Flow-optimized heat exchanger made of plastic

Abstract

Applications - Ground source heat collectors - Ground storage - Air absorbers - Fan convectors - Concrete core activation - Cooling of photovoltaic modules, simultaneous thermal utilization of waste heat. Advantages over conventional capillary tube mats: - No branch lines to the individual capillary tube mats of a hydraulic circuit - Faster installation - Reduced material requirements - Up to 50 kilowatts of heat transfer capacity per hydraulic circuit possible - Endoscopic repair option. Flow-optimized heat exchanger made of plastic, consisting of: - Distribution pipes (3) with each capillary tube mat having a constant inner diameter, gradually reduced in the flow direction of the hydraulic circuit from a maximum of 50 mm at the inlet (1) of the hydraulic circuit to a minimum of 6 mm - Parallel capillary tubes (5) with a constant inner diameter in the hydraulic circuit in the range of 2 mm to 6 mm - Collector pipes (4) with each capillary tube mat having a constant inner diameter,The inner diameter of the capillary tubes in the hydraulic circuit gradually increases in the direction of flow from a minimum of 6 mm to a maximum of 50 mm at the outlet (2) of the hydraulic circuit. End caps (6) The parallel spacing of the capillary tubes in the hydraulic circuit is a minimum of 8 mm and a maximum of 60 mm. The welded connections between the capillary tubes and the collector and distributor pipes are made using a capillary tube welding machine. The individual capillary tube mats have a maximum length of 20 m and a maximum width of 5 m. A hydraulic circuit has a maximum length of 20 m, corresponding to the maximum capillary tube length, and a maximum width of 50 m.

Description

The flow-optimized heat exchanger made of plastic is specifically developed for air heat absorbers, geothermal heat collectors, geothermal heat accumulators, concrete heat accumulators, foundation heat accumulators and latent heat accumulators.Known (prior art) are heat exchangers made of plastic (FIGS. 1 ; 2 ), consisting of:Distributor tubes (3) (the internal diameter of the distributor tubes (3) is generally constant between 15 mm and 22 mm; the length of the distributor tubes (3) is generally at least 0.7 m and at most 2.0 m)parallel heat exchange tubes (5) with an internal diameter of a maximum of 6 mm and a minimum of 2 mm welded to the distributor tubes (3) and the collector tubes (4) at a distance of a minimum of 8 mm and a maximum of 60 mm, with a length of a minimum of 2 m and a maximum of 20 mheader tubes (4) (the internal diameter of the distributor tubes (3) is generally constant 15 mm to 22 mm; the length of the distributor tubes (3) is generally at least 0.7 m and at most 2.0 m)The individual heating / cooling circuits are connected to one another at the distributor and collector pipes via sleeves and stubs with T pieces and pipe bends ( 7). The size of the individual heating / cooling circuits is limited to practically 20 m 2. by the constantly small inner diameter of the distributor and collector tubes. For air heat absorbers, geothermal heat collectors, geothermal heat accumulators, concrete heat accumulators, foundation heat accumulators and latent heat accumulators, heat exchange surfaces of up to 200 m 2 are required. This means that 10 heating / cooling circuits are necessary, so the number of assembly welds necessary and thus the possibility of welding defects is very high. The requisite stubs, T-pieces and pipe bends require a great deal of material and production time.The flow-optimized heat exchanger made of plastic described here (FIG. 4 ) consists of:distributing tubes (3) with an inner diameter which is gradually reduced in the direction of flow (the inner diameter of the distributing tubes (3) is at most 50 mm at the heat exchanger inlet (1) and at least 6 mm at the distributor tube end; the length of the distributing tubes (3) is at least 0.7 m and at most 5.m)parallel heat exchange tubes (5) with an internal diameter of a maximum of 6 mm and a minimum of 2 mm welded to the distributor tubes (3) and the collector tubes (4) at a distance of a minimum of 8 mm and a maximum of 60 mm, with a length of a minimum of 2 m and a maximum of 20 mheader tubes (4) with an inner diameter which is increased stepwise in the direction of flow (the inner diameter of the header tubes (4) is at most 50 mm at the heat exchanger outlet (2) and at least 6 mm at the header tube start; the length of the header tubes (4) is at least 0.7 m and at most 5.0 m)The different distributor and collector pipes are connected to one another via reducing sleeves and are closed at the end in the region of the smallest inner diameter by a closure cap (6). By eliminating the stubs, T-pieces and pipe bends, the number of assembly welds is reduced to a minimum. The fact that the heat exchanger can be completely preassembled and can be introduced into the soil or into the concrete under test pressure is also important.

Claims

The flow-optimized heat exchanger made of plastic (FIG. 4 ) is characterized in that the inner diameter of the distributor tubes (3) decreases stepwise in the flow direction, corresponding to the reduced flow speed, and that, parallel thereto, the inner diameter of the collector tubes (4) increases stepwise in the flow direction, corresponding to the increased flow speed. The heat transfer fluid, water with suitable antifreeze, is pumped by the heating / cooling unit into the heat exchanger inlet ( 1) via the distributor tubes ( 3) and then into the heat exchange tubes ( 5) through which flow takes place in parallel. In the collector tubes (4), the volume flows are combined and flow back to the heating and cooling unit via the heat exchanger outlet (2). Flow-optimized heat exchanger made of plastic (FIG. 4 ), comprising: - distribution pipes (3) with an inner diameter which is gradually reduced in the flow direction (the inner diameter of the distribution pipes (3) is a maximum of 50 mm at the heat exchanger inlet (1) and a minimum of 6 mm at the distributor pipe end; the length of the distribution pipes (3) is a minimum of 0.7 m and a maximum of 5.0 m) - heat exchange pipes (5) which are arranged in parallel and have an inner diameter of a maximum of 6 mm and a minimum of 2 mm, welded to the distribution pipes (3) and the collector pipes (4) at a distance of a minimum of 8 mm and a maximum of 60 mm, with a length of a minimum of 2 m and a maximum of 20 m - collector pipes (4) with an inner diameter which is gradually increased in the flow direction (the inner diameter of the collector pipes (4) is a maximum of 50 mm at the heat exchanger outlet (2) and a minimum of 6 mm at the collector pipe start; the length of the collector tubes (4) is at the minimum 0.7 m and at the maximum 5.0 m)Flow-optimized heat exchanger made of plastic according to claim 1, characterised in that during the production process additional thin-walled metal sleeves with a length of 30 mm to 80 mm are mounted on the heat exchange tubes (5) for the region of the 180° deflection (8). As a result, a smaller bending radius can be realized. The thin-walled metal sleeves offer additional protection for mounting in the ground or in the concrete and serve as coupling elements for mounting devices.Flow-optimized heat exchanger made of plastic according to claim 1, characterised in that advantageous heat exchanger geometries (FIG. 5 ) can be realised by the installation of angle sleeves (9) (with an angle of 20° to 180°) during the connection of the distributor tube and collector tubes. This reduces the required length of the connecting lines and increases the flexibility in the design.Method for endoscopic damage diagnosis and damage repair by rubber or silicone plugs of a flow-optimized heat exchanger made of plastic according to claim 1, in the region of the heat exchanger connection (FIG. 6 ).

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