Abstract : This paper takes the application of the Acrel-5000 energy consumption monitoring system in the SPA center of the Ramada Hotel project in Liuzhou as a case study. It introduces how the Acrel-5000 energy consumption monitoring system can achieve system integration of on-site equipment, data collection, transmission and storage, thereby realizing the classification and itemized energy consumption metering of buildings, and verifying the functionality and practicality of the system.
Keywords: Energy consumption monitoring, Acrel-5000 system integration, Liuzhou Ramada Hotel
1 Introduction
With the advancement of urbanization and economic development in China, the total energy consumption of buildings in the country has been continuously increasing, and the growth rate is accelerating. Currently, my country is the world's second-largest energy producer and consumer. Statistics show that building energy consumption accounts for approximately 28% of the country's total energy consumption. Of the 2 billion square meters of new buildings constructed annually in my country, 99% are high-energy-consuming buildings; while only 4% of existing buildings have adopted energy-saving measures. If building energy consumption continues to grow at this rate, it will inevitably put enormous pressure on China's energy supply security; therefore, building energy conservation is imperative. This article analyzes the energy consumption monitoring system of the Ramada Hotel SPA Center in Liuzhou, briefly introducing the application of the Acrel-5000 energy consumption monitoring system in hotel projects.
2 Design Basis
DGJ08-2068-2012 Technical Specification for Energy Consumption Monitoring System Engineering of Public Buildings in Shanghai
GB-T 15587-2008 Guidelines for Energy Management of Industrial Enterprises
GB 2009-2009 Guidelines for Evaluating Enterprises' Rational Electricity Use Technology
General Rules for the Preparation of Enterprise Energy Conservation Plans
General Technical Guidelines for Enterprise Energy Audits (GB)
GB/T 23331-2009 Energy Management System Requirements
GB-50052-2009 Code for Design of Power Supply and Distribution Systems
National and industry standards for energy consumption metering devices
DL/T 645-1997 Communication Protocol for Multifunctional Energy Meters
DL/T 645-2007 Communication Protocol for Multifunctional Energy Meters
CJ/T 188-2004 Technical Conditions for Data Transmission of Household Metering Instruments
GB/T 19582-2008 Industrial Automation Network Specification Based on Modbus Protocol
3. Project Overview
The Ramada Liuzhou Hotel is located in Liudong New District, Liuzhou City, Guangxi Province. The project covers a total area of 28,000 square meters and a total building area of 58,000 square meters. It has 16 floors above ground and 2 basement floors, with a building height of 63 meters. It is a five-star hotel and belongs to the category of high-rise buildings. The SPA center is located on the third floor of the hotel.
This project monitors the electricity consumption and air conditioning heat consumption of the hotel's spa center. The specific distribution of monitoring points is as follows:
The SPA center's power distribution circuit is equipped with an ACR220E multi-function meter, and the SPA center's central air conditioning system has an electromagnetic flow meter installed at the water inlet. Two temperature probes are also installed at the air conditioning inlet and outlet, which, together with a heat totalizer, calculate the air conditioning heat energy consumption.
Acrel Electric Co., Ltd. undertook the design and implementation of the energy consumption monitoring system for the SPA center of the Ramada Hotel in Liuzhou in 2014. The system adopts the Acrel-5000 energy consumption monitoring system, which mainly realizes online monitoring of the SPA center's electricity consumption and air conditioning heat consumption, facilitating the energy consumption management of the building.
4 System Architecture
Acrel-5000 Building Energy Analysis and Management System uses workstations, communication equipment, and measurement and control units as its basic tools, providing a foundational platform for real-time data acquisition at Ramada Hotel. It can be configured into any complex monitoring system. The system primarily employs a hierarchical distributed computer network structure, as shown in the system architecture diagram:
5 System Software Modules
5.1 Main Interface for Integrated Energy Consumption
It reflects the building's annual energy consumption by category and the comprehensive energy consumption converted to standard coal. The bottom of the interface displays the hourly energy consumption curves for electricity and air conditioning water on the same day.
5.2 Classified Energy Consumption Main Interface
This reflects the energy consumption (e.g., electricity) of a certain category as compared with the same period of the previous day, the same period of the current month and the same period of the previous month, and the same period of the current year and the same period of the previous year, along with the percentage increase and added value.
It reflects the energy consumption trend of a certain category over the past 48 hours, past 31 days, past 12 months, and past 3 years;
A pie chart showing monthly energy consumption for a specific energy item;
A year-on-year comparison chart of energy consumption for a specific category in each month of the current year;
5.3 Energy Consumption Statistics Report for Classified Energy Consumption Branches
Branch lines can be flexibly selected, and the daily, monthly, weekly, quarterly, and annual energy consumption of branch lines can be statistically analyzed over a certain period of time.
Pivot tables are powerful tools that allow users to perform various data statistics and combine and sort data.
