Refrigerator

1. A refrigerator, comprising:

a compressor including a compression portion, a rotating shaft attached to the compression portion, and a bearing axially supporting the rotating shaft, for compressing water vapor as a refrigerant by the rotating of the rotating shaft;

a condenser for condensing a refrigerant compressed by the compressor;

an evaporator for evaporating a liquid refrigerant condensed by the condenser;

a cooling-water line including a cooling-water pump to thereby send water for cooling a refrigerant in the condenser;

a lubricating-water supply line supplying water from the cooling-water line to the compressor as a lubricant for the bearing of the compressor, the lubricating-water supply line connecting a part downstream from the cooling-water pump on the cooling-water line and the compressor; and

a backup portion for supplying water to the lubricating-water supply line instead of supplying water from the cooling-water line when the cooling-water pump is not driven; wherein

the backup portion includes an emergency lubricating-water supply line for supplying water in the evaporator to the lubricating-water supply line.

2. The refrigerator according to claim 1 , further comprising a utilization circuit including a circulating pump to thereby circulate water through the evaporator and a utilization heat exchanger,

wherein the emergency lubricating-water supply line connects a part downstream from the circulating pump on the utilization circuit and the lubricating-water supply line.

3. The refrigerator according to claim 1 , wherein the backup portion includes a regulation portion for permitting water to flow through the emergency lubricating-water supply line from the evaporator to the lubricating-water supply line while preventing water from flowing through the emergency lubricating-water supply line from the lubricating-water supply line to the evaporator.

4. A refrigerator, comprising:

a compressor for compressing water vapor as a refrigerant;

a condenser for condensing a refrigerant compressed by the compressor;

an evaporator for evaporating a liquid refrigerant condensed by the condenser;

a cooling-water line including a cooling-water pump to thereby send water for cooling a refrigerant in the condenser;

a lubricating-water supply line supplying water from the cooling-water line to the compressor as a lubricant for a bearing of the compressor, the lubricating-water supply line connecting a part downstream from the cooling-water pump on the cooling-water line and the compressor; and

a backup portion for supplying water to the lubricating-water supply line instead of supplying water from the cooling-water line when the cooling-water pump is not driven,

wherein

the backup portion includes:

an emergency lubricating-water supply line for supplying water in the evaporator to the lubricating-water supply line;

a regulation portion for permitting water to flow through the emergency lubricating-water supply line from the evaporator to the lubricating-water supply line while preventing water from flowing through the emergency lubricating-water supply line from the lubricating-water supply line to the evaporator;

wherein, in the emergency lubricating-water supply line, the differential pressure of a pressure on the evaporator side when the cooling-water pump is driven with respect to a pressure on the lubricating-water supply line side when the cooling-water pump is driven is set below a predetermined value; and

if the differential pressure is below the predetermined value, the regulation portion prevents water from flowing from the evaporator side to the lubricating-water supply line side.

5. The refrigerator according to claim 1 , wherein the lubricating-water supply line is provided with a back-flow regulation portion for preventing water supplied from the emergency lubricating-water supply line from being leaded to the cooling-water line.

6. A refrigerator, comprising:

a compressor including a compression portion, a rotating shaft attached to the compression portion, and a bearing axially supporting the rotating shaft, for compressing water vapor as a refrigerant by the rotating of the rotating shaft;

a condenser for condensing a refrigerant compressed by the compressor;

an evaporator for evaporating a liquid refrigerant condensed by the condenser;

a cooling-water line including a cooling-water pump to thereby send water for cooling a refrigerant in the condenser;

a lubricating-water supply line supplying water from the cooling-water line to the compressor as a lubricant for the bearing of the compressor, the lubricating-water supply line connecting a part downstream from the cooling-water pump on the cooling-water line and the compressor; and

a backup portion for supplying water to the lubricating-water supply line instead of supplying water from the cooling-water line when the cooling-water pump is not driven; wherein

the backup portion includes a storage tank arranged on the lubricating-water supply line for storing water and supplying the stored water to the lubricating-water supply line, a storage quantity detecting portion for detecting a stored-water quantity in the storage tank and a regulating portion for regulating a water quantity supplied to the storage tank; and

the regulating portion supplies a water quantity to the storage tank in such a way that the stored-water quantity in the storage tank detected by the storage quantity detecting portion is equal to or larger than the quantity of the lubricant to be supplied to the compressor until the compressor actually stops after receiving a stop command.

7. The refrigerator according to claim 6 , wherein the storage tank is connected to the cooling-water line and supplied with water from the cooling-water line.