Flaw detection of engine components

FIELD: engines and pumps.

SUBSTANCE: water at pressure of P_in = 1.4…1.6 kgf/cm² is used as working fluid for gas turbine high-pressure turbine nozzle vanes. Water pressure difference upstream of analysed element is measured at definite section. Water flow rate through slit, bores in guide vanes and blades is defined to calculate current flow rates G_slit; G_{bore “C”}; and G_{g.v. bore}. Elements are evaluated by comparison of calculated current flow rates with preset optimum intervals of their magnitudes where G_slit is flow rate through slit of one blade; G_{bore “C”} is total flow rate through all bores of the unit; G_{g.v. bore} is mean arithmetic flow rate through one blade bore. Water flow rate through slit, unit bores and blade bore are defined with the help of direct and/or indirect measuring unit while new and/or used elements are used as analysed elements.

EFFECT: higher reliability and quality of repair, lower costs.

3 cl, 1 tbl

The invention relates to a method of sorting items of engines for different purposes, the former or in operation, in particular to methods of flaw detection in lots of elements in blocks of nozzle turbine blades for high-pressure gas turbine engine and their subsequent sorting on serviceable and recoverable.

Known method of detection elements of the engine, on the basis of checking and evaluating the quality of the spray environment (diesel fuel) and leakage before or after the operation (Evsikova A. V. and Popov, C. I. Technology of production and repair of fuel equipment of diesel engines. M: motor cycle", 1958, S. 222-227) /1/.

Feature of the work elements in the form of blocks of nozzle turbine blades, high pressure turbine engine is that the blocks are in the air, and the collection of air after each of the holes and evaluation of expiring jets of holes is difficult.

The closest in technical essence and the achieved result is a method of inspection of engine components, including the supply of pressure fluid to the input of the investigated element, the pressure change in the interval of values specific to the element of the engine, measuring characteristics of fluid after the investigational item, compared with a pre-determined the optimal values of the characteristics of the liquid after the studied item and assessment items in a serviceable and recoverable (EN 2047455 C1. IPC BR 6/00. Publ. 10.11.1995,) /2/.

The disadvantage of this method of sorting is that sorting items in a serviceable and recoverable, produce quality spray and leakage of the fluid after passing through the element, while the quality of spray and leakage is determined visually and by sound. Using sight and sound of a certain parameter of the quality of the fluid spray and leakage of spray, it is not possible to objectively determine the degree of wear of the elements and their residual life. Cost is also used as a liquid fuel (diesel fuel).

The objective of the invention to develop an effective method of flaw detection in units of nozzle turbine blades, high pressure turbine of the engine.

The expected effect of reducing unreasonably rejected and unreasonably recognized suitable for operation blocks of nozzle blades, increasing the reliability and quality of Assembly and repair of engines, reducing costs.

The technical result is achieved by the fact that in the known method of inspection of engine components, including the supply of pressure fluid to the input of the investigated element, the pressure change in the interval of values specific to the element of the engine, measuring characteristics of fluid p is the following of the investigated element, compared with predetermined optimal values of characteristics of the liquid after the studied item and assessment items in a serviceable and recoverable, on the proposal for elements in the form of blocks of nozzle turbine blades, high pressure turbine of the engine as the working fluid using water pressure P_I=1,6 1,4...kgf/cm²as the characteristics of the water to the studied item measure differential pressure measuring site, determine the water flow rate through the gap, the hole in the block and the blades and look forward current expenses G_slots; G_{re "C"}; and G_resp.nland assessment items are produced by comparing the calculated current expenses with pre-established optimum interval values,

where G_slots- the flow of water through the crack of one of the blades;

G_{re "C"}- the total flow of water through the holes in the block.

G_resp.nlthe average flow of water through the holes of one of the blades.

The flow of water through the gap, the hole in the block and the blades is determined using an instrument of direct and/or indirect measurements, and as the study of the elements by using new and/or used items.

The choice of water as the working fluid is made on the basis of gas-dynamic calculation with attract the of "similarity theory" with regard to the properties of the medium under the operating conditions of gas turbine engine and water as substances replacing the medium with the test items. It was found that the water pressure in the test batch of blocks of nozzle turbine blades, high pressure should be in the range of 1.4...of 1.6 kgf/cm².

