HIVE Demonstrator

Two demonstrators have been constructed by the FITS team, the function of these is to assess the "real" performance of these fabric integrated heat stores and compare this to modelling predictions. The demonstrators also highlight the real challenges associated with integrating heat stores into buildings.

HIVE_ext (1084K)

Exterior of the HIVE demonstrator
HIVE_int (762K)

Interior of the HIVE demonstrator

The first demonstrator is located at the University of Bath's HIVE facility. This is a demonstration of a wall-based thermal storage system, where the thermal mass is provided by wall mounted clay tiles, isolated from the building interior by a layer of insulation.

The wall mounted stores can be charged an discharged in the same way as a domestic hot water tank - the difference being that the store is integrated into the building fabric. This brings advantages (i.e. no need find space for a hot water tank) and challenges - the output temperature from the store decays as heat is drawn from it. The decay is less pronounced in hot water tanks due to stratification of the fluid.
HIVE_thermograph (54K)
A thermographic image of the wall tiles (with insulation removed) as they are being charged.

HIVE_schematic (33K)

A schematic of the charging and discharging circuit for the wall mounted store.
The charging system for the wall-integrated store system uses a variable temperature water heat source, that can be used to charge the store to different temperatures (40-80oC) this allows charging times, parasitic losses from the store and also the variation in output temperature as the store is discharged to be determined.

The system uses solenoid valves to change the ciircuit configuration (left) allowing the slab to be charged from the heat source, or the heat emitter to draw heat from the slab store. The heat is input and extracted from the slab using flexible hot water pipes commonly used in underfloor heating.

Ravenscraig Demonstrator

The second demonstrator is located at the BRE Innovation Park near Motherwell. This is a demonstration of a slab-based store - where the themal mass is provided by an underfloor concrete slab. The slab can be charged using a heat source such as a heat pump and discharged to provide heat to a heat emitter. In the demonstrator, heat is provided by a variable temperature source (40-85oC), allowing the slab to be charged to a range of temperatures, and mimicking a range of heat sources.
Craig_ext (1013K) External view of the Ravenscraig demonstration facility.
Slab casting
Casting of the demonstrator slabs with embedded heating pipes and thermocouples.

The Ravenscraig demonstrator features two storage slabs of different thicknesses: 125mm and 75mm, this is to assess the impact of thickness on storage charge and dischrge times.

The heating system (below) can be re-configured using solenoid valves such that the heat emitter (in this case a fan-convector unit) can be supplied directly from the heat source, from the slab-based store or from a mixture of the two.

Like the HIVE demonstrator heat is input and extracted from the store via flexible hot water pipes.

HIVE_schematic (33K)

A schematic of the charging and discharging circuit for the slab-based store.

HIVE_schematic (33K)

A cross section showing the two charging slabs.