[Mechanical Equipment Technology Edition] Daily Question 201708031: Exhaust Superheat in Refrigeration Maintenance Procedures
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This post was last edited by YORK Industrial Refrigeration on 2017-9-2 at 08:39. Starting from now, in order to enhance communication among users, a \"Question of the Day\" activity has been launched on the Mechanical Equipment Technology forum. We hope everyone will participate actively to progress and improve together! ! ! Rewards: 3 wealth for active participation, 10-15 wealth for complete answers. This question is valid for two days; no scoring will be given after that. Question: Exhaust superheat plays an important role in the commissioning phase after maintenance. How is exhaust superheat calculated? (Extra question: How is the optimal exhaust superheat calculated?) ) Exhaust temperature – Exhaust saturation temperature = Exhaust superheat ================================ Promotion campaign: Petrochemical sector – “Creative Ideas for Energy Savings” campaign (the second phase is currently in progress) http://bbs.hcbbs.com/thread-1666758-1-1.html (Source: Haichuan Chemical Industry Forum) 2017 Coal chemical industry – “My Technical Upgrades” http://bbs.hcbbs.com/thread-1786290-1-1.html (Source: Haichuan Chemical Industry Forum)
The exhaust superheat should be the temperature difference between the temperature at the compressor exhaust pipe or the inlet of the condenser and the saturation temperature corresponding to the actual condensing pressure. In other words, superheat refers to the number of degrees by which the actual temperature of the working fluid is higher than the saturation temperature corresponding to its actual pressure. Superheat = suction temperature of the compressor – evaporation temperature of the refrigerant in the evaporator. A certain level of superheat is necessary to ensure that the refrigerant entering the compressor is free of liquid, thereby preventing wet strokes. Generally, at the evaporator outlet and the compressor exhaust, the actual temperature of the working fluid is higher than the saturation temperature corresponding to the actual pressure. This is where superheat (intake superheat and exhaust superheat) comes into play
The exhaust superheat should be the temperature difference between the temperature at the compressor exhaust pipe or the inlet of the condenser and the saturation temperature corresponding to the actual condensing pressure. In other words, superheat refers to the number of degrees by which the actual temperature of the working fluid is higher than the saturation temperature corresponding to its actual pressure. Superheat = suction temperature of the compressor – evaporation temperature of the refrigerant in the evaporator. A certain level of superheat is necessary to ensure that the refrigerant entering the compressor is free of liquid, thereby preventing wet strokes. Generally, at the evaporator outlet and the compressor exhaust, the actual temperature of the working fluid is higher than the saturation temperature corresponding to the actual pressure. This is where superheat (intake superheat and exhaust superheat) comes into play. If there is no superheat at all in the intake air, it may lead to liquid entering the compressor, which can even cause wet-stroke liquid shock and damage to the compressor. To avoid this phenomenon, a certain degree of suction superheat is required to ensure that only dry steam enters the compressor (given the properties of the refrigerant, the presence of superheat indicates complete evaporation of the liquid refrigerant). However, too high a superheat also has its disadvantages; a high level of superheat leads to an increase in the compressor’s exhaust temperature (exhaust superheat), which deteriorates the operating conditions of the compressor and reduces its lifespan. Therefore, the suction superheat should be kept within a certain range. The expansion valve senses the temperature difference between the return gas temperature and the actual evaporation pressure (which corresponds to the saturation temperature) through a temperature-sensing element located on the compressor return pipe or at the evaporator outlet; this temperature difference is the suction superheat. Based on this set value for superheat, the expansion valve adjusts its opening degree, which in turn regulates the amount of liquid supplied to the evaporator, thereby allowing control over the suction superheat.
The exhaust superheat should be the temperature difference between the temperature at the compressor exhaust pipe or the inlet of the condenser and the saturation temperature corresponding to the actual condensing pressure; this is what is referred to as superheat
The exhaust superheat should be the temperature difference between the temperature at the compressor exhaust pipe or the inlet of the condenser and the saturation temperature corresponding to the actual condensing pressure; this is what is referred to as superheat
The exhaust superheat should be the temperature difference between the temperature at the compressor exhaust pipe or the inlet of the condenser and the saturation temperature corresponding to the actual condensing pressure. In other words, superheat refers to the number of degrees by which the actual temperature of the working fluid is higher than the saturation temperature corresponding to its actual pressure. Superheat = suction temperature of the compressor – evaporation temperature of the refrigerant in the evaporator. A certain level of superheat is necessary to ensure that the refrigerant entering the compressor is free of liquid, thereby preventing wet strokes.