Our story has begun when our team initiated the meetings with Çimko Narlı Cement Plant about the investments for establishing a Waste Heat Recovery (WHR) plant. This Energy Efficiency investment is an effort of the plant to find solutions to the problem of electricity consumption, as the largest cost item of the plant, aiming at meeting plant’s energy need of about 12% per year with the waste heat produced by the Clinker Cooling Unit. The real meat of this turnkey project which made us proud is that the entire project from stages of engineering to production, assembly to commission, has been delivered only using our own workforce and proprietary technology. If we are to detail the technical particularities of the project;
Preferred Technology
For Çimko Narlı Plant Waste Heat Recovery Project, CTP Team offered an innovative, ORC (Organic Rankine Cycle)-based New Heat Recovery system, preferred by many Cement plants in Europe and the USA, which does not consume underground resources, by taking into account the process design conditions of the plant, environmental facts as well as cost efficiency of the investment. The system, which will be applied in Turkey for the first time, caused an excitement both for our team and Çimko Narlı Plant team when it was chosen by the technical team of the plant and the project launched.
ORC Technology: A two-stage heat transfer in a closed loop
WHR electricity generation system is designed in order to maximize the NET electricity generation at “low temperatures”: P(net) electricity = P(gross) electricity – P(internal) consumption.
The working principle of the system can be outlined as such hot waste gas from clinker cooling unit is fed to the boiler unit of the system. Said waste gas heats “Heat Transfer Oil” in the boiler unit, and, thus, thermal heat transfer in the waste gas occurs.
Then, heat transfer oil in the boiler transfers its own heat energy to other “cyclopentane” liquid through special external heat exchangers making said liquid to pass to the gas phase. In the Organic Rankine Cycle, the system generates electricity through expansion of the organic liquid, which is now in the gas state, in a 3000 RPM turbine connected to the 8,2 kVA turbo generator.
In our Project, Heat Recovery Boilers are designed and produced by CTP
CTP Team designed and dimensioned the heat recovery boilers by ensuring a balance among many factors. These factors include;
• Gas flow rate between exchangers – This factor plays an important role in the size of boiler, requiring an advanced level of process know-how.
• Powder contents and powder quality – (for instance; abrasive or adhesive) It is normally considered in determination of the most suitable approach for feeding hot gas to the bundle and optimized using a CFD modelling.
• Thermal oil flow rate between exchangers – Together with gas flow rate outside the tube, this factor affects the general exchange co-efficient.
• Thermal oil working pressure – The most optimal oil path in the bundle is selected to keep pressure drops at a minimum level in the loop and to make them have power necessary for circulation.
All of the above factors are integrated homogenously both in the design of boil and the entire system.
As CTP, one of our strengths is our solid technical and business relationship with producers of turbines for the ORC system. CTP has a deep know-how about industrial processes, turnkey project management and equipment integration, as well as a solid technological and business structure.
Critical Points to Consider
Process Integration at a Suitable Point
In terms of process gas balance, ORC system degassing connection point and location is the most important issue. It is important to ensure that system properly reacts to the imbalances in the gas flows in the Rotary Kiln and Clinker Cooling units and not allowing any gas turbulences to occur in the system. The waste gas must be used in the very meaning of the term. Thanks to the deep know-how of the CTP Team on the cement production processes, WHR plant is fully integrated to the existing plant, without affecting the production parameters, only using the waste gas from Clinker cooling unit. In this context, entire automation, mechanical and electrical interfaces are included in the CTP scope of supply to make the system fully-integrated.
Turnkey System
The scope of Turnkey EPC project includes:
Engineering: General layout of the project is designed, ORC unit and boiler positioning and design works are carried out. Detail engineering works. As part of construction, foundation and detail reinforced concrete and steel engineering design, electrical and automation detail engineering works are delivered by CTP.
Purchasing and Manufacturing: All equipment are procured from the “vendor list” which includes European origin brands. All steel manufacturing is carried out in our Adana-based CTN Machinery plant.
Assembly/Installation: Repair and replacement of existing cooling ducts, entire civil works, steel mechanical assembly works, electricity and automation assembly works are carried out by our team of CTN Machinery
Commissioning: Our project is finalized after the commissioning of the system, training of the plant operators, and delivery of the documentation, handover and guarantee conditions.
All above steps are delivered to the European Standards.
A Fast Delivery Process
The system is commissioned in a short time as 14 months after the contract is signed.
Additional Energy Savings in the Cement Production Process
In the cases where gas cooling is required for filtering process (for example: Bag Filter), WHR heat dissipation capacity is partially used in place of said equipment minimizing the energy and water consumption of the gas cooling systems such as air-air heat exchangers or cooling tower.
Today, thanks to WHR Project, Çimko Narlı Plant will be able to generate additional electricity at the 110 thousand KwH levels per day if the plant runs at the full-capacity. In other words, net annually expected electricity generation will be 36 Million kWh. This figure means that cement plant will meet about 12% of the current electricity need and, in terms of environment, around 15.000 tonnage of CO2 per year will not be released into the nature. Upon commissioning of the system, entire WHR plant will be controlled via a SCADA system and monitored remotely by CTP.
To sum up, the WHR plant generates electricity from waste heat using a full automatic and remotely monitored system without requiring consumption of the natural resources such as water thanks to the technology it contains.
