cycle high-temperature dead steam as a driving heat source and a low-temperature dead steam as a low temperature heat source, the waste heat resources are fully used as far as possible, and the COP of the absorption heat pump cycle is increased. The CO2 power cycle and absorption heat pump combined heat and power cogeneration system improves the heat exchange matching between the circulation and the variable temperature heat source, effectively utilizes the recycled dead steam heat, realizes the cascade utilization of different tasteresidual heat energy, and improves the overall energy utilization efficiency of the system.

The invention is a carbon dioxide refrigerator, which includes compressor, condenser, two-position three-way electromagnetic valve, crisis spanned capillary, subcritical capillary, evaporator, temperature sensor, controller. The system uses carbon dioxide refrigerating agent, the compressor has two gears of rotation speed, and the output aperture of the condenser is distributed with temperature sensor for sensing the refrigerating temperature here. When the temperature measured by the sensor is lower than 28deg.C, the compressor uses low rotation speed, the subcritical capillary is connected; when the temperature is higher than 28deg.C, the compressor uses high rotation speed, the crisis spanning capillary is connected. The system can avoid the carbon dioxide condensing temperature from change in the near-critical area, thus it can upgrade the system efficiency effectively; the match of the system in critical spanning circulation and the subcritical circulation; it avoids the problem that the cold quantity generated by the compressor is not enough but it runs in a long time, it also can avoid the problem that the cold quantity is too large leading to that the starting-up and closing period is short.

A heat pump refrigerant system is provided with at least two sequential stages of compression. An intercooler is positioned intermediate the two stages. The refrigerant flowing through the intercooler. is cooled by a secondary fluid such as ambient air. The intercooler is positioned to be in a path of air flow passing over an outdoor heat exchanger, and preferably upstream of the outdoor heat exchanger, in relation to this air flow. Benefits with regard to efficiency and capacity are achieved due to proposed system configuration in both heating and cooling modes of operation, while no additional circuitry or components are required to provide the intercooler function for the heat pump refrigerant system. This invention is particularly important for the CO2 heat pump refrigerant systems operating in the transcritical cycle.

The invention belongs to the technical field of transcritical carbon dioxide (CO2) refrigeration heat pumps. A refrigeration heat pump unit of a CO2 transcritical cycle comprises a CO2 refrigerant compressor, a gas cooler, a regenerator, a throttle valve I, a gas-liquid separator, a throttle valve II, an evaporator, a controller, a pressure sensor, a temperature sensor and a superheat temperature sensor. All parts are connected through pipelines to form a closed system. The controller controls opening degrees of the throttle valve I and the throttle valve II according to detected refrigerant pressure in the gas cooler, detected refrigerant temperature of an outlet of the gas cooler, refrigerant superheat degree of an outlet of the evaporator and the highest cooling pressure Pg of system operation, and the unit is enabled to be operated under high cycling efficiency. The refrigeration heat pump unit of the CO2 transcritical cycle and a control method of the refrigeration heat pump unit of the CO2 transcritical cycle have the advantages that when environment temperature or environment temperature of a cooled department changes, the controller can adjust the unit and enable the unit to be operated under the high cycling efficiency, and the method is simple, easy to achieve, reliable and stable.

The invention discloses a compound heat pump system for co-production by adopting trans-critical circle and two-stage absorption type heat pump cycle. The compound heat pump system comprises a trans-critical compression subsystem and a heat pump subsystem which takes the trans-critical compression subsystem as a heat source, wherein the heat pump subsystem comprises first absorption type heat pump subsystems and second absorption type heat pump subsystems which are in energy coupling with the trans-critical compression subsystem. The invention further discloses a co-production method by adopting trans-critical circle and two-stage absorption type heat pump cycle. According to the compound heat pump system, by virtue of reasonable energy coupling of trans-critical cycle and two-stage absorption type cycle, heat energy output of conventional compression cycle is changed; by sufficiently utilizing condensation heat of the trans-critical circle and an extremely low-grade heat source, and the two-stage absorption type heat pump outputs an available conventional heat source, so that the integral performance of the heat pump system is improved; and according to analysis, in comparison with conventional trans-critical heat pump cycle, the heat pump system can increase a heating performance coefficient by more than 40%, has good economical efficiency, and is simple in integral structure.

