Abstract: This paper introduces the system structure, data acquisition, and software functionality of the online energy consumption monitoring system for the newly built office building of Jiangyin Port Group Co., Ltd. The system analyzes and processes the electricity consumption of air conditioners, lighting, and sockets in each office, and publishes the results through tables and images. Company managers can use this system platform to establish and improve the company's energy-saving management system, constrain energy consumption of each energy-consuming unit, and improve the operational efficiency of the company's offices.
Keywords: Office energy conservation; Energy management; Energy consumption monitoring; Port; Data acquisition
0 Introduction
Energy consumption is a significant and controllable component of a company's production costs, and reducing energy consumption is a crucial way to lower production costs. With continuous social progress and the development of science and technology, energy-saving technologies and equipment, such as high-efficiency boilers and kilns, motors and drive equipment, waste heat and pressure utilization equipment, and energy-saving instruments and equipment, have been widely applied to various stages of enterprise production processes. The energy consumption of office management in manufacturing enterprises (mainly electricity consumption) is also an important part of their energy consumption, but because it accounts for a small proportion of total energy consumption, it is often overlooked during the implementation of energy-saving renovations. Establishing an energy monitoring system in enterprise office buildings, and using computer-aided methods to classify and measure energy consumption, can identify high-energy-consumption points and unnecessary energy consumption. Strengthening energy use assessment and management based on this information can often achieve twice the result with half the effort.
This article, using the online energy consumption (electricity) monitoring system of the newly built office building at Pier 5 of Jiangyin Port Group Co., Ltd. as an example, provides a detailed introduction on how manufacturing enterprises can establish effective energy consumption monitoring for office management.
1. Power Distribution Situation and Construction Goals
The newly built office building at Pier 5 of Jiangyin Port Group Co., Ltd. is a three-story building. The main power supply line to the building is introduced from the 0.4kV distribution circuit of the No. 5 substation at the pier to the main distribution box. The main distribution box is located outside the network server room on the first floor, equipped with a main switch and main switches for each floor. Power is then distributed to each office using a hybrid radial and dry distribution method. Each office has its own PZ30 distribution box. To facilitate the classification of power consumption, the power supply to each office is allocated for air conditioning and lighting sockets. The following diagram shows the distribution of offices on the third floor of the building:
Figure 1. Schematic diagram of the office layout on the third floor of the office building.
After thorough discussion, the system builder and contractor agreed that the online energy consumption monitoring system should achieve the following objectives:
1. Electricity consumption in each office is metered separately for air conditioning and lighting sockets to track energy consumption fluctuations and achieve accurate energy consumption prediction;
2. Summarize and statistically analyze the electricity consumption of each office by department, and display it in various forms such as graphs and curves to achieve energy consumption monitoring and avoid unreasonable energy consumption;
3. Electricity consumption benchmarks can be established to provide reminders for excessive or abnormal electricity consumption, thereby achieving standardized energy consumption management and forming widely applicable standards and norms;
4. After the system is built, the displayed data of the system can be viewed on computers within the local area network; it can realize quantitative analysis of energy consumption, process-oriented and refined management of energy consumption, energy-saving effect evaluation, and comprehensive management of energy-saving renovation measures;
2 System Network Structure Design and Implementation
Based on the power distribution and office layout of the newly built office building, the energy consumption online monitoring system adopts a layered distributed structure, comprising: a station control management layer, a network communication layer, and a field equipment layer. The system network structure is shown in Figure 2.
Figure 2 System network structure diagram
The management and control layer serves as the human-machine interface for system users and maintenance personnel, and is also the top layer of the system. In the construction of this online energy consumption monitoring system, a data server was configured to collect, store, and process power consumption information from each circuit; a web server was set up to display a user-friendly interface to users via the internet; and an engineer workstation was also set up for routine system maintenance.
The communication control layer mainly consists of a communication server, interface conversion devices, and a bus network, serving as a bridge for data exchange. In this project, the communication control layer is configured with one 8-port data acquisition unit. Considering communication reliability and lightning protection, serial port isolation equipment is also included. An RS485 bus is run from the east to the west sides of floors 1-3, connecting the single-phase meters located in each office to the serial port server. The communication bus uses shielded twisted-pair cable (RVSP2×0.75), run through Φ25 conduit along the walls to each room.
The field equipment layer mainly consists of various types of instruments connected to the network for electrical parameter acquisition and measurement, and is also a necessary basic component in constructing this power distribution system. To establish a sub-metering system for electricity consumption, the project design includes installing two single-phase, single-access DIN rail-mounted energy meters in the PZ30 box of each office, respectively measuring the office's air conditioning and lighting socket consumption. Based on this design, the office building has 32 single-phase meters in 16 offices on the first floor, 34 single-phase meters in 17 offices (including meeting rooms) on the second floor, 34 single-phase meters in 17 offices (including meeting rooms) on the third floor, and 4 triple-box meters in the main distribution box.
