【 Weak current College 】 ground source heat pump engineering design and design principles

A, ground source heat pump works survey content

(A) General provisions
1. design of ground source heat pump system. Should conduct engineering site investigation, and response to shallow geothermal energy resources to carry out investigation.
Club site conditions and shallow geothermal resources condition is able to use ground-source heat pump systems. Ground source heat pump system design, according to the survey and survey, select the use of underground pipes, groundwater or surface water source heat pump system. Shallow geothermal resources survey including underground tube heat exchanger system surveys, groundwater heat exchanger system inspection and investigation of surface heat transfer system was.
2. to have the hydro-geological information or the area near wells, hydrogeological survey gets. Club in the engineering field near the wells in the region or regions, you can investigate collection has been engineering survey and wells. The RADIUS should be larger than the regions to develop heat transfer area 100 a 200m. Survey to collect information, in addition to the observation of the topography, should investigate the existing water well location, type, structure, depth, stratigraphic section, water discharge, water levels, water temperature and water quality situation, should also be aware of water wells, production methods, changes in water quantity and water level conditions appear.
3. engineering investigation should be handled by a professional team of reconnaissance and intelligence. Engineering survey completed, should prepare engineering investigation report and on the resources available to make recommendations.
4. Engineering site survey should include the following elements which may make use of the area of Engineering site should meet the construction of the surface water pumping structure (surface heat exchanger system) or the construction of the groundwater pumping wells and Reinjection wells (groundwater heat exchanger system) or laying horizontal or vertical ground heat exchangers (underground tube heat exchanger system). At the same time be of remembrance and action to meet the construction equipment and planted outdoor network needs to appear:
(1) site planning area, the shape and slope;
(2) premises has been building and planning the building footprint and distribution;
(3) venues trees vegetation, pond, drains and overhead transmission lines, telecommunications and cable distribution;
(4) venues already, planning the construction of underground pipelines and underground structure of distribution and buried;
(5) venues where existing wells;

(B) underground tube heat exchanger system survey
1. buried pipe design ground-source heat pump system, works to distribute soil body geological conditions to carry out investigation of organising geological conditions survey of rock may refer to the specification of geotechnical investigation and the water supply GB-50021 hydrogeological investigation code GB-50027 for this.
2. underground tube heat exchanger system exploration should include the following content Club use horizontal ground heat exchangers, underground tube heat exchanger system survey using Groove on, hang on or inquiry. Groove on in order to understand the construction line and broken width, formation and lithological boundaries and extend in the direction the surface mining exploration slot engineering exploration technology. Trenching is determined according to the site shapes, trenching of depth General over lateral depth 1m. Use vertical ground heat exchangers, underground tube heat exchanger system survey conducted by drilling. Drilling programmes should be determined according to the size of the venue, exploration and drilling the hole depth than at least deep 5m. Geo-thermal physical properties of a soil body of thermal physical parameters, including the soil body density and thermal conductivity, specific heat, etc. If the pipe areahas been recognized with the authoritative Department of thermal properties, can be directly used existing data, you should carry out soil body thermal conductivity, density and specific heat determination of Thermophysical properties, etc. Measurement method may use the laboratory method or field determination was:
(1) the structure of the soil layer (laboratory method: on exploration holes of varying depths for determination of rock and soil samples, and use the depth of the weighted average, calculated the geotechnical exploration holes; thermal physical parameters on different levels on the Groove length determination of rock samples, and use the length calculation of the weighted average, trenching and rock of thermal physical parameters);
(2) thermal physical properties of rock (spot test method: test of a soil body should be in the test tube in stable condition. According to the buried pipe depth or length, the test should normally be in the test tube installed 72h. On two exploration holes (Groove) and two or more exploration holes (Groove) test, the test results for arithmetic mean);
(3) soil body temperature;
(4) static water level of ground water, water temperature, water and distribution;
(5) the direction, speed, ground water runoff;
(6) the thickness of permafrost.

