Circulating Water Pumps - Motor Upgrade
Background
The main products of the pump industry include various centrifugal pumps, mixed flow pumps, axial flow pumps, vortex pumps, rotary positive displacement pumps, reciprocating positive displacement pumps and water ring vacuum pumps. The motors equipped with existing pumps are mainly three-phase asynchronous motors, which have a narrow overall economic operation range and high energy consumption. Most of them implement IE1 or IE2 energy efficiency standards. The motors with energy efficiency levels of IE2 and below are insufficient in energy consumption, carbon emissions, operating stability and intelligence level, and can no longer adapt to the increasingly stringent energy efficiency and environmental protection requirements in the world. Driven by the global energy transformation and carbon neutrality goals, upgrading to higher energy efficiency levels (such as IE3, IE4, IE5, etc.) has become a necessary choice for enterprises to reduce energy consumption, reduce carbon emissions, improve economic benefits and meet international standards.
Equipment Introduction
The HVAC circulating water pump is a key device used in the HVAC system. It is mainly responsible for circulating water in the system for heat exchange and temperature control. Its main applications include delivering hot water from the boiler to the radiator or floor heating system to achieve indoor heating; delivering cooling water from the cooling tower to the cooling coil or air conditioning unit of the air conditioning system to help reduce the indoor temperature. HVAC circulating water pumps are usually equipped with three-phase asynchronous motors, and the most common ones are asynchronous motors with IE2 energy efficiency ratings. However, this type of motor has some problems in actual operation:
1.The energy efficiency of IE2 motors is low, and they are usually less efficient under low load and partial load conditions, resulting in energy waste;
2.The operating power of IE2 motors is large, and the efficiency range is narrow, which often requires more frequent maintenance and higher operating costs
3.The IE2 motor lacks intelligent adjustment capabilities and cannot adjust the speed in real time according to load changes, further reducing the operating efficiency of the overall system.
Working Condition Introduction
① Load characteristics
Pumps and fans belong to the same type of fluid variable torque load, square torque. That is, the flow rate is proportional to the speed, the torque or water pressure is proportional to the square of the speed, and the shaft power is proportional to the cube of the speed. Low-speed load torque is small, the output power is small, high-speed load torque is large, and the output power is large; according to the actual working conditions, 3000rpm motors are generally used in cases where the head is slightly high and the flow rate is not large. 1500rpm motors can be selected for occasions with large flow and small head. For ultra-large flow and low head, choose 1000rpm motors. When choosing a 1000rpm motor, the power can be reduced by one level according to the shaft power.
② Starting characteristics
The working characteristics of the water pump are relatively small starting torque, relatively low starting frequency, and relatively long continuous operation time. The motor may be in a free rotation state before starting, and the speed tracking start is required, which is also called flying start. In simple terms, it is to start the rotating motor.
③ Power configuration
The common selection and design margin of water pumps in the stock market are large and the efficiency is low. The commonly used power configuration adopts industrial frequency direct drive or three-phase asynchronous motor + inverter solution. The motor has low energy efficiency, a narrow high-efficiency range, often runs in the low-efficiency range, and the comprehensive electricity economy is poor.
Haichuan Electric Solution
In order to improve the energy efficiency of the water pump system and meet the latest energy efficiency standards, we replaced the existing three-phase asynchronous IE2 motor with Haichuan HCM5 magnetic assisted synchronous reluctance motor. The HCM5 motor has IE5-level energy efficiency and can operate efficiently in a wider load range. Compared with traditional asynchronous motors, it can reduce energy consumption and reduce operating costs.
The specific replacement process includes the following steps: First, remove the original asynchronous IE2 motor, and check and clean the motor mounting base to ensure the smooth installation of the new motor; then, select an HCM5 motor with appropriate power to ensure that the motor can maintain an efficient working range under different loads. The motor power is usually determined based on the head and flow of the water pump.
The advantages after replacement are mainly reflected in the following aspects:
Improved energy efficiency: HCM5 motors have higher energy efficiency, especially under partial load, which far exceeds traditional asynchronous motors, can reduce overall energy consumption and save electricity bills.
Environmental benefits: Higher energy efficiency means less energy waste, which helps reduce carbon emissions and supports enterprises in achieving carbon peak and carbon neutrality goals.
Stability and reliability: HCM5 motors use magnetic-assisted synchronous reluctance technology, which has higher stability, reduces vibration and noise, and extends the service life of motors and related equipment.
Low maintenance cost: The motor operates in a more efficient range, reducing the risk of system overload and failure probability, and reducing maintenance and repair costs.
In summary, upgrading to the Haichuan HCM5 magnetically assisted synchronous reluctance motor can not only improve the operating efficiency and reliability of the water pump system, but also bring significant economic and environmental benefits to the enterprise.