Summary:An audit of the energy consumption for the 2016 fiscal year in a certain industrial park in Tianjin was conducted. The audit analyzed the park's total annual energy consumption, energy structure, composition of energy consumption costs, and energy consumption indicators per square meter of floor area and per employee. It also identified issues in the energy utilization process and proposed reasonable recommendations. The audit results showed that the comprehensive energy consumption of the park's buildings in 2016 was equivalent to 54.60 tons of standard coal, with electricity consumption of 402,400 kWh; 7.20 tons of alcohol-based fuel were used, and 16,900 cubic meters of water were consumed. The comprehensive energy consumption per square meter of floor area was 11.19 tons of standard coal per square meter per year, the energy consumption per employee per year was 0.38 tons of standard coal per person per year, the per capita water consumption was 118.66 cubic meters per person per year, and the average electricity consumption per square meter of floor area was 91.07 kWh per square meter per year.
Keywords:Industrial Park; Building Energy Consumption; Data Analysis
Introduction
Energy scarcity and environmental pollution are significant issues faced by countries worldwide. Energy conservation in buildings is a crucial component of China's energy policy. The energy consumption of the construction sector has already exceeded one-fourth of the country's total energy consumption. The construction industry has become a major energy consumer, with its energy consumption reaching 1.5 times that of the industrial sector. Based on current trends in building energy consumption, by 2020, China's building energy consumption will reach 1.089 billion tons of standard coal, three times more than in 2000, with peak air conditioning loads equivalent to the full output of ten Three Gorges dams. Among various types of buildings, office buildings and other public buildings are major energy consumers, accounting for less than 4% of the total urban building stock but consuming 22% of the total building energy consumption. Therefore, energy conservation in public buildings is a vital aspect of China's building energy conservation efforts. It is essential to understand the current state and characteristics of public building energy consumption as a foundation for energy conservation work. Conducting surveys and statistics on building energy consumption, understanding the level of building energy consumption, the energy consumption structure of building end products, and the modes of building energy use, and accumulating basic data on building energy consumption provide substantial data support for adjusting the national energy structure, formulating and testing relevant energy policies, and tapping into the potential for building energy conservation. Drawing on the author's experience in industrial park building energy audits and referring to guidelines such as the "Guidelines for Energy Audit of Public Buildings," a systematic summary of the complete workflow for building energy audits is provided, and key points for energy conservation in the industrial park buildings are proposed based on the audit results.
1. Overview of the Construction
The industrial park features a single building with an office building area of 4,419 square meters, total cooling area of 4,419 square meters, and total heating area of 3,977 square meters. There is a single office building for auditing purposes. The building structure is of reinforced concrete shear walls and glass curtain walls, with double-glazed ordinary glass used. Both the roof and exterior walls are insulated. Indoor lighting is equipped with thin tube fluorescent lamps, while outdoor lighting utilizes standard fluorescent lamps.
1.1 Types of Energy Consumption
The energy systems primarily include the electrical and water systems, as well as the consumption of alcohol-based fuel. The main energy systems are illustrated in Figure 1.
Figure 1: Illustration of the main energy systems in the industrial park
1.2 Energy Consumption Data Survey
The industrial park consumes various types of energy, including electricity, tap water, gasoline, and alcohol-based fuel. Electricity is primarily used for lighting systems, office equipment, air conditioning, water pumps for domestic use, and public service systems. Tap water is mainly used for landscaping, kitchen, and domestic purposes. Alcohol-based fuel is primarily used for kitchen cooking, while gasoline is主要用于government vehicles. The use of government vehicles has been discontinued since 2016.
1.2.1 Energy Consumption Structure
The industrial park consumed a total of 402,400 kWh of electricity, 16,690 cubic meters of water, and 7.2 tons of alcohol-based fuel in 2016. According to the conversion coefficients in Table 1, the comprehensive energy consumption was converted to 2,108.44 tons of standard coal equivalent. The specific energy consumption structure is shown in Table 2. The energy consumption structure for 2015 is shown in Table 3. The proportion of each energy source is visually analyzed in Figures 2 and 3.
