Soil Heat Exchanger Research Articles

Model of the non-stationary thermal processes in the ground heat pump system

One of the main directions for improving heat supply systems is the tendency to switch to low-temperature heating systems by using heat pump units is the tendency of implementation the low-temperature heating systems based on the use of heat pump units. In the work, the main attention is focused on the improvement of thermal parameters and circuit design features of elements of the heat pump system of heat supply using soil energy. For this purpose, the toolkit of mathematical modelling of processes in ground heat pumps is applied, taking into account the climatic conditions of Ukraine. The paper proves the technical possibility of creating an autonomous system of alternative heat supply for energy-saving technologies with the possibility of using ground energy, taking into account environmental requirements. It is substantiated that the use of the proposed systems is a promising direction for Ukraine, which is experiencing a shortage of its own energy resources, because it provides an opportunity to increase the share of organic fuel substitution and reduce the volume of heat emissions into the environment. A mathematical model of heat processes in the elements of the heat exchange equipment of the heat pump system based on renewable energy (soil energy) and secondary energy (wastewater) was developed, taking into account environmental requirements (preventing hypothermia of the soil during the operation of soil pipes and damage to vegetation, respectively), which allows choosing a rational mode of operation of the system under seasonal climatic changes and technological conditions. Numerical modelling of heat processes in elements of the heat exchange equipment of the heat pump system using groundwater and waste water was performed, and the energy and environmental efficiency of the system under variable climatic and technological factors was determined. Analysis and generalization of the calculation results of the heat pump heat supply systems using alternative energy based on the proposed mathematical model, taking into account environmental requirements (preventing thermal relaxation of the soil) allows to take into account the change in the temperature gradient around the soil heat exchanger and more accurately determine the heat flow from each section of the heat exchanger. It has been established that for heat pumps with soil heat exchangers, the maximum substitution ratio of the traditional fuel is 75 %, and the economically feasible quantity of soil heat exchangers is 9 units. Heat pumps using waste water can completely replace traditional heat supply systems. For individual consumers, it is possible to recommend heat pump units with soil heat exchangers, at the same time, it is necessary to provide a backup source of energy to increase the reliability of heat supply.

Research on heat pipe air-conditioner with soil heat exchanger for base station

The refrigeration system accounts for 40-60% of the total energy consumption of the base station, so an effective energy-saving technology is much needed. This paper proposes a heat pipe air-conditioner with an additional soil heat exchange unit. When the indoor and outdoor temperature difference is small, the indoor heat can be scattered to the soil to achieve energy-saving effect.

ENERGY EFFICIENCY OF USING THE ACCUMULATED IN THE SOIL OF SOLAR ENERGY IN THE HEAT PUMP HEATING SYSTEM

A heat pump scheme is proposed to ensure heat supply to the building, which during the heating period of the year uses the energy received in the summer by solar collectors located on this building and stored in the soil battery. A thermodynamic analysis of the efficiency of the heat pump heating system in combination with a vertical soil heat exchanger during the accumulation of solar radiation in the soil in the summer period and with the subsequent extraction of this heat from the soil in the heating period was carried out. The main operating parameters of the heat pump heating system (optimal speed of the heat carrier, minimum specific consumption of external energy, effective coefficient of transformation of the heat pump from the month of the heating period) were determined using balance equations at different values of the depth of the well and the diameter of the pipe. Graphical dependences of energy efficiency indicators on the determining parameters of the system were constructed and analyzed. The obtained ratios between the parameters can be used in calculating the optimal operating conditions of the vertical soil heat exchanger in heat pump systems of low-temperature heating in order to achieve its maximum energy efficiency.

