REFRIGERATION: What paradoxical at first glance, proves on closer inspection to be useful: the simultaneous, combined generation of heat and cold, for example, opened in the food industry and trade offer high potential. Appropriate combinations of refrigeration and heat pump save money and protect the environment.
Many industries have taken up the cause to emit less CO2, including the food industry and the food trade. This has a double effect, for a reduction of greenhouse gas emissions means less energy consumption and lower production costs.
One of many ways to achieve this objective, the combination of cold and heat supply in a system. Meaningful such "thermal hybrid" when heating and cooling are also needed. Which is for example in the milk production of the case where the in-house cooling chain is not interrupted for the pasteurization.
Most heat for such applications is generated using fossil fuels in hot water or steam boilers, electric chillers during work regardless - and leave it on the condensing side heat to the environment. The reason is the low temperatures at the capacitor, which usually can not even be used for heating.
The key to efficiency lies in the increase of the temperature of the waste heat from refrigeration compressors to a usable level - a classic task for the heat pump. The benefit of a maximum efficiency is not water is used as a heat source or carrier, as would be the case with ground source heat pumps.
"Instead, it is suitable for industrial applications, connect the refrigerant circuit to the compressor on the warm side directly to the cool side of the heat pump," said Andreas Meier, President of Sales D / A / CH at GEA Refrigeration Technologies. The combined systems therefore work with a closed refrigerant circuit. "To distinguish it from conventional heat pumps using water or air as the source, we are talking with our refrigeration systems hydraulically interconnected solutions, add-on heat pumps'."
Add-on heat pump stage is sufficient a temperature level on the cold side of 35 ° C in order to provide hot water at about 65 ° C. In the margarine production this is sufficient for many applications. The pasteurization of milk, however, demands higher temperatures of about 75 ° C, so that pathogenic microorganisms are destroyed. Here correspond to the temperature jump to around 80 ° C (necessary because of the line and heat exchanger losses) to master, it offers a heat pump cascade of two machines, such as, inter alia, in the UK milk processor Robert Wiseman Dairies is used.
Whether one or two step temperature increase: The heat pumps have in the described use cases typically have a COP (coefficient of performance) of about five. To provide a kilowatt hour of thermal energy thus only fifth kilowatt hour of electrical energy is needed.
Taking the local gas and electricity prices based on the feasibility study and will show a return on investment (ROI) within a few years. According to sales chief Meier of the ROI in the previous references is often achieved after only two years. That also benefits the environment is obvious: Proportional to reduction of fuel consumption decrease the local CO2 emissions, and also involving the power plant-related primary energy consumption, the situation is positive: The heat pump requires about two-fifths less primary energy than the gas boiler. Whether it is as a replacement or supplement to traditional gas boiler depends on the most commonly used temperature level.
What works on an industrial scale - there are cooling and heating services in the megawatt range are not unusual - is also demonstrated on a small scale effect. Here also, the food industry as an example: Many markets already rely on systems that bring together cooling, refrigeration and heating and use in this way, compressor waste heat to heat buildings
