Saving 3.422 million Kwh compared with electric boiler! Last month, Hien won another energy-saving award for university hot water project.
One-third of the universities in China have chosen Hien air-energy water heaters. The Hien hot water projects distributed in major universities and colleages have been awarded the “Best Application Award for Heat Pump Multi-Energy Complementarities” for many year. These awards are also a testament to the high quality of Hien’s water heating projects.
This article describes the BOT renovation project for the hot water system in the student apartment of Huajin Campus of Anhui Normal University, which Hien has just won the “Best Application Award for Multi-Energy Complementary Heat Pump” in the 2023 Heat Pump System Application Design Competition. We will discuss the aspects of design scheme, actual use effect, and project innovation separately.
Design Scheme
This project adopts a total of 23 units of Hien KFXRS-40II-C2 air source heat pumps to meet the hot water needs of more than 13,000 students on the Huajin Campus of Anhui Normal University.
The project uses air source and water source heat pump water heaters to complement each other, with a total of 11 energy stations. The water in the waste heat pool is heated by a 1 : 1 waste water source heat pump water heater, and the insufficient part is heated by air source heat pump and stored in the newly built hot water tank, and then the variable frequency water pump is used to supply water to the bathrooms at constant temperature and pressure. This system forms a benign cycle and ensures a continuous supply of hot water.
Actual Use Effect
Energy Conservation:
The waste heat cascade-utilized technology of water source heat pump in this project maximizes the recovery of waste heat, discharges waste water as low as 3 ℃, and uses a small amount (approx. 14%) of electric energy to drive, thus achieving the recycling of waste heat (approx. 86%). Saving 3.422 million Kwh compared with electric boiler!
The 1:1 control technology can automatically apply different working conditions to ensure the balance between supply and demand. Under the condition of tap water above 12 ℃, the goal of producing 1 ton of bathing hot water from 1 ton of bathing wastewater is achieved.
Heat energy of about 8 ~ 10 ℃ is lost in bathing. Through the waste heat cascade-utilized technology, the discharge temperature of wastewater is reduced, and extra heat energy is obtained from tap water to supplement the heat energy lost in bathing, so as to realize the recycling of bathing waste heat and achieving the maximization of hot water production capacity, thermal efficiency, and waste heat recovery.
Environmental Protection and Emission Reduction:
In this project, waste hot water is used to produce hot water instead of fossil fuels. According to the production of 120,000 tons of hot water (the energy cost per ton of hot water is only RMB2.9), and compared with electric boilers, it saves 3.422 million Kwh of electricity and reduces 3,058 tons of carbon dioxide emissions.
User’s Feedback:
The bathrooms before the renovation were far from the dormitory, and there were often queues to take a shower. The most unacceptable thing was the unstable water temperature during bathing.
After the renovation of the bathroom, the bathing environment has been greatly improved. Not only does it save a lot of time without queuing, but the most important thing is that the water temperature is stable when taking a bath in cold winter.
Innovation of the Project
1, Products are highly Compact, economical and commercialized
Bathing wastewater and tap water are connected to the wastewater source heat pump water heater, tap water instantly rises from 1 0 ℃ to 45 ℃ for bathing hot water, while wastewater instantly decreases from 34 ℃ to 3 ℃ for discharge. The waste heat cascade-utilization of heat pump water heater not only saves energy, but also saves space. The 10P machine covers only 1 ㎡, and the 20P machine covers 1.8 ㎡.
2, Ultra-low energy consumption, creating a new path of energy and water saving
The waste heat of bathing wastewater, which people dismiss and discharge in vain, is recycled and turned into a steady and continuous supply of clean energy. This waste heat cascade-utilized technology of heat pump with high energy efficiency and low energy cost per ton of hot water brings a new path to energy conservation and emission reduction of bathroom bathing in colleges and universities.
3, Waste Heat Cascade-utilized technology of heat pump is the first at home and abroad
This technology is to recover thermal energy from bathing wastewater and produce equal amounts of bathing hot water from the same amount of bathing wastewater for thermal energy recycling. Under standard working conditions, the COP value is as high as 7.33, and in practical application, the average annual comprehensive energy efficiency ratio is above 6.0. increase the flow rate and raise the discharge temperature of wastewater to obtain the maximum heating capacity in summer; And In winter, the flow rate is reduced, and the discharge temperature of wastewater is lowered, so as to maximize the utilization of waste heat.
Post time: Sep-07-2023