Case Study – Ningbo Jisheng Electric Co., Ltd. (Heat Recovery System)

Ningbo Jisheng Electric Co., Ltd. is a high-tech enterprise specializing in the development, production, and sales of oven products.

Since its first cooperation with Deman in 2017, and recognizing the effectiveness of Deman’s energy-saving solutions, the two parties have carried out over ten energy-saving projects together.

During the energy efficiency evaluation at Jisheng, we discovered that their cleaning line was still using a natural gas boiler to heat water—resulting in high energy consumption. Meanwhile, the large amount of waste heat generated by the air compressors was not being utilized effectively and was simply wasted.

Customer Challenges Before the Upgrade:

1. The cleaning line still relied on natural gas boilers to heat water, resulting in high energy consumption

2. The large amount of waste heat from the air compressors was not utilized, leading to unnecessary waste

3. Only 17% of electricity is converted into compressed air energy

 

After thorough inspection and discussion, the Deman team designed a customized heat recovery system for Jisheng to maximize the utilization of heat generated by the air compressors.

 

Deman's Air System Comprises of:

1. Added heat oil pipes inside and outside the compressors, channeling the heated oil to a heat recovery unit to serve as a heat source

2. Modified the existing boiler system by adding water pipelines connected to the heat recovery unit

3. Paired with a dual-pump circulation system (one active, one standby)

4. Equipped with an intelligent high-efficiency plate heat exchanger

① Enabling thorough and efficient heat exchange between the hot oil and cold water

② Heated water returns to the boiler via insulated pipes for cleaning line use

③ Hot water can also be used for boiler feedwater, industrial cleaning, workshop heating, showers, and geothermal heating

 

We carried out a total of three phases of heat recovery upgrades for both the new and old factories of Jisheng, resulting in annual natural gas savings of RMB 210,000. These upgrades not only reduce annual energy costs but also create infinite value for their efficient use of compressed air.

After Installation of Deman System:

√ Three phases of heat recovery upgrades for the customer’s new and old factories

√ Annual natural gas savings of RMB 210,000