A ventilation system including a building having a space inside, a subterranean facility arranged in a basement of the building and having a subterranean space inside, a communication passage establishing communication between the space and the subterranean space, and a ventilation hole establishing communication between an earth outside the building and the subterranean space is provided. A fuel cell unit having an exhaust port is arranged in the subterranean space. The communication passage has a lateral wall protruding downward from a ceiling of the subterranean space. The lateral wall is arranged on the exhaust port side when the communication passage is arranged on a straight line linking the exhaust port and a second opening portion of the ventilation hole on the subterranean space side. The lateral wall is arranged on the straight line side when the communication passage is arranged at a position spaced apart from the straight line.

Combination of an open and a hidden excavation for constructing a vertical orthogonal top exhausting air duct structure of a deeply-buried subway station is provided. Four horizontal air ducts: left and right piston air ducts, an exhaust air duct, and a fresh air duct are thrown out of the underground, respectively, leading to left and right piston air shafts, an exhaust air shaft, a fresh air shaft, and an entrance/exit of fire-fighting. The fourth underground floor is communicated with the hall floor of the station main body, and the fifth underground floor is communicated with the running tunnel and the platform floor of the station main body. During operation, the train will enter and exit the station through the fifth underground floor of the air duct, and the piston air and heat will enter the four transverse air ducts through the air duct main body.

Combination of an open and a hidden excavation for constructing a vertical orthogonal top exhausting air duct structure of a deeply-buried subway station is provided. Four horizontal air ducts: left and right piston air ducts, an exhaust air duct, and a fresh air duct are thrown out of the underground, respectively, leading to left and right piston air shafts, an exhaust air shaft, a fresh air shaft, and an entrance/exit of fire-fighting. The fourth underground floor is communicated with the hall floor of the station main body, and the fifth underground floor is communicated with the running tunnel and the platform floor of the station main body. During operation, the train will enter and exit the station through the fifth underground floor of the air duct, and the piston air and heat will enter the four transverse air ducts through the air duct main body.

Apparatus and process for securing a grating over an atmospheric opening of a ventilation shaft fluidly communicating through the ventilation shaft to an underground ventilation duct. A vertically extending support for arrangement in the shaft has horizontal flanges for projecting across a top of at least two opposing sides of said shaft to hang said support in said shaft for over topping by said grating. An anchoring member is supported in the support at a level below the flanges and proximate the atmospheric opening. A hold-down connects to the anchoring member to secure the hold-down and the grating to the anchoring member.

A nuclear island base slab of a nuclear power plant and a manufacturing method therefor, and a nuclear island of a nuclear power plant. The nuclear island base slab of a nuclear power plant includes a concrete base slab body and a plurality of air ducts embedded in the concrete base slab body. The air duct has an internal-penetrating bent pipe structure. A first end of the air duct is exposed on an upper surface of the concrete base slab body. A second end of the air duct is exposed on a side surface or the upper surface of the concrete base slab body.

A nuclear island base slab of a nuclear power plant and a manufacturing method therefor, and a nuclear island of a nuclear power plant. The nuclear island base slab of a nuclear power plant includes a concrete base slab body and a plurality of air ducts embedded in the concrete base slab body. The air duct has an internal-penetrating bent pipe structure. A first end of the air duct is exposed on an upper surface of the concrete base slab body. A second end of the air duct is exposed on a side surface or the upper surface of the concrete base slab body.

A ventilation duct 10, the duct 10 comprising a substantially rigid, elongate tube section 12 moulded from plastics material and having a tube wall 14 comprising a plurality of layers. At least one of the layers comprises an intumescent material which acts as a fire retardant in the event of exposure to extreme heat.

A ventilation duct 10, the duct 10 comprising a substantially rigid, elongate tube section 12 moulded from plastics material and having a tube wall 14 comprising a plurality of layers. At least one of the layers comprises an intumescent material which acts as a fire retardant in the event of exposure to extreme heat.

In one aspect, a track structure usable by a wheeled vehicle for hauling a payload up an inclined enclosed passageway comprises a hollow rigid center rail member configured to act as both a center rail for the wheeled vehicle and as a ventilation duct. Opposite lateral faces of the hollow center rail member have respective wheel contact surfaces grippable by an opposed pair of inwardly-biased drive wheels of the wheeled vehicle. Rail support structure depends from the hollow center rail member. An elevated pair of rails is attached to the rail support structure, the rails being on opposite sides of and substantially parallel to the hollow center rail member. Each rail is supported by the rail support structure so as to provide an upper, lower, and lateral surface suitable for rolling engagement by a weight-bearing wheel, undermount wheel, and guide wheel, respectively, of the wheeled vehicle.

In one aspect, a track structure usable by a wheeled vehicle for hauling a payload up an inclined enclosed passageway comprises a hollow rigid center rail member configured to act as both a center rail for the wheeled vehicle and as a ventilation duct. Opposite lateral faces of the hollow center rail member have respective wheel contact surfaces grippable by an opposed pair of inwardly-biased drive wheels of the wheeled vehicle. Rail support structure depends from the hollow center rail member. An elevated pair of rails is attached to the rail support structure, the rails being on opposite sides of and substantially parallel to the hollow center rail member. Each rail is supported by the rail support structure so as to provide an upper, lower, and lateral surface suitable for rolling engagement by a weight-bearing wheel, undermount wheel, and guide wheel, respectively, of the wheeled vehicle.