Turbo compressor and turbo chiller comprising same
This turbo compressor comprises: an impeller; a shaft part that causes the impeller to rotate; an electric motor that rotatably drives the shaft part; a casing that accommodates the electric motor; a magnetic bearing that supports the shaft part; a heat transfer plate of which one surface is attached to the outer surface of the casing; a magnetic bearing drive substrate that is in surface contact with the other surface of the heat transfer plate on the side opposite from the one surface; and a cooling unit to which a refrigerant is supplied from the outside, whereby the cold/heat of the supplied refrigerant is transmitted to the heat transfer plate.
1 . A turbo compressor comprising:
an impeller;
a shaft portion that rotates the impeller;
an electric motor that rotationally drives the shaft portion;
a casing that accommodates the electric motor;
a magnetic bearing that supports the shaft portion;
a heat transfer plate of which one surface is attached to an outer surface of the casing;
a magnetic bearing drive substrate that is in surface contact with another surface of the heat transfer plate opposite to the one surface of the heat transfer plate;
a cooling section that, by being supplied with a refrigerant from an outside, transfers cold of the supplied refrigerant to the heat transfer plate; and
a box that accommodates the magnetic bearing drive substrate in a state in which an opening faces the outer surface of the casing,
wherein the heat transfer plate fits into the opening of the box to form a closed space in which an inside of the box is airtightly separated from an outside, and
air in the closed space is replaced with an inert gas.
2 . The turbo compressor according to claim 1 ,
wherein the cooling section includes
a flow path portion that is formed in an outer wall of the casing and through which the refrigerant circulates, and
a groove portion that is connected to the flow path portion and is recessed from the one surface of the heat transfer plate toward the other surface side of the heat transfer plate to form a flow path of the refrigerant together with the outer surface of the casing.
3 . The turbo compressor according to claim 2 ,
wherein the groove portion extends along the one surface of the heat transfer plate in a meandering manner.
4 . The turbo compressor according to claim 1 , further comprising:
a displacement sensor that is capable of detecting a magnitude of a clearance between the shaft portion and the magnetic bearing; and
a displacement sensor substrate that is accommodated in the box and processes a signal detected by the displacement sensor.
5 . The turbo compressor according to claim 1 ,
wherein the heat transfer plate is formed of a metal material containing aluminum.
6 . A centrifugal chiller comprising:
the turbo compressor according to claim 1 ;
a condenser that condenses a refrigerant discharged from the turbo compressor;
an expansion valve that adiabatically expands the refrigerant condensed by the condenser;
an evaporator that evaporates the refrigerant adiabatically expanded by the expansion valve; and
a refrigerant supply unit that is capable of introducing the refrigerant condensed by the condenser to the cooling section.
7 . The centrifugal chiller according to claim 6 ,
wherein the refrigerant supply unit includes
an introduction line that introduces the refrigerant to the cooling section, and
an adjustment valve that is provided in the introduction line and decompresses the refrigerant flowing in the introduction line to put the refrigerant flowing toward the cooling section in a gas-liquid two-phase state.