Case Studies
Luddington & Garthorpe Primary (Containerized Firematic 50)
plug and play
Commissioned in August 2007, this 50kW boiler was delivered to site fully installed and operational. A concrete pad was the extent of the building works requirement on site.
The modified shipping container was fitted with a rolling roof section for a simple wood chip delivery solution via bucket loader or tipped delivery using a ramp.
A 50kW Herz Firematic boiler was installed along with a buffer tank, flue system and all associated plant including both mechanical and electrical components by Rural Energy prior to delivery.
Upon arrival the container was simply plumbed into the district heating pipe making for a truly ‘plug and play’ system. The use of a heat exchanger to interface with the existing system eliminated the need for modifications to the school plumbing.
Controls
Whilst installing the underground heating pipe to the container, the opportunity was taken to bury control cables along with the pipe. The boiler and circulation pumps are thus linked back to the school BMS (Building Management System). This allows the biomass boiler to automatically control the existing boilers for peak loading, and also reports any faults on the biomass system back to the main plant room. In addition, the circulation pump for the district heating pipe is automatically switched on and off by the BMS, reducing electricity consumption.
Burrough Court, Leicestershire (Herz FireMatic 150)
The wood-chip heating system was chosen as an economic way to heat several large warehouses and a group of offices via a small district heat network, with complete system payback envisaged within five years. A crucial part of the system is the heat meters on entry to each warehouse, allowing the owner to charge each lease holder for energy used.
Because of the large air change rate of the warehouses, a much larger buffer vessel was installed than is typical for a boiler of this size. The 5000ltr buffer means ‘peak loading’ of double the boiler output can be sustained for more than an hour.
A 12×6m building houses the entire system including a 6×6m chip store, back up oil boiler, and all valves pumps and controls for both systems. The back up boiler is controlled via the boiler control panel, making the system completely automated.
stand alone boiler house
The standalone boiler house allows a centralized location, with the building equidistant from the major heat requirements the underground piping and pumping costs are minimized.
The boiler house structure is built into the side of a bank, allowing direct tipping of fuel through a lifting roof without the need for a ramp or expensive scissor lift trailer. (see picture opposite)
Download the installation schematic here
Penistone Library, Barnsley (Herz Firematic 90)
A Herz FireMatic 90kW boiler configured for wood pellet fuel using a flexible auger system was installed at Penistone Library, Barnsley in late 2006. The boiler (along with a 2000ltr buffer tank, expansion vessel, all valves, pumps and controls) was installed in an existing plant room of just 4.5m by 3.3m. Following a simple conversion, the old coal bunker is now utilised as a pellet store containing over 7 tonnes (enough for around 42 days even in the coldest periods).
Integration
The boiler was interfaced with the existing heating system, including pre-existing controls, valves, and primary circulation pump as a replacement for an ageing coal boiler.
Operation and Maintenance
The installation is supported via a maintenance agreement with the site which includes regular operational checks (including ash emptying and fuel level monitoring) as well as annual maintenance.
Remote monitoring
A full Remote Monitoring system (courtesy of the advanced BioControl 3000 integrated in the boiler frame) allows visualisation and alteration of combustion parameters by our experienced commissioning engineers without the need for site visits. The advantages are:
•Enhanced combustion efficiency (e.g. when fuel varies between deliveries)
•Reduced downtime
•Lower cost maintenance agreement for the site.
Download the installation schematic here
Beacon College, Crowborough (2 x Herz Biomatic 500)
Fuel Transfer Mechanism
Twin Herz Biomatic 500kW boilers were retrofitted into the existing plant room at Beacon College, Crowborough in late 2006. The system features a unique rising auger, transporting fuel from the subterranean bunker at an angle of 30 degrees for a distance of over 8m. This allows the twin 6m diameter spring agitators within the bunker to be laid flat, maximising fuel storage below ground and enabling tipped fuel delivery without the construction of a ramp.
Boiler Control
Together the boilers supply the entire heating load for the building. Because the boilers are linked using the Herz cascade control system, the master boiler can predict when the slave boiler will be required via the buffer management system. The result is far superior load profile matching. In addition, the lead boiler is automatically switched periodically, ensuring even distribution of both wear and fuel usage between the two boilers. All of this is made possible by the advanced Biocontrol 3000 integrated controller, supplied as standard across the range.
Green school project wins at the South East Renewable Energy Awards
Download the installation schematic here
Alma House, Leicestershire
Automatic Wood-chip Heating System
Alma house Business Park is a farmyard conversion into 2,232sq feet of business units. Approximately 85% of the heat load is produced by a Nolting wood chip boiler. The system is housed in a purpose built boiler house with integrated chip store, designed and installed by Rural Energy
Full Case Study for Alma House
Orchard Community Primary School
Automatic Wood-Pellet Boiler
A wood-pellet boiler was installed at the school in 2004 to replace an ageing coal boiler. The school headteacher and governors were strongly in favour of a wood-fuel system, but the space available for fuel storage was insufficient for storage of wood-chips. The solution was to install a Nolting 200kW wood-pellet boiler which is fed from a standard agricultural silo located outside the boiler house. This silo can be filled pneumatically by an agricultural feed lorry, removing the need for the large tipping pit for fuel that would be needed for a wood-chip system. The total volume of fuel required per year will be about 50m3 (30 tonnes) supplied from Rural Energy’s pellet mill in Leicestershire.
Manor Farm, Kingthorpe (Herz Firestar 35)
Herz Firestar Manual Feed Log Boiler
A 35kW Austrian made manual feed log boiler and 3000-litre hot water accumulator tank are the central items in a district heating system at a private residence in Kingthorpe, Lincolnshire.
The system burns logs, wood off-cuts, pallet timber, and is capable of burning practically any clean waste wood if reduced to an appropriate size. The boiler is fired daily, for between 3 and 8 hours, depending on heat demand. The hot water produced is stored in the insulated accumulator tank and can be drawn off for heating purposes, for up to 72 hours. By eliminating the need to light the boiler when heat is required, a buffer store allows the use of a normal heating programmer. In addition, a buffer store provides an alternative location for both domestic hot water and solar thermal coils – eliminating the need for secondary tanks.
Highcliffe Community Primary School, Birstall
Automatic Wood-chip Heating System
Highcliffe is a school situated in a northern suburb of Leicester with a roll of around 400 and a floor area of over 1200 square metres. During summer 2004, the school’s ageing coal boiler was removed and replaced with a 200kW Thermia wood-chip boiler. Fuel is stored in a 40m3 agricultural trailer which is taken to a local farm when empty for re-filling. It is estimated that the school will use about 100 tonnes of wood-chip per annum (about 400 cubic metres). To avoid a loss of heating when the trailer is refilled and to provide heat during peak demand, a 200kW oil boiler was also installed. The school has also recently renovated its covered swimming pool to be heated all year round.
Full Case Study for Highcliffe Primary School