Investigation of the characteristics of a marine diesel engine when running on fuel with a water additive

Currently, environmental specifications of marine diesel engines become more stringent. There are two well-known and popular ways to improve engine environmental performance: the internal method is based on operation process improvement, as well as on the use of various fuel additives or air supply to the diesel cylinder. Another method is external (gas purification using catalysts and filters). The article considers one of these possible ways of reducing nitrogen oxides in marine diesel engines by using a water agent in fuel with various water phase dispersion degrees. The high-speed characteristics of the ship engine operation under various modes using “L” brand diesel fuel and emulsions are given. Studies have shown that when converting diesel from pure fuel to a microheterogenous emulsion (water inclusions’ diameter 5-10 microns), the concentration of NOx decreased by 1.4 times, fuel consumption increased by (4-5) g/(kWh), with an increase in the maximum combustion pressure by 0.7 MPa. The tests have confirmed the effectiveness of using a microheterogenous emulsion to reduce nitrogen oxide emissions.

Dimensional-time relationships of the technological process of manufacturing a "ТМЗ—450Д" diesel cylinder

Changes in the dimensions of the main bore of the cylinder of a "ТМЗ-450Д" diesel engine in the technological process of its mechanical and thermal treatment at the Tula Machine-Building Plant are analyzed. The accepted sequence of operations is presented: turning with CNC — aging — boring — aging — honing — aging — honing — honing — honing — aging. An incorrect choice of the cylinder basing scheme was noted during the first operations. A new version of the technological process of mechanical and heat treatments is proposed, including natural aging and the use of double boring on a modular boring machine, which made it possible to reduce the number of honing operations to one, including rough and finish steps. Keywords: shape and size errors, aging, dimensional changes, basing, boring, honing, Abbot diagram. [email protected]

Scientific substantiation of technology for manufacturing cylinder of TMZ-450D diesel engine

The analysis of complex technology for TMZ-450D diesel cylinder machining is presented. It is emphasized that a billet has a heterogeneous structure and that is why it is in need of ageing. It is proved that equipment rigidity in an acting engineering process is insufficient for the compensation of billet hereditary defects. New equipment with high rigidity is offered and introduced.

Diagnosing the technical condition of the diesel cylinder-piston group

The reliability of locomotive diesel engines largely depends on a timely and objective assessment of the technical condition of its equipment during operation. The article proposes a technique for the integral assessment of the technical state of the quality of the working process in a diesel cylinder using on-board diagnostics.

TECHNOLOGICAL SUPPORT OF WEAR RESISTANCE OF THE DIESEL CYLINDER MIRROR

The article is devoted to the achievement of the maximum wear resistance of the cylinder mirror of a diesel engine by technological provision of a given dimensional accuracy and geometric shape of the cylinder mirror, as well as roughness parameters in accordance with a given Abbott diagram. The solution of the problem is complicated by the inhomogeneity of the structure of the metal of the casting and the geometry of the outer surface of the cast cooling fins of the cylinder, which leads to variable stiffness and inconstancy of elastic deformations when cutting the cylinder. The problem was solved by optimizing the structure of the technological process and replacing the equipment with a new, more rigid and accurate one.