摘要:
Provided is a method for liquefying natural gas which can be readily adapted to LNG plants of all sizes without requiring expensive and special heat exchangers. The liquefaction of feed gas of natural gas and recycle natural gas is carried out with a single-component refrigerant or a mixed refrigerant in a high temperature stage, and with a substantially isentropic expansion in a low temperature stage, and a non-liquefied part of the recycle gas after the expansion step is pressurized with a compressor and recycled along with a recycle stream of non-liquefied par of the feed natural gas, the liquefied part by the refrigerant exchanging heat with the non-liquefied part stream produced from the substantially isentropic expansion, in a plate-fin heat exchanger or the like. The compressor is driven by the power obtained by the substantially isentropic expansion.
摘要:
Provided is a method for liquefying natural gas which can be applied to LNG plants of a wide range of capacity and can produce LNG both efficiently and economically. Feed gas of natural gas or a non-liquefied component of recycle gas which is produced during a process of liquefying natural gas is liquefied by using a first refrigerant, for instant consisting of a C3 refrigerant, and a second refrigerant which is different from the first refrigerant, for instance consisting of a C2 refrigerant, in a stepwise fashion. The flow is then liquefied by a substantially isentropic expansion process. The non-liquefied component remaining from this expansion process is then pressurized by a compressor, and combined with the non-liquefied component of the natural gas for recycling the combined flow. The compressor is driven by power obtained from the substantially isentropic expansion process.
摘要:
In a compressor drive system for a natural gas liquefaction plant including a plurality of gas turbines each provided in an individual refrigeration cycle for pressurizing a different refrigerant, an electric motor is provided for each of the gas turbines so as to serve both as an auxiliary electric motor for generating a startup torque and as an AC generator, and the excess output power of the gas turbine is converted into electric power by this electric motor when the power requirement of the associated compressor is less than the power output of the gas turbine. Additionally, at least two of the gas turbines are of an identical make which is suitable for driving the compressor of one of the associated refrigeration cycles requiring a larger driving power. Therefore, the gas turbines can be operated at optimum conditions at all times without regard to seasonal changes of the operating conditions, and the efficient operation of the gas turbines will result in a significant reduction in the operation costs through a substantial saving of fuel consumption. Moreover, any excess power output of one of the gas turbines can be allocated so as to reduce the burden of the in-plant power station and/or to supplement the shortage of the power output of the other gas turbine, and the management of the stand-by units and spare parts can be simplified. These factors have a compounded effect in reducing the investment costs of the plant.
摘要:
Provided is an improved refrigeration system for pre-cooling natural gas or cooling a mixed refrigerant for natural gas liquefaction in a propane refrigeration process widely used for the liquefaction of natural gas. The system comprises a plurality of plate-fin heat exchangers preferably arranged in a parallel relationship for passing a propane refrigerant as a vertical flow and pre-cooling natural gas or cooling a mixed refrigerant for liquefying natural gas, and a thermo siphon drum for the propane refrigerant consisting of a horizontally disposed, laterally elongated tank. Because the passages of the heat exchanger for the natural gas or the mixed refrigerant extend over their entire length in mutually separate relationship, even when the propane refrigerant, the natural gas or the mixed refrigerant is in both gas and liquid phases, a high efficiency of heat transfer can be attained, and the size of the heat exchanger can be reduced. In particular, from an economic view point, it is preferable if the thermo siphon drum serves also as a flash tank.
摘要:
In an ophthalmic measuring method, a traceable marker in particulate form is administered to the lachrymal fluid of a subject's eye, and the lachrymal fluid is irradiated with illuminating light. Images of the illuminated lachrymal fluid are electronically captured respectively at different times. Two images from among the captured images are selected, with each of the two selected images displaying the traceable marker. A characteristic point of each of the two selected images is specified. A movement speed of the traceable marker is measured based on positions thereof in the two selected images and on a time difference from specifying the characteristic point of one of the two selected images to specifying the characteristic point of the other of the two selected images. The measured movement speed of the traceable marker is outputted as the movement speed of the lachrymal fluid of the subject's eye.
摘要:
An object of the present invention is to provide a polypropylene polymer film superior in convenience in handling that does not generate troubles such as wrinkling, elongation or breakage during processing at a high temperature of 80° C. to 120° C., independently of the conveying method used in the drying step, and an adhesive film having the polypropylene polymer film as its carrier. Provided are a polypropylene polymer film, characterized by having a tensile modulus of 300 MPa to 1,000 MPa under an atmosphere at 23° C. and 60 MPa to 120 MPa under an atmosphere at 120° C. and an adhesive film containing it as the carrier.
摘要:
An apparatus has an antenna distance setting mechanism that sets a distance between a cosmetic cover and a radio antenna. An upper housing and a radio antenna, which has a ground and a radiating element and is movably attached to the upper housing, are covered by a cosmetic cover formed of a dielectric material. An antenna distance setting mechanism includes a radio antenna supporting member, elastic members, and protrusions. The radio antenna-supporting member is movably attached to the upper housing. When the cosmetic cover is attached to the upper housing, an inner wall of the cosmetic cover pushes the ends of the protrusions against an elastic force of the elastic members to set the distance between the radiating element and the inner wall of the cosmetic cover to a predetermined distance.
摘要:
A pipe coupling member for high-pressure fluid such as liquefied hydrogen includes a seal ring having a highly effective sealing function to prevent leakage of the fluid. The seal ring (72) is set in a seal ring setting space (39) defined by a second radial surface (36) and a seal ring setting surface (38) of a first tubular member (20), a forward end surface of a second tubular member (22), and the outer peripheral surface of a valve seat member (24). A forward end portion of the second tubular member (22) is provided with a communication hole (84) radially penetrating the forward end portion. The pressure of the high-pressure fluid on the downstream side of a valve seat surface (52) causes a fluid path in the second tubular member to be communicated with the sealing ring setting space (39) via the communication hole (84) and via a gap between the seal ring setting surface (38) and the outer peripheral surface of the forward end portion of the second tubular member.
摘要:
A mixture of fluorine-containing acrylic esters represented by CF3(CF2)nCH2CH2OCOCR1═CH2 wherein R1 is a hydrogen atom, a methyl group or a halogen atom and “n” is an integer of at least zero is subjected to distillation under such conditions that the esters are not polymerized, so as to give a mixture of the esters with a less content of impurities (that is, olefins represented by CF3(CF2)nCH═CH2 and alcohols represented by CF3(CF2)nCH2CH2OH) at a high yield.
摘要:
A vehicular anti-lock control system includes: a ground load calculation section for detecting or estimating a ground load of a wheel; a road surface friction coefficient calculation section for detecting or estimating a road surface friction coefficient; and a reference fluid pressure calculation section for calculating an upper side reference fluid pressure and a lower side reference fluid pressure in anti-lock control based on the ground load and the friction coefficient. The upper and lower side reference fluid pressures are respectively determined to be an upper limit value and a lower limit value of a fluid pressure in anti-lock control. Therefore, it is possible to suppress the amount of change in the fluid pressure during anti-lock control, thus improving the braking effect and the braking feel.