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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 163 records · Page 9

Proposed Material Properties, Allowable Stresses, and Design Curves of Diffusion Bonded Alloy 800H for the ASME Code Section III Division 5

Abstract Increased interest in compact heat exchangers (CHXs) to serve as intermediate heat exchangers of very high temperature reactors resulted in significant research and development on their design, analysis, and construction. Printed circuit heat exchangers are a type of CHXs with high thermal efficiency and compactness achieved through diffusion bonding a stack of etched plates with millimeter scaled channels. The diffusion bonding process changes the microstructural and mechanical properties of the wrought metal plates. The current nonnuclear design code ASME section VIII, division 1 captures the material property change through a “joint efficiency factor.” However, the current nuclear design code ASME section III, division 5 does not address or support the diffusion bonded material properties. Hence, there is a need to develop allowable stresses, isochronous curves, and fatigue life curves for various diffusion bonded alloys. In this study, Alloy 800H material was selected to establish the diffusion bonded material properties under tension, creep, fatigue, and creep-fatigue loads at elevated temperatures in the range 550–760 °C. A set of tests on diffusion bonded Alloy 800H (DB 800H) were performed and the acquired data are used in developing allowable stresses Sy, Su, Sr, Sm, St, Smt, So, isochronous curves and fatigue life curves according to the ASME section III, division 5 requirements. This paper also presents detailed procedures used in developing the ASME code section III division 5 design provisions for diffusion bonded Alloy 800H.

Engineering↗

Thermal Conductivity And Expansion Of Graphite/Copper

Report describes fabrication of graphite-fiber/copper-matrix composite plates, measurements of thermal conductivities of plates at temperatures from ambient to 1,073 K, and measurements of thermal expansions of plates from ambient temperature to 1,050 K. Composites promising lightweight, high-thermal-conductivity materials proposed for use in heat exchangers and other heat-transfer components of power systems in spacecraft and hypersonic aircraft. Graphite/copper also of interest as model composite material.

Mcdanels, David L.↗

Energy Efficient Microlith-Based Catalytic Reactor and Recuperator for Air Quality Control Applications

Precision Combustion, Inc. (PCI) and NASA’s Marshall Space Flight Center (MSFC) have been developing, characterizing, and optimizing high temperature catalytic oxidizers (HTCO) based on PCI’s patented Microlith technology to meet the requirements of future extended human spaceflight explorations. Previous efforts focused on integrating PCI’s HTCO unit with a compact, simple recuperative heat exchanger to reduce the overall system size and weight. Significant improvement was demonstrated over traditional approaches of integrating the HTCO with an external recuperative heat exchanger. While the critical target performance metrics were achieved, the thermal effectiveness of PCI’s recuperator remained a potential area of improvement to further reduce the energy requirements of the integrated system. Using the same material combinations and an improved recuperator design, the redesigned prototype has experimentally demonstrated 20 – 30% reduction (flow dependent) in steady state power consumption compared to the earlier prototype without compromising the destruction efficiency of methane and volatile organic compounds (VOCs). Moreover, design modifications and improvements allow our redesigned prototype to be more easily manufactured compared to traditional brazed plate-fin recuperator designs. The redesigned prototype was delivered to MSFC for validation testing. Here, we report and discuss the performance of the improved prototype HTCO unit with a high efficiency recuperative heat exchanger based on testing at PCI and MSFC. The device is expected to provide a reliable and robust means of disposing of trace levels of methane and VOCs by oxidizing them into carbon dioxide and water in order to maintain clean air in enclosed spaces, such as crewed spacecraft cabins.

Vilekar, Saurabh A.↗

An overview of bipolar plates in proton exchange membrane fuel cells

Bipolar plates are a crucial component of proton exchange membrane fuel cells. They are responsible for transporting reactant gases, carrying the current from the membrane electrode assembly to the end plates, providing heat and water management, and separating the individual cells. However, these plates also contribute to 80% of the fuel cell’s weight, 50% of its volume, and 40% of its cost, posing a barrier to the commercialization of fuel cells. This paper provides a comprehensive review of the materials and manufacturing processes used in the fabrication of bipolar plates as well as recent research conducted on the improvement of bipolar plate weight, volume, and cost through material selection and manufacturing methods. Additive manufacturing is highlighted in this work as an innovative manufacturing method to produce bipolar plates. Novel contributions in this paper include a detailed explanation of traditional manufacturing processes for metallic and graphitic-polymer bipolar plates as well as a cost comparison between additive and traditional manufacturing processes.

