Function of water pipe connected to circulating pump

In the automobile thermal management system, the water pipe connected with the circulating pump (usually referred to as electronic auxiliary circulating pump or coolant circulating pump) plays a key role in thermodynamics and fluid transmission, and its core role is to accurately control the coolant flow path, speed and heat exchange efficiency, so as to ensure that the engine, three electric systems (battery, motor and electronic control) and other key components maintain the optimal working temperature range. The functions of thermal management logic, system stability and energy efficiency optimization are described in detail as follows:

1. Build a controllable coolant circulation network.

Active heat exchange drive

The circulating pump is driven mechanically or electronically to provide directional flow power for the coolant. The water inlet and outlet pipes connected to the pump body form a closed loop, which ensures the continuous delivery of coolant from the low-temperature area (radiator/low-temperature heat exchanger) to the high-temperature components (engine block, battery module, drive motor), and realizes heat absorption, transfer and dissipation.

Multi-loop cooperative control

In new energy vehicles, the water pipe network is often divided into high-voltage battery cooling circuit, electric motor cooling circuit and passenger compartment temperature control circuit. The circulating pump cooperates with the valve through the branch pipeline to distribute the coolant flow as needed to avoid the temperature interference between different heat sources.

2. Realize dynamic temperature regulation

Cold start and quick warm-up

A small circulation path is established through the bypass water pipe, and the coolant bypasses the radiator and directly flows back to the heat source, which accelerates the preheating of the engine or battery, reduces the cold wear and improves the emission control efficiency.

Accurate heat dissipation under high temperature conditions

When the sensor detects the over-temperature of the components, the circulating pump increases the rotating speed, drives the coolant to circulate at high speed through the main cooling pipeline, and at the same time diverts heat to the auxiliary heat exchanger (such as air conditioner condenser) through the branch pipeline to ensure that the heat load of the system is within the safety threshold.

Intelligent temperature maintenance

The water pipe system integrating electronic thermostat and variable flow valve can adjust the flow direction and velocity of coolant according to real-time working conditions. For example, the hybrid vehicle closes the engine circuit in pure electric mode, and only maintains the cooling of the battery and motor; In extreme environment, multi-stage heat dissipation (air cooling+liquid cooling+refrigerant direct cooling) is started.

3. Ensure system pressure balance and medium integrity.

Pressure fluctuation buffer

The connecting water pipe of the expansion water tank can maintain the system pressure stability (usually 1.0~2.5 bar) by compensating the volume change of the cooling liquid due to thermal expansion and contraction, and prevent the water pipe from cracking or the pump body from cavitation due to sudden pressure change.

Gas removal and sealing protection

The layout design of water pipes (such as high-level exhaust passage) cooperates with the ventilation valve to exhaust the air mixed in the circulation in time to avoid air resistance reducing heat exchange efficiency. At the same time, high-pressure resistant pipeline materials (such as EPDM rubber+aramid reinforced layer) and the clamp sealing structure ensure no leakage at high temperature and high pressure.

4. Support energy efficiency optimization and fault redundancy.

Power supply on demand to reduce power consumption

The electronic circulating pump can be intelligently started/stopped or regulated according to the heat load, which can reduce parasitic energy loss compared with the traditional mechanical pump (for example, the power consumption of an electronic pump of a certain vehicle can be reduced by 60%), and directly improve the vehicle endurance (new energy vehicle) or fuel economy (traditional vehicle).

Redundant safety design

High-performance vehicles use double pumps in parallel or standby pipeline. When the main circulating pump fails, the standby pipeline will automatically switch to ensure the continuous flow of coolant and prevent the heat from getting out of control (such as battery pack thermal spread protection).

5. Adapt to complex working conditions and environmental challenges

Extreme temperature tolerance

The water pipe material should be elastic between -40℃ (cold start) and 150℃ (near the turbocharger) to avoid hardening, cracking or softening deformation. Silicone rubber hose (temperature -60℃~200℃) gradually replaces traditional rubber and becomes the first choice for high-performance vehicles.

Chemical corrosion resistance and vibration fatigue resistance

Compatibility design of coolant additives (ethylene glycol and corrosion inhibitor) with the inner wall of pipeline to prevent the inner layer from peeling off and blocking the flow passage; The pipeline is connected with flexible support to absorb engine vibration and body deformation stress and prolong service life.

Technical evolution and future trend

With the popularization of 800V high-voltage platform and intelligent domain control architecture, the circulating pump water pipe system presents integration and lightweight innovation;

Modular pipeline design: the pump body, valve body and sensor are embedded into the integrated cast aluminum manifold to reduce the connection nodes and potential leakage risks.

Intelligent leakage monitoring: built-in conductive layer or optical fiber sensor can detect pipeline leakage in real time and locate the fault point.

Ultra-low flow resistance topology optimization: 3D printed pipeline is designed based on CFD simulation to realize the optimal matching of flow channel shape and heat distribution.

summary

The water pipe system of automobile circulating pump is the "dynamic vein" of thermal management system, which plays a far more important role than basic fluid transportation, and undertakes multiple missions of thermodynamic regulation, system protection and energy efficiency optimization. From the traditional internal combustion engine to the electric platform, the precision of water pipe network directly determines the thermal efficiency, reliability and NVH performance of the whole vehicle. In the future, with the deep integration of material innovation and intelligent control technology, this system will continue to evolve in the direction of high response, low loss and self-adaptation.