Heating performance of a laboratory pilot-plant combining heat exchanger and air scrubber for animal houses

AbstractExhaust air treatment systems (EATS) are used in animal husbandry to reduce emissions. However, EATS are associated with high acquisition and operating costs. Therefore, a plant technology is being developed that integrates a recuperative heat exchanger into a biological air scrubber. The overall aim is to reduce total costs of livestock buildings with EATS by saving heating costs and to improve animal environment. In this study, a special pilot-plant on a small-scale, using clean exhaust air, was constructed to evaluate the heating performance on laboratory scale. Three assembly situations of the heat exchanger into trickle-bed reactor were part of a trial with two different defined air flow rates. In all three assembly situations, preheating of cold outside air was observed. The heating performance of the assembly situation with the sprayed heat exchanger arranged below showed an average of 4.4 kW at 1800 m3 h−1 (outside air temperature range 0.0–7.9 °C). This is up to 18% higher than the other two experimental setups. The heating performance of the pilot-plant is particularly influenced by the outside air temperature. Further research on the pilot-plant is required to test the system under field conditions.

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Heating Performance and Ammonia Removal of a Single-Stage Bioscrubber Pilot Plant with Integrated Heat Exchanger under Field Conditions

Energies ◽

10.3390/en14206484 ◽

2021 ◽

Vol 14 (20) ◽

pp. 6484

Author(s):

Manuel S. Krommweh ◽

Hauke F. Deeken ◽

Hannah Licharz ◽

Wolfgang Büscher

Keyword(s):

Heat Exchanger ◽

Thermal Energy ◽

Ammonia Removal ◽

Coefficient Of Performance ◽

Air Treatment ◽

Process Stage ◽

Heating Performance ◽

Recuperative Heat Exchanger ◽

First Time

In this study, biological exhaust air treatment was combined with a recuperative heat exchanger in one process stage. The aim of this plant development and testing is not only to reduce ammonia from the exhaust air of pig houses but also to recover thermal energy at the same time. This is intended to offset the high operating costs of exhaust air treatment with savings of heating costs in cold seasons and to use the plant more efficiently. This system was tested for the first time under practical conditions in a pig fattening house in southern Germany. Three different assembly situations of the heat exchanger were examined for 13 days each and then compared with each other. The heating performance of the plant is primarily dependent on the outside air temperature and secondarily on the scrubbing water temperature. Depending on the assembly situation of the heat exchanger, an average heating performance of between 6.0 and 10.0 kW was observed; the amount of recovered thermal energy was between 1860 and 3132 kWh. The coefficient of performance (COP) ranked between 7.1 and 11.5. Furthermore, ammonia removal up to 64% was demonstrated. A long-term investigation of the system under practical conditions is recommended to validate the data collected in this study.

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Optimization of the Performance of Hybrid Solar Biomass Dryer for Drying Maize Using ANSYS Workbench

Journal of Energy Research and Reviews ◽

10.9734/jenrr/2020/v4i130119 ◽

2020 ◽

pp. 50-69

Author(s):

Jackis Aukah ◽

Mutuku Muvengei ◽

Hiram Ndiritu ◽

Calvin Onyango

Keyword(s):

Heat Exchanger ◽

Air Temperature ◽

Small Scale ◽

Air Velocity ◽

Hot Air ◽

Permissible Range ◽

Feasible Option ◽

Input Variables ◽

Drying Chamber ◽

Ansys Workbench

In this paper ANSYS workbench was used to optimize the performance of hybrid solar biomass dryer for drying shelled maize in order to find the optimal operating input variables when the air temperature within the drying chamber set within the permissible range at reasonably high flow velocity. Hybrid Solar dryer with biomass as a source of fuel for auxiliary heating during absence or low solar insolation is a feasible option for small scale maize farmers [1]. At times high temperatures are induced in this dryer which may result in grain fissures and breakage during milling, thus reducing the grain quality. Optimization results indicate that in order to keep the air temperature within drying chamber to permissible range [2], the air velocity at collector inlet and biomass heat exchanger outlet should be improved to 3 m/s and 2.8 m/s respectively while the capacity of the biomass heat exchanger should also be enhanced to provide hot air at 85°C. It be concluded from the study that HSBD is suitable for drying maize as well as other agricultural products since continuous interrupted drying can be achieved. The capability of the dryer to maintain uniform temperature and air flow within the drying chamber enable high quality dried products within a short duration.

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OPERATING COSTS FOR A RECUPERATIVE HEAT EXCHANGER

Modern Technologies and Scientific and Technological Progress ◽

10.36629/2686-9896-2020-1-95-96 ◽

2020 ◽

Vol 2020 (1) ◽

pp. 95-96

Author(s):

Sergey Scherbin ◽

Anatoliy Glotov

Keyword(s):

Heat Exchanger ◽

Operating Costs ◽

Design Parameters ◽

Recuperative Heat Exchanger ◽

Heat Carriers

The operating costs of a recuperative heat exchanger are considered, taking into account its hydrodynamic and design parameters, properties of heat carriers

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Development and Testing of a Small-Scale Collins Type Cryocooler

Advanced Energy Systems ◽

10.1115/imece2004-60388 ◽

2004 ◽

Author(s):

C. L. Hannon ◽

B. J. Krass ◽

J. Gerstmann ◽

G. Chaudhry ◽

J. G. Brisson ◽

...