08 HYDROGEN↗

Sintered silicon nitrode recuperator fabrication

The preliminary design and a demonstration of the feasibility of fabricating submodules of an automotive Stirling engine recuperator for waste heat recovery at 370 C are described. Sinterable silicon nitride (Sialon) tubing and plates were fabricated by extrusion and hydrostatic pressing, respectively, suitable for demonstrating a potential method of constructing ceramic recuperator-type heat exchangers. These components were fired in nitrogen atmosphere to 1800 C without significant scale formation so that they can be used in the as-fired condition. A refractory glass composition (Al2O3 x 4.5 CaO.MgO x 11SiO2) was used to join and seal component parts by a brazing technique which formed strong recuperator submodules capable of withstanding repeated thermal cycling to 1370 C. The corrosion resistance of these materials to Na2SO4 + NaCl carbon mixtures was also assessed in atmospheres of air, hydrogen and CO2-N2-H2O mixtures at both 870 C and 1370 C for times to 1000 hours. No significant reaction was observed under any of these test conditions.

Gatti, A.↗

Droplet Evaporator For High-Capacity Heat Transfer

Proposed heat-exchange scheme boosts heat transfer per unit area. Key component is generator that fires uniform size droplets of subcooled liquid at hot plate. On impact, droplets spread out and evaporate almost instantly, removing heat from plate. In practice, many generator nozzles arrayed over evaporator plate.

Valenzuela, Javier A.↗

Generalized Fluid System Simulation Program, Version 6.0

The Generalized Fluid System Simulation Program (GFSSP) is a general purpose computer program for analyzing steady state and time-dependent flow rates, pressures, temperatures, and concentrations in a complex flow network. The program is capable of modeling real fluids with phase changes, compressibility, mixture thermodynamics, conjugate heat transfer between solid and fluid, fluid transients, pumps, compressors, and external body forces such as gravity and centrifugal. The thermofluid system to be analyzed is discretized into nodes, branches, and conductors. The scalar properties such as pressure, temperature, and concentrations are calculated at nodes. Mass flow rates and heat transfer rates are computed in branches and conductors. The graphical user interface allows users to build their models using the 'point, drag, and click' method; the users can also run their models and post-process the results in the same environment. Two thermodynamic property programs (GASP/WASP and GASPAK) provide required thermodynamic and thermophysical properties for 36 fluids: helium, methane, neon, nitrogen, carbon monoxide, oxygen, argon, carbon dioxide, fluorine, hydrogen, parahydrogen, water, kerosene (RP-1), isobutene, butane, deuterium, ethane, ethylene, hydrogen sulfide, krypton, propane, xenon, R-11, R-12, R-22, R-32, R-123, R-124, R-125, R-134A, R-152A, nitrogen trifluoride, ammonia, hydrogen peroxide, and air. The program also provides the options of using any incompressible fluid with constant density and viscosity or ideal gas. The users can also supply property tables for fluids that are not in the library. Twenty-four different resistance/source options are provided for modeling momentum sources or sinks in the branches. These options include pipe flow, flow through a restriction, noncircular duct, pipe flow with entrance and/or exit losses, thin sharp orifice, thick orifice, square edge reduction, square edge expansion, rotating annular duct, rotating radial duct, labyrinth seal, parallel plates, common fittings and valves, pump characteristics, pump power, valve with a given loss coefficient, Joule-Thompson device, control valve, heat exchanger core, parallel tube, and compressible orifice. The program has the provision of including additional resistance options through User Subroutines. GFSSP employs a finite volume formulation of mass, momentum, and energy conservation equations in conjunction with the thermodynamic equations of state for real fluids as well as energy conservation equations for the solid. The system of equations describing the fluid network is solved by a hybrid numerical method that is a combination of the Newton-Raphson and successive substitution methods. The application and verification of the code has been demonstrated through 30 example problems.

