Energy management system and energy consumption monitoring solutions

1 Overview

The energy management system is an information management and control system that aims to help industrial production enterprises to reasonably plan and use energy while expanding production, reduce energy consumption per unit product, and improve economic benefits.

Through energy planning, energy monitoring, energy statistics, energy consumption analysis, key energy-consuming equipment management, energy metering equipment management and other means, enterprise managers can accurately grasp the proportion of energy costs and development trends of enterprises, and decompose the energy consumption planning tasks of enterprises to various production departments and workshops, so that the responsibility for energy conservation work is clear and the healthy and stable development of enterprises is promoted.

Basic management functions of energy management system:

● Monitoring of the operating status of the main equipment of the energy system
● Centralized control, operation, adjustment and parameter setting of the main equipment of the energy system
● Realization of comprehensive balance, reasonable allocation and optimal scheduling of the energy system.
● Abnormal, fault and accident handling.
● Basic energy management.
● Real-time short-term archiving, database archiving and instant query of energy operation flow data.

In China's energy consumption, industry and large public buildings are the major energy consumers in China, and their energy consumption accounts for about 70% of the total national energy consumption. The process flow, device conditions, product types and energy management levels of different types of industrial enterprises will have different effects on energy consumption. Building a centralized and unified energy management system for the entire plant can complete the online collection, calculation, analysis and processing of energy data, thereby playing an important role in energy material balance, scheduling and optimization, energy equipment operation and management, etc. The

energy management system (EMS) is an important part of the enterprise information system. Therefore, in the architecture of the enterprise information system, energy management is regarded as a basic application component in the MES system. As an important part of the automation and informatization of large enterprises, Acrel's Acrel-5000 product, with a real-time database system as the core, can provide an overall EMS solution from data collection, networking, massive storage of energy data, statistical analysis, query, etc., so that the company's dispatching management personnel can directly control and adjust the dynamic balance of the system in real time in the energy control center to achieve the purpose of energy saving and consumption reduction.

2 System Software The

Acrel-5000 energy consumption monitoring system uses computers, communication equipment, and measurement and control units as basic tools, providing a basic platform for real-time data collection, switch status monitoring, and remote management and control of large public buildings. It can form any complex monitoring system with detection and control equipment. The system mainly adopts a hierarchical distributed computer network structure, which is generally divided into three layers: station control management layer, network communication layer and field equipment layer, as shown in Figure 1.

Figure 1 System structure diagram

1) Station control management layer

The station control management layer is the direct window of human-computer interaction for the management personnel of the energy consumption monitoring system, and is also the top layer of the system. It is mainly composed of system software and necessary hardware equipment, such as industrial-grade computers, printers, UPS power supplies, etc. The monitoring system software has a good human-computer interaction interface, calculates, analyzes and processes various types of data information collected on site, and reflects the operating status of the site in the form of graphics, digital display, sound, etc.

Monitoring host: used for data collection, processing and data forwarding. Provides data interface for the system or outside to carry out
system management, maintenance and analysis.
Printer: The system calls for printing or automatically prints graphics, reports, etc.
Simulation screen: The system exchanges data with the intelligent simulation screen through communication to display the operating status of the entire system.
UPS: Ensure the normal power supply of the computer monitoring system, and ensure the normal operation of the station control management layer equipment when there is a power supply problem in the entire system.

2) Network communication layer

The communication layer is mainly composed of communication management machine, Ethernet equipment and bus network. This layer is a bridge for data information exchange. It is responsible for collecting, classifying and transmitting the data information sent back by the on-site equipment, while conveying various control commands of the upper computer to the on-site equipment.
Communication management machine: It is the data processing and intelligent communication management center of the system. It has the functions of data acquisition and processing, communication controller, front-end machine, etc.
Ethernet equipment: It includes industrial Ethernet switches.
Communication media: The system mainly uses shielded twisted pair, optical fiber and wireless communication, etc.