MATHEMATICAL MODELING OF NON-STATIONARY HEAT PROCESSES IN THE GROUND HEAT PUMP SYSTEM

In the work, an analytical study of the efficiency of heat pumps using soil energy for heating, taking into account the climatic conditions of theregion of operation, is performed, which meets the tasks of energy saving and allows reducing emissions of harmful substances into the environment. The main attention is paid to increasing the efficiency of utilization of the technical potential of the soil energy source by the heat pump system using vertical soil heat exchangers. A methodology based on use of the mathematical modeling apparatus as a scientifically based toolkit for calculating non-stationary thermal processes, capable of ensuring the stability and reliability of the ground heat pump system in the short and long term, is proposed. The developed toolkit for calculation and analysis of heat exchange processes allows determining the power of the heat flow, which is removed from the soil, taking into account changes in climatic factors, temperature distribution in the soil around the soil tube and along its length over time, schematic and structural features of the soil tubes for further optimization of the parameters of the heat pump system . It was established that the power of the heat flow, which enters the evaporator of the heat pump from vertical soil pipes, depends on a number of influencing factors: the flow regime of the working fluid circulating in the soil circuit; physical properties of the working body; number of soil heat exchangers; temperature distribution in the soil around the soil tube along its entire length, which changes significantly during long-term operation of the system, affecting the course of heat exchange processes in the system elements. The proposed method makes it possible to perform numerical modeling of thermal processes in the elements of the heat pump, to determine the energy efficiency of the ground heat pump system, which is able to reliably provide consumers with heat during a long period of operation, which can be considered an innovative approach to the analysis of prospects for the development of heat pump heat supply.

Diffusion analysis of three kinds of species with two salts in two working fluids using Darcy's law using solar radiations

This specific research was carried out with the aim of investigating incompressible Casson fluid and Williamson liquid. Steady-state laminar boundary layer flow involving Brownian diffusion and thermophoretic diffusion is taken over a horizontal penetrating plate saturated with two distinct salts having distinct characteristics. Casson fluid motion was observed with the utilization of Darcy-Forchheimer technique. Whilst, Nanofluid motion and other salts motion induced by wall movement. Solar thermal collectors, Solar thermal systems, Solar cookers, Solar thermal energy, drying, generating electricity, chemical reactions, soil vapor extraction, medication and heat exchange medium. Physical quantities like density, temperature profile and concentration profile were addressed by aiding Bossiness approximation. Whereas the optimization of energy is carried out under the effects of cross-diffusion, regular diffusion and non-Fourier law for two different salt components. Formulation of acquired flow equations in terms of partial differential equations are further transformed into ordinary differential equations using similarity transformations. The numerical solution will be obtained by utilization of FE-method. It was found that the temperature field elevates on increasing solar thermal radiation number, modified Dufour numbers of salt 1 and salt 2. Thickness and width regarding momentum layers for Casson liquid rather than Williamson liquid while temperature field for Williamson liquid is higher than Casson liquid.

Heat transfer performance of large energy pile group in a hybrid system subjected to imbalanced thermal load - A numerical investigation

Introduction
 When a energy pile system is coupled with other heating or/and cooling systems, determining the share of thermal demand that energy piles can meet is crucial in designing the size of each system. In the long term, imbalance in thermal load can affect the heat transfer performance of energy piles, and may also lead to annual accumulation of ground temperature over the years, ultimately causing system failure. Furthermore, the mechanical responses of energy piles are also affected by the temperature changes in the pile body and surrounding soil during operation. While Current researches have predominantly focused on mechanical response under temperature load, understanding the heat transfer performance of energy pile groups is equally necessary. Existing studies on heat transfer largely draw from ground source heat pump (GSHP) systems, despite differences in depth and diameter between energy piles and borehole heat exchangers (BHEs), particularly for closely spaced piles. To address this gap, we conducted a series of numerical experiments based on the Tsinghua Science Museum project to investigate the thermal behavior of energy pile group under annual, imbalanced load and the influence of pile spacing. Based on simulation results, we provide design recommendations on how to determine the proportion of heat load that can be carried by energy piles in hybrid systems.
 Method
 We utilized COMSOL software to conduct three-dimensional modeling of a single pile, and developed a two-dimensional model of a pile group using a self-programmed Matlab program. The accuracy of the model was evaluated by comparing it with the results obtained from energy pile field tests (thermal response tests and thermal performance tests) conducted in Shunyi, Beijing. Subsequently, we established two-dimensional and three-dimensional numerical models for the Tsinghua Science Museum project in Beijing. We performed a series of numerical experiments to investigate the behavior of energy piles under balanced and imbalanced temperature loads for one year. Furthermore, we simulated the thermal responses of energy pile groups with different pile spacings of 2m, 2.85m, and 4m.
 Results
 The cooling load surpasses the heating load causing an imbalanced load. The soil temperature rises noticeably by 2.6 °C compared to the initial state after an operation period of 1 year, indicating an undesirable phenomenon of soil heat accumulation. With continuous running over years, the system will fail due to the excessive soil temperature. Moreover, the heat exchange liquid temperature ranges from -4.35 ℃ to +39.65 ℃, which exceeds the acceptable range of 2 ℃ to 33 ℃. To address this concern, a hybrid system can be utilized where the energy pile system bears a balanced portion of the thermal load, and the auxiliary system bears the remaining load. Simulation under various thermal load proportions reveals a linear relationship between the maximum/minimum outlet temperature and the total heat exchange volume. An energy pile system undertaking 60% heating load and 40% cooling load can run stably for long periods. The soil temperature varies in a range of 8.5 ℃ to 17.9 ℃, while the pile body temperature has a variation range of 4.0 ℃ to 22.8 ℃ (Figure 1).
 The study results for various pile spacings are presented in Table 1. Pile spacing plays a significant role in soil heat accumulation and heat exchange fluid temperature. Despite an invariable pattern in the inflow and outflow temperature curves for varied pile
 spacing, the flow temperature range is significantly influenced. The smaller the spacing, the more prominent is the thermal accumulation in the soil, leading to larger changes in soil temperature and the flow temperature. During design simulation, if the range of flow temperature exceeds the limits of the energy pile system, it may present a safety risk during system operation. In such cases, increasing the pile spacing can render the system more reliable and safe.
 Conclusions
 (1) Whether the system can operate normally can be judged by whether the simulation result of the heat exchange liquid temperature exceeds the limit value. There is a linear relationship between the flow temperature and the total heat exchange. Therefore, the proportion of the load that the energy pile system can bear in the hybrid system can be determined. For the Tsinghua project, the energy pile system can bear 60% of the heating load and 40% of the cooling load.
 (2) The pile spacing affects the magnitude of variation in heat exchange fluid temperature by influencing the degree of heat accumulation in soil. If the range of flow temperature exceeds acceptable limits, it is advised to increase the pile spacing during the design phase to ensure the energy pile system can operate effectively.

