HUT74649A - Pressure booster and gas transporter device - Google Patents

Abstract

The invention is an apparatus for transporting or increasing the pressure of gaseous fluids having a relatively high mass flow, which enables the thermal energy used to operate the apparatus to be utilized directly for compression work, using the supplied gas as a working fluid, thereby achieving a significantly lower primary energy requirement compared to the prior art. The equipment consists of assembled, well-known and proven elements. The gas arriving at a given pressure in the pipeline (11) is fed to a compressor (12), where the pressure increases above the required outlet pressure, and then the gas is passed to a heat exchanger (13) where its temperature rises. Exiting the heat exchanger (from the recuperator), the gas is fed into a gas-fired boiler (14), where the temperature of the fuel (15) is further increased, and the high-pressure gas heated in this way is supplied to an xiexpanSer (16) (turbine) with a pressure and temperature The expansion turbine (the pressure of the exiting gas is the pressure of the required outlet gas (17), which pressure exceeds the pressure of the incoming gas (11). The thermal energy of a relatively high temperature gas in the recuperator (13) is used to increase the temperature of the gas exiting the compressor (12), thereby increasing the pressure in the recuperator at a pressure higher than that of the incoming (11) in the exhaust pipe (17). ) and only the expansion turbine (16) is covered by a direct link between them, so that the thermal energy of the fuel introduced into the gas heating boiler (14) is very efficiently used as a compression work. Typical Figure 2. CO)

Description

Inventors: Dr. László Lengyel, Budapest, ψ Ec?%>

Dr. Gyergely Veres, Budapested%>

Date filed: June 1995

BACKGROUND OF THE INVENTION The present invention relates to an apparatus for increasing the pressure loss in the transport of gases in bulk, typically natural gas, or for other reasons to increase the pressure, which is achieved by a novel combination of known and practical machines and devices. Its most important application is the compressor stations of natural gas transmission in the pipeline, but it can be used in all places where the task is to compress a relatively large mass of gas stream.

For the transport of gases in bulk, typically natural gas, equipment and compressor stations are now used which generally produce the mechanical work required to drive the compressor by some thermodynamic heat cycle. (The exception is when the compressor is powered by electricity and the electricity is generated from hydropower.) In the typical field of application, at natural gas transmission line compressor stations, the usual solution is to use open-cycle gas turbines fueled by the natural gas to be transported (Figure 1). In this case, the working turbine 5 driving the gas purge compressor 2 is part of a gas turbine (Joule) cycle, the working fluid of which is compressed by a compressor 3 to the pressure required by the power requirements and then the air in the combustion chamber 6 is fuel.

-7 is heated by its combustion, and then the working fluid expands in a gas turbine 4 which is in direct axial engagement with the air compressor 3. The working fluid leaving the gas turbine, since both its pressure and temperature are higher than the environment, expands further in the working turbine 5, which drives the gas compressor 2, also generally by direct coupling.

It can thus be seen that the total expansion work of the working fluid is divided into two parts: on the one hand it is used to compress the working fluid and on the other hand - and this useful work only - can be used to drive an external machine. The working turbine 5 is either discharged at the end of the full expansion without any working fluid or heat recovery, according to the open nature of the cycle, or into a recuperator 7 where it transfers its heat content to the working fluid leaving the compressor and is then released into the environment. Thus, the gas compressor 2 is driven by an open-circuit gas turbine cycle (Joule cycle) with air working fluid, optionally equipped with a heat exchanger 7, the overall efficiency of which is determined by two factors: the efficiency of the circulating machines and the thermodynamic efficiency of the cycle. The resulting total efficiency is the product of these two factors. It can be stated that as long as the efficiency of the circulating machines (3 compressors, 6 combustion rooms, 4 turbines, 7 recuperators) is very good in the present state of the art, the thermodynamic efficiency is in the II. As a result of its principle, it is very low in relation to machine efficiency, at best only around 40%.