The invention relates to the technical field of heat pump drying, in particular to a drying system based on a CO2 transcritical heat pump cycle. The system comprises a drying chamber, a refrigerant loop and a drying medium loop. A compressor, a gas cooler, a regenerator, a throttling valve and an evaporator are sequentially arranged on the refrigerant loop. The gas cooler, the drying chamber, a heat exchanger and the evaporator are arranged on the drying medium loop. The heat exchanger comprises first pipelines and second pipelines which mutually exchange heat. An air outlet of the gas cooler communicates with an air inlet of the drying chamber. An air outlet of the drying chamber communicates with inlets of the first pipelines. Outlets of the first pipelines communicate with an air inlet of the evaporator. An air outlet of the evaporator communicates with inlets of the second pipelines. Outlets of the second pipelines communicate with an air inlet of the gas cooler. According to the drying system based on the CO2 transcritical heat pump cycle, the transcritical cycle is adopted, the drying system can adapt to the drying work conditions within the wider temperature range, recycling is conducted on waste heat, and the energy efficiency is improved greatly.

A refrigerant system is provided with at least two stages of compression connected in series. An intercooler is positioned intermediate the two stages and is cooled by an indoor air stream. The intercooler is positioned to be in a path of air flow passing over an indoor heat exchanger, and preferably downstream of the indoor heat exchanger, in relation to this airflow. The intercooler cools the refrigerant flowing between the two compression stages as well as provides the reheat function. Benefits with regard to system performance (efficiency, capacity and reliability) are achieved with no additional circuitry or components required to provide the intercooler and reheat functions. This invention is particularly important for the CO2 refrigerant systems operating in the transcritical cycle. Methods of control are presented for both the intercooler and reheat functions.

The invention relates to a device for measuring trans-critical cycle heat exchange of CO2-oil mixture in the technical field of refrigeration and air conditioning. A condenser is sequentially connected with a second electronic expansion valve, a sixth stop valve and an evaporation bypass section which is connected between a third stop valve and a compressor module oil path; the condenser is also sequentially connected with a first stop valve, a first viewing mirror, a CO2 mass flow meter, a mixing chamber, a first electronic expansion valve, a preheater and a CO2 trans-critical cycle heat exchange characteristic test section; the condenser is further sequentially connected with a fifth stop valve of a lubricating oil branch, a piston-type oil storage device, an adjustable valve of the lubricating oil branch, a high pressure oil pump, a second viewing mirror, a lubricating oil mass flow meter and a check valve, wherein the check valve is connected between the CO2 mass flow meter and a mixing chamber oil path; and the condenser is also sequentially connected with a rear heater, a second stop valve, a high-efficiency oil separator, a fourth stop valve in the lubricating oil branch, and the piston-type oil storage device. The device adopts an intermittent oil returning method so that the measurement of the lubricating oil mass flow is accurate.

The vapour compression device according to the invention comprises an internal heat exchanger, a low-pressure compressor and an associated gas cooler, a fluid distributor separating the fluid into a main circuit of the cycle and into an auxiliary cooling circuit of the cycle, an auxiliary expansion system placed on the auxiliary cooling circuit, and a main expansion system placed on the main circuit of the cycle. The device also comprises a high-pressure compressor and an associated gas cooler placed on the main circuit of the cycle. The method for performing a transcritical fluid cycle according to the invention preferably comprises an isentropic compression step of the fluid, on the main circuit of the cycle, to reach a maximum high pressure greater than a critical pressure of the fluid, and an isobaric cooling step of the fluid to substantially reach a cold source temperature.

The invention discloses a combined heat pump system adopting trans-critical circulation and absorption heat pump co-production. A trans-critical compression subsystem comprises a compression unit, an air cooling unit, a throttling unit and an evaporation unit which are connected through working medium circulation. The air cooling unit is divided into a first heating pipe, a second heating pipe and an air cooling device in the flowing direction of a working medium, wherein the first heating pipe, the second heating pipe and the air cooling device release heat step by step and condense. A heat pump subsystem comprises a generator, a condenser, a first solution pump, a condensing evaporator, an absorber, a solution heat exchanger, a throttling device and a second solution pump. According to the system, by means of reasonable energy coupling, generation heat of the heat pump system comes from condensation heat of the trans-critical compression subsystem completely, a high-temperature heat source with the temperature of above 100 DEG C can be manufactured at the absorber only by inputting a small amount of electric energy, the system has the function of co-production of multiple kinds of energy, the performance coefficient is high when the electric energy is utilized for refrigerating and heating, and the whole system is simple in structure and low in manufacturing cost, and is economical.

The invention discloses a trans-critical cycle double-stage heat absorption providing composite refrigeration system. The refrigeration system is composed of a trans-critical compression subsystem, a high-pressure absorption subsystem and a low-pressure absorption subsystem and is a novel closed compression absorption composite system. The generation heat of both the high-pressure absorption subsystem and the low-pressure absorption subsystem is from the trans-critical compression subsystem through reasonable energy coupling, the grade of the usable waste heat of the low-pressure stage of the double-stage absorption is reduced, and the utilization rate of the waste heat of exhaust air at an air outlet of a trans-critical compressor is improved, so that the absorption subsystem does not need additional heat input, only needs necessary electric energy input from the compressor and has good independence and application scope. Compared with simple trans-critical cycle compression, the composite cycle system has the COP increased by about 30% to 40%, thereby having good economical efficiency.