Numerical Evaluation of the Benefits Provided by the Ground Thermal Inertia to Urban Greenhouses

Communities operating urban greenhouses need affordable solutions to reduce their heating consumption. The objective of this study was to compare the ability of different simple ground-based solutions to reduce the heating energy consumption of relatively small urban greenhouses operated all year round in a cold climate. An urban greenhouse located in Montreal (Canada) and its thermal interactions with the ground were modeled with the TRNSYS 18 software. The following greenhouse scenarios were simulated: partially insulating the walls, partially burying the greenhouse below the ground level, reducing the inside setpoint temperature, and using an air–soil heat exchanger (ASHE) or a ground-coupled heat pump (GCHP). The heat exchangers for the last two cases were assumed to be located underneath the greenhouse to minimize footprint. The results showed that reducing the setpoint temperature by 10 °C and burying the greenhouse 2 m below the surface has the most impact on fuel consumption (−33% to −53%), while geothermal systems with a limited footprint (ASHE and GCHP) can reduce the fuel consumption by 21–35% and 18–27%, respectively, depending on the soil thermal conductivity and ground heat injection during summer. The scenarios do not provide the same benefits and have different implications on solar radiation availability, growth temperature, electrical consumption, and operation that must be considered when selecting a proper solution.

A Two-dimensional Numerical Model of Heat Exchange in the Soil Massif During the Operation of a Shallow Horizontal Soil Heat Exchanger

The current article uses a two-dimensional numerical model to represent the results of theoretical studies of the heat exchange in the soil massif during the operation of a shallow horizontal soil heat exchanger. The analysis of literature sources showed that one of the important conditions for the effective operation of a shallow-soil heat exchange is its rational design parameters, such as the total length of the pipeline, the diameter of the pipe, the distance between the axis of the adjacent pipes, the depth of the heat exchanger placement, etc. A two-dimensional heat exchange model in the soil mass was developed, which made it possible to investigate the operation of a shallow horizontal soil heat exchanger. It was found that the step between the axis of the adjacent pipes of the multi-loop heat exchanger, which is 0.95 m, is optimal when creating a shallow horizontal soil heat exchanger in the soil conditions of Kyiv.