3) Field equipment layer

The field equipment layer is the data acquisition terminal, which is mainly composed of intelligent instruments. It uses a distributed I/O controller with high reliability and field bus connection to form a data acquisition terminal to upload the stored building energy consumption data to the data center. The measuring instrument is responsible for the most basic data collection task. The energy consumption data it monitors must be complete, accurate and transmitted to the data center in real time. [page]

3 Functions of energy management system and energy consumption monitoring system

3.1 Energy management function

3.1.1 Data collection and storage

Data collection and storage are the basis of the entire system. Without a large amount of data, effective analysis cannot be carried out, and without effective analysis, correct energy management measures cannot be obtained. Data can be collected through the building equipment management system (BAS system). The
data content mainly includes: building environmental parameters, equipment operation status parameters, energy consumption data of each equipment, etc. The more parameters are obtained and the longer the operation cycle is, the easier it is to get an accurate conclusion. However, if there are too many parameters, the construction cost will increase significantly. Therefore, the data can be divided into basic data and auxiliary data (optional data) required for system operation according to the specific situation of each building, so as to strike a balance between management effect and construction cost.

3.1.2 Building reference model and energy consumption calculation

According to the definition of "energy conservation" proposed by the World Energy Commission in 1979: take all measures that are technically feasible, economically reasonable, environmentally and socially acceptable to improve the utilization efficiency of energy resources. That is, reduce energy consumption as much as possible to produce the same quantity and quality of products as before; or use the same amount of energy consumption to produce more or equal quantity and better quality products than before. Extending from this, energy conservation of buildings can be defined as: minimizing energy consumption without affecting the function and comfort of the building. Therefore, to judge whether a building is energy-saving or not, and how much energy it saves, a reference is needed, and a conclusion can be drawn by comparing with the reference. For renovated buildings, historical energy consumption data under the same climatic conditions can usually be used as a reference. New buildings are relatively complex. The following methods are commonly used in actual projects:

Analogy method: The energy consumption of buildings with similar types, scales and functions is used as a reference. It is mainly applicable to buildings under the same group or management company with similar building conditions and the same management model, such as chain hotels, chain supermarkets, and chain shopping malls.

Test method: After the building is operating normally, the daily energy consumption with and without energy management measures is tested under various climatic conditions. Usually, several days can be selected in summer and winter, and the alternate-day test method can be adopted, that is, on the first day, the daily energy consumption with energy management measures is tested; on the second day, the energy management software is turned off to test the daily energy consumption; and so on. The disadvantage of this method is that the time span of the test is relatively long.

Calculation method: By building a model for the building, setting parameters, and simulating and calculating the energy consumption of the building. The advantages of this method are obvious. The model can comprehensively calculate the energy consumption of various equipment in the building and provide directional guidance for energy management. However, there are differences in the energy consumption values ​​calculated by different software. At present, there are disputes over the accuracy and authority of the calculated energy consumption values. Whether the calculation results can be used as the basis for calculating the energy saving rate in the energy-saving contract is the main point of disagreement.

3.1.3 Energy consumption data analysis

Through statistics and analysis of building energy consumption data, combined with model building energy consumption comparison, determine the building energy consumption comparison, determine the building energy consumption status and equipment energy consumption efficiency, and provide building energy management optimization measures. The energy consumption data analysis module is the essence of energy consumption management software. At present, the algorithms of various software on the market are different, and their effects still need to be verified by the market. However, the development of computer intelligent control technology based on fuzzy language variables and fuzzy logic reasoning will greatly promote the level of energy management.

3.1.4 Energy control and management

Building energy-saving measures are mainly implemented through the building equipment management system (BAS system). The perfect combination of energy management platform and BAS system is the guarantee for the realization of energy control and management measures. At present, energy management and BAS still belong to different intelligent systems, and the mutual integration of the two systems should be the direction of development of intelligent systems.

3.1.5 Energy management reports

use tables and pictures to reflect the energy use of buildings, equipment energy consumption, equipment operation efficiency, energy consumption history curves, etc. to meet the needs of different groups of people. The system should generally be able to provide WEB services, and authorized remote users can understand the energy usage status of the building through the browser.