Statistical data can be displayed using various charts such as bar charts, line charts, stacked charts, and pie charts;
Statistical data can be exported to Excel;
5.4 Classification of Energy Consumption Branches: Energy Consumption on Non-Working Days
Statistics are compiled on energy consumption for each branch on both weekdays and non-weekdays, and non-weekdays can be flexibly set through the system;
Statistical data can be exported to Excel;
5.5 Year-on-Year Analysis of Energy Consumption by Category Branch
Statistics on the monthly energy consumption of each branch road in the current year and the energy consumption in the same period last year;
5.6 Classification of Energy Consumption Branches and Energy Collection
Query the meter readings for any two times on each branch and calculate the difference, with time accuracy to the minute;
5.7 Classified Energy Consumption Branch Energy Collection
You can query the energy consumption parameters (such as voltage, current, power, power factor, harmonics, etc.) of any branch within a certain period of time. The specific parameters that can be queried are related to the installed instruments and system configuration. Queries cannot span months.
Data is displayed in the form of charts or tables. Charts can be zoomed in, zoomed out, and moved using the mouse. Data can also be sorted (maximum value, minimum value).
All statistical data can be exported to Excel;
5.8 Configuration Options
Configure basic building information in accordance with relevant technical specifications, such as building function, building area, air-conditioned area, building address, etc. Among them, the building area and other information will be analyzed for energy consumption per unit area.
Configure the basic information of the instruments used in the project, such as the type, model, and manufacturer, and add the monitoring parameter information that the instrument can provide. The configuration here will affect the energy consumption statistics, time-of-use energy consumption statistics, and parameter query functions.
Configure all metering instruments used in the project, and save information such as the metering instrument's address, transformation ratio, corresponding data acquisition unit, code, and monitoring loop name;
When configuring the sub-item energy consumption statistics, the information involved, such as the meter, the proportion, and the calculation method, can be flexibly configured according to the project situation. The configuration information here will affect the functions in the sub-item energy consumption analysis modules of each category.
Configure the metering instruments, calculation methods, proportions, and energy consumption plans for each department. After completing this configuration, the departmental energy consumption analysis function module will be enabled.
Configure the metering instruments, calculation methods, and proportions corresponding to a specific energy-consuming area in the building. After completing this configuration, the regional energy consumption analysis function module will be enabled.
6 Hardware Selection
The station control management layer uses one industrial computer, one A4 printer, and one online UPS power supply. The communication layer equipment uses an 8-port serial server.
Field equipment layer: This is the data acquisition terminal, mainly composed of smart meters. Power meters are connected to the communication server via shielded twisted-pair RS485 interface and MODBUS communication protocol bus type connection. The data then reaches the monitoring host through the communication server and switch. Field meters are connected to each other in a daisy-chain manner via twisted-pair cables. The number of meters on each bus is limited to 25.
The monitoring point for this project is located in the SPA center on the third floor of the Ramada Hotel. An ACR220E multi-function instrument is installed on the distribution box in the SPA center's electrical shaft. An electromagnetic flow meter is installed at the water inlet of the SPA center's central air conditioning system, and two temperature probes are installed at the air conditioning inlet and outlet. These, along with a WTX-6610R heat totalizer from Welltech, are used to calculate the air conditioning's heat energy consumption. Both types of instruments are connected to the data acquisition device via two separate buses.
7 Software Design Ideas
The principles to be followed in the design of energy consumption monitoring system software are: system security, system usability, system real-time performance, system stability, system scalability, and system maintainability.
8. Outlook
Based on the energy consumption operation analysis of the Ramada Hotel SPA Center in Liuzhou, a typical energy consumption analysis model was established for unified analysis.
● Establish a building energy consumption metering system to analyze building energy consumption, uncover energy consumption irregularities, and make energy-saving renovations more targeted. At the same time, consolidate the results of energy-saving renovations through management measures such as metered charging and performance evaluation.
● Select energy-saving equipment (frequency converter, heat recovery device).
● Even the best energy-saving equipment cannot achieve its energy-saving effect if waste cannot be controlled. By increasing automated energy-saving equipment, formulating equipment operation strategies, reducing human intervention, and centralizing management, energy-saving equipment is realizing energy saving.
The results of energy-saving renovations are quantified by using year-on-year and month-on-month analysis data provided by the energy consumption monitoring system, thus showcasing the energy-saving effects to the greatest extent.
9. Conclusion
With increasing energy scarcity, energy conservation and consumption reduction have become an inevitable choice for the intelligent construction of large buildings. This article introduces the Acrel-5000 energy monitoring system, which can monitor the operating status of energy-consuming equipment and generate various reports, analysis curves, and graphs based on the collected data, facilitating analysis and research and providing a reference for energy-saving technologies in intelligent buildings. The system is safe and reliable in operation, greatly simplifying user operation. With social development and increasing energy scarcity, remote monitoring and management of categorized and itemized energy consumption has become an inevitable trend in the development of intelligent buildings.
References
Ren Zhicheng and Zhou Zhong, eds., *Principles and Application Guide to Digital Instruments for Power Measurement*, China Electric Power Press, April 2007.
Zhu Liquan, Analysis of Intelligent Management System for Power Distribution Systems, Intelligent Building Electrical Technology, 2007, Vol. 1, No. 4
About the author : Wu Haiying, female, Bachelor's degree. Employer: Currently employed at Acrel Electric Co., Ltd.
