Briefly describe the ventilation and cooling design requirements for diesel generator rooms

In order to enable the diesel generator set to start smoothly, the temperature of the engine room should not be too low. After the unit is running, due to heat generation, in order to ensure the health of the on-duty personnel and complete the normal operation and duty tasks, the temperature and humidity of the engine room should not be too high. Usually, the lowest temperature in the generator room is required. It should not be lower than 5°C, and heating should be performed next to the standby generator room in cold areas. The maximum temperature should not exceed 35°C, and the relative temperature should not be greater than 80%.

 

       In order to enable the diesel generator set to start smoothly, the temperature of the engine room should not be too low. After the unit is running, due to heat generation, in order to ensure the health of the on-duty personnel and complete the normal operation and duty tasks, the temperature and humidity of the engine room should not be too high. Usually, the lowest temperature in the generator room is required. It should not be lower than 5°C, and heating should be performed next to the standby generator room in cold areas. The maximum temperature should not exceed 35°C, and the relative temperature should not be greater than 80%.

 

       After the generator is in normal operation, the diesel generator, generator, exhaust pipe, etc. will heat up, and will be scattered in the engine room, which will increase the temperature of the engine room. The oil, diesel, etc. leaked due to other reasons will be volatilized in contact with the hot body and air, causing the harmful gas in the air of the computer room to increase continuously. NO), nitrogen dioxide (NO₂), sulfur dioxide (SO2), dinitrogen tetroxide (N₂O₄), as well as formaldehyde, acrolein, etc. Among them, nitric oxide (NO) and acrolein are more harmful to the human body. The allowable concentrations in the gas are 0.03mg/L and 0.002mg/L, respectively, so the diesel generator set must be ventilated to remove harmful gases and reduce them to below the allowable concentration.

 

       The ventilation and cooling design of the diesel generator room should be able to eliminate the waste heat and harmful gases in the engine room, and meet the design of the combustion air volume required by the diesel generator. For the engine room located on the ground, the doors and windows of the engine room are directly connected to the atmosphere. Try to use natural ventilation or install exhaust fans on the wall of the equipment room to meet the ventilation and cooling requirements.

 

       If the diesel generator room is closed, for example, the diesel generator set is installed in the basement, the combustion air and exhaust smoke of the diesel engine need to pass a considerable distance to communicate with the outdoor atmosphere. This kind of machine room should be designed for ventilation and cooling. The air inlet and exhaust systems and cooling equipment in the machine room are provided. For the design of the enclosed generator room, the following points should be paid attention to:

 

       1. Determination of harmful gases of diesel generators and their ventilation

       The amount of harmful gas generated in the diesel generator room varies with the type of diesel generator set, installation and operation status, the laying form of the exhaust pipe, and the technical level of operation and maintenance. It is theoretically difficult to accurately calculate, so determine the ventilation of the engine room. The air exchange rate is relatively difficult, and the generator manufacturer has come to a conclusion based on a series of engineering test data: for most series of diesel generator sets, it should be determined according to 14~20m³/(kw·h).

 

       2. Calculation of combustion air volume of diesel generator set

       When calculating the combustion air volume of the diesel generator set, it can be calculated as 6.7m³/(kw·h) according to the rated power of the diesel engine.

 

       3. Heat load calculation of diesel generator set

       The heat load of the diesel generator room should mainly include the heat dissipation of the diesel engine, the generator and the exhaust pipe. For the specific algorithm, please consult the professional and technical personnel of Dingbo Electric Power.