Reliability evaluation of ground source heat pump in interval parameters of stochastic model

The paper establishes reliability evaluation model of random variable parameters with interval changes of ground source heat pump (GSHP) according reliability design method to GSHP based on stochastic analysis of thermal resistance inside borehole, the geotechnical thermal resistance outside borehole of the GSHP. Practical projects show that small deviation of random variable parameters leads great influence on evaluation results. To take 5% deviation as an example,calculation results show that the max failure probability is 521375 times of the min failure probability. Therefore the advance of backfilled material thermodynamic properties and geotechnical thermodynamic properties outside borehole testing technology have infinite influence on GSHP reliability.