3. System Function Design and Implementation
The online energy consumption monitoring system is designed with the following software functions in mind, based on the system construction goals:
1. A clearly defined metering system for electricity usage circuits.
The Jiangyin Port Group office building has three floors. The energy consumption system has two electricity meters installed on the main power line, on each floor, and in each office. These meters measure the electricity consumption for air conditioning and lighting sockets, respectively. Combined with four main meters, the entire system has 104 metering points, establishing a comprehensive electricity metering system covering the entire office building. The system software includes a metering system display function, as shown in Figure 3. Users can easily understand the power distribution hierarchy of the office building through this interface.
Figure 3. Measurement system illustration
2. Power Management ERP
System administrators or maintenance personnel can also configure information such as the name of the power branch, power consumption type (air conditioning power, lighting socket power), department, and electricity meter type through the power circuit information maintenance function. This function allows the system to automatically calculate the power consumption of each power circuit by department and divide the managed power consumption by department, establishing an energy management ERP allocation function similar to a financial ERP. This function facilitates system maintenance when information such as changes in the office's department changes. The configuration interface is shown in Figure 4;
Figure 4 Power Circuit Information Maintenance
3. Electricity consumption display and energy consumption ranking
The system's main interface intuitively displays the office building's electricity consumption for the current month, the previous month, the current year, and the same period last year in the same period of the previous year, as well as the daily air conditioning power consumption trend combined with temperature changes, the average and trend comparison of lighting socket power consumption for the current month, and the ranking of each department's monthly power consumption in the form of data and bar charts. The company's energy conservation office or management personnel can intuitively understand the company's electricity consumption overview through this interface. (See Figure 5).
Figure 5 System display screen
4. Energy-saving potential exploration – Electricity consumption analysis during off-peak hours
This power management system software displays the daily power consumption of each circuit, distinguishing non-working day power consumption with blue bars and marking the daily average power consumption line. If the power consumption on a certain day is significantly higher than the normal daily power consumption, the system can analyze the power consumption circuits hourly to find the power consumption points, make necessary adjustments, and prevent abnormal power consumption from occurring. See Figure 6 for the daily power consumption trend of the circuit and Figure 7 for the hourly power consumption analysis trend of a certain circuit.
Figure 6 shows the daily power consumption trend of the circuit.
Figure 7. Hourly power consumption trend analysis of a certain circuit
5. Time-of-use power management
The power management system can set peak, flat, and valley periods and rates in the software according to the power supply bureau's electricity fee standards. It can also set working and non-working periods according to the customer's actual situation. The energy consumption system can find unreasonable power consumption of each circuit during non-working hours. Reward and punishment measures can be used to encourage employees to develop the habit of turning off electrical equipment in time after get off work, as shown in Figure 8, which displays power consumption during peak, flat, and valley periods.
Figure 8 shows the power consumption during peak, average, and valley periods.
6. Establish performance appraisal measures
The office building is mainly used for administrative work. The system divides each office into departments according to customer requirements. The system automatically completes the statistics and analysis of departmental energy consumption. Information such as the number of departmental personnel and the building area of each department can be entered in the system information maintenance. The system performs comprehensive ranking analysis based on total power consumption, per capita power consumption, and power consumption per unit area. The system can also enter power consumption limit information for each department and office. When the power consumption is close to or exceeds the limit, a prompt message will automatically pop up. Figure 9 shows the ranking of departmental comprehensive power consumption.
Figure 9. Ranking of Departmental Total Power Consumption
7. Electricity Consumption Statistics Report
The system software automatically collects and generates monthly electricity consumption reports by department. These reports can be submitted to the finance department or automatically transferred to the financial ERP system, facilitating independent accounting for each department, as shown in Figure 10, Monthly Electricity Consumption Report.
Figure 10 Monthly Electricity Consumption Report
By implementing the above software functions, the energy management and assessment unit has rationally established benchmark values for electricity consumption in each department and fed back the electricity consumption data to each department in the form of financial data, thus establishing an effective energy management and assessment system. Through the construction of the system and the establishment of the system, the energy-saving awareness of the company's management and office staff has been greatly improved, effectively saving energy consumption in the company's management and office work.
4. Conclusion
The design of the enterprise management office energy consumption online monitoring system mainly involves combining information technology to establish a set of computer-aided management software that meets the actual needs of users. The system software obtains raw data of the power consumption process through real-time data collection and automatic storage. Through functional design and implementation, the data is optimized and integrated, and presented to enterprise managers in a user-friendly and intuitive human-computer interface. This provides data support for improving their power consumption management model, establishes a power consumption assessment mechanism, and thus achieves scientific management of office power consumption.
References:
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