Table 1: Standardized Coefficient Table
The liquid alcohol-based fuel used by this unit has a calorific value of 5000 kcal/kg, resulting in an equivalent calorific value index coefficient of approximately 0.7143, calculated as 5000 divided by 7000.
Table 2: Energy Consumption Structure in 2016
Table 3: 2015 Energy Consumption Structure
From Table 2 and Figure 2, it can be observed that electricity accounts for a significant portion of the total energy consumed, with electricity consumption accounting for 90.58%. This is a key focus of the energy audit, as well as a key area for identifying energy-saving potential. Ethanol-based fuel consumption accounts for 9.42%.
(1) Electricity: During this audit period, the institution purchased 402,400 kWh of electricity, with a net consumption of 402,400 kWh, equivalent to 494.6 tons of standard coal, accounting for 90.58% of the total energy consumption. In 2015, the actual electricity consumption was 396,100 kWh, with an equivalent of 486.8 tons of standard coal. The electricity consumption increased by 1.61% compared to 2015 in 2016.
(2) Gasoline: The physical consumption of gasoline in 2015 was 16,200 liters, equivalent to 17.44 tons of standard coal.
(3) Alcohol Fuel: During the audit period, the unit consumed 7.20 tons of alcohol-based fuel, equivalent to 5.14 tons of standard coal, accounting for 9.42% of the total energy consumption.
1.2.2 Energy and Resource Cost
The energy costs for the industrial park, primarily consisting of electricity, water, gasoline, and alcohol fuel expenses, reached a total of 450,700 yuan in 2016. The energy acquisition costs for 2016 and 2015 are detailed in Table 4, and the proportions of various energy resources are illustrated in Table 4 and Figure 3.
Table 4: Total Costs and Share of Various Energy Resources in the Industrial Park
Figure 3: Proportion of Various Energy Resources Costs in 2016
Figure 3 reveals that the industrial park administration committee's electricity expenses during the audit period were 357,400 yuan, accounting for 79.29% of the total energy costs; followed by water supply expenses, totaling 82,600 yuan, which constitutes 18.32% of the overall energy expenses.
(1) Electricity: During this audit period, the institution purchased 402,400 kWh of electricity, with a net consumption of 402,400 kWh. The electricity cost was 357,400 RMB, accounting for 79.29% of the total energy consumption. In 2015, the actual electricity consumption was 396,100 kWh, with electricity costs amounting to 365,500 RMB, representing 65.81% of the total energy expenses. Compared to the electricity costs in 2015, the costs during the audit period decreased by 2.21%.
(2) Potable Water: During the audit period, the unit purchased 16,900 cubic meters of potable water, with a cost of 82,600 yuan, accounting for 18.32% of the total energy consumption. In 2015, the actual consumption of potable water was 10,800 cubic meters, with a cost of 53,000 yuan, representing 13.86% of the total energy expenses. Notably, the potable water costs during the audit period increased by 7.23% compared to those in 2015.
(3) Gasoline: In 2015, 16,200 liters of gasoline were purchased, with a total cost of 102,100 yuan, accounting for 18.39% of the total energy expenses.
(4) Alcohol Fuel: During the audit period and in 2015, 7.2 tons of alcohol fuel were purchased, with a cost of 10,800 yuan, accounting for 1.94% of the total energy expenses. In summary, due to the suspension of public vehicles at the industrial park during the audit period, there was a reduction in gasoline consumption, resulting in a 19% decrease in total energy expenses compared to 2015.
1.2.3 Calculation of Key Energy Consumption Indicators
The comprehensive energy consumption per unit area is calculated as follows:
The energy consumption indicator per unit area = total building energy consumption / floor area.
The total energy consumption per unit area indicator = 49.46 tons of standard coal ÷ 4419㎡ = 11.19 kg of standard coal/(㎡·a).