THERMODYNAMIC EFFICIENCY OF HEAT PUMP AIR CONDITIONING SYSTEM BASED ON VERTICAL GROUND HEAT EXCHANGER

An analysis of literary sources in which heat pump heating and air conditioning systems were studied over the past 10 years was carried out. It was determined that research for heat pumps using vertical soil heat exchangers was conducted more in the empirical plane. The authors analyzed the effectiveness of using existing systems that work for heating and air conditioning in different countries. The results of many studies are given, which show that, in fact, the use of ground heat pumps in a temperate climate only in the heating mode entails the exhaustion of the thermal potential and the impossibility of its use in the future. Theoretical studies at the system design stage are not sufficiently presented, and the issue of predictioning the efficiency of the use of such systems is not disclosed. In this regard, it is proposed to investigate the energy efficiency of the heat-pump air conditioning system based on vertical soil heat exchangers. A heat pump air conditioning system based on a vertical soil heat exchanger is considered. Two research tasks were defined: analysis of efficiency in active and passive modes of conditioning. A thermodynamic analysis of the efficiency of the proposed scheme was carried out. The main operating parameters of the system at nodal points are defined. With the help of balance equations, the framework of the system's operation in passive and active modes according to the main parameters is determined. Graphical dependences of energy efficiency indicators on the determining parameters of the system were constructed and analyzed. It is shown at which parameter values the system has optimal operating costs. The results of the study are compared with those for the split system. The advantages and disadvantages of using the proposed solution are determined. It was determined that the heat pump system using soil heat for air conditioning with a vertical soil heat exchanger has stricter requirements for the thermal insulation of the air conditioning object than the system based on the air heat pump.

The Arrangement Concept and the Energy Potential of the Vapor Compression Heat and Cooling Supply Based on a Binary Low-Temperature Source

The combined use of low-potential soil heat and air flows in heat pump heat supply systems allows for its regulated redistribution in the processes of customers’ consumption. Herewith, the intensity of energy extraction by the soil heat exchanger decreases, excess heat is accumulated with a decrease in the depth of wells, and the costs of installing and operating probe heat exchangers are also reduced. An improved version of the conceptual arrangement of a vapor compression system for heat and cool supply of buildings based on the integrated heat of soil and ventilation air has been developed. Its distinguished features are the possibility of automatic redistribution of generated heat flows in the subsystems of customers’ heat consumption and accumulation of excess part in the soil mass. When the system is operating in the warm season with the extraction of heat only for hot water supply, there is a more intensive accumulation of excess heat of the ventilation air in the soil mass, which restores its temperature in the accumulation mode for further use with the coming of the heating period. Multifactor analytical dependences of the heat flows of the main equipment have been established, taking into account the initial parameters and operating conditions of the structural subsystems for the extraction, transformation and consumption of heat, which are the basis for determining the energy potential of vapor compression heat and cold supply using a binary low-temperature source.

Free Convection and Heat Transfer in Porous Ground Massif during Ground Heat Exchanger Operation.

Heat pumps are the ideal solution for powering new passive and low-energy buildings, as geothermal resources provide buildings with heat and electricity almost continuously throughout the year. Among geothermal technologies, heat pump systems with vertical well heat exchangers have been recognized as one of the most energy-efficient solutions for space heating and cooling in residential and commercial buildings. A large number of scientific studies have been devoted to the study of heat transfer in and around the ground heat exchanger. The vast majority of them were performed by numerical simulation of heat transfer processes in the soil massif–heat pump system. To analyze the efficiency of a ground heat exchanger, it is fundamentally important to take into account the main factors that can affect heat transfer processes in the soil and the external environment of vertical ground heat exchangers. In this work, numerical simulation methods were used to describe a mathematical model of heat transfer processes in a porous soil massif and a U-shaped vertical heat exchanger. The purpose of these studies is to determine the influence of the filtration properties of the soil as a porous medium on the performance characteristics of soil heat exchangers. To study these problems, numerical modeling of hydrodynamic processes and heat transfer in a soil massif was performed under the condition that the pores were filled only with liquid. The influence of the filtration properties of the soil as a porous medium on the characteristics of the operation of a soil heat exchanger was studied. The dependence of the energy characteristics of the operation of a soil heat exchanger and a heat pump on a medium with which the pores are filled, as well as on the porosity of the soil and the size of its particles, was determined.

Earth Tube Heat Exchanger

Abstract: Devices that utilise the ground as a wellspring of or sink for warming or cooling are called ground-to-air heat exchangers, ground pipe heat exchangers, or soil heat exchangers. Numerous concepts and experiments with EAHE have so far been developed and tested to determine the best parameter values to increase performance based on location and other variables. In this study, we will review the studies conducted so far from the viewpoint of performance evaluation considering the influence of various parameters such as construction materials, depth from the ground surface, wind speed, and pipe length.

