In the near future, urban bus transportation will remain the main type of passenger transportation for most cities of Ukraine and are of great social importance.
A decrease in the energy intensity of transportation is ensured by a more optimal (efficient) use of fuel resources. At the same time, the specified goal can be achieved only on condition that the established rate of fuel consumption for each brand of bus is sufficiently justified.
It is obvious that the perfection of planning and the development of scientifically based standards for fuel consumption are becoming an important area of resource conservation in road transport and reducing the cost of transportation.
Considering that at present the normative documents of Ukraine do not provide for the regulation of the microclimate in buses of city routes and fuel consumption depending on the microclimate in the cabin, there is an urgent need to study the reduction of the energy consumption of buses of the M3 category when operating with air conditioning.
Owners of buses of all forms of business, operating on the territory of Ukraine and operating them on the routes, carry out calculations of the standard fuel consumption in accordance with the current methodological recommendations "Norms of fuel and lubricants consumption in road transport", approved by order of the Ministry of Infrastructure of Ukraine No. 411 dated 10/07/2011 According to these standards, fuel consumption when using an air conditioner is increased to 5% of the base linear rate for one hour of inactivity with the engine running. For cooling the interior of the bus while driving, in the case of using an air conditioner, surcharges are provided for fuel consumption at an actual outside air temperature, starting from +20 ˚С. The increase in the forced switching on of the air conditioner due to the deterioration of the temperature environment in the cabin during the hours of increased passenger activity is not provided.
At the same time, the experience of operating city buses equipped with air conditioning indicates that the value of the recommended allowances is clearly incorrect, since it does not provide the established objective norms of fuel consumption and does not fully contribute to fuel saving at an enterprise that provides route passenger services.
The research carried out within the framework of this thesis shows that the operation of modern shuttle buses equipped with air conditioning is advisable to be considered as a complex dynamic system, the functioning of which occurs under the action of stochastic factors affecting fuel consumption. This is a combination of internal processes in the bus cabin and the influence of external factors.
This significantly underscores the relevance of scientific research to improve fuel efficiency while providing comfort.
The task of economically oriented operation of the city bus air conditioner during the technological process should be solved by the methods of system and technical and operational analysis, taking into account all operational features.
Thus, the determination of optimal solutions to reduce the energy intensity of air-conditioned M3 buses operating on city routes is an important scientific and applied problem.
The scientific novelty of the obtained results of the study lies in the fact that for the first time the positive effect of preliminary cooling of the passenger compartment with air conditioning on the fuel efficiency when working on the route has been substantiated; the established dependences of the fuel consumption of an air-conditioned bus on the outside air temperature and the number of passengers carried; it is proposed to introduce air conditioning cooling of the city bus interior, depending on the presence of passengers during the hours of increased passenger activity. Improved simulation model for determining air exchange through an open door at a stop in the summer along the neutral plane of the door section.
The practical significance of the results obtained is important in that their implementation is expedient in mathematical analysis and software of an automobile enterprise as a component of the technology of modern integrated monitoring of the operation of buses on city routes. An algorithm and programs for calculating the heat load on the passenger compartment and the standard fuel consumption, taking into account the temperature indicators and the number of passengers carried, are proposed. This allows us to consider the possibility of using these approaches to other models of buses and to form an information database of the enterprise. At the same time, the use of the proposed methodological approaches makes it possible to reduce the fuel consumption of one bus by up to 3% per shift while ensuring the optimal microclimate in the passenger compartment.
Key words: city bus M3, energy intensity, air conditioner, microclimate, fuel consumption, heat input, rationing, interior cooling.