The calculation for unit floor area electricity consumption is as follows:
Unit Floor Area Energy Consumption Indicator = Total Building Energy Consumption / Floor Area.
The unit floor area energy consumption index is 40.24 million kWh ÷ 4419㎡ = 91.07 kWh/(㎡·a).
The calculation for water consumption per unit area is as follows:
Unit Floor Area Water Consumption Index = Total Building Water Consumption / Floor Area.
The unit area water consumption index is 1.69万m³ ÷ 4419㎡ = 3.81m³/(㎡·a).
Square Meter Building Area Heating Consumption Index = Total Heating Energy Consumption / Heating Area
The unit floor area heating total indicator is calculated as follows: 22.82 tons of standard coal ÷ 3977㎡ = 5.74 kg of standard coal/(㎡·a)
Unit personnel energy consumption calculation as follows:
Total Energy Consumption Per Unit = Total Annual Energy Consumption / Number of Energy Consumers
The total energy consumption per employee indicator is calculated as follows: 54.60 tons of standard coal ÷ 142 employees = 0.38 tons of standard coal per employee per year.
Unit personnel electricity consumption calculation is as follows:
Unit Energy Consumption Indicator = Total Energy Consumption / Number of Energy Consumers.
Unit personnel electricity consumption target = 402,400 kWh ÷ 142 people = 2.8万kWh/(person·year).
Unit personnel water consumption calculation is as follows:
Unit Personnel Water Consumption Index = Total Water Consumption / Number of Energy Users.
Unit personnel water consumption indicator = 16,900 m³ / 142 people = 118.66 m³/(person·year).
2. Ankelei Building Energy Consumption Analysis System
2.1 Overview
The Acrel-5000web Building Energy Consumption Analysis System is a user-side energy management analysis system. It builds upon the electrical energy management system by adding centralized collection and analysis of water, gas, coal, oil, heat (cooling) consumption. By细分 and statistically analyzing all energy consumption at the user end, it presents various energy usage and consumption patterns to management or decision-makers through intuitive data and charts. This facilitates identifying high-energy consumption points or inefficient energy consumption habits, effectively saving energy, and providing accurate data support for users to further improve energy-saving renovations or equipment upgrades. Users can implement energy calculations according to national regulations, analyze the current situation, identify issues, explore energy-saving potential, propose practical measures, and submit energy calculation reports to departments responsible for energy conservation at or above the county level.
2.2 Application Scenarios
System design, construction, and operational maintenance for energy consumption monitoring and management applicable to various industries such as public buildings, corporate groups, industrial parks, large-scale properties, schools, hospitals, and enterprises.
2.3 System Features
2.3.1 System Overview
The platform displays the operational status, monthly energy consumption calculations, map navigation, hourly and monthly energy consumption curves, and a rolling comparison of daily and monthly energy consumption year-on-year.
2.3.2 Energy Consumption Overview
The company compares energy consumption across buildings, departments, regions, branches, and categories. It supports hourly trends for the current day, daily trends for the current month, segmented energy consumption statistics, and total energy consumption comparisons with both same and prior periods.
2.3.3 Energy Consumption Statistics
The company's statistics on classified energy consumption are conducted in the form of daily, monthly, and annual reports for structures such as buildings, regions, sub-items, and branches. The reports support exporting data to Excel and generating bar charts from selected building data.
2.3.4 Reimbursement Rate Statistics
The report on the composite rate analyzes the peak, peak, flat, and valley electricity consumption and cost for different branches under a single building on a daily, monthly, and annual basis. It supports data export to Excel.
2.3.5 Year-on-Year Analysis
The energy consumption of buildings, sub-items, regions, and branches is analyzed through year-on-year comparisons, presented in a combined graphical and tabular format by day, month, and year.
2.3.6 Energy Flow Diagram
The Energy Flow Map illustrates the energy flow from source to end for various types of energy within a specified time period for a single building, supporting views by both original values and normalized values.
