Central air conditioning energy-saving control system

1. Introduction to the Design of Energy saving Control System for Central Air Conditioning

The working process of central air conditioning system is an energy conversion process that continuously exchanges heat, which transfers the heat load to the atmosphere through water medium and refrigerant medium. Therefore, maintaining the balance of energy transfer throughout the entire system is a necessary condition.

The XBZD-KD series central air conditioning energy-saving system collects operational data from various parts of the air conditioning system through various sensors, including chilled water inlet temperature, chilled water outlet temperature, cooling water inlet temperature, cooling water outlet temperature, and chilled water pressure difference (due to significant differences in actual operating conditions of the central air conditioning system, the above parameters are collected as required), and sends them to the PLC for comprehensive calculation; Then transmit the air conditioning load parameters to the coil fan cabinet, refrigeration pump energy-saving cabinet, cooling pump energy-saving cabinet, and cooling tower fan energy-saving cabinet. The energy-saving cabinets for refrigeration pumps, cooling pumps, and cooling tower fans use frequency conversion equipment to control the operation of coil fans, refrigeration pumps, cooling pumps, and cooling tower fans according to the energy of air conditioning load, so that the energy of air conditioning load is balanced and transmitted in each subsystem, reducing operating energy consumption.

This system can also expand communication with office PCs to achieve remote monitoring.

2. Characteristics of energy-saving central air conditioning energy-saving system

(1) The XBZD-KT system breaks through the traditional operation mode of the central air conditioning refrigerant system by achieving load tracking of the air conditioning system. Through dynamic monitoring and closed-loop control of the central air conditioning energy operation system, the fixed flow operation of the air conditioning unit is changed to variable flow operation, realizing that the refrigerant flow of the air conditioning unit changes synchronously with the end load demand. Under any load condition of the air conditioning system, it can ensure the comfort of the central air conditioning system while achieving energy savings of 10% -15% for the unit and 30% -70% for the fan and water pump.

(2) The basic idea of the XBZD-KT system to ensure that the air conditioning unit always maintains high thermal conversion efficiency is to control the operation of the central air conditioning system according to the optimal operating parameters required by the central air conditioning unit. Based on the operating conditions of the system and changes in the refrigerant parameters, the intelligent controller dynamically adjusts the operating parameters of the air conditioning system to ensure that the air conditioning unit is always at the optimized optimal working point, so that the unit always maintains high thermal conversion efficiency.

(3) Effectively balancing the energy load of central air conditioning and transferring it to the central air conditioning system is a complex system engineering. To achieve optimal operation and energy conservation of the central air conditioning system, it is impossible to solve the problem locally (such as using a universal frequency converter PID control). It is necessary to consider and comprehensively control all aspects of the air conditioning system, including the main unit, refrigerant water system, cooling water system, cooling air system, etc., in order to ensure coordinated operation of the entire system and effective balance of load energy transmission, in order to achieve optimal comprehensive energy conservation.

(4) Multi parameter control, safe and reliable operation

① Overcoming the oscillation of the central air conditioning system: The XBZD-KT system adopts various intelligent sensors and multi parameter intelligent control to comprehensively monitor the operating status of the central air conditioning. When external disturbances (such as load changes) occur in the system, it can adaptively adjust the operating parameters and transition process parameters of the air conditioning system, so that the system can quickly approach a new optimized operating state without causing oscillation, and the system runs stably and reliably.

② Overcoming the problem of severe wear and tear on water pumps and fans: using frequency conversion to continuously adjust the speed of fans and water pumps, greatly reducing the speed, reducing mechanical and bearing wear, lowering the failure rate, and extending the service life of equipment.

③ Comprehensive protection functions: The XBZD-KT system is equipped with the following protection functions:

Ⅰ. Electrical protection: overvoltage protection, overcurrent protection, overload protection, etc.

Ⅱ. Mechanical protection: Variable frequency soft start and soft stop function, reducing mechanical and electrical shocks.

Ⅲ. Temperature protection: Low temperature and low flow protection of refrigerant water effectively prevents the evaporator of the air conditioning unit from freezing.

Ⅳ. Electromagnetic interference protection: The software and hardware design of the XBZD-KT system fully considers the electromagnetic compatibility of the product and adopts a series of anti electromagnetic interference measures to ensure the reliable operation of the system.

