Improvement and application of the cooling system of the roadheader tank

1,The original design cooling principle and existing problems of the roadheader

The original cooling system of the roadheader consists of four radiators arranged in different positions in the radiator. The coolers are respectively arranged on a return valve group for controlling the star wheel and the scraper conveyor, a two-way valve group for controlling the left and right travel, and a returning oil side of the seven-group valve group for controlling the oil cylinder. The roadheader is mainly water cooled. The working principle is as follows: after the high-pressure oil coming out of the hydraulic pump is working through the hydraulic components, the spent oil flows back to the oil tank through the cooler through the oil return pipe. The cooler is connected to the dustproof water. The hot water exchanged with the high temperature oil exchanges the hot water exchanged from the spray head to prevent dust and temperature.

The dust-proof moisture entering the roadheader is 3 branches. The first branch is an external spray that directly ejects the outside water; the second split is a cooling cut motor and an oil cooler; and the third split is an internal spray. The cooling effect depends directly on the length of the dust supply and the length of time required. Due to geological conditions and construction procedures. When the roadheader sweeps the bottom, brushes and crosses the fault, the rock cuts for a long time. The dustproof water volume should not be too large, and the dustproof water can not be used when supporting the roadway, resulting in poor cooling effect, high oil temperature rise, easy to break through the cooler, causing oil and water to mix, and the oil temperature reaches about 100% at the highest. Hydraulic components and the working environment have a negative impact.

2,Improvement plan

To reduce the oil temperature of the roadheader, it is necessary to increase the amount of dust that passes through and extend the passage time. The greater the amount of water that passes through, the longer the time, the better the cooling effect. The hydraulic oil of the roadheader is recycled. The temperature of the hydraulic oil in the fuel tank and each branch is basically the same. As long as the temperature inside the fuel tank is lowered, the problem of excessive oil temperature in the hydraulic system can be solved. According to the experience of using the roadheader on site, it was found that the water consumption was large when supporting the roadway. Moreover, the time is long, which is closely related to solving the oil temperature of the roadheader. It is proposed to add φ25.4mm seamless steel pipe inside the fuel tank, and bend the steel pipe into a ring shape to increase the contact area of the hydraulic oil and the cooling water pipe as much as possible ( see picture 1). Put the water pipe in the fuel tank. The water inlet and the water outlet are respectively fixed on the fuel tank cover, and the water inlet is connected with the main dustproof pipe, and the water outlet is connected to the drilling machine for dustproof and roadway support. When the head support is arranged to drill and dustproof, the dustproof water is discharged from the water outlet through the annular pipe in the fuel tank to achieve the purpose of reducing the oil temperature.

3,Improvement effect

In use. By adopting the above method, even if the roadheader stops working after cutting the coal, there is still dust water passing through the oil tank during the support and dustproof, and the high temperature oil is cooled, which solves the problem that there is no dustproof water before the roadheader is stopped. Passing, the problem of cooling the high temperature oil cannot be achieved. The temperature inside the fuel tank can be reduced by 30 to 50 °C compared with before the improvement, which not only improves the working environment, but also prolongs the service life of the hydraulic components, reduces the accident of the roadheader, and improves the efficiency.