2.3.7 Nighttime Energy Consumption Analysis
The night-time energy consumption statistics are presented in tables, curves, and pie charts, comparing the energy usage of selected branches during working hours and non-working hours in specified time periods, with the capability to export reports.
2.3.8 Equipment Management
Equipment management encompasses functions such as equipment types, inventory records, and maintenance logs, assisting users in the rational management of equipment to ensure smooth operation.
3.9 User Reports
Users report automatically calculates the monthly usage trends of various energies for selected buildings, providing simple energy consumption analysis results, and offers a separate dual-rate energy consumption analysis for electricity. The report is editable.
Conclusion
4.1 Main Issues in the Energy Utilization Process of the Industrial Park
Energy management issues.
Management capabilities need enhancement. There are still shortcomings in professional training, the construction and renovation of energy-saving projects, and the lack of unified and effective synergy, which has not yet formed an integrated energy-saving management system.
Lack of advanced and reasonable energy-saving targets. Although an energy consumption quota management system has been established, an effective energy consumption evaluation system has not been set up, and there has been no accountability assessment. Employees' awareness of energy-saving needs to be enhanced. The sense of conservation has not permeated the hearts and minds of all staff, and their energy-saving awareness needs to be further strengthened.
(2) Energy metering system issues.
The public institution has installed a total metering device for electricity and water purchased externally; however, the energy consumption of major energy-consuming systems such as air conditioning systems, office electricity (including lighting and power outlets), and integrated service systems has not been itemized, which does not comply with the "Requirements for the Equipment and Management of Energy and Resource Meters in Public Institutions." The energy consumption statistical management system is imperfect, and accurate statistics have not been conducted on the purchase, consumption, and flow of energy, which hinders the timely understanding of the energy consumption status and issues of major energy-consuming equipment and systems.
(3) Energy-efficient equipment operation issues.
Key energy equipment management personnel require an enhancement in technical proficiency. During the audit, the temperature difference between the chilled water inlets and outlets of the air conditioning units was generally within 1-2°C, resulting in high pump energy consumption and wastage of energy resources. This indicates that the technical skills of the air conditioning unit operation and maintenance staff, as well as the qualifications and capabilities of the energy consumption supervisors, need to be improved.
4.2 Energy-saving Technical Reform Measures and Recommendations
4.2.1 Energy Management
Establish energy consumption quotas and assessment methods, and implement the good system through rewarding savings and penalizing excesses, thereby enhancing energy management levels.
(2) Regular training for energy management personnel and operators should be conducted to enhance their professional qualities and skills, and efforts should be made to ensure that both energy managers and operators are certified before taking their posts.
(3) Conduct accurate statistics on energy procurement, consumption, and flow, while relevant departments should conduct regular energy consumption analysis.
4.2.2 Behavior Energy Efficiency
Enhance energy-saving promotion and boost employees' awareness of energy conservation.
(2) Display energy-saving labels.
4.2.3 Technical Energy-Saving Recommendations
Operators should be able to adjust the outlet temperature of the heat pump appropriately in response to climate changes, while ensuring indoor comfort for winter heating and summer air conditioning. By optimizing operation management, the performance coefficient of the unit can be improved, leading to reduced energy consumption.
(2) Gradually phase out existing standard fluorescent lights and replace them with more energy-efficient lighting fixtures to reduce electricity consumption for illumination.
(3) Improve the measurement of primary energy-consuming equipment and systems, achieving both area and itemized measurement.
Reference
Rong Weiguang, Li Yong'an, Gao Tingjin, et al. Analysis and Comparison of Primary Energy Efficiency of Different Air Conditioner Heat Sources[J]. Heating, Ventilation, and Air Conditioning, 2012, 42(10): 77-80.
Han Xiaopeng, Ma Shuo. Energy Consumption Survey and Analysis of a Tianjin Industrial Park[J].
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