New 4-Way Reversing Valve for R744 trans-critical heat pump
4-Way Reversing Valve, Our customers are global Japanese manufacturers specialized in highly energy efficient electric heat pump and water heaters for domestic, industrial and commercial use. Instead of the more conventional ammonia or fluorinated refrigerants and hydrocarbons, supercritical carbon dioxide is used as a refrigerant: this technology offers a means of energy conservation and reduces the emission of greenhouse gas.
They are engaged in constant re-engineering of their control valves for catering to the needs of developing markets. One such valve is required to working pressure up to 120bar and under the full differential pressure of the heat pump system (70bars). The customer asked us to verify Kv, capacities and temperatures attained by critical components of the new developed design using numerical simulations.
PREMISES: The European Legislative Framework
In 2007 EU leaders endorsed an integrated approach to climate and energy policy that aims to combat climate change and increase energy security while strengthening its competitiveness. In 2008 the European Commission proposed binding legislation to implement the 20-20-20 targets. This “climate and energy package” became law in 2009.
The 20-20-20 targets by 2020 include:
• Reduction of EU GHG emissions by at least 20% below 1990 levels;
• 20% of EU energy consumption to come from renewable resources;
• 20% reduction in primary energy use compared with projected levels, by improving energy efficiency.
PREMISES: The Heat Pump Technology
Renewable energy is generated from natural resources such as the sun, wind, and water, using technology which ensures that the energy stores are naturally replenished. By adding a small amount of drive energy, a heat pump can move heat from a low temperature to a high temperature. This means that the same piece of equipment can be used to remove heat from a space (cooling) at one end while at the same time adding heat to another space(heating).
The most prevalent use of heat pumps is for cooling, e.g. the common household refrigerator or air conditioner, but increasingly heat pumps are also used to upgrade heat to useful heating temperatures.
PREMISES: The heat pump efficiency
The more efficient a heat pump is the more cost-effective and less energy consuming it will be.
The COP, or Coefficient Of Performance, describes the efficiency of the heat pump and is defined as the ratio between the useful heat transfer for heating or cooling and the required drive energy. The useful energy can either be heating or cooling energy depending on if the heat pump is used to provide heating or cooling.
There are a number of factors that will affect the efficiency of a heat pump.
Major improvements in the efficiency of heat pump systems have been
achieved through developments in the fields of heat exchangers, compressors, motors and components.