Ⅴ. Operation permission protection: The system has set up operation permission management function, which can effectively prevent unauthorized personnel from unintentionally or intentionally accessing the system, ensuring the security of system data collection, transmission, storage, and use.

(5) Humanized design, easy to use and operate

The XBZD-KT system follows the humanized design concept of "people-oriented", and the software and hardware design of the system is based on the convenience of user operation and use.

3. Control Function Characteristics of Energy saving Central Air Conditioning Energy saving System

★XBZD-KTEight Innovative Technologies for Central Air Conditioning Energy Management and Control System
◆ Load dynamic pre judgment control technology
Regional cooling balance control technology
Optimal combination control technology for pump units
Dynamic bidirectional variable flow control technology
◆ Host small temperature difference compensation control technology
Host group control technology based on COP optimization
The optimal temperature control technology for cooling water
Variable air volume cascade control technology for cooling towers

★XBZD-KTControl function of central air conditioning energy management control system
▲ Realize automatic control and intelligent management of the entire central air conditioning system equipment
——Realize remote start stop, operation status, and centralized monitoring of all controlled equipment such as chillers, circulating water pumps, cooling towers, valves, etc;
——Implement fault alarm monitoring for all controlled equipment such as chillers, circulating water pumps, cooling towers, valves, etc;
——Implement soft interlock switch control for all controlled equipment such as the host, circulating water pump, cooling tower, valves, etc;
——Real time display and operation recording of the host, circulating water pump, and cooling tower equipment;
——The system implements multi-level control, including ordinary level, operator level, administrator level, and engineer level, to ensure the security of the system;
——The system can achieve multiple control modes, including intelligent mode, single machine linkage mode, and administrator mode;
——The system can achieve automatic switching between primary and backup devices;
——Realize automatic control and save manpower;
——Realize the protection of equipment and extend its lifespan;
——Realize cumulative device operating time and promptly remind users to perform device maintenance;

▲ Realize energy conservation, consumption reduction, and optimization of central air conditioning system equipment
——Implement a host group control strategy with high overall efficiency of air conditioning, to maximize the overall efficiency of the entire air conditioning system equipment;
——Realize the dynamic hydraulic balance adjustment function of air conditioning system based on energy optimization;
——Implement variable flow regulation technology for chilled water pumps based on improving the overall efficiency (COP) of air conditioning system equipment, achieving high efficiency and energy conservation;
——Implement control technology for variable air volume of cooling tower fans based on improving the overall efficiency (COP) of air conditioning system equipment, achieving high efficiency and energy conservation;
——Energy management control system overall air conditioning COP online monitoring interface
——Energy Management Control System Energy Management Center Historical Data Query Interface

★XBZD-KTRemote login of central air conditioning energy management control system

★ Characteristics of XBZD-KT Central Air Conditioning Energy Management Control System
◆ Advanced technology
The XBZD-KT central air conditioning energy management control system fully utilizes the latest technological achievements of contemporary times, adopting fuzzy control technology with intelligent control functions and the ability to perform knowledge processing and reasoning similar to the human brain. It is more in line with the complexity, dynamics, and fuzziness of central air conditioning and is currently the most advanced central air conditioning control system in the world.
◆ Efficient and energy-saving
The XBZD-KT central air conditioning energy management control system is based on system comprehensive optimization control. By comprehensively collecting and analyzing the operating information of the entire system, it achieves matching and coordinated operation of the water system and air system, and optimizes the comprehensive performance of the entire system under variable load conditions. It can ensure that the air conditioning system can operate efficiently under any load condition, minimize the energy consumption of the air conditioning system, and reduce the energy consumption of the air conditioning system by 25% to 40%.
◆ Safe and reliable
Meeting the time-varying and dynamic requirements of central air conditioning, and providing multiple safety protections such as temperature, flow rate, and pressure, it can effectively ensure the safe and stable operation of air conditioning equipment under variable flow conditions.
◆ Easy to operate
The XBZD-KT central air conditioning energy management control system follows the concept of humanized design and adopts a fully Chinese graphical user interface. The system operation is fast, convenient, and easy to understand, learn, and use.
Good openness and scalability
The XBZD-KT central air conditioning energy management control system provides open OPC interfaces and hardware interfaces, with good compatibility and openness, and can be integrated with any third-party system that supports OPC protocol to achieve information exchange and resource sharing.