Size computing method of Vertical Borehole Heat Exchangers in Ground-coupled heat pump systems

摘要

The present invention relates to an underground heat exchanger capacity calculation method in a geothermal heat pump system which can calculate a capacity of an underground heat exchanger by using an optimization algorithm to allow an entering water temperature (EWT) of the underground heat exchanger to satisfy driving conditions. According to the present invention, the underground heat exchanger capacity calculation method comprises: a first step of inputting a setting temperature (Tset) by arbitrarily setting to satisfy operating conditions of a heat pump; a second step of considering an installation space or installation conditions to designate at least one among three design parameters of the number (N) of underground heat exchangers, depths (H) of underground heat exchangers, and intervals (B) of underground heat exchangers as a design variable, and inputting the remaining design parameters excluding the designated design variable as fixed parameters having designated constant values; a third step of using an arbitrary value within a set range as a variable value of the design variable to calculate an entering water temperature (EWT) of an underground heat exchanger; a fourth step of determining whether a temperature difference value between the setting temperature (Tset) and the calculated entering water temperature (EWT) of the underground heat exchanger is included in a preset limit range in a range of values closed to a value of 0; and a fifth step of using the inputted value as the design variable and the constant values of the fixed parameters as the number (N) of underground heat exchangers, the depths (H) of underground heat exchangers, and the intervals (B) of underground heat exchangers to calculate the capacity of the underground heat exchangers.