RU2624159C1 - Device for air sampling from aviation gas turbine engines for testing in flying laboratories - Google Patents

Abstract

FIELD: engine devices and pumps.

SUBSTANCE: invention relates to a technique for air sampling from a compressor of aviation turbine engines (ATE) to study the extent of air pollution by products coming in with air into the air conditioning system (ACS), as well as determining the composition of harmful impurities, hazardous concentrations in the air of gases and vapors. The device contains a diffuser with an internal nozzle oriented in the direction of the flow of air sampled from the gas turbine engine, a tee, solenoid valves, samplers with built-in concentrators and vacuum tanks. The diffuser nozzle is made with one internal output connected to a flat tee, located in the same plane with the diffuser. The solenoid valves are mounted directly on the sampler inlet branch pipes in such a way that the inlet branch pipe of the corresponding sampler is screwed into an adapter fixed in the body of the solenoid valve and at the outlet to the valve body by a lock nut to reduce losses of the sample components. The internal output of the adapter is made merging into a saddle for mounting a solenoid valve directly onto the inlet branch pipe of the corresponding sampler, and the input contacts with the valve piston interconnected with the electromagnet. The body of the solenoid valve is in the form of an expansion chamber, at the ends of which there is an expansion nozzle supplying air sampled from the engine and an outlet branch pipe in the opposite side of the body for the release of excess air through a jet. At the same time, its flow cross-section is designed to control the temperature inside the expansion chamber in order to avoid the condensation of impurities in it. The solenoid valve, installed on the surface of the expansion chamber, is configured to open during air sampling and to shut off the sampler with a piston with a rubber valve after air sampling in flight testing of aviation gas turbine engines.

EFFECT: reduction of the dimensions of the device without deteriorating its metrological characteristics providing for installation on a flying laboratory and reduction of the error in measuring the impurity concentrations in the air of gas turbine engines sampled for the needs of the aircraft air conditioning system by decreasing background pollution.

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Description

The invention relates to techniques for sampling air samples taken from the compressor of aircraft gas turbine engines (GTE) to study the degree of air pollution by products entering air conditioning system (SCR) together with air, as well as determining the composition of harmful impurities, dangerous concentrations of gases in the air and vapor, in order to increase the sensitivity and accuracy of determining the assessment of the degree of air pollution.

The main source of air pollution in aircraft cabs is the removal of lubricating oil from the front engine mounts with its subsequent complete or partial decomposition in the compressor path of a gas turbine engine (GTE) in different modes of operation. A complex mixture containing vapors and aerosols of lubricating oil, vapors of hydrocarbons, acrolein, formaldehyde, phenol and other products of oil decomposition, comes from the air conditioning system into the aircraft cabin.

The proposed device can be used in factory and certification tests of gas turbine engines in flying laboratories (LL) for compliance with the requirements of §831 AP-250 § 66 and §75 AP-33 (2). AP-25, (Aviation regulations. Part 25. Airworthiness standards for transport category aircraft. 2008), AP-33 (Aviation rules. Part 33. Airworthiness standards for aircraft engines. 2012). This type of LL test is carried out on modern gas turbine engines in addition to the bench tests, since the operating conditions of the engine on the stand and in real flight conditions are very different, which can lead to an error in evaluating the oil protection of the air conditioning system from engine oil ingress.

A known bench for testing a gas turbine engine, which contains a device for sampling gas samples and can be used to take the environmental characteristics of a gas turbine engine. A device for sampling gas samples contains an analyzer device, samplers located at the engine outlet, and pipelines with quick-acting locks and regulating bodies, a pipeline connecting the analyzer device with quick-acting locking elements, has a heated section made in the form of a pipe-in-pipe heat exchanger ”, Where, to set the required temperature of the sampled gas, immediately before sampling the gas, the entrance to the analyzer opens the regulator and then closes quickly The action shut-off and the regulatory body, provided with a temperature sensor connected to a recording device (US Pat. for useful model RU 44820 U1, G01M 15/00, 2004).

However, due to the peculiarities of the technical layout, this stand can be used mainly for the selection of emission gases.

Known devices for sampling gas turbine engines in the form of a long pipeline (goes beyond the box where the gas turbine engine tests are carried out) and devices for concentrating impurities in the form of absorption vessels or cartridges with adsorbent, which are then used for analysis (Methods for checking the purity of air taken for the needs of aircraft (No. N28In161 FSUE “Plant named after V.Ya. Klimov”, 2005).

