91 results about "Transcritical cycle" patented technology

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 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 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 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 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.

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.

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.

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.