District-heating stratified thermal store (charge and discharge)

A stratified hot-water thermal energy store on a district-heating loop, shown at one operating point in both directions. The charge leg sends 90 °C supply water through the store, which is standing at four layers of 350 / 335 / 320 / 305 K (hottest on top): the water exhausts in contact with the coldest layer and leaves at 305 K, so the whole 85 K drop goes into the store. The discharge leg draws 30 °C network return through the same store and takes it from the hottest layer, leaving at 350 K. That asymmetry is the entire reason to stratify — a fully mixed store holding the same energy would deliver its 328 K average. The blocks report the stored energy above the 300 K floor, the state of charge over the 300-360 K window, the standing loss through an 80 W/K vessel, and the time to full or empty at the current net rate. Honest scope: this is a steady-state picture — the store's layers do not move within a solve, and the two legs are drawn as separate blocks on one store. The transient (how far the thermocline travels over a six-hour charge, and what outlet temperature the morning discharge actually delivers as the hot layers are consumed) is the Thermal energy storage analysis tool.