Inheriting the ingenuity and teaching people to fish - Denso's road to carbon neutrality

In the past two years, China has clearly put forward the dual carbon goals of carbon peak and carbon neutrality by 30·60. As a major industrial manufacturing country, the establishment of this goal means that China's future economic growth will gradually get rid of its dependence on fossil energy consumption . In order to promote the realization of carbon neutrality, promote industrial and technological changes, deepen the practical path of sustainable development, and accelerate the transformation from green and low-carbon to decarbonization, it is imperative.

Under the common vision of promoting carbon neutrality, the Denso Group has formulated an environmental strategy based on its basic philosophy of coexisting social issues and sustainable business, and has set a clear goal of achieving carbon neutrality (zero CO₂ emissions) by 2035. It will strengthen implementation in three important areas: manufacturing (production and manufacturing), mobile travel products, and energy recycling, and effectively enhance competitiveness. Among them, manufacturing, as the basis of production activities, involves production materials, parts, energy use, and other aspects, and has a more important role and influence.

Denso Corporation (hereinafter referred to as "Denso") was established in 1949. As a parts manufacturer trusted by automobile manufacturers, it provides parts and systems to customers in many parts of the world. Looking forward to the future mobile travel society, Denso focuses on the automotive industry and develops its business in a wide range of fields, focusing on electrification, active safety/unmanned driving, Internet of Things (IoT) and other fields. While providing new smart mobility value, it is also committed to FA (Factory Automation) and the industrialization of agriculture. It aims to create new value for society that meets future needs through technological development in the above fields.

In terms of creation, Denso has developed production lines from the research and development of single production equipment to the production of automatic production lines. It has expanded production lines to factories in many parts of the world, and has always ensured that customers in many parts of the world can provide products and services with high reliability and durability with higher flexibility and high efficiency. Especially in terms of energy saving, Denso has accumulated rich experience with more than 70 years of craftsman spirit inheritance and continuous improvement. Since the establishment of the Japan Energy Conservation Award in 2009 (sponsored by the General Consortium Foundation Energy Conservation Center, focusing on commending outstanding energy-saving activities or energy-saving products of enterprises or autonomous groups), it has won more than 20 awards for 12 consecutive years, making it the company with the most awards in the field of energy-saving cases.

On the basis of fully absorbing and flexibly applying the energy-saving experience of the headquarters, the carbon neutral creation team of DENSO (China) Investment Co., Ltd. (hereinafter referred to as "DENSO China") not only passed on this ingenious creation spirit to DENSO China, but also integrated local production and technology to achieve greater breakthroughs.

Yang Min, head of DENSO China's carbon neutrality team

Yang Min is the head of the carbon neutrality team of DENSO China. He is from the Safety and Environmental Facilities Department of DENSO China and has 10 years of experience in equipment management and energy-saving management. He is currently in charge of carbon neutrality creation, energy-saving education and renewable energy promotion business of DENSO in many production companies in China. He said: "In order to actively respond to the 30·60 dual carbon goals, DENSO China strives to achieve carbon neutrality in 2035 through measures such as energy conservation and emission reduction, solar rooftop power generation, and green electricity procurement. As the person in charge of carbon neutrality of DENSO China, I will work hard to promote energy-saving activities in multiple production bases in China. With the goal of reducing CO₂ emissions by 5% each year, we will continue to explore energy-saving and improvement actions at the production site." The State Council clearly pointed out in the "Action Plan for Carbon Peaking before 2030" issued in 2021 that energy conservation and emission reduction are important tasks for carbon neutrality. It can be seen that energy-saving activities have become a topic faced by most manufacturers. As an action that can be implemented immediately, DENSO China, with the support of the headquarters' rich experience in energy-saving, has promoted energy-saving activities in more than 20 production bases of DENSO China from the perspectives of "technological innovation", "eliminating waste" and "full participation", and achieved many results.

1.Technological innovation: waste heat recovery from air compressors on the supply side

Innovating in the midst of precipitation, Denso integrates its own high-level skills and technical product manufacturing capabilities to realize innovative energy-saving ideas. In the past, the constant temperature and humidity air conditioners (21±1℃, 55±5%) used in the production equipment room needed to be kept running for a long time to ensure the temperature and humidity of the air conditioning heating. The annual power consumption for heating was 680,000 kWH, and the air compressor generated high temperature during operation, and the heat was discharged into the atmosphere through the cooling tower. Taking 2020 as an example, the heat pump heating electricity consumption was 680,000 KWH/year, the electricity and other expenses were 515,000, the heat generation was 2.99 million KW, and the heat generation of the air compressor (8.97 million KW/year) was discharged.

In order to improve the utilization rate of waste heat and save electricity, the Denso production base transformed the oil and water circuits of the air compressor, and converted the high-temperature waste heat of the air compressor into 50°C hot water through the exchanger to replace the heat pump operation. Through the above transformation, 1/3 of the heat generated by the air compressor (5 units of 110KW) was used for preheating and recycling, and the heat pump system was controlled as a backup system, with an energy saving rate of up to 91%.

Schematic diagram of air compressor operation and waste heat recovery

After the above transformation, electricity and maintenance costs can be reduced by 480,000 yuan per year, and CO₂ emissions can be reduced by 663 tons, and the investment can be recovered in 2 years.

Effect after import

2. Eliminate waste: Combine production plan and centralize NB (brazing) furnace production

Adhering to the production philosophy of lean production and eliminating all waste, Denso has embarked on production improvement measures to improve energy efficiency and eliminate waste. By visualizing the production status of the NB furnace equipment with the highest energy consumption and combining it with a plan for centralized production, the NB furnace is continuously operated to reduce standby time. Through the above energy-saving actions to eliminate waste, the utilization rate of the NB furnace has increased from the original 47% to 100%. It greatly improves energy utilization and employee work efficiency, reduces working hours and standby time, and thus promotes cost reduction and efficiency improvement at production bases.

3. Full participation: Develop an energy-saving action map with full participation of all employees

Full participation is the key to implementing lean production. In view of the energy conservation and emission reduction issues on the production line, we create a factory with visualized problem points, formulate an energy conservation action map, and let all employees work together for continuous improvement, so as to cultivate energy conservation awareness among all employees. By standardizing the ON/OFF of the production line and making it into an easy-to-understand visual action map, we clearly define the energy (water, electricity, gas) that needs to be turned off during mid-term breaks, lunch breaks, leaving the post, leaving get off work, and rest days, and clarify the action guidelines to ensure that new employees can also refer to the implementation and implement it in the continuous improvement actions with the participation of all employees.

The above activities are the result of repeated practice by the carbon neutral creation team of Denso China and the staff of each production company, based on the reference to the excellent energy-saving cases of the headquarters. "Creating things is creating people. No matter how excellent the technology and methods are, they cannot be separated from the implementation of people." Yang Min said that compared with "giving fish to people", "teaching people how to fish" is more important. Denso China has trained about 200 energy-saving improvement instructors in various production companies. Through the investigation of each base, the energy-saving level and awareness of each company are mastered. The training method is formulated with the theme of training the personnel who promote energy conservation in each production base to "be able to discover energy-saving cases and implement improvements on their own". At the same time, in order to train more energy-saving talents as soon as possible, Denso China selects 3 core energy-saving talents in each production base for intensive training. With these core talents as the center, the scale of energy-saving promoters is gradually expanded, thereby comprehensively improving the efficiency of popularization of energy-saving education.