First working reference of CTP with WHR-ORC

Kiln exhaust streams from clinker cooler and the kiln preheater system contain useful thermal energy that can be converted into power.

shuttle blu

36.000.000 kWh

Power production per year

carbon-dioxide

15.000 TPY

Avoided CO2 emissions per year

plant

No water consumption

Protect natural resources

coin

Payback 3 years

Expected saving 3.060.000 €/year

Basic design data

BOILER GAS FLOW Nm3/h 320.000
TURBOGENERATOR CAPACITY MW 7
TURBINE RATED SPEED RPM 3.000
MAX WHR THERMAL POWER kWt 26.200

Scope: WHR SYSTEM ORC-based
Country: Turkey
Full Epc Turn-key project: overall management from Engineering to Commissioning & Start-up
Technological choice: Organic Rankine Cycle
Neutral impact on environment: no exploitation of natural resources (water)
Turbogenerator capacity: 7MW
Full integration of mechanical and electrical scope.

How the installation of a Waste Heat Recovery System supported the efficiency and sustainability objectives in Cimko Narli Cement plant.

The request of the customer or Customer goal

The story began in 2017, when CTP Team entered into discussions with Cimko Narli Cement about the new investment of USD millions to install a Waste heat recovery “WHR” power plant. As one further step in the steady growth of the Cement plant and one piece towards Cimko Narli more efficiency and sustainability efforts. During early discussions about the WHR new investment, it became apparent that CTP Team could not only provide the equipment that Cimko Narli was looking for, but also assist with engineering, procurement and construction activities as requested by a Turn-key EPC Contract.

This means that CTP Team would supply the whole system and would become the main contractor for the project taking care about everything necessary for the execution and proper performance of the system.

Top view of air coolers and boiler in Narli cement factory, Turkey

Two-stage heat transfer process in a closed loop

The WHR power generation system has been designed to maximize the NET power production of the system, defined as: Pnet electric = Pgross electric – Pauxiliary consumption. In the Organic rankine cycle the output electric energy is allowed by the organic fluid expanded though the 3000 RPM turbine, which is connected to a 8,2 kVA turbo generator. The WHR boiler is fed by hot exhaust air from the clinker cooler and it is responsible of the first heat transfer from waste gas to the heat transfer fluid (i.e Thermal oil). Therefore, in the second transfer, the high temperature thermal oil transfers the thermal power to the organic fluid (ORC) in dedicated external heat exchangers.

Critical points to be faced

  • Smart Tie-in brown field

One of the most critical point to be faced with it has been the definition of smart Tie-in in brown field which should avoid any turbulences in the cement production. Thanks to CTP Team deep knowledge of the process conditions we were able to fully integrate WHR in the existing plant without affecting production parameters (process, automation, mechanical and electrical interfaces are all in CTP scope of supply).

  • High Complexity

High level of complexity typical of turn-key basis EPC project which includes in details: in house capacity basic and detail engineering design, supply the New equipment manufacturing of all steelworks in our workshop, modification of the existing cooler ducts, civil works, assembly and erection; mechanical and electrical scope and cabling, Training of plant operators, handing over and guarantee all the works at the expected standard quality.

  • Quick delivery time

Just 14 months from the signature of the contract to the commissioning of the system.

The technological choice

Considering the process design conditions, the environmental data together with the economic investment, CTP Team has proposed a new Waste Heat Recovery system, based on the innovative ORC technology as the preferred technology for Cimko Narli power generation project.

Own design and direct manufacturing of Heat Recovery Boilers in the proprietary workshop

CTP Team has designed and sized the heat recovery boiler balancing many interconnected factors:

  • Gas velocity through the bundles – this plays an important role in the size of the boiler.
  • Dust content and nature of the dust (i.e., abrasive or sticky). This is normally considered to decide the most suitable approach of the hot gas to the bundle and optimized through a CFD modelling.
  • Velocity of the thermal oil inside the bundle. Together with the gas velocity outside the tubes, this factor impacts on the global exchanging coefficient.
  • Thermal oil Operating pressure. The oil path inside the bundles must be properly selected to keep low the pressure drops of the circuit and contains the power needed for its circulation.

All the above factors are homogenously integrated in the boiler design and, in general, in the global design of the delivered WHR system as well. In addition, CTP directly deals and keep an open dialog with the main producers of turbines with Organic fluids. Building a strong technological and commercial partnership based on common know-how of the industrial process and integration of equipment.

Further energy savings in the industrial process

In those cases in which gas cooling is requested for filtration process (i.e Bag Filter), the WHR dissipation capacity could also be used in partially substitution of these equipment reducing the energy and water consumptions of existing gas cooling systems such as air-to-air heat exchangers or cooling tower.

Final conclusions

Today Cimko Narli WHR is producing in steady condition a net power production in the range of 110 thousands kWh per DAY, in one year the expected net power production will be about 36 million kWh. This means that the system will cover about the 12% of the current electricity needs of the cement plant and from an environmental point of view, the avoided CO2 emission will be about 15,000 ton/year.
All the WHR process is controlled by a Scada system and remotely monitored by CTP.

This WHR systems offer a suitable and reliable way for Cimko Narli cement plant to produce energy internally without additional greenhouse gas emissions as well as enhance the energy efficiency of the cement plant. Moreover, unlike the Steam Ranking cycle, adopting the ORC technology maintains a neutral impact on the environment avoiding completely the use of natural resources such as water. A precious natural resource especially in those countries where its availability is extremely limited.