Sinvent As

Norskhydro Asa

Petter Nekså

Geir Skaugen

Jostein Pettersen

Håvard Rekstad

Kåre Aflekt

Armin Hafner

Arne Jakobsen

Einar Brendeng

Gholam Reza Zakeri

Trond Andresen

Espen Tøndell

Munan Elgsæther

Munan Elgæther

Sergio Girotto

Yves Ladam

Sigmund GJØRVEN

Asbjørn Solheim

Bjørn Petter Moxnes

The present invention relates to a process plant and method for cooling and optionally liquefaction of a product gas, particularly for liquefaction of natural gas, based on a closed loop of multi-component refrigerant in heat exchange with the gas to be cooled and optionally condensed. The process plant is comprises at least one primary heat exchanger () arranged to cool the product gas directed to the heat exchanger (), at least one compressor () arranged to compress the low level refrigerant directed from the first of the at least two secondary heat exchangers (), at least one pre-cooling heat exchanger () to sub-cool and partly liquefy the compressed refrigerant, at least one phase-separator () arranged to separate the partly liquefied multi-component refrigerant into a more volatile fraction and a less volatile fraction, at least two secondary heat exchangers (), the first of the at least two secondary heat exchangers () arranged to cool the more volatile fraction from the phase-separator (), and the second of the at least two secondary heat exchangers () arranged to cool further the more volatile fraction, a throttling device () arranged to reduce the pressure of a part of the more volatile fraction to become the low level refrigerant to be heat exchanged in the second of at least two secondary heat exchangers, a throttling device () arranged to reduce the pressure of a part of the more volatile fraction to become the low level refrigerant to be heat exchanged in the at least one primary heat exchanger (), a throttling device () arranged to reducing the pressure of the less volatile fraction from the at least one phase-separator () to become part of the low level refrigerant, for mixing with the low level refrigerant from the at least one primary heat exchanger (), and the low level refrigerant from the second of at least two secondary heat exchangers () this directed to heat exchange through the first of at the least two secondary heat exchangers ().

Method for liquefaction of gas

A method for operating a closed circuit vapour compression refrigeration system is disclosed. The system may operate with supercritical pressure on a high pressure side, and includes at least one compressor, at least one heat rejector, at least two in parallel connected heat absorbers, at least one variable expansion means up flow of each heat absorber and at least one control unit for controlling the variable expansion means, connected to a set of sensors. The flow rate of the refrigerant through each of the variable expansion means, is controlled by the control unit, coordinating the flow of refrigerant through each of the variable expansion means to maintain a control parameter within a set range. Any surplus charge resulting from the control is buffered on a low pressure side of the system. Furthermore a refrigeration system based on a closed vapour compression circuit is described.

Closed circuit vapour compression refrigeration system and a method for operating the system

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.

Method of operation and regulation of a vapour compression system

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.

Vapor compression heat pump system

Reversible vapor compression system including a compressor (), an interior heat exchanger (), an expansion device () and an exterior heat exchanger () 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 (andrespectively). 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. The first and last sections are inter-connected whereby the refrigerant fluid flow in the heat exchanger can be changed from heating to cooling mode by means of flow changing devices provided between the respective sections.

Reversible vapor compression system

A compression refrigeration system includes a compressor (), a heat rejector (), expansion device () and a heat absorber () 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&#xb0; C. Carbon dioxide or a mixture of a refrigerant containing carbon dioxide may be applied as the refrigerant in the system.

Compression system for cooling and heating purposes

A method of defrosting of a heat exchanger (evaporator) in a vapor compression system including, downstream of a heat exchanger (evaporator) () to be defrosted, at least a compressor (), a second heat exchanger (condenser/heat rejecter) (), and an expansion device () connected by conduits in an operable manner to form an integral closed circuit. The heat exchanger () to be defrosted is subjected to essentially the same pressure as the compressor's () discharge pressure. Thus, the heat exchanger () is defrosted as the high-pressure discharge gas from the compressor () flows through to the heat exchanger, giving off heat to the heat exchanger (). In the circuit, in connection with the expansion device () a first bypass loopwith a first valve ('), is provided. A pressure reducing device (&#x2032;) is provided in a second bypass loop in conjunction with a second valve (&#x2032;&#x2033;) disposed downstream of the heat exchanger () being defrosted, whereby the first valve (&#x2032;) is open and the second valve (&#x2032;&#x2033;) is closed when defrosting takes place.

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Trondheim, Norway

Petter Nekså