TDP fuel consumption

The fuel consumption of an agricultural tractor may change depending on the configuration of the power take-off and the slope of the land.

Agricultural production systems have undergone changes over the years, transforming into a business agriculture model. Furthermore, global society's concern for the environment creates pressure on the use of fossil fuels, such as Diesel oil, which represent high production costs and are largely responsible for the emission of greenhouse gases.

In the business model adopted by Brazilian agriculture, agricultural activities seek not only an increase in productivity, but also a reduction in production costs, with a view to increasing the profit of the rural producer, also known as rural entrepreneur, in this new scenario.

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In this sense, for this objective to be achieved, it is necessary to know and seek alternatives that aim to optimize the use of agricultural machinery. Due to its versatility, the tractor is used in most agricultural operations, and contributes to the development of global agriculture.

Due to the cost of fuels, the polluting potential generated by burning them, and the need to reduce energy consumption, it is necessary to develop alternative ways of managing agricultural activities, more specifically the main source of power for them, the tractor. .

The efficiency of an agricultural tractor can be obtained in the field, in a practical way, and consists of expressing the amount of fuel consumed by the tractor engine during a given operation. The main function of the tractor's power take-off (TDP) is to transmit the power generated in the engine, to drive active parts of agricultural machinery.

In view of the need to reduce production costs, many manufacturers began to make tractors equipped with the so-called “economic TDP” available to rural producers, which, unlike the TDP considered normal or conventional, drives an agricultural machine, maintaining the same standardized PTO speed (540 rpm) at a lower engine speed. In this way, the PTO rotation is maintained and fuel consumption can be reduced. However, due to the low engine speed, the use of economical TDP is limited to carrying out light agricultural operations, using equipment such as sprayers, brush cutters, centrifugal distributors, among others.

Thus, this work aimed to quantify the fuel consumption of an agricultural tractor using economic TDP and normal TDP, in two areas of different relief, when applying broadcast fertilizer.

DATA COLLECT

Data were collected in the 2011/2012 agricultural harvest with wheat cultivation (Triticum aestivum L.) in an experimental area at the Federal University of Santa Maria. To carry out the field experiment, a Massey Ferguson agricultural tractor was used, model MF 4283 with auxiliary front-wheel drive (TDA), with a maximum engine power of 85 hp (62,50 kW), 12.4-24 R1 front tires. and rear 18.4-34 R1. The machine for applying fertilizers was a broadcast distributor (with gravitational dosing mechanism and centrifugal distribution mechanism) from the Massey Ferguson brand, model MF 2013 M with hydraulic drive, capacity of 1.300 liters and working width of 20 meters, for the type of applied product, which was nitrogen fertilizer (urea) at a dose of 200 kg/ha.

To quantify hourly fuel consumption, an Oval brand flowmeter (Flowmate OVAL M-III), model LSF 41L, was used and the system used to acquire (storage) this data was a datalogger Campbell Scientific brand, model CR1000. Information was recorded continuously over a 2-second acquisition period.

Operational fuel consumption was determined through the relationship between hourly fuel consumption and effective field capacity, according to (MIALHE, 1974). The effective field capacity was determined by the relationship between the useful area of ​​the worked plot and the time spent traveling through the plot.

The field work was conducted in two areas (a relief area considered flat, with a slope of 2º, and another relief area with a gentle slope, with 13,6º, using two tractor TDP settings (economic and normal). To equalize travel speeds and the rotational speed of the TDP (economical and normal) at 540 rpm, the rotational speed was predetermined at 1900 rpm in the engine and the third (3rd) gear of the low gear group for the normal TDP and, 1700 rpm in the engine and the third (3rd) gear of the group reduced high for the economical TDP. The rotation at the TDP was checked using a Minipa brand photo/digital contact tachometer, model MDT-2238A. Each experimental unit totaled four minutes route, which consisted of a back and forth circuit (uphill and downhill).

For statistical analysis, a two-factor experiment was considered, in which the factors were: TDP configuration (normal and economical) and Area (flat and gentle slope), in a randomized block experimental design, with three replications. Afterwards, the data (hourly consumption and operational fuel consumption) were subjected to analysis of variance and the Tukey test to compare means at a 5% level of significance.

RESULTS OBTAINED

When analyzing the hourly fuel consumption values, it is clear that there was no interaction between the factors Area and TDP configuration. This means that using different areas (working in different areas) did not significantly change fuel consumption when using different TDP settings, so the data is analyzed separately. When using the economical TDP (7,00 L/h), there was a statistical difference in hourly fuel consumption, with a reduction of 11,25% in relation to the use of the normal TDP (7,89 L/h). Regarding the Area factor, there was a statistical difference for this factor, with an hourly consumption value 6,81% lower being obtained in the flat area (15,6 L/h) than in the one with a gentle slope (8,07 L/h ). This can be explained by the lower effort of the tractor engine, due to the lack of steep slopes in the former.

Regarding operational consumption, it was noticed that there was no interaction between the two factors evaluated. As was the case for hourly consumption data, when using the TDP configuration in economical mode, this provided a saving of 11,43% in operational consumption, compared to using normal TDP.

The operational consumption values ​​verified are relatively low due to the large working width of the agricultural machine (20m), as the greater the operational capacity for the same hourly consumption, the lower the operational consumption will be. Analyzing the data relating to the working areas, the same trend can be seen, that is, when operating in an area considered flat, operational consumption was reduced by 15,59%, when compared to the area with a gentle slope.

Conclusions

It is concluded that the use of economical TDP can reduce hourly and operational fuel consumption, as well as being influenced by the slope of the area.

Ulisses Giacomini Frantz, Unipampa – Dom Pedrito Campus; José Fernando Schlosser, Marcelo Silveira de Farias, NEMA – UFSM; Alexandre Russini, Unipampa – Campus Itaqui

Article published in issue 158 of Cultivar Máquinas.