Development of RZ-SHAW for simulating plastic mulch effects on soil water, soil temperature, and surface energy balance in a maize field

A shortcoming of the RZ-SHAW model (A hybrid version of Root Zone Water Quality Model and The Simultaneous Heat and Water Model) is that it cannot simulate the plastic mulching technology which is widely used in arid areas. Our objectives in this study were to develop RZ-SHAW to include a new plastic module, and to evaluate the model’s performance over three years of maize (Zea mays L.) production in China. A new plastic module was added to compute changes in the shortwave and longwave radiation transfer, turbulent heat and vapor transfer from the surface, and the energy and water balances in the system associated with a plastic mulch layer. The modified RZ-SHAW model can adequately simulate soil water (0.017 cm3 cm−3 ≤ RMSE ≤ 0.030 cm3 cm−3) and capture the evaporation reduction and transpiration increase under plastic mulch. The model overestimated the increased soil temperatures under plastic mulch (2.3 ℃ over the 100-cm profile) compared to the measured data (1.4 ℃). Overall, the revised RZ-SHAW model adequately simulated soil water and heat exchange under plastic mulch conditions. The modified RZ-SHAW model can be used as an effective decision tool for management optimization in plastic mulched cropland.

SIMULATION MODELING OF THE MICROCLIMATE SYSTEM IN POULTRY HOUSES IN THE SUMMER

Modern microclimate systems for keeping poultry require new approaches. Air cooling and heating systems in the poultry house environment require significant water and energy resources. Therefore, the authors proposed an energy-efficient microclimate system in poultry houses using low-potential water energy from the use of shell and tube heat exchangers and soil heat exchangers. Among the included control parameters, the most important are the temperature in the room, the amount of harmful substances and air humidity. The amount of pollutants in the air is determined by the amount of air entering the room and the number of animals in it. When creating a mathematical model of the ventilation system in the poultry house, a material balance of harmful substances is created. One of the important factors is air consumption. Approximate functions of the required air exchange, as well as the required amount of water depending on the temperature of the outside air, were found. Depending on the required water consumption, the heat exchangers will be connected to work in autonomous mode using magnetic valves. One by one. At an outside air temperature of +23 ºС, it is necessary to use three heat exchangers with a water consumption of 2.5 m3/h. And in the temperature range from +35 ºС to +40 ºС, six heat exchangers with a water consumption of 57 to 108 m3/h are needed. A simulation model of heat and mass exchange in poultry houses in the summer period of the year was developed using heat exchange equipment in the MATLAB Simulink software complex. The indoor humidity change time constant will be equal to the time required to establish the indoor humidity set point once the humidity change rate is equal to the initial one. Model studies showed that the constant duration heating is 118.4 s. The productivity of the ventilation system is expressed as an approximate function and ranges from 36,000 to 170,000 m3/h. In fact, the simulation model system stabilizes in the summer period of the year in terms of temperature and humidity for up to 1000 seconds. Relative humidity is 60 %.

A New Approach for Characterizing Pile Heat Exchangers Using Thermal Response Tests

Pile heat exchangers offer a cost effective route to implementation of ground-source heat pump systems for many large commercial buildings compared with traditional boreholes. Such projects typically use thermal response tests to determine the key input parameters for system design, namely soil thermal conductivity and heat exchanger thermal resistance. However, this brings challenges for pile heat exchanger based systems, where in situ thermal response tests are known to be less reliable due to the large thermal capacity of the pile. This paper presents a new “black box” resistance capacitive model for applications to pile thermal response tests. The approach is tested against case study data and shown to perform well. Additional test duration savings are shown to be possible if a novel combination of borehole and pile thermal response tests is applied together to determine design parameters.

Modeling of Joint Operation of a Ground Soil Heat Exchanger and a Thermal Pump Evaporator

Modeling of Joint Operation of a Ground Soil Heat Exchanger and a Thermal Pump Evaporator

Thermal performance analysis of multiple borehole heat exchangers in multilayer geotechnical media