3.2 Energy consumption analysis software function The

energy consumption data collection methods of Acrel-5000 building energy consumption analysis management system include manual collection method and automatic collection method. The data collected through manual collection methods include basic building data collection indicators and other energy consumption data that cannot be collected automatically, such as the energy consumption of coal, liquefied petroleum, artificial gas, etc. consumed by the building. The data collected through automatic collection methods include building sub-item energy consumption data and classified energy consumption data, which are collected in real time by automatic metering devices and transmitted to the data center in real time through automatic transmission methods.

3.2.1 The information management system of large public buildings or building buildings

provides a standard manual information entry interface, which can organize and enter the basic information of each monitored building, and supports the function of manually entering historical energy consumption data.

The database of Acrel-5000 building energy consumption analysis and management system is also established in full accordance with Document No. 114. According to the use function and energy consumption characteristics of the buildings, state office buildings and large public buildings are divided into the following 8 categories:

1. Office buildings 2. Shopping mall buildings
3. Hotel and restaurant buildings 4. Cultural and educational buildings
5. Medical and health buildings 6. Sports buildings 7.
Comprehensive buildings 8. Other buildings

3.2.2 Real-time monitoring

system for energy consumption data The collection station regularly collects the instrument parameters of each monitoring point and uploads them to the local building energy consumption analysis and management system database. Users can query the energy consumption monitoring situation in real time locally.

3.2.3 Building Classification Energy Consumption Analysis

System will classify and analyze building energy consumption while completing data processing and uploading. This part of the function complies with the definition of Document No. 114, that is, building energy consumption is classified into the following six categories:

1. Electricity consumption
2. Water consumption
3. Gas consumption (natural gas or coal gas)
4. Central heating heat consumption
5. Central cooling cooling consumption
6. Other energy applications (such as central hot water supply, coal, oil, renewable energy, etc.)

3.2.4 Electricity sub-item energy consumption analysis

Lighting socket electricity consumption: It is the electricity consumption of indoor equipment such as lighting and sockets in the main functional areas of the building. It mainly includes lighting and socket electricity, corridor and emergency lighting electricity, and outdoor landscape lighting electricity.
Air conditioning electricity consumption: It mainly includes electricity consumption of hot and cold stations and air conditioning terminals.
Power electricity consumption: It mainly includes electricity consumption of elevators, water pumps, and ventilators.
Special electricity consumption: It mainly includes information centers, laundry rooms, kitchen restaurants, swimming pools, gyms or other special electricity consumption.
The total energy consumption of a building is the sum of the standard coal volume converted from each category of energy consumption (except water consumption) of the building.
Total electricity consumption = ∑direct measurement value of each transformer total meterClassified
energy consumption = ∑direct measurement value of each category energy consumption
meterSub-item electricity consumption = ∑direct measurement value of each sub-item electricity meterElectricity
consumption per unit building area = total electricity consumption/total building areaElectricity
consumption per unit air-conditioning area = total electricity consumption/total air-conditioning area3.2.5Same-

and month-on-month analysis

of energy consumptionStatistics of hourly, daily and annual energy consumption of a building or area are displayed in different ways such as curves and bar graphs, and report output is supported.

3.2.6The building energy-saving auxiliary diagnosis

system can extract various energy consumption data for same- and month-on-month comparative analysis, establish benchmark values ​​and determine the energy consumption level of each monitoring point, propose a complete set of diagnostic processes for energy consumption improvement, and provide an energy consumption analysis report.

4 Conclusion

As the country's efforts to develop energy conservation and emission reduction are intensified, the Acrel-5000 building energy consumption management system uses modern measurement and control technology, data processing and communication technology, based on a complete energy consumption monitoring and management method, using distributed controllers and AC sampling technology, relying on a powerful high-flow and high-reliability communication network, to provide a comprehensive and professional solution for the full-time dynamic energy management and control of energy facilities such as industrial and civil buildings, production enterprises and large-scale infrastructure, so as to fully grasp the energy consumption details and energy consumption process of users' energy consumption facilities.

References:
[1] Shanghai Acrel Electric Co., Ltd. Product Manual. 2010.08 Edition.
[2] Nanjing Changjiang Urban Architectural Design Co., Ltd. Product Manual. (end)