Feature Article5TH Generation District Heating and Cooling (5GDHC) | Sustainable City Solution
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5GDHC(5th Generation District Heating and Cooling system) is the integration of different renewable energy through high (low) temperature water circuits to provide cooling/heating, energy storage and heat transfer, it is mainly used for buildings or districts where heating and cooling are needed. The main advantage is to reduce thermal imbalance, and increase the efficiency of renewable energy or waste heat.
5GDHC Working Principle
In Europe, the demand for heating is far greater than cooling. 5GDHC not only utilizes geothermal and water source, but also including wind and solar power into 5GHC network, through providing cooling water to power plant and exchange heat source into network.
Providing 15-25C water and 5-15C water through high (low) temperature water circuits and integrate different area/district/location into the same network. And set a mid station at the final user (Ex. Residential building) .
Installing water source heat pump/water cooled chiller/heat exchanging module at every mid station.
In an example of water sourced heat pump, two scenarios are set up depending on end user's needs.
Heating：Evaporator takes heat from cold water circuit and heat warm water in the condenser to provide hot water.
Cooling：Condenser releases the heat into warm water circuit and cold water is cooled in the evaporator to provide chilled water.This cycle will improve the energy efficiency by providing cold water from residential usage to power plant for cooling, and waste heat from power plant goes to end users.
District Heat/ Cooling -Sweden
| Sweden | Temperature | Residential | Commercial | Industrial | Wind Power | Solar Power | Seasonal Energy Storage |
Summer | 12~22°C | Heating Requirement(Low) | Heating Requirement(Low) | Waste Heat (High) | Heat Generated(High) | Heat Generated(High) | Heat Storage |
| Winter | 3~12°C | Heating Requirement(High) | Heating Requirement(High) | Waste Heat (Low) | Heat Generated(Low) | Heat Generated(Low) | Cold Storage |
BPHE for 5GDHC System
As mentioned earlier, setting up a 5GDHC network require many mid stations, and mid stations uses water source heat pump or heat exchanging units, thus plate heat exchangers are required.
In order to efficiently recover the waste heat from power plant, heat recovery system is needed, this increases the demand of relate heat exchangers.
Some end users require ideal hot/cold water and water quality, internal loop is required, this also increases the demand of plate heat exchangers.
BPHE for Residential 5GDHC System
Some residential application requires high quality water, BPHEs are required for the heat exchange between external and clean water source.
BPHE for Commercial 5GDHC System
Brazed plate heat exchanger is a fundamental component for commercial liquid server cooling (CDU), it cools down the high temperature non-conductive liquid, and keep server operating at high efficiency.
BPHE for Industrial 5GDHC System
Water source heat pump is one of the most critical part of 5GDHC, and heat pumps in 5DHC system all uses BPHE as the heat exchanger.
