On July 11^th, 2017, the intelligent energy management & control system developed by CISDI independently has been put into service at the Jiangbeizui River Water Source Heat Pump House, Chongqing. The River Water Source Heat Pump House is currently the largest individual water source heat pump system, with a maximum cooling capacity 287MW. Facing the new round of energy restructuring and energy technology changing, CISDI has researched and developed the intelligent energy management & control system to perform whole-process intelligent management & control of water intaking, ice bank, energy supply and production scheduling, thus setting a model for building Smart City with highly efficient use of clean energy.

Cost and energy savings by relying on local resource, consuming electricity during off-peak hours

In Chongqing air-conditioning is indispensible in summer. More than 40 high-rise and super-high-rise buildings housing financial institutions like Bank of Chongqing, Bank of Communications of China, Ping An, landmark public buildings like Chongqing Grand Theater, Chongqing Science & Technology Museum, many large supermarkets and shopping malls sit in the Jiangbeizui Central Business District. If every room, every building in such a CBD is air-conditioned electrically, it will inevitably result in huge electricity consumption, low energy efficiency, heavy maintenance, and urban diseases like Heat Island Effect and noise pollution as well. In an effort to shape Jiangbeizui into a showcase of the city, Chongqing Jiangbeizui CBD Investment Group Co. decided to invest 1.4 billion RMB in building a river water source heat pump house to realize centralized production, management & control of cold and heat sources. Instead of following a traditional electric heat exchange process, the heat pump house operates by intaking clean water from Jialingjiang River as the cold and heat sources to the heating and refrigerating units where water is heated, cooled and stored as ice bank. And then the conditioned air can be supplied on demand into the 4,000,000m² buildings, thus achieving efficient use of clean energy.

Every July and August, the daily mean temperature in Chongqing can be 35°C or even 40°C, while the temperature of water in the middle of Jialingjiang River is 3°C~5°C lower than the air. The larger the temperature difference between water and air is, the lower the electricity consumption for ice making is, the higher the energy efficiency is. According to statistical data, 5°C of the temperature difference lead to 20~30% higher ice-making capacity. Peak electricity consumption takes place in the time period from 9:00am to 18:00pm of every business day, while in summer, the electric power system may fail due to overloads, causing inconvenience to the people. Now the River Water Source Heat Pump House, conforming to the peak-valley characteristics of electricity consumption at daytime and at night and the electricity billing policy, consumes electricity principally to make ice bank at night and melt the ice bank at daytime. It can effectively help realize electricity load adjustment, reduce energy production cost, while not using the large electricity resource during the peak hours at daytime. During the process of cold supply, no other energies except only a small amount of electric energy is consumed, and no pollutants are discharged. It’s a greener and more eco-friendly option than air-conditioning which is using Freon as refrigerant, driven by electricity.

Highly efficient production because of intelligent energy management, optimization and scheduling

The River Water Source Heat Pump House has been equipped with 8 duplex units, 10 on-board heat pump units, 30MW ice bank system, more than 50 variable-frequency water pumps and over 110 valves. Scientific and reasonable planning, management and control of such a large number of equipment are much necessary to dozens of buildings, thousands of users. CISDI has integrated the field instrumentation, automation control system, energy management, load prediction, optimized control, video monitoring and electricity monitoring systems to constitute the “nerves” and “brain” of the heat pump house to allow for optimum operation with intelligent analyses and scheduling of the energy system.

How much electric energy, how much cool air is required on Monday when the temperature is up to 30°C? How many watts of ice are to be made on Tuesday when it’s 35°C? How many users will need energy as tomorrow is a holiday? Which companies have frequent overtime workers? What’s the estimated total volume of cool air to be needed by users in the upcoming month? Aiming to these questions, CISDI, by relying on Neural Network model and Priority Scheduling, has developed independently the load prediction system which is able to analyze and mine the massive data such as historic loads, real-time climate, air humidity and temperature, wind force, sunshine duration, etc. in Jiangbeizui area and predict the cold and heat energy demand trends, thus provide support for production scheduling, avoid excessive or inadequate production of cold/heat energy, enable the different units to work in a synergic and optimized way, thus achieving efficient use of energy, balanced and economic operation of pipe networks.  

For integration with the latest information technology, CISDI has developed an app oriented to intelligent terminals for the river water source heat pump house, by which one can check the operating status of the pump house on his/her mobile phone. Moreover, the Remote Monitoring and Maintenance Center located in the CISDI R&D Center can carry out diagnosis and maintenance of the heat pump house by duly monitoring and trouble-shooting so as to ensure safe and uninterrupted operation.

So far utilizing river water heat source to meet the heat/cold energy demand of buildings has been adopted only in a few cities in China, though it’s found wide applications overseas. Featuring high efficiency, clean production, low consumption and low cost, the Jiangbeizui River Water Source Heat Pump House equipped with the intelligent energy management & control system of CISDI will be an important model for providing large public buildings with intelligent centralized HVAC systems and building Smart City with highly efficient use of clean energy in China.