This project includes two identical mine air heaters and supply fans to be installed at the Shaft #2 to provide fresh air into the mine. The intake air will be heated during times of freezing ambient temperatures. Total design flow capacity of the Shaft #2 mine air heater is approximately 950 m3/s. Each fan is combined with an 875 kW motor.
The electrical scope of design will include the following:
• Power supply to the heater modules (includes cable trenching between the electrical modules and the Shaft #2 sinking/permanent electrical room
• Power & Control, lighting and earthing design
Materials, components, and the systems are selected to withstand temperature ranges and harsh weather typical to the Gobi desert of Mongolia.
Mine air is to be heated by glycol heating coils where propylene glycol water circulates through hot water / glycol heat exchangers. The hot water is supplied from the central heating plant (CHP) through pipelines to the battery limit of the heater modules.
Based on the Central Heating Plant (CHP) and pipelines information available, CHP hot water temperature drop is estimated about 0.5°C for about 4.5 km distance from CHP to the Shaft #2 heater modules. Namely 129.5 Degree C hot water is to be supplied to the heater hot water-glycol HEXs.
The mine air heaters and fans are designed to heat and supply the required amount of outdoor air at minimum heater discharge temperature of 2°C during winter heating season; and to supply the required amount of outdoor air to the mine during non-heating seasons.
The mine air heaters and fans are designed for continuous operation except for dust storm periods. All air intakes are designed facing east or south as much as possible where there is less impact from dust storms and the prevailing wind.
The equipment vendor has optimized and modularized the mine air heaters and associated equipment as much as possible to simplify maintenance, installation and spares inventory.