Objective
Greater use of heat pumps could offer substantial energy savings in several European Countries. Gas fired absorption heat pumps offer additional environmental benefits, namely reduced CO2 emissions avoidance of fluorocarbon refrigerants such as CFC, HCFC and HFC. One of the primary barriers to their uptake, especially in the residential market sector is the relatively high first-cost of small-scale appliances. Rotex technology, through the use of process intensification and process integration, reduces the size and cost of appliances for the residential and small-commercial sectors. production cost estimates for the Rotex appliances show costs which are attractive, but these assume the machine can be made by high-volume, low cost production techniques.
Market research reveals a level of resistance amongst specifiers and installers to greater use of heat pumps. To overcome this, the project will demonstrate the Rotex under real operating conditions showing their attractiveness in low energy consumption and hence low operating costs.
The first field trial test machine is currently being commissioned. The targeted goals of cooling [ 10,5 kW; 52°C (exhausting Temperature) and 7°C (cooling temperature)] have only been recently achieved. Materials improvements are now carried out before to produce the testing machine.
Rotex is an absorption cycle heat pump in which the primary energy input is from gas combustion. Absorption cycle technology is not available for residential dwelling or small-commercial premises because of the relatively high first-cost of appliances. the size and cost of absorption appliances is controlled by the large surface areas required for heat and mass transfer are greatly increased by the use of high centrifugal forces created by rotation. In the Rotex equipment the absorption fluid is entirely contained within a hermetically scaled rotating cylinder. The centrifugal forces inside the vessel, which has a radius of 30 cm and rotates at 500 rpm exceeded 100 times the gravity. This greatly enhances the rates of physical process. The integration of the absorption, desorption, condensation solution pumping and heat exchange all within the rotating vessel helps to further reduce size. An appliance based on these dimensions can provide sufficient heating and cooling for a large residential dwelling, ie 10 kW cooling and 14 kW heating. This reduction in size reduces the mass of material and the projected production costs to level that allows substantial penetration of the residential and small-commercial markets.
In addition to its novel design the Rotex appliance uses a patented absorption fluid, an aqueous mixture of inorganic hydroxides, in combination with water as a refrigerant. The thermodynamic properties of this fluid allow the machine to operate with high efficiency cycle, the so called "double effect" cycle. This cycle is used in some conventional absorption equipment but with normal fluids the temperature of the heat rejected is low and water cooling towers are required. the fluid used the Rotex machine results in the heat being rejected at a higher temperature, so as a dry fan coil can be used. Furthermore, because of this "high-temperature" lift, the Rotex can be used as a heat-pump to provide heat to the residential dwelling as well as cooling.
Topic(s)
Call for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
LE11 3GR LOUGHBOROUGH
United Kingdom