JPS5825551A - Construction for cooling the cylinder covering etc. of a diesel engine - Google Patents

Abstract

PURPOSE:To hold the temperature at the external surfaces of an engine at a low value so as not to required provision of any insulation and to highly utilize the exhaust heat by furnishing within the cylinder covering a high-temperature cooling water passage near the wall of combustion chamber and a low-temperature cooling water passage near the outside. CONSTITUTION:A high-temperature cooling water passage 1 is composed of cooling parts 1a, provided near the walls of combustion chamber 3a of the cylinder covering 3, and a flowout passage 1b leading upward, and is processed by boring. Cooling pats 1a are provided radially in a large number being in connection to the main tube 22 for high-temperature cooling water passage through conduits in the cylinder liner 26. The outlet therefrom is led to a groove 25 provided at the oversurface of the covering 3 in the form as serving as a header, and then connected to the outgoing main tube 16. Low-temperature cooling water passage 2 is provided near outside the covering 3, being separate from the wall of combustion chamber 3a, consisting of a number of holes stretching radially aslant to be connected with the incoming 17 and outgoing 11 main tubes. Thus the high- temp. cooling water temperature is selected to a specific value and, at the same time, the temp. of engine's external surfaces are held at such a low temperature as does not require provision of any insulation, and these together with holding the low-temp. cooling water temperature at approx. 60 deg.C are utilized for equipment in the ship.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling structure for a large diesel engine such as a main marine engine.

Cooling of the combustion chamber of a diesel engine is an extremely important issue from the perspective of engine durability, but recently there has been a growing focus on how to increase the thermal efficiency of the entire ship and how to improve the engine's operating characteristics. From this point of view, cooling water not only cools the engine, but also effectively utilizes the waste heat of the engine. Alternatively, in order to improve the operating performance of the engine, the temperature of the cooling water has been increased. That is, in the conventional combustion chamber-related cylinder cover/exhaust valve box cooling system, the cooling water outlet temperature was at most 90°C. This waste heat was used for heating hot water, heating living quarters, etc. However, if this cooling water is pressurized to have an outlet temperature of 100° C. or higher, this waste heat can be introduced into a low-pressure steam generation heat exchanger and can be used as a driving source for a turbo generator. On the other hand, if the outlet temperature rises to 100'c or more, it is necessary to prevent the temperature of the cylinder cover/exhaust cover 9 from rising in the engine room or from causing burns to the operator. On the contrary, maintenance and maintenance is a two-stage cooling water system with a high and low temperature cooling water system that covers the installed part of this high temperature cooling water system, and this low temperature cooling water system is used as the above-mentioned heat insulating material. This solved the problem and made it possible to increase the utilization of waste heat from nine engines. This will be explained below using figures.

FIG. 1 is a longitudinal sectional view including a cylinder cover without an exhaust valve box and related parts thereof. 25 is a piston, 26
3 is a cylinder liner, 3 is a cylinder cover, 27 is a fuel injection valve, and 28 is a cylinder jacket. Reference numeral 1 denotes a high-temperature cooling waterway, which consists of a cooling part 1a provided near the combustion chamber wall 5a of the cylinder cover 3 and an outflow passage 1b to the upper part of the cover 3, both of which are constructed by drilling holes in the members of the cover 5. ing. A large number of cooling parts 1a are thrown radially,
This is connected to the main pipe 22 of hot cooling water through a passage in the cylinder liner 26. Its outlet enters a header-like groove 23 on the top surface of the cover 3 and is connected to the main pipe 16.

2 is a low-temperature cooling waterway, which is provided by diagonally drilling a large number of holes radially near the outside of the cover 5 away from the combustion chamber wall 3a. Its inlet is connected to the pipe 21 by the header 19.
The outlet is connected to the low-temperature cooling water inlet main pipe 17 through the header 20 and to the outlet main pipe 11 through the header 20 . Double arrows indicate high temperature cooling water, and single arrows indicate low temperature cooling water.

FIG. 2 shows a longitudinal section of the cylinder cover with the exhaust valve box, the exhaust valve, etc. 5 is an exhaust valve, 6 is an exhaust valve seat, 4 is an exhaust valve box, 5, 25, 26, etc. are the same parts as in FIG. 1, and the arrows are also the same. The high temperature cooling water channel 1 is arranged in multiple stages radially near the combustion chamber 5a.

The high-temperature cooling water inlet main pipe 12 is connected to the high-temperature cooling water inlet main pipe 12 through the header 13, and the outlet is connected to the connecting pipe blade to the high-temperature cooling water chamber 15 of the exhaust valve box 4 through the header 14. Low-temperature cooling waterway 2 is high-temperature cooling waterway 1
Around the part where ? Mari cylinder cover 6
The inlet is connected to the low-temperature cooling water main pipe 7 by a header 8, and the outlet is connected to the low-temperature cooling water chamber 10 of the exhaust valve box 4 by a header 9 through a connecting passage 31.

The exhaust valve box 4 has a high temperature cooling water chamber 1 surrounding the exhaust passage 30.
5 also surrounds the high temperature cooling water chamber 15 and the low temperature cooling water chamber 10
, and each of them receives coolant and low-temperature cooling water from the cylinder cover 3 and sends them to the outlet 16.
, 11.

Figure 3 shows these high temperature and low temperature cooling water systems.

32 is a low-pressure steam boiler using high-temperature cooling water, 33 is its pressurizing pump, 54 is a low-temperature cooling water circulation pump, 35 is a hot water utilization device, 56 is a cooler, and 37 is a head tank. For reasons such as this, the temperature of the high-temperature cooling water is selected to the required value, and the temperature of the external surface of the engine is maintained at a low temperature that does not require heat insulation, and the low-temperature cooling water is kept at around 60℃ and used for various equipment on board. By doing so, the exhaust heat of the engine can be utilized to a high degree.

[Brief explanation of the drawing]

FIG. 1 shows the case without the exhaust valve box of the present invention. FIG. 2 shows a vertical cross section of the cylinder jaws in the case of having an exhaust valve box, and FIG. 3 is a system diagram of high temperature and low temperature cooling water in the case of the present invention. 1 High temperature cooling water channel 2 Low temperature cooling water channel 3 Cylinder cover 4 Exhaust valve box 5 Exhaust valve 1-6 Exhaust valve seat △ 10 Low temperature cooling water chamber 15 High temperature cooling water chamber 25 Piston 30 Exhaust channel applicant Mitsui Engineering & Shipbuilding Co., Ltd. Agent River 1) Shigeru Ubiki Kaimo 2

Claims (1)

[Scope of Claims] 1) A cooling structure for a diesel engine cylinder cover in which a high-temperature cooling waterway is provided inside a cylinder cover member near the combustion chamber wall, and a low-temperature cooling waterway is provided near the outside. 2) A high-temperature cooling channel is provided inside the cylinder cover part near the combustion chamber wall, and a low-temperature cooling channel is provided near the outside. In addition, the exhaust valve box has a high temperature cooling water chamber surrounding the exhaust path. Furthermore, a low-temperature cooling water chamber is installed surrounding the high-temperature cooling water chamber. Connect the high-temperature cooling water channel of the cylinder cover to the high-temperature cooling water chamber of the exhaust valve box, and connect the low-temperature cooling water channel of the cylinder cover to the low-temperature cooling water chamber of the exhaust valve box, respectively. Place the high-temperature cooling water and low-temperature cooling water inlets on the cylinder cover side.
A cooling structure such as a cylinder cover with an outlet on the exhaust valve box side.