Calculation of energy consumption for 85℃ hot water
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I would like to ask everyone: since hot water at 85°C is required in the device, how is the energy equivalent value for calculating energy consumption determined?
Is this a heat exchange device? . . . Then his energy consumption is simply determined by looking up the enthalpy values based on the inlet and outlet temperatures. . Calculated
You need to know the temperature and mass before heat exchange, right?
Where does this 85°C hot water come from? 1) If it is a dedicated hot water generation unit, the calculation shall be carried out in accordance with GBT-50441-2007 \"Standard for Calculating Energy Consumption in Petrochemical Design\", using the relevant quotas; for example, the gas/fuel consumption required to produce 1 ton of hot water, the electricity consumption of the hot water pump, and the amount of water needed for initial filling ； 2) If the hot water source is a waste heat recovery device, such as hot water recovered after cooling engine cylinders ； It is then necessary to consider the entire energy consumption system, because from the perspective of end-users, it is about energy consumption, while from the perspective of the entire plant, it is about energy recovery; when calculating the overall energy consumption, this amount needs to be deducted. For heat exchange with end-users, if the temperature of these end-users rises to 60–120°C after heat exchange, the energy consumption associated with this is calculated as half of the energy corresponding to a lower temperature level. The energy obtained by the end-users can be determined by converting it to MJ and then dividing that value by 2; this result represents the energy consumption for this portion
I’m working on a feasibility study; the new installation will require hot water at 85°C, but it’s not yet clear what the source of this water will be.
Once the water is heated, do you leave it there or use it to heat other things? Is a certain amount of 85-degree water consumed per hour, or is this water reused? If it is consumed, the heat required is calculated based on the specific heat capacity; if it is reused, the heat consumption is calculated based on the flow rate, the temperature difference between the outlet and inlet water, and the specific heat capacity. If none of these details are known, the calculation is done based on the final unit of heat usage.