Micro Magnetic Gear Pumps for Cooling Systems

The Suofu NP series micro magnetic gear pumps are characterized by leak-free operation, low flow rates, high pressure capability, a wide operating temperature range, ability to handle low to medium viscosity fluids as well as gas-liquid two-phase fluids, dry-run capability, strong self-priming ability, and minimal flow fluctuation under varying pressures, with control precision up to 0.5%. These performance characteristics make the NP series micro pumps widely applicable in many small-scale cooling and refrigeration systems. Suofu NP series micro magnetic gear pump products have been successfully applied in systems using traditional refrigerants such as R134a, R410a, R141b, R245fa, R1233zd, as well as various 3M fluorinated fluids.

Typical characteristics of Suofu NP series products and their applications in cooling/refrigeration systems:

1. Handling ultra-low viscosity, volatile fluids.

   Different cooling systems use different refrigerants and fluorinated fluids, which typically have low viscosity and are prone to volatilization. Pumps selected for such systems must possess excellent self-lubrication to ensure reliability within the cooling system. Particularly after prolonged system shutdown, a significant amount of gas may accumulate at the pump inlet. Upon restart, the pump must expel this gas under dry-run conditions (without lubrication), self-prime the subsequent liquid, and pressurize it into the working cycle. Pumps lacking dry-run or self-priming capabilities cannot function properly in such systems.

   During the design of the Suofu NP series micro magnetic gear pumps, the selected materials, gear profile, and manufacturing processes underwent repeated testing. Consequently, all NP series products can perform dry-running at high speeds for up to one hour without additional wear and can pressurize low-viscosity refrigerant fluids up to 20 bar for long-term stable operation. To ensure reliable performance, all Suofu NP series products are tested at their maximum operating speed under complete dry-run conditions.

2. High-precision temperature control systems.

   High-end chillers also have stringent requirements for temperature control precision. The flow rate of traditional centrifugal pumps fluctuates significantly with pressure changes, making precise flow control difficult. Due to their unique pump structure, gear pumps enable precise flow control. As evident from the comparison chart below, when the system pressure at the pump outlet fluctuates by 0.5 bar, the flow fluctuation of a centrifugal pump reaches 0.45 m³/h even at constant speed. In contrast, the Suofu micro magnetic gear pump experiences a flow fluctuation of less than 0.06 m³/h even with an outlet pressure fluctuation of 4 bar.

3. Low-flow, high-pressure microchannel cooling systems.

   Microchannel cooling systems refer to those with flow channel diameters ranging from 0.01 to 1 mm. Compared to conventional liquid cooling systems, micro heat exchangers are characterized by a very large heat transfer area per unit volume. Correspondingly, their volumetric heat transfer coefficient is 1 to 2 orders of magnitude higher than that of ordinary heat exchangers. However, the reduced fluid flow channels also lead to a significant increase in required pump outlet pressure, typically from around 1 bar (approximately 10 meters of head) to 3-6 bar or even higher. The combination of low flow and high pressure parameters is ideal for leveraging the performance of gear pumps.

4. High pressure resistance.

   Some refrigerant systems operate at relatively high pressures, reaching 40-60 bar. Suofu NP series products, rated for 100 bar pressure, are well-suited for such high-static-pressure systems.

5. Leak-free operation.

   Suofu magnetic gear pumps use a magnetic coupling, eliminating the dynamic seals that are prone to leakage. Furthermore, the NP series can provide fully welded pump bodies with no static seals. For highly integrated systems, low failure rates and maintenance-free operation offer great convenience. Suofu series products use high-grade rare-earth magnets as drive components, providing zero-leakage service within a temperature range of -120 to 150°C.

6. Extremely wide operating temperature range.

   Standard Suofu micro magnetic pumps can operate within -40 to 150°C. Customized products can work within a range of -120 to 150°C.

7. The NP series micro pump products can be customized according to different client needs. Options include dry installation or submerged pump head installation, and they can be paired with DC brushless motors, AC variable frequency motors, or servo motors. The structural form of the pump body and motor can be custom-designed to meet various system requirements regarding product dimensions, port orientations, power supply types, and control methods.

In practical system applications, to ensure the cleanliness of the conveyed fluid for magnetic gear pumps, it is recommended to install a filter with a rating of at least 400 mesh at the pump inlet. The nominal flow rate of the filter should be 1.5 to 2 times greater than the pump's flow rate.

Parameters such as pump inlet pipe diameter, layout, degree of subcooling, insulation, and pump operating speed significantly impact the stable operation of systems using refrigerants. Suofu has accumulated considerable practical experience in these areas and can provide customization during selection based on specific application requirements.