LPC-e High performance Low Power Consumption Stable fans
The new Ecodesign requirements incite vendor subcontractors to manufacture and optimize fans ac-cording to BEP. Even though this point is the theoretical best point, the operating point that agricultural-fans usually work in results in ineffective fan-blades in the actual operating-area.
As the market no longer delivers energy-efficient fan-blades optimized for agricultural purposes a new Danish-produced cost-effective and energy-efficient fan-series LPC-e with associated dimensioning and simulation tool is developed. The fan (motor+control+blade+mounting) is developed against a steep, non-characteristic power-consumption curve. In cooperation with new PM-motor-technology, this will allow the fan pressure and flow to be determined. This eliminates the balancing dampers that causes large throttle pressure and energy losses.
The project focuses on the entire system (the stables and AC-system) and the influence of individual subcomponents on this system. The single components are optimized for the annual operating area.
This takes into account the number of operating hours and the parts of the operating area that are rele-vant and their impact on the system. With this strategy the energy consumption is reduced to a mini-mum and the system cost-price is optimized. The success criterion is an optimization that results in an electricity saving of 40% with a payback less than 2-years.
The project has developed a design of two new energy efficient barn fans LPCe, respectively a chimney fan Ø800 and a gable fan Ø1400.
The efficiency evaluation focused at the combined system. Instead of evaluation of the fan in best efficiency point, the fan has been optimized according to barn design, indoor climate, system solution and individual components.
Special focus has been to develop a fan, with clear connection between fan performance and power absorption. Normally the fan has a stalling point, but without a stalling point the fan controller will be able to give the air flow from recording of power (W) and round per minute (RMP); see figure 1.1.
The project has with success developed the design of an propeller without stalling for Ø1400. From recording power and RMP the airflow can be given. Normally an exact air flow on a farm requires instruments to measure. So, it is unique the air flow can be detected direct.
Figure 1.1: Energy consumption as a function of air flow for 600 RPM
- Blue curve shows the curve for existing fan characteristic with stalling point
- Pink curve shows the show fan characteristic for new designed fan without stalling
The project has also developed a prototype of a controller, which is able to maintain the required air flow even the pressure varies (for instance when the wind is blowing outside). Today is used dampers to maintain the air flow when the wind is blowing outside, but the vision could be that this should not be necessary for low air flow in the future.
Energy reduction
In order to simulate the energy reduction a new sub routine has been developed for the recognized simulation software Staldvent. The sub routine calculates the wind load at the building based at pressure coefficient for different wind directions.
Simulations are done for a finishing unit in Denmark and a farrowing unit in Vietnam, and depending of baseline the potential energy reduction is 22-34% compared to best practice today with Dynamic multistep.
The project is co-financed by the ELFORSK program with project no. 350-019 during the period 1 April 2018 to 1 April 2020 and was carried out by the following project participants:
- SKOV A / S
- Institute of Technology
- Danish Exergy Technology A / S
- Fabrika A / S
- OJ electronics A / S.
Key figures
Category
Participants
| Partner | Subsidy | Auto financing |
|---|---|---|
| Teknologisk Institut | ||
| Danmarks Tekniske Universitet (DTU) | ||
| OJ Electronics A/S | ||
| FABRIKA | ||
| DXT, Danish Exergi Technology A/S |
