Qiaozhuang Centralized Heat Exchanger Station located in one of the cities in Shandong Province was completed and put into operation in 2004. Since
the originally designed and installed circulation pumps couldn’t adapt to the wide fluctuation of load demand, the station was retrofitted for energy saving
with ENERGYWIN’s pump efficiency technology in 2008 and the client chose our Energy-saving Benefits
Sharing Plan(Post-payment Plan).
The retrofit includes installation of the ENERGYWIN Pump Energy-saving Control System, replacement of a 710KW water pump and a 6,000V high-voltage
electric motor, and installation of a wave-chopping inner feedback speed regulation system. During the heat supply season of 2008, the station saved
electricity consumption by 51% (987,828 kWh), which translates into a saving of electricity cost of RMB580,000 and a simple payback of 1.9 years.
Plan Chosen
Energy-saving Benefits Sharing Plan (Post-payment Plan)
Term of Contract (Year)
3
Cost of Retrofit (RMB)
1,120,000
Energy Savings per Year (RMB)
580,000
Simple Payback (Year)
1.9
Electricity Consumption Reduced (MWH)
985
Emissions Reduced per Year (Ton)
855
Project Overview
Qiaozhuang Centralized Heat Exchanger Station is the biggest steam-water heat exchanger station in the city. With the residual heat from the thermal power plant
of an iron and steel company as its heat source, the station has a designed heat supply capacity of 80 GJ and provides heating for residential and commercial customers.
With a diameter of 800mm of the main pipeline network, it is connected to 30-odd secondary heat exchanger stations.
Project Background
Qiaozhuang Centralized Heat Exchanger Station has three single-stage dual-suction centrifugal pumps for heat circulation, of which one has a power rating
of 350KW and the other two each has a power rating of 710KW. At the beginning and ending stage of the heating (non-bitter cold period) season, the station
will be operating at 100% of the designed load with the 710KW circulation pumps in operation, while at the middle stage (bitter cold period), it will be operating
at 50% of the designed load with the 350KW circulation pump put into operation. With its load varying significantly, the original pump system couldn’t adapt to
the wide fluctuation of load, resulting in high energy consumption. There was room for energy saving and ENERGYWIN’s pump efficiency technology can be used to
retrofit the station for energy saving.
業務案例的現金流量及利潤圖
Project Team
The project team consisted of the owner’s engineers and ENERGYWIN’s engineers. The project also invited a high-voltage motor wave-chopping inner feedback speed regulation
equipment supplier to participate in the design of the electrical component.
Old Systems
At the beginning and ending stage of the heating season (totally 1.5 months) when the 710KW circulation pumps were in operation, the circulation flow rate of the system
was 2,400 ton/hour, while at the middle stage of the heating season when the 350KW circulation pump was in operation, the circulation flow rate of the system was
1,436 ton/hour. The annual electricity consumption benchmark was 9.73 kWh per ton of steam.
Result
In order to evaluate the effect of energy efficiency improvement, the project team consulted the historical data for the electricity and steam consumption in the
heating seasons of 2006 and 2007 and used the average figures of these two years as the benchmark for energy efficiency evaluation. After the new system was put into
operation, the actual electricity and steam consumption in the heating season were recorded. The results show that the energy consumption of the system was reduced
from 9.73 kWh per ton of steam to 4.78 kWh per ton of steam, a 51% reduction and an annual power bill savings of about RMB580,000. With an investment of RMB1,120,000
in retrofitting the system for energy saving, the simple payback is 1.9 years. In addition to significant reduction of energy consumption, the vibration and noise of
the new system have also been significantly reduced, leading to improved reliability of the new pump system.
Energy and Cost Saved:
Cost of Retrofit: RMB1,120,000
Annual Energy Savings: RMB580,000
Simple Payback: 1.9 years
Energy Saved Annually: 985MWH
Total CO2 Emissions Reduced per Year: 855 tons
New Systems
According to the characteristics of the project, the energy-saving design of the new system includes the following three major parts:
Installation of EnergyWin’s pump energy-consumption automatic control system;
Replacement of a 710KW circulator pump; and
Addition of a high-voltage motor wave-chopping speed regulation system.
