Marine Cast Steel Cooling Water Pump

I. Product Overview

Marine cast steel cooling water pumps are the "heat dissipation core" of ship power systems, specifically designed for cooling cycles of equipment such as diesel engines, gas turbines, and generators. Constructed with high-strength alloy cast steel (WC6) or carbon cast steel (WCB), they achieve efficient circulation of seawater, freshwater, or antifreeze through centrifugal pump principles. Their working principle involves a power source (electric motor or diesel engine) driving an impeller to rotate, generating centrifugal force to draw cooling medium from water tanks or overboard, pressurize it, and deliver it through equipment cooling channels to absorb heat, then discharge it overboard or to coolers for temperature reduction, forming a closed-loop heat dissipation system. The pump body undergoes integral forging and anti-corrosion treatment, with a corrosion-resistant service life of ≥10 years in seawater and industrial coolants. It meets the IMO International Convention for the Safety of Life at Sea (SOLAS) and certification requirements of classification societies such as LR and ABS, widely used in cooling systems for power equipment on cargo ships, oil tankers, passenger ships, and offshore platforms.

II. Core Technologies and Material Characteristics

1.Cast Steel Material Selection and Performance

2.Key Technical Parameters

Flow range: 50-500m³/h, suitable for equipment power 1000-30,000kW

Head coverage: 10-60m, meeting the pressure requirements for conveying from cooling medium sources to equipment cooling chambers

Medium compatibility: Capable of conveying seawater (with Cl⁻≤35,000ppm), freshwater, and ethylene glycol antifreeze (concentration ≤50%)

Corrosion resistance design: Seawater cooling models adopt duplex stainless steel impellers + epoxy resin coatings (thickness ≥300μm), passing 2000-hour salt spray tests without rust

Temperature adaptability: Wide-temperature operation at -20℃~120℃; high-temperature models can withstand short-term 150℃ medium impact (e.g., abnormal equipment overheating)

3.Safety Heat Dissipation Design

Equipped with flow monitoring devices, automatically alarming when cooling medium flow drops below 80% of the rated value to prevent equipment overheating

Shaft seals adopt a "mechanical seal + cooling jacket" combined structure, with seal chamber temperature ≤80℃ and leakage ≤2mL/h

III. Technical Advantages and Innovative Design

1. Efficient Heat Dissipation Capacity

Dual-flow impeller design: Adopts symmetric double-suction impellers, increasing flow by 50% compared to single-suction pumps while balancing axial force, with vibration values ≤2.8mm/s, reducing equipment resonance losses.

Wide high-efficiency range optimization: Optimized volute curves through CFD flow field simulation, achieving efficiency ≥85% in the 60%-120% rated flow range, saving 15% energy compared to ordinary cooling pumps and adapting to heat dissipation needs under variable equipment operating conditions.

2. Extreme Environment Adaptability

Enhanced seawater corrosion resistance: Seawater cooling pump bodies adopt WC6 alloy cast steel + aluminizing treatment, with Cr and Mo element content over 12% and pitting resistance equivalent (PREN) ≥30, doubling service life in high-salinity sea areas.

Anti-cavitation and dry-running protection: A spiral inducer is installed at the inlet to reduce net positive suction head (NPSH) by 30%, avoiding cavitation at low liquid levels; equipped with dry-running sensors, automatically shutting down within 3 seconds of dry operation to protect impellers and seals.

3. Long Life and Low Maintenance

Wear-resistant flow components: Impellers use high-chromium cast iron (Cr26) with hardness up to HRC58, 3 times more wear-resistant than ordinary cast steel, capable of conveying seawater with sand content ≤1% without significant wear.

Modular structure: Pump covers and bodies adopt quick-opening flange connections, allowing replacement of mechanical seals without disassembling pipelines, with single maintenance time ≤1 hour, 70% shorter than traditional structures.

IV. Typical Application Scenarios

1. Main Engine and Power Equipment Cooling

Low-speed diesel engine cooling: 150,000-ton cargo ship main engines are equipped with two WC6 alloy cast steel cooling water pumps (single pump flow 300-500m³/h) with head 40m, controlling main engine cylinder liner temperature at 85±5℃ through seawater circulation to ensure combustion efficiency.

Gas turbine heat dissipation: LNG carrier gas turbines use high-temperature cooling water pumps with flow 100-200m³/h and pressure 3.0MPa, conveying cooling medium (ethylene glycol solution) to turbine blade cooling channels and withstanding 120℃ medium temperatures.

2. Auxiliary Engines and Power Generation Systems

Generator set cooling: Cruise ship diesel generators are matched with carbon cast steel cooling water pumps, with flow 50-100m³/h and head 20m, controlling generator stator temperature at 65±3℃ through freshwater circulation to ensure power generation stability.

Propulsion motor cooling: Propulsion motors of electric propulsion ships adopt dual-pump parallel cooling systems, with single pump flow 80-150m³/h and pressure 1.6MPa, adapting to heat dissipation needs during instantaneous motor overload.

3. Special Vessels and Platforms

Polar ship low-temperature cooling: In -30℃ environments, through pump body insulation and antifreeze heating designs, cooling systems are prevented from freezing, with cooling water pumps starting within 30 seconds to dissipate heat for icebreaker power systems.

Drilling platform compressor cooling: Offshore platform air compressors are equipped with salt spray-resistant cooling water pumps, with flow 60-120m³/h, operating stably in high-humidity, high-salt spray environments, controlling compressor discharge temperature within 100℃.

V. Selection and Maintenance Specifications

1. Key Selection Parameters

Cooling medium: WC6 alloy cast steel + duplex stainless steel impellers for seawater cooling; WCB carbon cast steel for freshwater/antifreeze

Heat dissipation requirements: Configure flow at 1.2 times the equipment heat generation; e.g., 10,000kW main engines recommend flow ≥300m³/h (seawater) or ≥200m³/h (freshwater)

Environmental conditions: Large-flow models for tropical sea areas (high heat dissipation needs); -30℃ start-up models for polar regions; wear-resistant impeller models for sandy sea areas

2. Maintenance Key Points

Daily monitoring: Check outlet pressure (fluctuation ≤±0.1MPa), bearing temperature (≤75℃), and medium inlet-outlet temperature difference (≤15℃) every 500 hours

Regular maintenance: Clean suction filters monthly (seawater systems with precision ≤5mm); replace mechanical seals every six months (silicon carbide-silicon carbide materials for seawater models); inspect impeller wear annually (allowable deviation ≤0.5mm)

In-depth maintenance: Conduct water pressure tests (1.5 times the rated pressure) every 4 years; re-spray anti-corrosion coatings for seawater cooling pumps and inspect electrochemical protection (sacrificial anode effectiveness)

VI. Compliance and Certification

International standards: Complies with IMO SOLAS Convention Chapter II-1 and ISO 8791 cooling water pump performance standards

Classification society certifications: Passed type approval for cooling pumps by LR, ABS, CCS, and other institutions (including corrosion resistance, high-temperature, and safety tests)

Environmental requirements: Seawater cooling systems are equipped with anti-biofouling devices, meeting IMO anti-pollution requirements to prevent algae growth and pipeline blockage