Thus, in the gas pressure booster system described above, to generate 1 kW of mechanical power, a heat output of 3-4 kW, due to the efficiency of the cycle, must be introduced into the combustion chamber. This thermal power is usually obtained from the natural gas burned. If you want to reduce the amount of gas you need to burn for boosting, you need to think of a structural solution that is capable of boosting the gas pipeline as an open and flow thermodynamic system by burning less gas than a conventional solution.

The booster device of the present invention is such an assembly. It is readily apparent that by utilizing the features of the thermodynamic system, less fuel is required to produce 1 kW of power.

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-4- / ΗThe essence of the proposed solution is to avoid the loss of heat during the conversion of heat energy into mechanical work by injecting the heat energy required to drive the gas compressor directly into the gas to be compressed and not into the working fluid of a separate Joule cycle. Thus, the present invention is based on the recognition that the gas compression problem does not require the use of a separate working fluid heat cycle - usually a Joule air operated process - but that the gas to be compressed can itself serve as the working fluid. Thus, in the present invention, the compression is based on a Joule cycle, but since the gas to be compressed is the working fluid itself - there is no thermodynamic loss, the efficiency of the proposed cycle is significantly improved, i.e. the amount of fuel used for gas compression is significantly reduced.

The most common circuit diagram is shown in Figure 2. The inlet gas entering the unit via pipeline 11 enters a gas purge compressor 12 where the pressure of the gas increases above the desired outlet pressure and the temperature of the gas outlet gas compressor exits in a heat exchanger 13 as it meets the expander 16 temperature, already leaving the unit. In the recuperator 13, the flow of flowing gas is heated to approximately the outlet temperature of the expansion turbine 16. The difference in temperature between the two media essentially depends on the efficiency of the recuperator. The gas exiting the heat exchanger enters a heating device 14 where it is heated to the inlet temperature of the expansion turbine 16. Therefore, the gas-fired boiler 14, which is normally used in chemical technology and is powered by an external fuel 15, is only required to supply the amount of heat required for expansion expansion (recuperator gas turbine cycle). It should be noted that the required enthalpy increase in gas flow is not necessarily achieved by combustion of fuel 15; waste heat recovery. In this case, the gas heater 14 is not a boiler-like fixture, but a heat exchanger, which, of course, enters a heat transfer medium, not fuel. The gas pressurized at the desired outlet pressure heated in the gas heater 14 passes to the expansion turbine 16 where it expands to the final pressure of the required compression, thus the pressure exiting the expansion turbine 16 is above the pressure in the inlet pipe 11. compression end pressure.

The still high-temperature gas leaving the expansion turbine 16 enters the recuperator 13 where it transfers its energy content to the upstream 12

-1, • 5 "/ H · gas outlet compressor gas. Thus, the temperature of the gas leaving the recuperator 13 and entering the outlet pipe 17 will be above the outlet temperature of the gas purge compressor 12, depending on the efficiency of the recuperator 13. The outlet gas pressure corresponds to the required transport gas pressure. If the temperature of the exhaust gas is too high for the conditions of transport or the means of transport, it is possible to apply post-cooling, not shown in the figure, and thereby reduce the temperature of the gas leaving the recuperator.

The setting of operating parameters, that is, the outlet pressure of the gas purge compressor 12, which is above both the inlet and outlet pressures, and the inlet temperature of the expansion machine 16 depend in part on the physical properties of the gas to be compressed and the required and the absolute level of the pressures. The power requirement of the compressor 12 in normal operation is fully covered by the expander 16, external drive only required at start-up.

Claims (1)

A patent claim Apparatus for increasing the pressure of a gaseous medium flowing in a tube, characterized in that the gas entering the apparatus (11) is supplied to a compressor (12) in which the pressure of the gas increases above the desired outlet pressure; whereupon the flowing gas enters the gas heating boiler (14), where the temperature is further increased by the use of the fuel (15), and this high pressure and temperature gas is fed to an expansion turbine (16) which drives the inlet gas compressor (12); and the gas exiting the expansion turbine in the recuperator heat exchanger (13) transfers its thermal energy content to the gas exiting the compressor (12), and when cooled, the gas exits the apparatus (17) at a pressure higher than the pressure in the incoming pipe.