Rewatemp – heat pump and chiller in one hybrid unit
Rewatemp
Rewatemp is a specially designed heat pump, which meets the heating and cooling demands of modern energy efficient buildings and sets new standards in heat pump technology.
It is designed to use the most energy efficient renewable energy sources such as open or closed loop systems: e.g. groundwater, surface or seawater or technological water, geothermal probes and ground heat exchangers.
Its special hybrid concept with two separate refrigerant evaporators provides simultaneous heating and cooling function. Most conventional solutions for simultaneous heating and cooling include reversible heat pumps, water-to-water heat pumps with complicated hydraulic connections and combinations with chillers, but none of them can provide energy efficient simultaneous function.
Rewatemp heat pump replaces water-to-water heat pump and a chiller, both functions are integrated into just one refrigerant cycle, which enables highly efficient simultaneous operation.
Optional desuperheater enables warm water heating to temperatures up to 70°C in the same refrigerant cycle, working at all operational modes of the unit.
At a glance:
- Simultaneous preparation of heating and cooling medium,
- Continuously controlled heating and cooling capacity
- Oil management with oil level control for each compressor
- Optional simultaneous warm water heating, in all operational modes
- Refrigerant R410a
- Scroll compressor technology
- COP over 5 possible
- EER over 6 possible
Advantages:
- Heating, cooling and warm water heating achieved with just one refrigerant circle
- Minimum energy consumption, because of real simultaneous function (without switching between heating and cooling modes, like at reversible heat pumps)
- Minimal electric power connection – chiller, heat pump, water heater in just one device
- Minimal possible space requirements
- Highly reliable function and long lifetime, due to integrated compressor oil management
- Easy maintenance, due to just one refrigerant cycle
- Simple hydraulic integration
- Use of most energy efficient renewable energy sources
Operational modes
Winter
Summer
Transition
Only heating mode
Only cooling mode
Simultaneous cooling and heating mode
During periods of exclusive heating demand (e.g. winter), only heating mode will automatically activate.
The unit will work as water-to-water heat pump, activating the heat extraction evaporator from the energy source and producing heating medium, continuously controlled to meet the heating demands. Medium flow on heat extraction and heating medium side will be stageless controlled, so that demanded temperature levels on heating side will be achieved and at the same time with minimal required medium flows on the energy source side.
Maximal heating medium outlet temperatures are about 55°C, which ensures heating energy supply for most heating systems.
During periods of exclusive cooling demand, only cooling mode will automatically activate.
The unit will work as a water cooled chiller, automatically activating the cooling medium production on the cooling medium evaporator and activating condensation heat transfer to the open or closed loop systems that are in heating modes used for energy extraction. In this mode, those energy source systems will be in function of a heat sink. Medium flow on heat sink and cooling medium side will be stageless controlled, so that demanded temperature levels on cooling side will be achieved and at the same time controlled outlet temperature of excess condensation heat, so that heat sink – energy source will not be overheated.
Optional, the condensation heat can be evacuated to a separate heat sink.
During periods of heating and cooling demand, simultaneous cooling and heating mode will automatically activate.
The heating and cooling capacities will be stageless controlled to meet the requirements. According to the balance of heating and cooling demands, the unit will automatically activate evaporators for cooling medium production, evaporator for heat extraction or both of them.
When the cooling and heating demands are balanced or cooling demands are bigger than heating demand, evaporator for cooling medium will activate.
Heating energy, which is normally wasted at conventional water-cooled chillers, is used for covering the heating demand. When more heating and less cooling energy is needed, both cooling energy and heat extract evaporator will activate, providing the demanded cooling and heating energy.
Energy sources
Open loop systems
Groundwater heat is very efficient renewable energy source for heat pump systems. It is an open loop system.
Main advantage is b>relatively constant temperature level (between +7 and +12°C).
An open loop system uses groundwater for heat exchange by extracting and returning water through supply and diffusion wells installed in permeable aquifers. Water flow in extract well(s) has to meet the heat pump demands at maximal heating (or cooling) capacities. At least two borings are needed, one for extract and the other for diffusion, but two diffusion wells are generally recommended for each supply well, because returning water to the aquifer is often more difficult than extracting it. The well water pump is located in the bottom of the extract well.
For well water pumping environmental license has to be obtained, chemical analysis of the well water has to be carried out.
Groundwater is because of its relatively constant and high temperature level the ideal renewable energy source, high COPs are achieved. Other open loop systems that are applicable, are surface or seawater intakes.
Closed loop systems
Basically all ground loop systems are heat exchangers in form of pipe loops with circulating liquid, either groundwater or an anti-freeze solution in closed piping installed in the ground. Energy from ground rocks or soil will be induced into system.
Energy in near-surface ground is mostly sunlight energy, stored in the ground and a small part of geothermal energy. Energy amount, which can be extracted through the closed loop systems, depends on composition of the soil, demanded heating and cooling capacities and extracting method.
Heat transfers from the ground via liquid medium, which circulates in closed loop pipe system, installed in vertical boreholes in the depths of 60 – 150 m (geothermal probe) or horizontal-near surface installation (ground coupling) in depths of 120-130 cm.
The circulating liquid will then provide the demanded heat to the heat pump, which transforms the low-temperature heat of the energy source to usable temperature levels in heating mode.
In cooling mode, the condensation heat of the heat pump system will be transferred via ground loop system back to the ground, which enables the closed loop heat regeneration after longer periods of heat exploitation (e.g. after winter mode operation). This enables partial or full heat recovery of a closed loop system.
To sum up
Rewatemp is the right answer to the needs of modern buildings. Focusing on a sustainable aspect, system for achieving maximum reliability and long service life, reduces the required energy input and costs throughout the life cycle of the device, including maintenance costs, to a minimum. In an energy-saving facility with heating and cooling needs, Rewatemp is the central energy device to deliver optimum comfort conditions, with incredibly low operating costs.
You can read more about Rewatemp on this link