The invention discloses a membrane type liquid desiccant air conditioner. The membrane type liquid desiccant air conditioner comprises a compressor, an auxiliary gas cooler, a first heat exchanger, a second heat exchanger, a liquid storage tank, a hollow fiber membrane type regenerator, an auxiliary cooler and a hollow fiber membrane type desiccant device. The liquid desiccant air conditioner is driven by a carbon dioxide circulating heat pump, carbon dioxide is used as a refrigerating working medium, is environmentally friendly and free of pollution and has obvious advantages over traditional refrigerants such as R134a, R22 and R407c causing environment destruction, and the carbon dioxide working medium has small influences on the environment. Meanwhile, carbon dioxide transcritical cycle is high in heat release temperature, and the desiccant liquid regeneration demand can be well met. In addition, the hollow fiber membrane type regenerator and the hollow fiber membrane type desiccant device are used as liquid desiccantion and regenerating parts, and thus the problem that fed air carries desiccant liquid due to the fact that liquid desiccant of a traditional liquid desiccant air conditioner makes contact with the air is solved.

The invention relates to a carbon dioxide heat pump heat supply system. The carbon dioxide heat pump heat supply system comprises a first circulating loop, a heat supply circulating loop, a second circulating loop and a shunting pipeline, wherein carbon dioxide is used as a refrigerant in the first circulating loop; circulating water is used as a medium in the heat supply circulating loop; and Freon is used as a refrigerant in the second circulating loop. A gas cooler is arranged between the first circulating loop and the heat supply circulating loop, and a second evaporator is arranged between the heat supply circulating loop and the second circulating loop. The gas cooler is used for carrying out heat exchange between the carbon dioxide and the circulating water. The second evaporator is used for lowering the temperature of the circulating water. By adopting the second circulating loop to lower the temperature of the circulating water entering the gas cooler, the temperature difference between the inlet water and the outlet water of the gas cooler is increased, and the transcritical circulating heat exchange efficiency of the first circulating loop is increased. The heat supply system can stably and efficiently run at low environmental temperature. Heating capacity attenuation is low, the energy efficiency is high, and high-temperature heating or drying can be realized.

The invention relates to a pressurization and heat absorption transcritical cycle hot dry rock geothermal power generation model based on a CO2 mixed working medium, which comprises a geothermal watercycle, a mixed working medium cycle and a cooling water cycle; and an underground coaxial sleeve heat exchanger is arranged in the mixed working medium cycle. The innovation is reflected in that a pressurization and heat absorption process is realized by utilizing a gravity field, so that the cycle heat absorption capacity is increased, and the cycle power generation is increased. A binary mixedworking medium composed of CO2 and an organic working medium is adopted; and therefore, a transcritical cycle with pressurization heat absorption and temperature reduction heat release can be achieved, irreversibility of heat exchange of a heat source and a cold source can be effectively reduced, and the cycle efficiency is improved. The mixed working medium adopted by the cycle comprises (but notlimited to) CO2 / R32, CO2 / R161, CO2 / R1270, CO2 / R1234yf, CO2 / R134a, CO2 / R152a and CO2 / R1234ze. The pressurization and heat absorption transcritical circulation hot dry rock geothermal power generationmodel based on the CO2 mixed working medium mainly aims at hot dry rock geothermal resources, but is not limited to the hot dry rock geothermal resources; and the power generation system is also suitable for application occasions of other binary cycle geothermal power generation systems.

A heat pump refrigerant system is provided with at least two sequential stages of compression. An intercooler is positioned intermediate the two stages. The refrigerant flowing through the intercooler. is cooled by a secondary fluid such as ambient air. The intercooler is positioned to be in a path of air flow passing over an outdoor heat exchanger, and preferably upstream of the outdoor heat exchanger, in relation to this air flow. Benefits with regard to efficiency and capacity are achieved due to proposed system configuration in both heating and cooling modes of operation, while no additional circuitry or components are required to provide the intercooler function for the heat pump refrigerant system. This invention is particularly important for the CO2 heat pump refrigerant systems operating in the transcritical cycle.

A refrigerant system is provided with at least two sequential stages of compression. An intercooler is positioned intermediate the two stages. The refrigerant flowing through the intercooler is cooled by a secondary fluid such as ambient air. A vapor / liquid injection function is also provided for the refrigerant system. The intercooler function and the vapor / liquid injection function are selectively activated on demand depending on environmental conditions and thermal load in a conditioned space. This invention is particularly important for the CO2 refrigerant systems operating in the transcritical cycle.

