PDF Publication Title:
Text from PDF Page: 015
where: Qc – VA – ρA – cA – tA1 – tA2 – total output of the condenser (kW), air flow rate (m3), air density (kg/m3), air specific heat capacity (kJ/kg∙K), air temperature at condenser inlet (°C), air temperature at condenser outlet (°C). Usually it is difficult to determine the air flow rate because it requires recording the air speed. The air flow rate can be calculated by measuring the dynamic air pressure. The air is normally non homogeneous, temperature and speed distributions from the heat exchanger are also difficult to measure. The real output can be calculated only by measurement of liquid cooling medium (Kreider et al., 2010). 5.6. Throttle valves A throttle valve reduces the freon pressure from the condenser to the evaporation pressure. The low pressure is required so that the refrigerant can evaporate at low temperatures. It is an important significance in terms of optimum system recovery that the evaporator is always supplied with as much refrigerant as it can process in the correct operating conditions. If too much freon reaches the evaporator, the liquid will not be fully evaporated and liquid lock can occur in the compressor. If the evaporator is provided with too little refrigerant, it will not operate correctly and excessive overheating of the refrigerant can take place, which will result in too high a final compression temperature. The change of state in the throttle element can be viewed as isenthalpic. Practically, there is a slight increase in enthalpy in the valve (Althouse et al., 2013). Expansion valves do not control the evaporation temperature straightforwardly. They regulate the superheating by controlling the mass flow of freon into the evaporator and upholding the pressure difference between the condenser (high pressure) and the evaporator (low-pressure). The evaporation temperature depends on the capacity of the compressor and efficiency of the evaporator. Throttle elements are divided into three categories depending on their regulation of freon mass flow rate: 1. non-regulating throttle elements,; 2. mechanical self-regulating throttle elements, 3. electric self-regulating throttle elements. 5. Heat pumps 159PDF Image | Heat Pumps 978-83-65596-73-4
PDF Search Title:
Heat Pumps 978-83-65596-73-4Original File Name Searched:
Buildings-2020-part2-rozdz5.pdfDIY PDF Search: Google It | Yahoo | Bing
CO2 Organic Rankine Cycle Experimenter Platform The supercritical CO2 phase change system is both a heat pump and organic rankine cycle which can be used for those purposes and as a supercritical extractor for advanced subcritical and supercritical extraction technology. Uses include producing nanoparticles, precious metal CO2 extraction, lithium battery recycling, and other applications... More Info
Heat Pumps CO2 ORC Heat Pump System Platform More Info
| CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com | RSS | AMP |