Based on the finite line source (FLS) model, A heat transfer model considering both multilayer soil and multiple Borehole Heat Exchangers (BHEs) is proposed. The accuracy of the model is verified by experiments. The model is used to study the effect of thermal physical properties of multilayer geological media on the overall thermal efficiency of multiple BHEs. The dimensionless regional thermal efficiency (E) is introduced as an evaluation index of heat transfer characteristics of multiple BHEs. Under a certain geological structure, the heat transfer efficiency of multiple BHEs in homogeneous soils and multilayer soils were compared with the analytical model. The results show that the E of the multilayer multiple BHEs model is less than that of the homogeneous multiple BHEs model, with the maximum difference being 11.43% in 2,000 h. With these thermal properties and soil layer structure, the rate at which E decrease for the multilayer model is a factor of 4 higher than that for the homogeneous model. In the soil layer where the thermal interaction is the most intense, the unit Heat Transfer Rate (HTR) decreased by 25.3%. At a fixed spacing, the thermal diffusivity is the key to determining the degree of thermal interaction. Under the 4 × 4 BHEs layout, the dynamic performance loss increases by about 4% for every 1 × 10−7 m2/s increase in soil thermal diffusivity. When the multiple BHEs are in a multilayer geological media with a large difference in thermal properties (especially thermal diffusivity), a comprehensive multilayer analysis is needed to obtain the thermal efficiency of the overall multiple BHE area accurately. The multilayer multiple finite line source model can be used during the engineering design stages of a BHE field to predict the regional thermal efficiency with borehole spacing and the number of boreholes.

Influences of different factors on the three-dimensional heat transfer of spiral-coil energy pile group with seepage

Abstract Energy pile group is an important component of ground source heat pumps with foundation piles as ground heat exchangers. Among different energy piles, those with spiral pipes have a large heat exchange area between the pipe and the concrete, achieving good heat exchanging performance and wide applications. To analyze the influence of geometrical parameters (pile layout, pile spacing and pile depth) and external parameter (groundwater velocity) on the heat transfer of spiral-coil energy pile groups, a three-dimensional analytical model of spiral-coil energy pile groups with seepage is used, considering the thermal interaction among different piles, the geometry of spiral pipe and the velocity of groundwater. The soil temperature distribution in the energy pile group is studied under conditions with different factors (pile layouts: 3 × 2, L shape and line shape; pile spacing distances: 3, 5 and 7 m; pile depths: 10, 30 and 50 m; and groundwater velocities: 0, 1.2 × 10−6 and 2.0 × 10−6 m/s). The 3-year outlet fluid temperature of energy pile group affected by the above different factors under different inlet fluid temperatures and velocities or soil thermal exchange ratios is investigated. Results show that for the low fluid velocity inside the piles, the influence of above factors on the thermal performance of energy piles is more obvious. Large groundwater velocity, line shape pile layout, large pile spacing distance and short pile depth can alleviate the long-term temperature variation caused by unbalanced soil heat exchange. This work will facilitate the research, design and application of the energy pile group in ground source heat pumps.

EFFICIENCY OF SOLAR GROUND THERMAL STORAGE

Non-stationary processes of heat exchange in seasonal solar ground thermal storage with a heat pump and 9 soil vertical heat exchangers, with daily cycles, storage charging in summer and discharging in winter for various regions of Ukraine are investigated. The research method is numerical. The iterative method selected the conditions for the complete autonomous heating. The possibility of increasing the efficiency of thermal storage by selecting a rational step of pipes and the temperature of the coolant in the ground heat exchanger is shown. In the cluster method of a seasonal battery organizing, recirculation of the coolant in heat exchangers in the case of solar radiation absence (in the passive phase) contributes to an increase of heat supply efficiency of the ground. The boundary velocity of the coolant at the entrance of the heat exchanger in the passive phase is 0.8 m/s. Such conditions make it possible to achieve an increase of the ground enthalpy and to reduce the required area of solar collectors. This also contributes to the rational value of the coolant temperature at the entrance of the soil heat exchangers, which can be recommended at 50 °C. The rational step of pipes in cluster is mainly a function of the thermophysical properties of the ground and can be determined from the obtained formula.

STUDY OF THERMAL INTERFERENCE OF ELEMENTS OF THE UNDERGROUND HEAT EXCHANGER IN ELECTROLYTIC BATH

A study was made of the mutual thermal eff ect of the tube elements of soil heat exchangers. It was determined that the number of pipe elements of the soil heat exchanger has the greatest eff ect on the amount of heat infl ux from the soil mass. It is established that when placing the pipe elements at a distance of one diameter from each other, it causes a signifi cant decrease in the heat infl ux to the soil heat exchanger. Increasing the distance between the pipes reduces the thermal interference of the elements. The coeffi cients of thermal interference are found for various confi gurations of ground heat exchangers, which depending on the number of pipes and the distance between them vary from 0.621 to 0.99.