Since pressure and air temperature drop here occurs in the pipeline (this leads to the subsidence of most of the air impurities here and, consequently, to an analysis error), there are no special requirements for the design of concentration devices (samplers). Such devices, until recently, were used at most enterprises of the aircraft engine industry.

The disadvantage of such devices is the deposition of impurities in the pipeline to absorbing cartridges, the long selection time and the need to recharge them with a fresh portion of the sorbent, which requires special training.

A device for sampling aerosol oil from a gas turbine engine is described in the US patent for a method for determining oil leakage from a gas turbine engine No. US 6,957,569 B1, 10/25/2005. In the described method, the air flow from the gas turbine compressor flows into a metal chamber, where it is carried out in real time counting aerosol oil particles in a spectral manner. We are talking only about an aerosol of oil and actually discrete sampling is not performed. According to the Aviation Rules, we are interested in a much wider list of air polluting substances, and oil is in the air both in the form of aerosol and in the form of vapors, which are not determined at all in this method.

The closest in technical essence to the present invention is the device described in MU 1.1.258-99 (introduced 01.07.2000 NIISU), made in the form of an air sampling system of aircraft GTE (SOP), including a diffuser, tees with nozzles, samplers with concentrators , solenoid valves, evacuated containers with pressure sensors, vacuum pump and connecting tubes. The air taken from the gas turbine engine enters the inlet of the samplers through the transmission devices of minimum size and only slightly reduces the temperature before entering the concentrator. After sampling, the samplers are disassembled, the concentrators are disassembled for chromatographic analysis by desorption of impurities into the evaporator of the chromatograph, after which they are again suitable for sampling without special purification.

The disadvantage of this device is the rather bulky design (weight more than 50 kg) with a large number of elements that must be rigidly fixed in flight conditions. In flight conditions, it is also difficult to use, since the electromagnetic valves are located behind the samplers, and their inlet is constantly connected to the pipeline from the diffuser, which with a constant change in pressure at the inlet to the sampler (flight conditions) and in the tube between the valve and the sampler will lead to an additional pendulum pumping some non-fixed volumes of air from the gas turbine engine through the sampler concentrator. With long flights, such pollution will be very significant, because it is not possible to remove the samplers during the flight. This distorts the results of the subsequent gas chromatographic analysis in the direction of their significant overestimation, which may be an erroneous reason for rejecting the gas turbine engine (according to §75 AP-33, exceeding the maximum permissible concentration given in the introduction of impurities in the air taken from the gas turbine engine is considered as engine failure). In addition, the same containers in the SOP serve different samplers, which requires the installation of a vacuum pump in the system for periodic evacuation, and the air of the tanks themselves after sampling and pressure measurement does not go for analysis, which reduces the list of components for which it is possible to control the sampled air. There is also a more complicated version of this device, described in RF patent No. RU 2 494 366 C2, with the addition of additional evacuated containers with sensors, which further complicates the design and increases its dimensions, and the differences are not fundamental, and therefore, this is not considered as a prototype.

The technical result to which the claimed invention is directed is to reduce the dimensions of the device without impairing its metrological characteristics so that it can be installed on a flying laboratory and reducing the error in measuring the concentration of impurities in the air of a gas turbine engine selected for the needs of an SCR of an aircraft, by reducing background pollution.

To achieve this technical result, in a device for sampling air from aircraft gas turbine engines when tested in flying laboratories, containing a diffuser with an internal nozzle oriented in the direction of the flow taken from the gas turbine engine, a tee, electromagnetic valves, samplers with built-in concentrators and vacuum capacity, the nozzle of the diffuser is made with only one internal outlet connected to a flat tee located in the same plane as iffuzorom, and the solenoid valves are mounted directly on the inlets sampler such that the sampler inlet corresponding to reduce the loss of sample components is screwed into the adapter body to the solenoid valve and is fixed to the housing outlet valve locknut. The internal outlet of the adapter is made passing into the saddle to install the solenoid valve directly on the inlet pipe of the corresponding sampler, and the input contacts the valve piston, interconnected with the electromagnet. The solenoid valve body is made in the form of an expansion chamber, at the ends of which there is an expansion nozzle for supplying sampled air from the engine and an outlet pipe in the opposite side of the body to discharge excess air through the nozzle. Moreover, its bore is configured to control the temperature inside the expansion chamber in order to avoid condensation of impurities in it. An electromagnetic valve mounted on the surface of the expansion chamber is configured to open the sampler after the air sampling in flight tests of aircraft gas turbine engines with a piston with a rubber valve and open during air sampling.

