REHOS Product Designs

trading the IP gained by the former R&D company Heat Recovery Micro Systems

REHOS Autarkic Water (RAW)-Pump

Heat Transformer technology (HT-technology), although commercially available, is relatively unknown. The fact that HT-technology use only ~ 1% of the electricity of the conventional vapor compression (VC)-technology for the same heat load, drive rapid revolutionary new heat recovery possibilities, however.

The example Bubble Reactor Absorption Heat Transformer (BRHT) pictured below demonstrate the simplicity in designing a heatpump to "upgrade" low temperature (30°C) heat to a more usable 70°C. This Heat Transformer use the sensible heat in a 30°C waste heat water source to power the heat pumping process, and in the process also chill a portion of the waste heat source water from 30°C down to 20°C. Note that the only electricity used for achieving this 3 kW heat pumped is a mere 5 Watt for the liquid pumping! This type of economy could therefore power your household geyser very nearly for free....

The sketch of the BRHT below reflect the process parameters of a real design, with heat-, mass-, and species balance calculations done to confirm the values displayed here.

Apart from the obvious heating applications like household hot water systems and pool heating applications, also the cooling side of the heatpump may be utilized. Water chilling, even de-humidification to extract water from air and other cooling applications also come to mind. 

Other uses of such cheap heat of a more indirect and advanced nature are also very practical, as we think of the simplicity of the simple Organic Rankine Cycle (ORC) pictured below. 

The ORC technology is very popular in the lower (eg. below ~ 250 Celsius) temperature range of generating power from heat applications, like geothermal and waste heat recovery. The thermodynamic cycle consist of a refrigerant liquid pump, a power expander or turbine, and two heat exchangers (H/E's), one for heating and evaporating a high pressure refrigerant, while the other is used for condensing the low pressure side, enclosing a suitable refrigerant, and can utilize low temperature heat sources efficiently to generate power.

Using an ORC therefore allow us to generate power from the extremely low cost heat that we extracted from waste-, and ambient heat sources if we combine the ORC power cycle with the Heat Transformer shown earlier. 

Using the BRHT shown, it allows a full Regenerative coupling where the latent heat in the turbine exhaust does not go to waste, but may be recovered to partly power the heat transformer, as shown in the REHOS water pump in the sketch below. It is called autarkic because it can operate as water pump without the need for any electricity or other energy source. It recovers thermal energy from the water it is pumping. The sketch below was made from a design of a pump where all the heat-, mass-, and species balance calculations were done so the process parameters displayed in the sketch are real values 

The power expander (sketched as a turbine) exhaust vapor at 5 Bar Abs is directly routed back to the bubble reactor bottom, where it is regeneratively re-used to produce heat in the reactor bottom. This ORC share the refrigerant media (90%NH3 in aqua) with the heat transformer, and therefore only has a single evaporator coil in the hot bottom of the bubble reactor. It uses the bottom section of the reactor as absorber instead of the condenser coil sketched in the basic ORC sketch. Although the ORC efficiency is only ~ 12% in this example, as 50 kW of heat exchange in the reactor H/E is required to deliver about 6 kW power from the isentropic expansion of the high pressure vapor, the regeneration has the effect of recovering ~ 40 kW exhaust heat back to the reactor, bypassing the evaporator. Only ~ 10 kW heat in the form of vapor is required from the evaporator, making the actual overall REHOS cycle conversion efficiency ~ 60%, which is very much higher than the stand-alone ORC machine. 

In this RAW-Pump (REHOS Autarkic Water pump) the REHOS cycle Prime Mover driving the water pump, does not need any electricity, but use its own AHT sub-cycle to extract thermal energy from the water being pumped! The high conversion efficiency also guarantee a relatively small (cheap) Prime Mover... 

What value does the RAW-Pump add to any pump manufacturer's products arsenal with the knowledge that it is priced at 4 - 6 times the price of the same size water pump fitted with an electrical motor as prime mover? The RAW pump would pump water in remote area's, not requiring any electrical cables, switch-gear or electricity bills and would pay for itself within a very short period of time, using the electricity savings!

Larger RAW-Pumps could obviously also power marine vessels and river boats, drawing the boat propulsion energy directly from the ocean or river.......possibilities are limitless for this revolution!

Much more detail and facts are presented with a more scientific/academic tone in the papers downloadable from the Downloads page....