Abstract: The present invention involves a compression refrigeration system including a compressor, a heat rejector, expansion means and a heat absorber connected in a closed circulation circuit that may operate with supercritical high-side pressure. An apparatus and method are provided to optimize energy efficiency.

Abstract: A compression refrigeration system that includes a compressor, a heat rejector, expansion means and a heat absorber connected in a closed circulation circuit that may operate with supercritical high-side pressure.

Abstract: A method of liquefying a hydrocarbon-rich gas, wherein the gas flows through a cascade of three refrigeration stages, each stage comprising a refrigerant circuit and a compressor, wherein at least part of the flow of refrigerant from the second circuit is used for the pre-cooling of the hydrocarbon rich gas in the first refrigeration stage. This balances the load on each of the compressors. By standardizing the drive units and compressors of the three coolant circuits, it is possible to maximize the attainable liquefaction capacity of the liquefaction process using tried-and-trusted drive units and compressors respectively. This method can be applied to mixed refrigerant cascades and circuits with a carbon dioxide pre-cooling circuit. This latter option has benefits for offshore use where large amounts of hydrocarbons are undesirable.

Abstract: Reversible vapor compression system including a compressor (1), an interior heat exchanger (2), an expansion device (6) and an exterior heat exchanger (3) connected by means of conduits in an operable relationship to form an integral main circuit. A first device is provided in the main circuit between the compressor and the interior heat exchanger, and a second device is provided on the opposite side of the main circuit between the interior and exterior heat exchangers to enable reversing of the system from cooling mode to heating mode and vice versa. The first and second device for reversing of the system include a first and second sub-circuit (A respectively B) each of which is connected with the main circuit through a flow reversing device (4 and 5 respectively). Included in the system solution is a reversible heat exchanger for refrigerant fluid, particularly carbon dioxide. It includes a number of interconnected sections arranged with air flow sequentially through the sections.

Abstract: A compression refrigeration system includes a compressor (1), a heat rejector (2), expansion device (3) and a heat absorber (4) connected in a closed circulation circuit that may operate with supercritical high-side pressure. The refrigerant charge and component design of the system corresponds to a stand still pressure inside the system which lower than 1.26 times the critical pressure of the refrigerant when the temperature of the whole system is equalized to 60° C. Carbon dioxide or a mixture of a refrigerant containing carbon dioxide may be applied as the refrigerant in the system.

Abstract: A compression refrigeration system includes a compressor (1), a heat rejector (2), expansion means (3) and a heat absorber (4) connected in a closed circulation circuit that may operate with supercritical high-side pressure.

Abstract: A compression refrigeration system includes a compressor (1), a heat rejector (2), expansion means (3) and a heat absorber (4) connected in a closed circulation circuit that may operate with supercritical high-side pressure.

Abstract: A method of defrosting of a heat exchanger (evaporator) in a vapor compression system including, downstream of a heat exchanger (evaporator) (3) to be defrosted, at least a compressor (1), a second heat exchanger (condenser/heat rejecter) (2), and an expansion device (6) connected by conduits in an operable manner to form an integral closed circuit. The heat exchanger (3) to be defrosted is subjected to essentially the same pressure as the compressor's (1) discharge pressure. Thus, the heat exchanger (3) is defrosted as the high-pressure discharge gas from the compressor (1) flows through to the heat exchanger, giving off heat to the heat exchanger (3). In the circuit, in connection with the expansion device (6) a first bypass loop 23 with a first valve (16?), is provided.

Abstract: Reversible vapor compression system including a compressor (1), an interior heat exchanger (2), an expansion device (6) and an exterior heat exchanger (3) connected by means of conduits in an operable relationship to form an integral main circuit. A first means is provided in the main circuit between the compressor and the interior heat exchanger, and a second means is provided on the opposite side of the main circuit between the interior and exterior heat exchangers to enable reversing of the system from cooling mode to heat pump mode and vice versa.

Abstract: Method for defrosting of a heat exchanger (evaporator) in a vapor compression system including, beyond a heat exchanger (evaporator) (3) to be defrosted, at least a compressor (1), a second heat exchanger (condenser/heat rejecter) (2) and an expansion device (6) connected by conduits in an operable manner to form an integral closed circuit. The heat exchanger (3) to be defrosted is subjected to essentially the same pressure as the compressor's (1) discharge pressure whereby the heat exchanger (3) is defrosted as the high-pressure discharge gas from the compressor (1) flows through to the heat exchanger, giving off heat to the said heat exchanger (3).

Abstract: A refrigerating or heat pump system includes an evaporator (23), a compressor (20), an air-cooled heat rejecting heat exchanger (21) and an expansion device (22) being connected in a closed circuit and operating in a trans critical vapor compression cycle. The heat rejecting heat exchanger (21) is cooled by natural upwards circulation/convention of air. In a preferred embodiment the heat rejecting exchanger (21) is built into an air flow conduit or shell (11) to improve the natural air circulation by obtaining a chimney effect.

Abstract: Reversible vapor compression system including a compressor (1), an interior heat exchanger (2), an expansion device (6) and an exterior heat exchanger (3) connected by means of conduits in an operable relationship to form an integral main circuit. A first means is provided in the main circuit between the compressor and the interior heat exchanger, and a second means is provided on the opposite side of the main circuit between the interior and exterior heat exchangers to enable reversing of the system from cooling mode to heating mode and vice versa. The first and second means for reversing of the system include a first and second sub-circuit (A respectively B) each of which is connected with the main circuit through a flow reversing device (4 and 5 respectively) Included in the system solution is a reversible heat exchanger for refrigerant fluid, particularly carbon dioxide. It includes a number of interconnected sections arranged with air flow sequentially through the sections.

Abstract: A heat exchanger comprises a plurality of flat tubes for heat exchange between a first fluid flowing inside the tubes and a second fluid flowing outside the tubes. A pair of hollow headers is connected to the ends of the flat tubes. An inlet and outlet are provided in the headers for introducing the first fluid into the flat tubes and discharging it therefrom. Each header is composed of at least two parallel tubes with substantially circular cross-section, two adjacent tubes having integrated wall portions, thereby providing a substantially flat header.

Abstract: A vapor compression system includes a compressor, a heat rejecting heat exchanger, an expansion device and an evaporator connected in series to form a closed circuit operating at supercritical pressure in a high pressure side of the circuit. A large part of the internal volume of the circuit is incorporated at or close to a refrigerant outlet from the heat exchanger. The actual refrigerant charge corresponds to an optimum overall density ensuring self-adaptation of the supercritical high-side pressure to maintain maximum energy efficiency at varying heat rejection temperatures of the heat exchanger.

Abstract: An apparatus and a method is provided for varying high side pressure in a transcritical vapor compression cycle by means of variable volume element(s) connected to a flow circuit thereof. A variable volume element having a compartment is connected to and communicates with the high side to permit entry of refrigerant into the compartment. A movable partition defines at least one side of the compartment and is displaceable between first and second positions respectively defining first and second volumes of refrigerant within the compartment.

Abstract: High side pressure in a transcritical vapor compression cycle system is regulated by varying a liquid inventory of a low pressure refrigerant receiver provided in a circuit of the system. The circuit includes a compressor, a gas cooler, a throttling valve, an evaporator and the receiver connected in series in a closed circuit operating at supercritical pressure in a high pressure side of the circuit. The degree of opening of the throttling valve is controlled to regulate the high side pressure in the circuit. It is possible to control capacity, and it also is possible to achieve minimum energy consumption for a given capacity requirement by regulating high side pressure.