(3) groundwater heat exchanger system survey
1, ground water source heat pump system design, water source heat pump system on the base area, water temperature and water quality requirements, engineering field of hydrological conditions for exploration (prospecting and hydrogeological conditions may refer to the water code of the hydrogeological survey, the water supply pipe GB50027 specification GB50296. Through investigation, identified the proposed sources of heat well hydrogeological conditions in the lot, that is, an area of distribution, the burial of groundwater, groundwater supplies, runoff, excretion, and water quality and quantity, and other features. Tomake a reliable assessment of water resources, the proposed groundwater utilization scenarios and predict groundwater dynamics and their impact on the environment, the design for heat well. Permeability coefficient means the unit of time through a unit cross section of flow (m/d), generally used to measure the ground water in the aquifer of the speed in the runoff. Hydrogeological exploration holes for identifying hydrological conditions, ground structure, gets the necessary information, press the hydrogeological and hydrological and geological drilling requires the construction of drilling).
2. groundwater heat exchanger system exploration should include the following elements;
(1) groundwater type;
(2) aquifer lithology, distribution, depth and thickness;
(3) of the aquifer water abundance and permeability;
(4) ground water runoff direction, speed, and hydraulic gradient;
(5) the temperature of the water and its distribution;
(6) groundwater quality;
(7) changes in groundwater level.
3. groundwater heat exchanger system survey hydrogeological test should be carried out. Tests should include the following:
(1) pumping test;
(2) recharge;
(3) Measure water temperature;
(4) for tiered samples and laboratory analysis of water hierarchy;
(5) in the direction of flow;
(6) permeability coefficient calculation.
4. When groundwater heat exchanger system survey results meet the requirements for ground-source heat pump system, you should use technology to improve the hydrogeological exploration holes into heat well. Well drilling process should be hydrogeological professionals conduct supervision.

(4) surface water heat exchanger system survey
1. surface water source heat pump system design, dealing in surface water source to carry out inspection of hydrological conditions. (Surface, water temperature, water level and flow investigation should include nearly 20 years the highest and lowest temperature, water level andthe maximum and minimum water; surface water quality survey should include: caused by corrosion and fouling of the main chemical composition, surface water source in aquatic organisms and bacteria, the amount of solid content and alkaline, etc.).
2, surface water heat exchanger system exploration should include the following:
The nature of the surface water sources, water use, depth, size and distribution;
Different depth of surface water, water temperature, water level changes;
Surface water velocity and flow dynamics;
Surface water quality and dynamic changes;
The status of surface water use;
The surface water intake and the backwater of suitable locations and routes.

Second, ground source heat pump system design principles

Organising a starting ground water-source heat pump systems
1. design requirements
Club 1 in underground geothermal heat pump system design, consulting, knowledge of local laws and regulations allow groundwater exploitation. Use of groundwater heat pump system should not undermine, doesn't pollute groundwater resources.
Club 2 in policy license conditions should conduct a survey of Engineering site, determine the availability of groundwater resources, works for hydro-geological exploration and hydrogeological test.
This should be based on the last 3 groundwater heat exchanger system design for groundwater ground source heat pump system feasibility and the technical and economical comparison to determine whether the use of ground water-source heat pump systems. Use of ground water-source heat pump systems, water resources should be made to the local administrative authorities, access to water.
Club 4 f. groundwater heat exchanger system should be based on the hydrogeological investigation information design. Groundwater is used, you should take the reliable measures, recharging will use groundwater recharge after all into the same aquifer and groundwater resources may result in waste and pollution.
Club 5 pipes and safeguarding groundwater recirculation pipe shall be connected to the municipal network.
2. design principles
The water temperature was 1 in suitable, adequate stability, water quality is better, mining easy and do not cause hazards and local regulations allow, the air conditioning system and heat source may be a preferred ground source heat pump system.
Club 2 was well design unit heat source should have the hydrogeological investigation qualification, heat well should be designed to conform to the current state of the water supply pipe specification GB50296-99.
Club appear when 3 groundwater heat exchanger system survey results meet the requirements of underground water source heat pump system, improvement of exploration holes into heat well.
Club 4 was to ensure that groundwater ground source heat pump system for long-term stable operation, the continued outflow of groundwater should meet the ground source heat pump system for maximum heat or smoke heat requirements. Pumping tube and recirculation pipe measurement devices should be set on, and on the ground floor of pumping, recharge amount and water quality shall regularly carry out testing.
Club 5 f. groundwater ground source heat pump unit performance should be consistent with existing national standards of the water source heat pump unit of GB/T19409 — 2003 related requirements and meet the ground source heat pump system operating parameters.

