Solar Water Heating Project Of Huimin No.3 Middle School In Shandong

Solar Water Heating Project of Huimin No.3 Middle School in Shandong

I. Project Background: Alignment of Campus Livelihood Needs and Green Development

As a key public middle school in Huimin County, Shandong Huimin No.3 Middle School undertakes the teaching and living needs of nearly 3,000 teachers and students, with boarding students accounting for over 60%. Daily hot water supply is directly related to basic livelihood guarantees such as students' daily washing and canteen cleaning. Previously, the school relied on gas-fired boilers for hot water supply for a long time, which not only had problems of high gas procurement costs and unstable supply during the winter heating period, but also failed to meet the policy orientation of green campus development under the "dual carbon" (carbon peaking and carbon neutrality) context due to combustion emissions.

In 2023, the Education and Sports Bureau of Huimin County launched a special campaign for "Green Campus" construction, clearly requiring primary and secondary schools as well as secondary vocational schools to give priority to renewable energy to meet energy needs for livelihood purposes. Combining its own water consumption scale and building layout, Huimin No.3 Middle School decided to implement the solar water heating project – which not only responds to local policy calls, but also fundamentally reduces the cost of hot water supply and improves service stability, creating a better campus living environment for teachers and students. The project started construction in the second half of 2023 and was officially put into use in early 2024, becoming the first large-scale campus hot water supply project in Huimin County that realizes "solar energy as the main source and auxiliary energy as a supplement".

II. Core Project Scale: Precisely Matching the Campus' Daily Demand of 180 Tons of Hot Water

1. Basic Parameters and Coverage Scenarios

The core design scale of the project is 180 tons of hot water supplied per day, with the hot water temperature stably controlled at 55-60℃ (meeting the requirements for campus domestic hot water temperature in the national "Sanitary Standard for Drinking Water"). It can fully cover three core scenarios:

Dormitory water use for students: Serving more than 2,200 boarding students, with a daily demand of 110 tons (calculated at 50 liters of hot water per student per day), accounting for 61% of the total supply;

Logistics water use for canteens: Meeting the needs of tableware cleaning and food pre-processing in 3 canteens, with a daily water consumption of 40 tons, accounting for 22%;

Water use for teaching buildings and offices: Covering cleaning and emergency water needs in teachers' offices and multi-functional classrooms, with a daily water consumption of 30 tons, accounting for 17%.

2. System Layout and Production Capacity Design

To achieve the supply target of 180 tons per day, the project adopts a "centralized heat collection + distributed heat storage" mode: A total of 300 sets of flat-plate solar collectors (with a heat collection area of 2.5㎡ per set and a total heat collection area of 750㎡) are laid on the roofs of the teaching buildings on the east and west sides of the school sports field, matched with 4 insulated hot water storage tanks of 50 cubic meters each (with a total heat storage capacity of 200 cubic meters and a 10% emergency buffer capacity reserved). A smart temperature control system monitors the water temperature and water level in the tanks in real time. When solar heat collection is insufficient, air-source heat pumps (non-direct electric heating type, complying with campus safe electricity standards) are automatically activated for auxiliary heating, ensuring stable and up-to-standard supply even in extreme rainy or cloudy weather.

III. Core Advantages of the Project: Targeted Solutions to Campus Hot Water Supply Pain Points

1. Significant Energy Saving and Cost Reduction Advantages, Alleviating School Operation Burden

Compared with traditional gas-fired boilers, the project reduces operating costs by 72%: Based on the market price of natural gas in Huimin County (3.8 yuan per cubic meter), gas-fired boilers need to consume 2,880 cubic meters of natural gas to produce 180 tons of hot water per day, with a daily cost of 10,944 yuan; while the solar water heating system only requires daily payment for auxiliary electricity consumption of air-source heat pumps (about 800 kWh, with an electricity price of 0.56 yuan per kWh) and equipment maintenance fees, totaling a daily cost of less than 3,000 yuan. This saves the school more than 2.8 million yuan in annual expenses. At the same time, the system has a service life of 15 years and an investment payback period of only 3.5 years, featuring prominent long-term economic benefits.

2. Technology Adapted to Campus Scenarios, Balancing Safety and Convenience

Targeting the characteristics of campus water use – "high demand during peak hours and stable demand during off-peak hours" – the project has made three targeted designs:

Peak-hour water supply optimization: During the three water use peak periods (6:00-8:00 in the morning, 11:30-13:30 at noon, and 18:00-22:00 in the evening), variable-frequency water pumps are used to increase water supply pressure, ensuring no insufficient water pressure when 6 dormitory buildings and 3 canteens use water simultaneously;

Safety protection upgrade: The hot water storage tanks are equipped with dual overflow valves and water quality filtration systems, which automatically detect water hardness and bacterial indicators monthly to avoid scale accumulation and microbial growth, ensuring the health of teachers and students in water use; anti-fall brackets are installed for the collectors, and roof pipelines are wrapped with thermal insulation cotton and aluminum sheets to prevent freezing and cracking in winter and accidental contact by students;

Convenient smart management: The school logistics department can check real-time hot water output, water tank level, and equipment operation status through a mobile management platform. Faults trigger automatic alarm notifications, eliminating the need for 24-hour manual on-duty and reducing management costs.

IV. Implementation Value of the Project: From "Livelihood Guarantee" to "Development Empowerment"

The implementation of the solar water heating project at Huimin No.3 Middle School in Shandong not only solves the long-standing problem of campus hot water supply, but also achieves a triple value upgrade: First, in terms of economic value, it significantly reduces school operating costs, and the saved funds are invested in the update of teaching equipment and teacher training; second, in terms of ecological value, it practices the concept of green campuses with concrete actions, providing a model for the application of renewable energy in the regional education system; third, in terms of educational value, it transforms the project into a carrier for environmental education, cultivating students' low-carbon awareness and scientific literacy.