RU30365U1 - GAS BLASTING MACHINE - Google Patents

Description

 ° ° ° ° MPKE01N5 / 10

DESCRIPTION OF A USEFUL MODEL

GAS BLASTING MACHINE

The proposed utility model relates to the field of gas-jet machines designed to clean ice, snow, moisture, dust of various coatings, in particular, to protect them from destruction in emergency situations.

Gas-jet machines based on aircraft turbojet engines that have developed a flight resource are much more efficient than mechanical devices. The gas-jet machine consists of a turbojet engine mounted on a self-propelled chassis and a specially designed gas duct ending in a nozzle supplying gas to the surface to be cleaned (airfield runway, road, etc.) 1.

As you know, aircraft engines have a perfect control and monitoring system, including elements of protection against possible malfunctions. This makes it possible, in order to ensure operational safety, to turn off the engine in a timely manner or to reduce its operation mode when a non-alphabet is detected by measured gyrameters, including thermodynamic-dynamic 2. It is advisable to extend this principle to the gas-jet machine as a whole, i.e. not only on the engine, but also on the gas duct, experiencing significant power and thermal loads. The utility of the proposed utility model consists in the fact that a system of automatic emergency shutdown of the engine at the initial stage of destruction of the gas duct, which determines this stage by changing the engine parameters, is introduced into the design of the gas-jet machine.

To achieve this goal, we consider the issue of the influence of gas duct destruction on the thermodynamic characteristics of a turbojet engine. The destruction of the elements of the gas duct changes its hydraulic resistance, therefore, it changes and the joint work line with coordinates of 3 is presented in the form: -

Here 1 is the braking pressure of air (gas) in any section of the engine flow section; P is the air braking pressure at the engine inlet; Tg is the braking temperature of the air at the engine inlet; n is the rotation frequency.

Functional dependence (1) reflects the line of joint operation of the engine components with the geometry of the flowing part of the engine and the gas duct unchanged. Depending on (1), the set of parameters-p: g is often replaced by the reduced rotation frequency Ppr-P I of the pressure in the compressor l ,. or the degree of increase in pressure in the fan for a dual-circuit engine Here P, and Р „„ - braking pressure

air behind the compressor and a ventilator. Thus, the collaboration line or the working line of the compressor (fan) has the form:

7t, (nnp) (2)

In FIG. 1 shows the line of compatible work in coordinates (2). Line 1 corresponds to the normal technical condition of the gas-jet machine. If a partial destruction of the gas pipe elements has occurred, which has led to an increase in its throughput, the collaboration line decreases (line 2). If the result is an hour r, it is advisable to choose the degree of engine units for the characteristic pressure ratio, which in generalized / n i-f VV in /

In the event of destruction, the flow part becomes cluttered, then the line of joint work rises (line 3). Thus, the position of the collaboration line reflects the technical condition of the gas-jet machine, and if it deviates from the normal position by a certain amount that exceeds the permissible value, the engine must be turned off. The value of the achievable value for each type of gas-jet machine is individual. For the jet engine we adopted the maximum permissible deviation ± S%. The scheme of the proposed gas-jet machine with an emergency engine shutdown is shown in FIG. 2. Gas jet machine consists of engine 1 and gas duct

2. The sensors 3, 4, 5,6 measurements, T, p, Rd, P or P are installed on the engine 1. The emergency shutdown system 7 contains the following blocks: forming a gated speed 8, shaping the degree of pressure increase 9, comparing the actual working line with reference 10, the formation of a command to turn off the engine 11. The system operates as follows. Block 8 receives signals from sensors 3 and 4 about the parameters Tg and n, and in it the calculation of the n parameter of the PDR is performed. Block 9 receives signals from sensors 5 and 6 about the parameters P and Pj (or) and it calculates the parameter TC to (or Lvn) - The signals from blocks 8 and 9 go to block 10, where a real working line is formed and compared with the reference working line recorded in it. The reference characteristic can be both statistical and individual for each instance of a gas-jet machine, determined at the beginning of operation. If, when comparing the difference between the working Jshn exceeds the permissible value, then from block 10 the signal enters block 11, where the signal is formed on the stop valve of the engine control system.

The described gas-jet machine allows for efficient surface cleaning with a high degree of operational safety. Bibliography.

1. Ivanov A.N., Mishin V.A. Drop-down snowplows. M., Mechanical Engineering, 1981, pp. 85 ... 144.

2. Practical diagnostics of gas turbine engines (edited by Stepanenko V.P.) M, Transport, 1985, p. 58 ... 74.

3. Litvinov Yu.A., Borovik V.O. Characteristics and operational properties of aircraft turbojet engines M., Mechanical Engineering, 1979, pp. 93 ... 111, 135 ... 150.

Authors: ((J AJt5 // - Elizarov

. l, A ... M. Idelson

0 "-"

, M.A. Ekel ™

I /. // VV.N. Chernogorov

Claims (1)

Gas-jet machine for cleaning surfaces from ice, snow, dust, moisture, consisting of a turbojet engine and gas duct, equipped with sensors for measuring the temperature and air pressure at the inlet of the engine air pressure behind the compressor or engine fan, the rotor speed of the engine, characterized in that it equipped with an emergency engine shutdown system made of a unit for generating a reduced speed and a unit for generating a degree of increase in pressure in the engine, which are connected by their outputs they are connected with a unit for comparing the actual degree of pressure increase with a reference one, which in turn is connected to the engine shutdown command generation unit, and the reduced speed generation unit is connected to the input air temperature and rotation speed sensors by the input thereof, the formation unit the degree of pressure increase by its inlet is connected to air pressure sensors behind the compressor and at the engine inlet, and the engine shutdown command generation unit is connected to stop-cr Mr. fuel-regulating system of the engine.