Keyword(s):

Heat Exchanger ◽

Room Temperature ◽

High Efficiency ◽

Modular Design ◽

Rapid Cool ◽

Small Scale ◽

Control Logic ◽

Prototype Development ◽

Multi Stage ◽

Recuperative Heat Exchanger

Future spacecraft cooling and sensing systems will require advanced multi-stage cryocoolers capable of providing continuous cooling at multiple temperature levels ranging from 10K to 95K. A multi-stage 10K cryocooler is under development that applies modern microelectronic sophistication to achieve high efficiency in a reliable, compact design. The cryocooler is based upon a novel modification of the Collins cycle, a cycle commonly used in many high-efficiency terrestrial cryogenic machines. Innovations of the design include floating piston expanders and electromagnetic smart valves, which eliminate the need for mechanical linkages and thereby reduce the input power, size, and weight of the cryocooler in an affordable modular design. The floating piston expander and smart valves have been successfully developed in room temperature experiments using a series of proof-of-concept component prototypes. These experiments have resulted in a new warm-end configuration with improved expansion power dissipation and a new cryogenic valve design that reduces expander clearance volume and improves cold-end integration. A sophisticated LabView based control algorithm was developed over the course of the room temperature experiments that enables electronic control of the expansion cycle. Software based control will enable variable valve timing and adaptive control logic. This will result in a cryocooler with rapid cool-down and transient response capabilities as well as the ability to operate at high efficiency at arbitrary steady state load points. In parallel to this effort, a manufacturing method was developed to enable production of very long continuous lengths of small bore finned tubing. This tubing is used in the highly effective recuperative heat exchanger associated with each stage of the cryocooler. An engineering prototype has been designed that integrates the floating piston expander and recuperative heat exchanger as a functional cryocooler. The engineering prototype has been assembled and is currently undergoing development testing. This paper will present the results of the room temperature component development testing, the design of the engineering prototype, the results of initial engineering prototype development testing, and the direction of future development.

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Experimental Study to Investigate the Effect of Backfilling Materials on Thermal Performance of Ground Air Heat Exchanger System

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4044176 ◽

2019 ◽

pp. 1-36 ◽

Cited By ~ 3

Author(s):

Kamal Agrawal ◽

Rohit Misra ◽

Ghanshyam Das Agrawal

Keyword(s):

Thermal Properties ◽

Heat Exchanger ◽

Air Temperature ◽

Thermal Performance ◽

Small Scale ◽

Outlet Section ◽

Experimental Setup ◽

Land Area ◽

Pipe Length ◽

Soil Thermal Properties

In ground-air-heat exchanger (GAHE) system, the heat transfer between air and underground soil largely depends on soil thermal properties and therefore, any improvement in soil thermal properties will shorten the pipe length required and the land area needed for its installation. The objective of the present study is to investigate the effect of different backfilling materials (low cost and locally available) on the thermal performance of GAHE system using a small-scale laboratory experimental setup laboratory scale experimental setup. Seven different backfilling materials have been considered for the study and It was observed that after 6 hours of continuous operation, the drop in air temperature was 6.2°C at outlet section of pipe (2.4m away from inlet) for the native soil. However, for sand-bentonite with graphite as a backfilling material (BFM), the drop in air temperature of 6.2°C was obtained at a pipe length of 1.15m only. Therefore, the use of sand-bentonite with graphite as a BFM reduces the pipe length of GAHE system by more than 50%. The study establishes the fact that the length of pipe and land area requirement for GAHE system can be substantially reduced by using thermally enhanced backfilling materials at the close vicinity of GAHE pipes.

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Water Pollution Abatement in Small Paper Mills in India

Water Science & Technology ◽

10.2166/wst.1988.0006 ◽

1988 ◽

Vol 20 (1) ◽

pp. 37-48 ◽

Cited By ~ 1

Author(s):

L. Panneerselvam

Keyword(s):

Water Pollution ◽

Wastewater Treatment ◽

Raw Materials ◽

Pollution Abatement ◽

Pulp And Paper ◽

Operating Costs ◽

Small Scale ◽

Pulp And Paper Mills ◽

Paper Mills ◽

Recovery System

In order to reduce the demand for the forest based raw materials by the organised industrial sectors like the large integrated pulp and paper mills, the Government of India started promoting several small-scale pulp and paper mills based on non-wood agricultural residue raw materials. However promotion of these small mills has created another environmental problem i.e. severe water pollution due to non-recovery of chemicals. Because of the typical characteristics like high silica content etc. of the black liquor produced and the subsequent high capital investment needed for a recovery system, it is not economically feasible for the small Indian mills to recover the chemicals. While the quantity of wastewater generated per tonne of paper produced by a small mill is same as from a large integrated pulp and paper mill with a chemical recovery system, their BOD load is four times higher, due to non recovery of chemicals. However the existing wastewater disposal standards are uniform for large and small mills for e.g. 30 mg BOD/l. To meet these standards, the small mills have to install a capital intensive wastewater treatment plant with heavy recurring operating costs. Therefore the feasible alternative is to implement various pollution abatement measures, with the objective of not only reducing the fibre/chemical loss but also to reduce the investment and operating costs of the final wastewater treatment system. To illustrate this approach, a case study on water pollution abatement and control in a 10 TPD mill, will be discussed.

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