Ground source heat pump technology is to use the formation of shallow part through a dedicated PE pipeline transmission underground heat resources of technology, this is very environmental protection, which is loved by many people. What are the requirements for connecting the relevant equipment? Ground source heat pump buried pipe is according to the results of the survey at the scene to decide, first consider the scene usably surface area, the local soil type and drilling cost, determine heat exchanger using vertical shaft arrangement or horizontal arrangement. While horizontal arrangement is usually shallow buried pipe, can use artificial digging, initial investment generally will be cheaper, but its heat transfer performance than vertical buried tube much smaller, and are often limited by available land area, so in the practical engineering, usually using vertical buried tube arrangement. According to the method of buried pipe, there are basically three kinds of vertical buried pipe: U tube, casing type, single pipe type.
There is heat loss in the inside and outer tube flow heat exchange. The use of single pipe type is restricted by hydrogeological conditions. U-shaped tube application, most general under 50 mm diameter, the deeper the buried pipe, the better the performance of heat transfer, the data indicate that most of U type pipe buried depth has reached 180 m. loop has three kinds of typical u-shaped tube, one of the most common use is in each shaft arrangement of the u-shaped tube.
Series or parallel circuit of underground heat exchangers in the fluid flow form has two kinds of series and parallel, serial system larger diameter, higher cost of pipeline, and the length of the pressure drop characteristics of limiting the system capability. Paralleling system pipe diameter smaller, pipeline cost is low, and often decorated with the program, when the flow balance between each parallel loop, its heat transfer is the same, the pressure drop characteristics to improve system capacity. As a result, practical projects are generally adopted and combined. In combination with the above, the form of heat exchanger with single U tube and cohoming process.
Choice of tubing in general, once buried heat exchanger underground, basic impossible for repair or replacement, which requires the guarantee of buried pipe chemical stability and corrosion resistance. Conventional air conditioning system used in the metal pipe serious deficiencies in this respect, and the number of buried pipeline is more, should give priority to use lower prices of pipes. As a result, the soil source heat pump system usually adopts plastic tubing. The most commonly used ones are polyethylene (PE) and polybutylene (PB) pipes, which can be bent or heated to form a stronger shape and can be used for more than 50 years. The PVC pipe is not easy to bend, and the pressure capacity of the receiver is poor, so it is easy to leak, so it is not recommended for underground pipe system.
The proper embedding method can make the ground source heat pump achieve the best use effect.