The air taken from the gas turbine engine, in this case, continuously blows the adapter with the screwed inlet of the sampler. Prior to sampling, it is covered by a rubber valve moving under the influence of the valve's electromagnet, and excess air is discharged into the nozzle, the diameter of the passage section of which controls the temperature inside the expansion chamber, which makes it impossible to condense the components of the sample to the sampler and get into the sampler when the valve is closed. This avoids the background (not taken into account) contaminations of the sampler and thereby reduces the required volume of evacuated containers, and hence their dimensions, which is especially important for flight tests of aircraft engines.

In FIG. 1 is a diagram of the proposed device for sampling air aircraft gas turbine engines when tested in flying laboratories.

The device contains: 1 - diffuser, 2 - nozzle, 3 - flat tee, 4 - expansion nozzle, 5 - expansion chamber, 6 - solenoid valves, 7 - outlet pipe (nozzle), 8 - electromagnet, 9 - valve piston, 10 - adapter, 11 - locknut, 12 - sampler, 13 - evacuated container, 14 - rubber vacuum hose, 15 - plug.

The proposed device contains a diffuser 1 with an internal nozzle 2, oriented by the flow of air taken from the gas turbine engine, air from which through a flat tee enters through the expansion nozzle 4 into the expansion chamber 5 of the electromagnetic valve 6, is discharged through the nozzle 7 of the outlet pipe. The piston of the valve 9, which is opened by the electromagnet 8, opens up air access (sampling) to the adapter 10, which is fixed with a lock nut 11 on the valve body and supplies air through the inlet to the sampler 12, which is connected to a vacuum tank 13, at the outlet of which a vacuum rubber is attached hose 14 with plug 15.

Device operation

The device is mounted in the pylon or spacer of the test engine in a flying laboratory. Air from the gas turbine exhaust flange enters the diffuser 1 and is discharged overboard. Part of it through the nozzle 2 and the tee 3 enters the inlet of the expansion nozzle 4 and then into the expansion chamber 5 of the electromagnetic valve 6. The excess air is discharged through the nozzle 7 overboard. The orifice of the nozzle controls the temperature inside the expansion chamber to prevent condensation of impurities in it. Sampling occurs when the electromagnet 8, which draws in a piston with a rubber valve 9, frees up air access to the saddle, which is the pointed part of the adapter 10. The adapter is attached to the valve body using a lock nut 11. Air when the valve is triggered goes further to the sampler 12, inside which there is a concentrator with a sorbent for absorbing organic impurities (oil, fuel and products of their decomposition), and air with inorganic impurities (carbon oxides) enters the evacuated containers (evacuation before the flight). After the flight, the entire device, except the diffuser and tee, is dismantled from the aircraft and sent to the laboratory. In the laboratory, through the rubber hose 14, with the plug removed, the pressure in the containers 13 is measured to determine the size of the taken air sample. Part of it is taken into syringes for analysis on the content of inorganic compounds. Concentrators are extracted from the samplers, and then according to MU 1.1.258-99 their gas chromatographic analysis for the content of organic impurities is carried out.

Thus, even during a long flight, it is possible to avoid additional pendulum pumping of non-fixed volumes of air from the gas turbine engine through the sampler concentrator due to the fact that the entrance to the sampler is constantly blocked (except for the time of sampling), and due to the special design of the electromagnetic valve, the sampling is not contaminated condensate before entering the sampler.

Claims (1)

A device for sampling air from aircraft gas turbine engines when tested in flying laboratories, containing a diffuser with an internal nozzle oriented in the direction of flow of air drawn from the gas turbine engine, a tee, electromagnetic valves, samplers with built-in concentrators and evacuated containers, characterized in that the nozzle the diffuser is made with one internal output connected to a flat tee located in the same plane with the diffuser, and electromagnetic pans are installed directly on the inlet nozzles of the samplers in such a way that the inlet nozzle of the corresponding sampler is screwed into the adapter, fixed in the solenoid valve body and fixed at the outlet to the valve body with a lock nut, the internal outlet of the adapter is made into the saddle to install the electromagnetic valve directly at the inlet of the corresponding sampler, and the input is in contact with the valve piston, are interconnected m with an electromagnet, the solenoid valve body is made in the form of an expansion chamber, at the ends of which there is an expansion nozzle supplying air drawn from the engine and an outlet pipe on the opposite side of the housing for venting excess air through the nozzle, while its bore is configured to control the temperature inside the expansion chamber in order to avoid condensation of impurities in it, the electromagnetic valve mounted on the surface of the expansion chamber is made with the possibility of to cover during air sampling and to block the sampler after pistoning with a rubber valve after air sampling in flight tests of aircraft gas turbine engines.

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