Cooling device and method for magnetic resonance imaging system

1. A cooling device for a magnetic resonance imaging (MRI) system, the cooling device comprising:

a refrigerant for subjecting the MRI system to refrigeration;

at least one motive power component for driving the refrigerant to perform a refrigeration cycle based on a step frequency signal; and

a regulation unit for driving the refrigerant based on a pre-collected cooling power demand corresponding to a state of the MRI system, wherein the regulation unit is configured to determine the step frequency signal for the at least one motive power component based on the cooling power demand.

2. The cooling device as claimed in claim 1 , further comprising a frequency converter for regulating a rotation speed of the at least one motive power component based on the step frequency signal to drive the refrigerant to perform the refrigeration.

3. The cooling device as claimed in claim 1 , wherein the refrigeration cycle comprises a cooling liquid loop acting on the MRI system.

4. The cooling device as claimed in claim 3 , wherein the regulation unit is also configured for acquiring in real-time a cooling liquid temperature returned by the cooling liquid loop and further regulating the step frequency signal according to the cooling liquid temperature.

5. The cooling device as claimed in claim 1 , wherein the state comprises a sequence scan state, a standby state or a shutdown state.

6. An MRI system comprising:

a control unit configured to send a state of the MRI system to a regulation unit;

a refrigerant for subjecting the MRI system to refrigeration;

at least one motive power component for driving the refrigerant to perform the refrigeration cycle based on a step frequency signal; and

the regulation unit for driving the refrigerant based on a pre-collected cooling power demand corresponding to the state of the MRI system, the regulation unit configured to determine the step frequency signal for the at least one motive power component based on the cooling power demand.

7. The MRI system as claimed in claim 6 , further comprising a frequency converter for regulating a rotation speed of the at least one motive power component based on the step frequency signal to drive the refrigerant to perform the refrigeration.

8. The MRI system as claimed in claim 6 , wherein the refrigeration cycle comprises a cooling liquid loop acting on the MRI system.

9. The MRI system as claimed in claim 8 , wherein the regulation unit is also configured for acquiring in real-time a cooling liquid temperature returned by the cooling liquid loop and further regulating the step frequency signal according to the cooling liquid temperature.

10. A cooling method for an MRI system, the method comprising:

determining a state of the MRI system; and

based on a pre-collected cooling power demand corresponding to the state of the MRI system, driving a refrigerant to subject the MRI system to refrigeration

based on the cooling power demand, determining a step frequency signal for making at least one motive power component of a cooling device run, the motive power component driving the refrigerant to perform the refrigeration based on the step frequency signal.

11. The cooling method as claimed in claim 10 , wherein the refrigeration comprises using a cooling liquid loop to act on the MRI system.

12. The cooling method as claimed in claim 11 , the method further comprising: acquiring in real time a cooling liquid temperature returned by the cooling liquid loop, and further regulating the step frequency signal according to the cooling liquid temperature.

13. The cooling method as claimed in claim 10 , wherein the state comprises a sequence scan state, a standby state or a shutdown state.