Monthly Progress Report (39) November 2022

Major Activities of the Month

The PI consultant team members’ assignment during the month of November was rather sparce compared with that of the previous month. Major activities of the PI consultant team during the reporting month are summarised below: 

1. Steel Re-rolling Mill Energy Advisory Visit 

On 3rd of November, the PI Consultant Team, with the attendance of SREDA officials, conducted an energy advisory visit to one of the mid-large scale steel re-rolling mills in Bangladesh using induction furnaces for its foundry. It was the third steel re-rolling mill to be visited by the PI Consultant Team after the steel mill with the latest arc furnace model (November 2019), and one of the largest induction furnace mill (March 2022). Its direct rolling process was one of the most striking energy efficient features to be observed.

An introductory presentation was given by the Project Director, followed by a walk-through inspection. Common practice for energy audits is, to share and collect a questionnaire / EE&C performance check sheet with the operating entity in advance, so that the audit team can make a preliminary analysis of the basic operational information, such as energy consumption and energy intensity and already implemented energy conservation measures. 

Item Information
■ Company name
■ Factory name
■ Address of factory
■ Contact person name & e-mail address
■ Starting year of operation 
■ Product name
■ Production capacity (ton/year)
■ Production amount in 2021 (ton/year)
■ Number of engineers
■ Number of employees
Table 1 Excerpt of the Questionnaire (1)
No.EnergyAnnual consumption
1Electricity from grid kWh
2Natural gas for production m3
3Natural gas for captive power generation m3
4LPG kg
5Fuel oil Litre
6Diesel oil Litre
7Other fuel, Oxygen kg, L
8Captive power generation kWh
9Contract demand of electricity KVA
Table 2 Excerpt of the Questionnaire (2)

However, in this case obtaining the required information in advance was not possible, so the focus was set on the on-sight survey. The steel re-rolling mill visited had already implemented two major energy conservation measures. One is the application of the steel billet direct rolling process. The natural gas consumption savings through the application of this technology for the steel re-rolling mill, based on estimated data, is as follows: 

1) Annual steel bar production = 100,000 ton/y,
2) Direct rolling ratio = 40%
3) Fuel intensity of reheating furnace = 400 Mcal/ton
4) Natural gas heat value = 8,500 kcal/m3

Annual natural gas saving volume = 100,000 * 0.4 * 400,000 / 8,500 = 1,882, 000 m3/y

Fig 1 Comparison between direct rolling process and conventional rolling process

The second EE&C measure is the installation of inverter-controlled dust collector fans. The steel re-rolling mill operates a dust collector with an inverter-controlled fan motor to improve the working condition of its induction furnace and to save power consumption. As shown in the figure below, power consumption of a 100kW dust collector fan motor can be saved by up to 32kW through inverter-controlling.

Fig 2 Energy saving effect of inverters for 100kW motors

Nevertheless, there were still several opportunities to further improve the plant’s energy performance. One major example was the reheating furnace. The furnace is operated by a manual valve control for natural gas and combustion air. Following recommendations were made by the audit team.

  • Installation of an automatic combustion control system, to keep heat pattern of furnace stable. Automatic combustion control has the advantage, that it can control the flowrate of natural gas and combustion air to keep a low air ratio. It can also control the temperature and heat pattern in the furnace.
  • Installation of a regenerative burner. The installation of a regenerative burner would require a huge renovation of the plant, but it would improve the energy efficiency drastically by utilising the exhaust heat.
Fig 3 Evolution of Heat Recovery Features in Heating Furnace 
Fig 4 Thermal image of the reheating furnace

Another recommendation was the improvement of the reheating furnace’s insulation. As shown in the thermal image above, the refractories of the side wall are showing a temperature of 68.2 degrees centigrade, which is reasonable. Meanwhile, the insulation material of the inspection doors is showing temperatures of 100.5 and 126.3 degrees centigrade. This is a sign, that the insulation material of the inspection doors needs to be replaced.

For the long-term scope, the audit team recommended the installation of ECOARC for induction furnaces. The steel re-rolling mill produces molten steel by using 2 20 ton/charge and 1 15 ton/charge induction furnaces. The installation of an electric arc furnace with scrap preheater, would have a huge power saving potential. 

Fig 5 Overview of an electric arc furnace with scrap steel preheater
EquipmentPower intensity
Induction Furnace610 – 620 kWh/ton
Electric Arc Furnace with Scrap Steel Preheater 250 – 350 kWh/ton
Table 3 Power Intensity Comparison of Furnace Types

2. Compilation of the Golden Procedure of Building Energy Audit Documents 

On 17th of November, Dr Kimio Yoshida, the EE&C promotion policy and technology expert of the PI Consultant Team, made a comprehensive presentation on the Golden Procedure of Building Energy Audit. The presentation was the comprehensive compilation of the fragmented findings and recommendations which were presented on many occasions in the past. 

