Location and Drainage of Silent Diesel Generator

The choice of silent diesel generator room is always a problem encountered by customers. It is very important to select a good installation position of diesel generator set, which is related to the future use and maintenance of the generator set. So how to select the location of silent diesel generator room?

1. The location of diesel generator room takes into account the intake of diesel generator, smoke exhaust and so on.

If conditions are available, the genset room is best located on the first floor. However, high rise buildings are expensive, especially the first floor usually used for external business. As a result, generator rooms are generally located in the basement. As the basement is not suitable for entry and exit and the natural ventilation condition is poor, it brings a series of unfavorable factors to the design of the genset room, which should be handled well in the design.

Attention should be paid to the following points when selecting the location of the diesel generator room.

① Diesel generator set should not be located in the surrounding room without an external wall for the hot air pipe and smoke pipe export outdoor conditions.

② Avoid as far as possible the main entrance of the building, elevation and other parts, so as not to exhaust smoke, exhaust wind to its impact.

③ Pay attention to the impact of noise on the environment.

④ The substation should be close to the buildings, so that it is convenient for wiring, reducing power loss and facilitating operation management.

2. Ventilate

The ventilation problem of diesel generator room should be paid special attention to in the design of genset room, especially when the generator room is located in the basement, otherwise it will directly affect the operation of diesel generator set. The exhaust air of the genset should generally be quipped with hot air pipes. It is not advisable to let the heat from the radiator of the diesel engine disperse in the generator room and then be drawn out by the exhaust air machine. There should be enough fresh wind in the computer room. When the diesel generator is running, the amount of air exchange in the genset room should be equal to or greater than the sum of the amount of fresh air required by the combustion of the diesel generator and the amount of fresh air required to maintain the room temperature of the genest room.

The amount of fresh air required to maintain room temperature is calculated as follow:

C=0.078PT  

C——The amount of fresh air needed (m3 / s)

P——Diesel engine rated power (kW)

T——Engine room temperature rise (℃)

The fresh air required to maintain diesel engine combustion can be obtained from the genset manufacturer.

If there is no data are available, users can calculate by 0.1m3/mim(diesel engine power is provided at 1.1 times of the main generator power kilowatt number).

The ventilation of diesel generator room generally adopts the way of setting hot air duct with exhaust air and natural air inlet. The hot air pipe is connected with the radiator of the diesel engine, and the joint of the hot air pipe is provided with a flexible joint, and the hot air pipeline should be straight. If you want to turn the duct, the turning radius is as large as possible and the inside is smooth, the air outlet is as close as possible and right against the radiator. The inlet and outlet should be arranged at the two ends of the genset separately, so as to avoid short circuit of air flow and influence the effect of heat dissipation.

The area of the air cutlet and inlet of the generator room shall meet the following requirements:

S1≥1.5s

S2≥1.8s 

S—— Heat dissipation area of diesel engine

S1——Air outlet area

S2——air-admitting surface

In the cold area, attention should be paid to the influence of inlet and outlet on generator room temperature in order to avoid the low temperature of generator room affecting the start up of genset. The connection between outlet and outdoor can be equipped with tuyere, usually in closed state, the genset can be automatically opened when in operation.

3. The function of the exhaust system is to discharge the exhaust gas from the cylinder outside.

Exhaust system should minimize back pressure. The reason is that the increase of exhaust resistance will lead to the decrease of diesel engine outpit and the increase of temperature.

There are two common ways of laying exhaust pipes.

① horizontal overhead laying, the advantage is less turning, small resistance, the disadvantage is to increase indoor heat loss, so that the engine room temperature rise.

Ditch laying, the advantage is that the indoor heat dissipation is small, the drawback is that the exhaust pipe turns more, the resistance is relatively large. ②Horizontal overhead laying is commonly used in the basement. Exhaust pipe should be isolated, as far as possible to reduce the elbow. The exhaust smoke temperature is 350 ~ 550 ℃. In order to prevent scald and reduce radiation heat, the pipe should be treated with heat preservation. Smoke exhaust noise is one of the most intense noise in the unit. Silencers should be installed to reduce the noise.

4. Foundation

The foundation is mainly used to support the full weight of the diesel generator set and the base, which is located on the foundation, and the unit is installed on the base, on which the shock absorption measures are generally adopted. High speed diesel generator sets are generally used in high-rise buildings. When the units are not installed on the floor, heavy concrete foundation is not used, so as to avoid the overweight of the foundation and increase the floor load. When the unit is located on the ground floor of the building, the concrete foundation shall be set according to the unit requirements. Bottom screw can be pre-buried, or after the arrival of the unit with electric drill drilling installation.

5. Three kinds of earthing methods are generally adopted in the ground diesel generator room of engine room

① working grounding

② Protective earthing, normal uncharged metal case grounding of electrical equipment.

③ Anti-static grounding, fuel system equipment and pipeline grounding. All kinds of earthing can be shared with other earthing devices in tall buildings, that is, joint earthing.

6. Domestic demand for fuel storage generator room installation of daily fuel tank for 3 to 8 hours.

Its volume can be calculated by the following formula:

v=g·Y·a·t

V-Daily tank volume(m3)

G-Diesel fuel consumption, detected by sample(kg/h)

Y-Fuel heavy(kg/m3), Light diesel oil is 810~860kg/ m3

A-Tank filling coefficient. Generally take 0.9; oil supply time, generally take 3-8 hours.

What should be noted about water tank drainage of mute generator sets.

So what are the precautions for water tank drainage of mute generator sets?

The use of mute generator sets generally requires continuous operation, and the machine itself will heat up when it is in continuous operation, so it needs to be cooled. Because the temperature of the external environment of the mute generator set is too low when discharging water, the cooling water should be discharged after 15 minutes after the shutdown. It is not to say that the engine will be discharged when it stops, otherwise, the temperature difference between the fuselage and the external environment will be too large, which will cause some parts of the mute generator set to deform, thus affecting the performance of the diesel engine.

While discharging water, the unit should pay attention to observe the concrete condition of the water flow around, mainly check whether the flow of water is smooth, see whether the flow of water becomes smaller or the phenomenon of time, speed and time slow. If these conditions occur, it means that there are impurities in the cooling water, which hinders the normal outflow of water. The best way is to remove the release switch and let the cooling water flow directly from the body. If it is found that the flow is still not smooth, it is time to use hard and slender steel objects such as wire to clear the flow until the flow is clear.

Finally, when the cooling water stops flowing out, we'd better turn the mute generator around a few more times. In this way, in order to use the vibration of the diesel engine to clean up the remaining water inside, the cooling water that is not easy to flow out. After the end of the discharge, the discharge switch should be in an open state to prevent the cooling water from flowing out for a while and the corresponding parts of the diesel engine to be damaged unnecessarily.

If the cooling water of diesel engine should pay attention to the steps of discharge, it must be ensured that the cooling water is discharged at one time, so as to avoid unnecessary losses caused by the residual water in the cooling water, so as to ensure the normal operation of the unit.