As the characteristics of the water to investigational use element pressure drop at the measuring site and the flow of water through the gap, the hole in the block and the blades. The water flow is easily and accurately determined value. For registration there are devices of direct action, such as counters or devices-machines that can be easily adapted to automatic control systems. The flow rate can be calculated by weight passed through a water unit time and its passage.

Using the pressure difference across the measuring section and the measured water flow through the gap, the hole in the block and the blades, expect running costs: G_slots- the water flow through the slit one shoulder; G_{re "C"}- the total flow of water through the holes in the block and G_resp.nlthe average flow of water through the holes of one of the blades.

Compare given in the accompanying documents of the party blocks intervals the optimal values of these costs with the calculated current expenditures. If at least one of the current expenses of the holes of the block is outside the optimal values for these costs, the unit recognizes the nepr is useable. As the study units can use the new blocks.

Example

It is necessary to conduct the fault detection block nozzle turbine blades, high pressure turbine engine received after the operation.

The test block for example G, mounted on the test bench.

To the unit attach the fixture, through which the fitting is connected to the water supply pipeline. Shed the output gap of each blade unit at a pressure P_I=1,5^±0,05kgf/cm². Record the weight of Q_slots=8,215 kg last water through the gap of each of the blades and time pouring t_slots=49,67 C. Shed holes "C" in each blade unit. Record the weight of Q_resp=1,370 kg last of the water through the hole of each of the blades and time pouring t_resp=18,87 C.

Replace the fixture.

Shed holes of the unit and record the differential pressure gauge the pressure drop. For example: Δ_nlor =0.51 kgf/cm².

Disconnect the device from the unit and disassemble the test block test stand.

Similarly, test every block party.

The results of the calculations and comparisons with the optimal parameter values given in the table.

Analysis of the results and fault detection blocks

1. G_slots=(Q_slots/t_slots)*1000=(8,215/49,67)*1000=165,39 g/s

2. G_resp=(Q_resp/t_{from the} )*1000=(1,370/18,87)*1000=72,603 g/s

3. G_{re "C"}G_resp1+G_resp2+G_resp3=72,603+73,786+79,64=226,029 g/s

4. G_nl=(0,045516+(5,916728*(√Δ_nl)))*1000=4270,9 g/s

5. G_resp.nl=(G_nl-G_{re "C"})/3=1348,29 g/S.

where

G_slots- the flow of water through the crack of one of the blades;

G_resp- the flow of water through the holes of the block under one shovel;

G_{resp <<>>}- the total flow of water through the holes in the block.

G_nl- the flow of water through the holes in the block and blades;

G_resp.nlthe average flow of water through the holes of one of the blades;

Δ_nl- pressure drop water on dimensional plot;

0,045516 - factor dimensional plot;

5,916728 - factor dimensional plot.

The optimal value of the cost

G_slots=160±20 g/s; G_{resp <<C>>}=230±25 g/s; G_resp.nl=1550±150 g/s;

Calculation formula in Excel

G_slots=OKRUHLIK(C3/D3*1000;3)

G_resp=OKRUHLIK(F3/G3*1000;3)

G_{re "C"}=SUM(H3; H4; H5)

G_nl=(0,045516+(5,916728*(ROOT(J4))))*1000

G_resp.nl=OKRUHLIK(((C4-I4)/3);3)

G_slots=IF(ABS(E3-160)<=20;"+";"-")

G_{re "C"}=IF(ABS(I4-230)<=25;"+";"-")

G_resp.nl=IF(ABS(L4-1550)<=150;"+";"-")

The table shows that all series are deviations beyond the optimal values of the compared parameters, not one of the blocks of the series and not the mod is et to be recommended for further use. It is similarly possible to conduct research units not previously operated.

The application of the proposed method of inspection, reduces calculation errors, reduce the number unreasonably rejected and unreasonably recognized suitable for operation blocks of nozzle blades, to increase the reliability and quality of Assembly and repair of gas turbine engines, to reduce costs.