Club II was buried pipe heat pump system
1. design requirements
Club 1 in a buried pipe design ground-source heat pump system, should be carried out before the project status, and respond to shallow geothermal resources and engineering field area of rock-geological conditions to carry out investigation.
Club 2 was buried pipe heat pump systems engineering investigation should include the following: the structure of the soil layer and distribution, soil body of thermal physical parameters, the temperature distribution of rock; groundwater temperature, static water level and flow direction, speed and distribution; the thickness of permafrost.
This should be based on the last 3 investigation result evaluation of underground tube heat exchanger system implementation feasibility and economic efficiency.
2. design principles
Club appear when 1 there are suitable for shallow geothermal resources and through technical and economical comparison can use, should give priority to the use of underground pipe heat pump system.
Club 2 in field engineering survey results, based on the combination of onsite available surface area, rock types and thermal physical parameters and drilling costs and other factors used to determine the ground heat exchangers using standard pipe, or vertical buried way.
Club 3 was buried tube heat exchanger system design should be as dynamic load calculation, the minimum calculation period shall not be less than 1 year, within the count, the total release of ground source heat pump system with its total absorption of heat to heat to balance.

(3) surface water heat exchanger system
1. General provisions
1.1 surface water heat exchanger system design, response surface water source heat pump system run on water environmental impact assessments.
1.2 surface water heat exchanger system design should be based on water use, water depth, size, surface water quality, water level, water temperature is determined.
1.3 surface water heat exchanger coil heat exchanger should meet the ground source heat pump system maximum absorption of heat or heat release.
2, surface water heat exchanger system design
2.1 open-water heat exchanger system intake vents should be away from home, and it is located on the back gate River. Intake should be set dirt filter
2.2 closed surface heat exchange system should reverse return system. Each loop collection tube heat exchanger should be the same number of loop, and preferably parallel connection; loop set pipe layout should be commensurate with the water body shape, for, return pipe separately.
2.3 surface water heat exchanger coil should be securely installed at the bottom of the water, surface water, the minimum water level and heat transfer coil distanceShould not be less than 1.5m. Heat exchanger coil set and water pressure in the heat exchanger coil of pressure range.
2.4 surface water heat exchanger system can be open or closed in two forms, water systems use variable-flow design.
2.5 surface water heat exchanger coil pipe and heat transfer media should conform to the specification section 4.2.
2.6 local table to the sea, the water and seawater contact of all equipment, components and piping should be anti-corrosion, anti bio attached capability; all with sea-connected devices, components and pipelines with filtration, cleaning functions.
3. construction of surface heat transfer system
3.1 surface water heat exchanger system before construction with surface water heat exchanger system survey information, design and construction drawings and complete construction organization plan.
3.2 surface water heat exchanger coil tubing and fittings should be consistent with the design requirements, and have a quality inspection report and certificate of production plant. Heat exchanger coil should follow the standard length is made by the manufacturers of prefabricated parts required, and there should not be distorted.
3.3 surface water heat exchanger coil fastened to the bottom of the water, the heat exchanger coil should install gasket.
3.4 for, return pipe into surface water source should be clearly marked.
3.5 surface water heat exchanger system during the installation, hydrostatic test should be carried out. Hydraulic test shall conform to the specification section 6.4.2. Surface water heat exchanger system installation should be washed before and after the pipe.
4. surface water heat exchanger system testing and acceptance
4.1surface water heat exchanger system installation process, you should conduct on-site inspection, and shall provide the inspection reports and test content should satisfy the following requirements:
(1) pipes, pipe fittings and other materials should be provided with the product certificate of quality and performance of the inspection report;
(2) heat exchanger coil length, arrangement and tunnel setting should meet the design requirements;
(3) the hydraulic test should be eligible;
(4) the loop flow should be balanced, and should meet the design requirements;
(5) antifreeze and antiseptic properties and concentration should meet the design requirements;
(6) circulating water flow and temperature difference between in and out of water should comply with the design requirements.
4.2 hydraulic test should satisfy the following requirements:
1, closed surface water pressure heat exchanger system should meet the following requirements:
1) test pressure: when working pressure is less than or equal to 1.OMPa, should be a working pressure of 15 times, and should not be less than 0.6MPa; when working pressures greater than l.OMPa, should work pressure 0.5MPa.
2) hydraulic test steps: heat exchanger coil Assembly is complete, you should do first hydrostatic test, pressure test, the voltage after at least 15min, Zener pressure should not be greater than 3%, and no leakage phenomenon; heat exchanger coil and loops set pipe Assembly is completed, a second hydraulic test, pressure test, the voltage after at least 30min, Zener pressure should not be greater than 3%, and no leakage phenomenon; loop set pipe water with room for diversity connection completed, should be the third to the hydraulic test, pressure test, the voltage after at least 12h, Zener pressure should not be greater than 3%.
2, open-water heat exchanger system water pressure testing should be consistent with existing national standards of the ventilation and air-conditioning engineering construction quality approval standard, the relevant provisions of GB50243.