The invention discloses an air treatment system combining trans-critical circulation and a solution dehumidification system. The air treatment system is characterized in that the system comprises a trans-critical compression subsystem and a solution dehumidification subsystem, heat discharged by a high-pressure side of the trans-critical compression subsystem serves as a heat source of the solution dehumidification subsystem, the solution dehumidification subsystem comprises a strong solution dehumidification unit and a dilute solution regenerating unit, and a dehumidification process is a heat insulation dehumidification process. The invention further discloses an air treatment system combining trans-critical circulation and a solution dehumidification system, and a dehumidification process is a constant-temperature dehumidification process. Reasonable energy coupling of the trans-critical circulation and the solution dehumidification system is achieved, dehumidification and temperature falling of the air can be simultaneously achieved, overall performance of the dehumidification system is improved, the heat discharged by the high-pressure side of the compression subsystem basically meets regenerated heat requirements when trans-critical compression refrigeration circulation refrigerating temperature ranges from 7 DEG C to 12 DEG C and can completely meet the regenerated heat requirements when the cooling temperature of a dehumidifying agent drops, compression work can be decreased by 10% or more, and the system is simple in structure and excellent in overall economy and environmental protection.

The invention relates to a trans-critical CO2 heat pump system meeting requirements of high return water temperature and different heating conditions and a manipulation method of the trans-critical CO2 heat pump system, belongs to heating circulation technologies of heat pumps, and solves the problem that the conventional CO2 heat pump product cannot meet the high temperature cyclic heating requirement; the heat pump system is formed by combining a subcritical circulation loop taking a high temperature refrigerant as a coolant and a trans-critical circulation loop taking CO2 as a coolant; the two circulation loops share one evaporative cooler; the evaporative cooler serves as the auxiliary gas cooler of the trans-critical circulation loop and further serves as the main evaporator of the subcritical circulation loop; the trans-critical circulation loop supplies circulating hot water to users, wherein the circulating hot water has an outlet water temperature of 70-90 DEG C and a return water temperature of 70-80 DEG C; the subcritical circulation loop can prepare hot water of 50-60 DEG C. According to the trans-critical CO2 heat pump system meeting requirements of high return water temperature and different heating conditions and the manipulation method of the trans-critical CO2 heat pump system, provided by the invention, the efficiency of the trans-critical CO2 heat pump system meeting requirements of high return water temperature cyclic heating conditions is improved, and the technical problem that a single-stage CO2 circulation system cannot realize cyclic heating with the return water temperature of 70 DEG C or above is solved.

The invention discloses an air source transcritical CO2 heat pump and a multi-melting-point phase change heat storage coupling heating system. The multi-melting-point phase change heat storage coupling heating system comprises a CO2 air source heat pump machine set, a first variable frequency pump, a high-melting-point phase change heat storage device, a user, a second variable frequency pump, a low-melting-point phase change heat storage device and a plurality of electromagnetic valves, wherein the secondary heat exchange side of a CO2 transcritical circular heat pump heating system is combined with the multi-melting-point phase change heat storage device; the low-melting-point phase change heat storage device is used for absorbing waste heat of return water, so that the temperature of the return water is reduced, and then the temperature of a working medium before a throttling valve and the throttling loss are reduced, thereby causing the temperature glide in the CO2 exothermic process to be in temperature matching with hot water very well and giving full play to the unique advantages of the CO2 transcritical circular heat pump heating system. In addition, when the peak value of electric power or the heat supply efficiency of the heat pump is relatively low, the system is switched into a heat release mode, and the heat of the phase change device is used for heat supply. The multi-melting-point phase change heat storage coupling heating system provided by the invention has the beneficial effects that the multi-melting-point phase change heat storage coupling heating system can operate and be controlled at different period of time during wave crest and wave trough of electric power, and then the comprehensive utilization performance of the heat pump machine set is improved.

The invention relates to a multi-heat exchanger series transcritical CO2 heat pump heating system which comprises a first compressor, a first air cooler, a second air cooler, a cooling evaporator, a first throttling device, a low-temperature evaporator, a second compressor, a condenser and a second throttling device. The first compressor, a refrigerant channel of the first air cooler, a refrigerant channel of the second air cooler, one refrigerant channel of the cooling evaporator, the first throttling device and a refrigerant channel of the low-temperature evaporator are sequentially connected through a pipeline to form CO2 transcritical circulation loop. The second compressor, a refrigerant channel of the condenser, the second throttling device and the other refrigerant channel of the cooling evaporator are sequentially connected through a pipeline to form an auxiliary circulation loop. A secondary refrigerant channel of the second air cooler, a secondary refrigerant channel of the condenser and a secondary refrigerant channel of the first air cooler are connected through a pipeline form a water supply flow path. According to the system, the heat exchange uniformity can be improved, and the overall energy efficiency of the CO2 heat pump heating system is improved.