Cooling method natural gas compressor stations
(57) Abstract:Natural gas is successively cooled in an air cooler, regenerative heat exchanger, and then in energoraspredelitelnaya device made in the form of shell-and-tube heat exchanger having a gas outlet cold and hot gas, supersonic channels with profiled nozzles and diffusers, where the gas flow is divided into two streams, one of which passes through a supersonic channels, accelerates to Mach number M = 2-5 and then using the booster compressor is fed to a compressor station, and the other is cooled, the flow from the annulus energoraspredelitelnaya apparatus enters the pipeline. Thus the ratio of the total temperature at the inlet into the supersonic channels to the total temperature at the exit of the supersonic channels is in the range of 0.85 to 1.2. The use of the invention will reduce the temperature in the output manifold compared to other cooling methods. 1 Il. The invention relates to the transport and use of natural gas, in particular to the last stage of the cooling of the gas after the compressor station (CS) to work in the summer in terms of Krino cooling natural gas after the COP using propane or propane-butane vapor compression refrigeration systems, operating on a closed cycle (A. C. Language "System and apparatus for cooling natural gas." - M.: Nedra, 1986, S. 119-123).The main disadvantages of this method is the complexity of the operation and management, the high cost of equipment.The closest in technical essence and the achieved result with the claimed invention is a method of cooling natural gas, according to which the transported gas after the COP comes first in the recuperative heat exchanger live stream (RTO), where due to heat exchange with gas back-flow is heated and fed into the compressor, where it is heated by compression. Further, the heated gas enters the air cooler (AVO) where it is cooled by heat exchange with atmospheric air, and pre-cooled in the air cooler gas is then douglasdale in RTT due to heat exchange with direct gas flow, after which the gas is directed into the expander (expansion machine) or through the throttle device, where it is cooled and then goes into the pipeline, which moves to the next COP. (see Handbook, Ed. by N. And. Ryabtseva Gas equipment, fixtures and fittings, M.: Nedra, 1985, S. 358-362).The known method POI cooled gas, however, it is also difficult to operate, are not effective in conditions of permafrost and requires significant increases in capital and operating costs and does not allow to obtain the required temperature of natural gas at the outlet of the collector of the cooling system.The technical result of the proposed method according to the invention is greater reduction in gas temperature in the outlet manifold in comparison with the throttle means, which is achieved in an easier way than using the vapor compression, expansion devices and other refrigerating machines.To achieve a technical result, in the cooling method natural gas after the COP, including sequential air cooling natural gas to the air cooler, cooling direct gas flow in the RTO, the final deep cooling is carried out in a device in the form of a shell-and-tube heat exchanger, in which part of the gas flow in a supersonic channels accelerates to Mach number M=2-5, and after passing through the diffuser passes through the booster compressor to the input of the COP, and the other part of the gas flow from the annulus - (subsonic channel) is fed into the pipeline.The temperature Toye channels T0T1/T0= 0,85-1.2 for real gas, which is caused by heating of a supersonic flow of gas due to heat from subsonic gas flow and cooling due to the pressure drop in the flow (see drawing ).As an air cooler (air cooler) way to use a known ABO - AP-75, AVG-75S, etc.Used in this way energiantuotanto device differs from known devices (EN 210 6581, 1998) because it supersonic for is not in the same channel, located centrally in the outer tube and the beam with two pipe boards shaped nozzles and diffusers. This allows us to dramatically increase the heat exchange surface, almost without compromising heat transfer in the annular space.Not known to others the same invention, having attributes that match all the features of the proposed method according to the invention.The invention is illustrated in the following.The Mach number in supersonic channels energoraspredelitelnaya device is in the range M=2-5. When M < 2 the effect of temperature reduction in subsonic flow through the recovery temperature in a supersonic flow will be too small. When M > is th booster compressor.The ratio of the total temperatures (temperatures braking) at the exit of the supersonic channels T1(after diffusers) and the entrance into the supersonic channels T0lies in the interval T1/T0=0,85-1,2.At T1/T0< 0,85 too much will decrease the gas pressure in supersonic channel or too large mass fraction of a supersonic gas flow, which will lead to unduly increase the capacity of the booster compressor, but perhaps the main pumping unit.At T1/T0> 1,2 efficiency of heat transfer in energonesejiem the device will be very low, which will require artificial surface development, and, consequently, a significant increase in pressure drop, which will lead to the growth of output of the booster compressor and the low efficiency of energoanduesso device.The following example presents a specific description of the method according to the invention.Example
CA, located in the Northern district - Nadim has a capacity of gas 4103nm3/h, the diameter of the pipe in the linear part of the pipeline Dn= 1420 17 mm Average air temperature in July (the warmest month) 28 the one collector KS P= 7,46 MPa, T=314,7 K.After CS gas enters the AVO, where its temperature is reduced to 302,9, then in the CNS, where its temperature is reduced to K.Then the gas enters energiesparlampe device, where it is split at subsonic and supersonic flows. In a supersonic gas channels accelerates to Mach number M=4.0 and has a temperature of braking at the exit of the diffuser due to the heat from the subsonic gas flow and cooling due to the Joule-Thomson K (T1/T0=0,945, where T0and T1respectively the initial and final temperature (input and output)).Then the stream that came out of supersonic diffusers channels, using a booster compressor is input to the COP.The gas at the outlet of subsonic channel (annulus) energoanduesso device has a temperature of 283K and then fed into the pipeline.As a result we obtain at the output of CS gas temperature the same as it was at the entrance of the COP, and thus prevents the danger of thawing permafrost beneath the first after the COP support of the pipeline. Cooling method natural gas compressor stations, clocapramine heat exchanger and deep cooling in refrigerating apparatus, characterized in that deep cooling is carried out in energoraspredelitelnaya device in the form of a shell-and-tube heat exchanger with ducts cold and hot gas, the supersonic beam channels with shaped supersonic nozzles and diffusers, energoraspredelitelnaya device, the gas is divided into two streams, one of which is in a supersonic channels accelerates to Mach number M = 2 - 5 and then the gas flow through the booster compressor is fed to the input of the compressor station, and the other cooled gas flow from the annulus - subsonic channel energoraspredelitelnaya devices served in the pipeline, thus the ratio of the total temperature at the inlet into the supersonic channels to the total temperature at the exit of the supersonic channels is in the range of 0.85 to 1.2.
FIELD: metallurgy; metallohydride alloys for thermal pumps, air-conditioners, cold generators.
SUBSTANCE: proposed metallohydride pair of alloys contains low-temperature and high-temperature alloys; low-temperature alloy has composition mm1-xLaxNi4CO(0.1≤x≤0.999) and high-temperature alloy has composition LaNi5-xAlx (0.001≤x≤0.5).
EFFECT: increased cold generating capacity of thermal pump at pressure in system not below atmospheric.
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