A computer Model of Fuel Consumption Estimation for Different Agricultural Farm operations

The primary purpose of agricultural tractors is to perform dynamic drawbar works (Zoz and Grisso 2003). The value of a tractor may be measured by the amount of work carried out relative to the cost incurred in getting the work done. Therefore, the ideal tractor converts most of the energy from the fuel consumed into useful work at its drawbar. 

Several methods have been used for fuel consumption prediction, some of these methods are generally based on power requirements and others are for individual engines, which require extensive engine testing to verify the amount of consumption. Grisso et al. (2004) developed a general model to predict fuel consumption for full and partial loads and for reduced throttle conditions using data from Nebraska Tractor Test Lab (NTTL) in U.S.A. for a specific tractor models. Using these, mathematical equations make it possible to predict fuel savings for different operating and loading tractor conditions (Grisso et al. (2008). 

An artificial neural network (ANN) approach was used to model fuel consumption of wheat production. The developed model is capable of predicting fuel consumption under different field conditions and can help farmers to reduce their expenditure (Safa et al. 2009). According to Siemens and Bowers (1999), and depending on the type of fuel and the amount of time a tractor or machine is used, fuel and lubricant costs usually represent at least 16% to over 45% of the total machine costs. 

Since most tractors tested and used for agricultural purposes in the last 25 years have had diesel engines, the following equation may be used for diesel engines fuel consumption estimation:

 Q = 0.223 × P ( Bower 2001). avg pto 

Where: Q = average diesel fuel consumption, L/h 

avg P = maximum PTO power, kW pto 

The average fuel consumption of a tractor operating under a range of load conditions, over a period of time may be determined by using the power ratio (PR) as in the following equation (ASAE 2002): 

 Q = 2.64PR+3.91- 0.203 (738PR + 173)^½ 

This equation estimates the specific volumetric fuel consumption (SVFC) in L/kW-h along the full throttle or governor response curve. It does not provide estimates of the fuel consumption during reduced engine speed settings that are often recommended for partial load applications. Kotzabassis et al. (1994) reported that the volumetric fuel consumption for a diesel engine at partial loads and full throttle can be calculated as 

Q = (2.64PR+3.91-0.203 (738PR+173)^½  ) × PR ×Ppto

 where : 

Q = diesel fuel consumption at partial load, L/h (gal/h)

 PR= the ratio of equivalent PTO power (PT) to rated PTO power  (Ppto), decimal 

As the technology is becoming increasingly integral part of our lives, the computer is considered one of the most modern technologies that are used in statistical analysis of agricultural information and in taking decisions for managing agricultural implements. There are other computer models developed for analyzing machinery performance and management decisionmaking (Ruiyin et al. 1999; Mechalilie 1996). Computers are used also to record, keep and analyze agricultural information. Computer programmes consisting of mathematical equations are developed to estimate the cost of agricultural operation performance, to choose suitable implements and to evaluate and apply production inputs such as irrigation water, fertilizers and chemical pesticides (Landers 1992; Alam et al. 2001; Dahab and Mohamed 2006; Dahab et al. 2009). 

The main objective of the present study was to estimate fuel consumption rate of agricultural farm operations by computer programming. This may be achieved through 

1. Developing a computer model with programming language that can help in estimation of fuel consumption for tractor with implement. 

2. verifying and validating the programme by actual field data, and testing its sensitivity and accuracy