Modular tube bundle heat exchanger and geothermal heat pump system

An improved ground source heat pump system, comprising:

• an in-ground heat exchanger and a building heat exchanger coupled via conduits for refrigerant to at least one compressor and at least one expander, the compressor having at least one intake line and at least one discharge line, the compressor and the expander being coupled to the conduits such that the refrigerant is circulated in the conduits through pressure changes and corresponding temperature changes in the refrigerant, the in-ground heat exchanger comprising at least one modular tube bundle comprising a plurality of substantially horizontally oriented subterranean tubes, buried in a stacked vertical array for vertical installation in trenches, said at least one bundle having a top and bottom displaced vertically from one another, and the refrigerant being subjected to phase change in the conduits;
• and,
• wherein said compressor comprises a scroll compressor having a spiral impeller orbiting relative to a fixed spiral scroll, whereby orbiting of said impeller pumps refrigerant through the system in a manner insensitive to phase of the refrigerant.

An improved ground source heat pump system of the type having an in-ground heat exchanger and a building heat exchanger coupled via conduits for refrigerant to at least one compressor and at least one expander, the at least one compressor having at least one intake line and at least one discharge line, the improvement comprising:

• said in-ground heat exchanger having a plurality of tubes disposed in a substantially planar array which is inclined along a wall of a trench, said trench being backfilled for setting the planar array in thermal engagement with the earth.