The focus was on the basic knowledge on building energy consumption features by building type which should be recognized among the auditors, before conducting the field visits. The most important among the preparation is to collect the following data. 

Fig 6 Averaged or target energy intensity (energy consumption per square metre) by building type 
Fig 7 Averaged energy consumption by purpose by building type 

Requirements are not only data collection, but also before conducting the field survey, expected output and potential recommendation should be imaged based on preliminary collected data and knowledge platform. The measuring equipment should also be chosen so that visualization of the imaged output will be possible. The template of standard building audit report should also be identified before the field survey. 

Information collected from the actual field survey is also used as essential findings. The examples below are the findings on the absence of proper insulation in the case of some buildings in Bangladesh. Visualization using thermo-camera is quite effective and persuasive for to be included in the report. 

Figure 8 Examples of Visualisation of the Field Survey Findings (1)
Figure 8 Examples of Visualisation of the Field Survey Findings (2)

3. Zero Energy Buildings Promotion 

Also on 17th November, Dr Kimio Yoshida also presented the key points of Japan’s Zero Energy Building (ZEB) guidelines to SREDA. The presentation focused on a striking trend of the very rapid pace of ZEB and ZEH (Zero Energy House) penetration in Japan. The following elements were pointed out the major reasons why ZEB/ ZEH are increasing: 

  • Government had set the target to accelerate ZEB/ ZEH, 
  • To realize this target, the Government formulated comprehensive supporting mechanisms including the introduction of certification for ZEB planners and ZEH planners/ builders. As of end of October 2022, around 400 ZEB planners and around 3,700 ZEH planners/ builders have been certified. It is through these planners that the end users are given easy access to ZEB and ZEH. 
  • The Government has also published several ZEB guidelines and design tools, such as for mid-size office, small size office, hospital, hotel, school, nursery. Guidelines are also available for ZEH, 
  • The official ZEB/ZEH logos are becoming the status for the home and building owners, contributing to the awareness raising, 
  • Financial incentive mechanism for ZEB/ ZEH construction involving the central government, local municipality, and the financial institutions has been introduced. 

4. Facilitating the Project Loan Utilisation

4.1 Observing the Issuance of NOCs and MIS Registration 

As of the end of November, there were 15 NOCs issued during the months of September – October – November but were not registered on the Project MIS. The PI consultant team consulted with the SREDA PIU to confirm that the NOCs have been issued following requires steps and supported the PIU to catch up with the MIS record keeping. The following NOCs are now uploaded onto the Project MIS with an updated work record of the eligibility checking. 

IDIssue dateSectorEquipment
AD2208230129 Sep 2022PharmaceuticalCompressor, chiller, LED, elevator 
AF2208210124 Oct 2022SpinningGas engine for cogeneration 
AF2208210224 Oct 2022SpinningGas engine for cogeneration 
AF2208210324 Oct 2022Weaving Gas engine for cogeneration 
AF22082104*24 Oct 2022TextilesGas engine for cogeneration 
AF2208210524 Oct 2022TextilesGas engine for cogeneration 
AF2208210624 Oct 2022TextilesGas engine for cogeneration 
AF2208210724 Oct 2022TextilesGas engine for cogeneration 
AF2209020124 Oct 2022SpinningGas engine for cogeneration 
AF2209020224 Oct 2022SpinningGas engine for cogeneration 
AF2209020324 Oct 2022TextilesGas engine for cogeneration 
AF2209020424 Oct 2022SpinningGas engine for cogeneration 
AF2209020524 Oct 2022SpinningGas engine for cogeneration 
AF22091901*03 Nov 2022TextilesSewing machine
AD2209140107 Nov 2022CementGas engine for cogeneration 
Table 1 Fifteen NOCs Not Registered on the Project MIS
(Note: AF22082104 and AF22091901 are awaiting manager approval.)

4.2 Project MIS Improvement 

The Project MIS was found be in requirement for technical update in that the latest file encryption is not being accepted, resulting in difficulty to upload the scanned NOCs. CSL Software Resources conducted a minor maintenance to have this function updated. It was on this occasion that the list of the PI Consultant Team’s members who are involved in the issue management of the Project MIS was also updated. 

5. Appendices 

Appendix 39-1: Zahir Steel & Re-Rolling Mills Limited – Energy Advisory Visit Report 

Appendix 39-2: Golden Procedure of Building Energy Audit – Hints for Bangladesh 

Appendix 39-3: Introduction for the ZEB Guidelines in Japan