Experimental and CFD analysis of wire coil turbulators in biomass boilers
Апстракт
To achieve as complete fuel burnout with as little excess air as possible, small wood log boilers (< 50 kW) use stage combustion. The first stage is often a process similar to downdraft gasification that consequently produces a flue gas laden with particulates. To prevent the build-up of solids and promote heat transfer in pipes of the convective part of these boilers, wire coils are used. The paper presents their in-situ examination together with CFD analysis. The analysis is carried out in a 460 mm long pipe, with a diameter of 82.5 mm, equipped with different wire coils for flue gas temperatures in the range between 300 °C and 150 °C. The analyzed coils are with and without a conical spring at their free end. The addition of this conical top is economical and should influence the rotation of the core flow. Proper pipe surface cleaning limited the analyzed wire coil designs to the dimensionless pitch, p/d, in the range between 0.36-0.61, dimensionless wire diameter e/d = 0.04-0.1, an...d pitch to wire diameter ratios p/e = 3.75-14.3, and three different angles (60⁰, 90⁰, and 120⁰) of the conical top. The goals are to find the optimal flue gas velocity for the given operating conditions, pipe, and wire coil dimensions, and to investigate the addition of the conical top on heat transfer enhancement. Several evaluation criteria are used to achieve the goals.
Кључне речи:
wire coils / heat transfer enhancement / turbulators / CFD model / biomass boilerИзвор:
Thermal Science, 2023, 27, 1A, 71-87Издавач:
- University of Belgrade, Vinča Institute of Nuclear Sciences
Финансирање / пројекти:
- Министарство науке, технолошког развоја и иновација Републике Србије, институционално финансирање - 200108 (Универзитет у Крагујевцу, Машински факултет, Краљево) (RS-200108)
- Министарство науке, технолошког развоја и иновација Републике Србије, институционално финансирање - 200105 (Универзитет у Београду, Машински факултет) (RS-200105)
Колекције
Институција/група
Mašinski fakultetTY - JOUR AU - Novčić, Đorđe AU - Nikolić, Miloš AU - Todorović, Dušan AU - Karamarković, Rade AU - Obradović, Marko PY - 2023 UR - https://machinery.mas.bg.ac.rs/handle/123456789/4831 AB - To achieve as complete fuel burnout with as little excess air as possible, small wood log boilers (< 50 kW) use stage combustion. The first stage is often a process similar to downdraft gasification that consequently produces a flue gas laden with particulates. To prevent the build-up of solids and promote heat transfer in pipes of the convective part of these boilers, wire coils are used. The paper presents their in-situ examination together with CFD analysis. The analysis is carried out in a 460 mm long pipe, with a diameter of 82.5 mm, equipped with different wire coils for flue gas temperatures in the range between 300 °C and 150 °C. The analyzed coils are with and without a conical spring at their free end. The addition of this conical top is economical and should influence the rotation of the core flow. Proper pipe surface cleaning limited the analyzed wire coil designs to the dimensionless pitch, p/d, in the range between 0.36-0.61, dimensionless wire diameter e/d = 0.04-0.1, and pitch to wire diameter ratios p/e = 3.75-14.3, and three different angles (60⁰, 90⁰, and 120⁰) of the conical top. The goals are to find the optimal flue gas velocity for the given operating conditions, pipe, and wire coil dimensions, and to investigate the addition of the conical top on heat transfer enhancement. Several evaluation criteria are used to achieve the goals. PB - University of Belgrade, Vinča Institute of Nuclear Sciences T2 - Thermal Science T1 - Experimental and CFD analysis of wire coil turbulators in biomass boilers EP - 87 IS - 1A SP - 71 VL - 27 DO - 10.2298/TSCI2301071N ER -
@article{ author = "Novčić, Đorđe and Nikolić, Miloš and Todorović, Dušan and Karamarković, Rade and Obradović, Marko", year = "2023", abstract = "To achieve as complete fuel burnout with as little excess air as possible, small wood log boilers (< 50 kW) use stage combustion. The first stage is often a process similar to downdraft gasification that consequently produces a flue gas laden with particulates. To prevent the build-up of solids and promote heat transfer in pipes of the convective part of these boilers, wire coils are used. The paper presents their in-situ examination together with CFD analysis. The analysis is carried out in a 460 mm long pipe, with a diameter of 82.5 mm, equipped with different wire coils for flue gas temperatures in the range between 300 °C and 150 °C. The analyzed coils are with and without a conical spring at their free end. The addition of this conical top is economical and should influence the rotation of the core flow. Proper pipe surface cleaning limited the analyzed wire coil designs to the dimensionless pitch, p/d, in the range between 0.36-0.61, dimensionless wire diameter e/d = 0.04-0.1, and pitch to wire diameter ratios p/e = 3.75-14.3, and three different angles (60⁰, 90⁰, and 120⁰) of the conical top. The goals are to find the optimal flue gas velocity for the given operating conditions, pipe, and wire coil dimensions, and to investigate the addition of the conical top on heat transfer enhancement. Several evaluation criteria are used to achieve the goals.", publisher = "University of Belgrade, Vinča Institute of Nuclear Sciences", journal = "Thermal Science", title = "Experimental and CFD analysis of wire coil turbulators in biomass boilers", pages = "87-71", number = "1A", volume = "27", doi = "10.2298/TSCI2301071N" }
Novčić, Đ., Nikolić, M., Todorović, D., Karamarković, R.,& Obradović, M.. (2023). Experimental and CFD analysis of wire coil turbulators in biomass boilers. in Thermal Science University of Belgrade, Vinča Institute of Nuclear Sciences., 27(1A), 71-87. https://doi.org/10.2298/TSCI2301071N
Novčić Đ, Nikolić M, Todorović D, Karamarković R, Obradović M. Experimental and CFD analysis of wire coil turbulators in biomass boilers. in Thermal Science. 2023;27(1A):71-87. doi:10.2298/TSCI2301071N .
Novčić, Đorđe, Nikolić, Miloš, Todorović, Dušan, Karamarković, Rade, Obradović, Marko, "Experimental and CFD analysis of wire coil turbulators in biomass boilers" in Thermal Science, 27, no. 1A (2023):71-87, https://doi.org/10.2298/TSCI2301071N . .