Magnetic Bearing Chiller for King Oyster Mushroom Farming: 40% Energy Savings and Stable Yield Growth

1. Temperature Requirements for King Oyster Mushroom Growth

The cultivation cycle lasts approximately 50–60 days.

Mycelium Growth Stage

1.Growth range: 10–30°C

2.Optimal temperature: 22–25°C

3.Below 15°C or above 25°C: growth slows

4.Below 10°C or above 30°C: growth stops

Primordia Differentiation & Fruiting

1.Differentiation temperature: 12–18°C

2.Optimal range: 15–17°C

3.Day-night temperature difference: 3–5°C

4.Fruiting development: 15–20°C

5.Above 22°C: elongated stems, soft tissue, contamination risk

6.Below 12°C: slow growth, darker cap color

Additional control requirements:

1.Humidity: 85–90%

2.CO₂ concentration: <800 ppm

Precise coordination of temperature, humidity, and ventilation is essential.

2. Project Background

The project is located in Xingtai, Hebei Province, with an annual capacity of 2,000 tons.

Climate challenges:

1.Summer temperatures up to 38°C

2.Winter temperatures as low as -10°C

Existing piston chillers had:

1.COP of 3.2

2.Electricity costs exceeding 1.5 million RMB annually

3.High maintenance cost

4.Large temperature fluctuations

Summer overheating caused deformities and yield loss

3. System Solution: Magnetic Bearing Centrifugal Chiller

The project adopted a dedicated mushroom cultivation magnetic bearing centrifugal chiller as the central cooling system.

Operating Principle

1.Produces 7°C chilled water

2.Delivered via circulation pumps to fan coil units

3.Air-water heat exchange reduces room temperature

4.Return water at 12°C recirculated

5.This creates a stable and energy-efficient cooling loop.

4. Technical Advantages

Energy Efficiency

1.Oil-free magnetic bearing technology

2.90% reduction in friction loss

3.IPLV up to 10.5

4.Over 40% electricity savings

5.Variable frequency control (10%–100%)

Precise Environmental Control

1.Water fluctuation: ±0.5°C

2.Room accuracy: ±0.8°C

3.Humidity variation ≤5%

Low Maintenance

1.No lubrication oil

3.60% maintenance cost reduction

5. Economic Benefits

After implementation:

1.Annual electricity savings: RMB 600,000

2.Maintenance savings: RMB 150,000

3.Total annual savings: RMB 750,000

4.Investment payback period: 2 years

The stable cooling system significantly improved product quality and yield consistency.