Majumdar, A. K.↗

Mitigating CaCO 3 crystal nucleation and growth through continuous ion displacement via alternating electric fields

Mineral crystal formation poses a challenge on surfaces (e.g., heat exchangers, pipes, membranes, etc.) in contact with super-saturated fluids. Applying alternating currents (AC) to such surfaces can prevent surface crystallization under certain conditions. Here, we demonstrate that ion displacement induced by periodic charging and discharging of the electrical double layer (EDL) inhibits both heterogeneous and homogeneous nucleation (and crystal growth) of CaCO 3 . Titanium sheets (meant to simulate metallic heat exchanger surfaces) are immersed in super-saturated CaCO 3 solutions with a saturation index >11. We show that at relatively high AC frequencies, incomplete EDL formation leads to an alternating electric field that propagates far into the bulk solution, inducing rapid ion migration that overwhelms the Brownian motion of ions. Electrochemical characterization reveals EDL charging/discharging under AC conditions that greatly inhibits precipitation. Operating at 4 V pp , 0.1–10 Hz reduces turbidity by over 96% and reduces CaCO 3 coverage on the metal plates by over 92%. Based on electrokinetic and crystallization models, the ion displacement velocity (exceeding the mean Brownian velocity) and displacement length disrupts ion collision and crystal nucleation. Overall, the technique has potential for preventing mineral crystal formation in heat exchangers and many other industrially relevant systems.

42 ENGINEERING↗

Characterization of the Heat Extraction Capability of a Compliant, Sliding, Thermal Interface for Use in a High Temperature, Vacuum Microgravity Furnace

Much of the material science gained in microgravity research requires processing a sample in a high performance furnace. One such furnace currently being designed is the Quench Module Insert (QMI). The Principle Investigators, for whom the furnace is proposed, require high temperature gradients in their cylindrical samples to achieve the science objectives. One of the components critical to achieving high sample axial temperature gradients in the Quench Module Insert is a high performance cold zone to extract the heat from the sample. This cold zone employs a compliant, sliding thermal interface based on a Vel-Therm felt. This felt provides a conductive path between the Sample Cartridge Assembly (SCA) exterior surface and the interior surface of the water cooled chill block while allowing movement of the sample relative to the chill block. The Vel-Therm felt is composed of long polymer-based fibers affixed to a thin flexible substrate layer. The fibers are oriented perpendicular to this substrate giving the felt the appearance of a velvet fabric. The Vel-Therm felt heat extraction capability was quantified in earlier tests performed in an inert gas environment. The current activity, described in this paper, is intended to characterize the extraction capability of Vel-Therm felt in a vacuum environment similar to the QMI environment. This testing is necessary to quantify the thermal performance of the Vel-Therm felt and the sensitivity of that performance to key variables. The data derived from these tests will be incorporated into the current thermal models to improve the quality of the models and reduce uncertainty of the analytical results. In addition, the data will be used to help select the appropriate Vel-Therm felt and set proper operating limits as well as assess the performance range of the furnace. The objective of this test is to measure the heat extraction rate of the Vel-Therm felt as specified by the effective heat transfer coefficient. Therefore, the test setup was designed to force the bulk of the heat transfer through the area where the Vel-Therm felt was applied. A heat source, consisting of a ceramic heating element encased in a Copper (Cu) housing is mounted on four isolated support rods. A 6-layer molybdenum radiation shield is used to insulate against heat loss from the heater and prevent heat exchange between the hot and cold sides of the test apparatus. The Vel-Therm felt is affixed to the surface of the cold sink, a water-cooled Cu chill block. An adjustable plate supports and isolates the cold sink from above and is used to control the amount of the deflection of the Vel- Therm when in contact with the Cu heating element housing. The primary means of establishing the power being conducted through the felt is to measure the energy being transferred to the water passing through the chill block. Analysis was performed to support the assumption that the source and sink surfaces were approximately isothermal under the specific test conditions. As a check on the amount of power passing through the felt, the power supplied to the heater was also measured. Thermocouples were strategically located throughout the test apparatus for measurement purposes. A bell jar was lowered over the assembly to impose vacuum conditions. Currently, variables tested have been fiber compression and fiber type and surface temperatures (both the hot and cold side temperatures are hypothesized to be important to the performance of the Vel-Therm.) Selected runs were repeated to ensure consistency and repeatability. Results obtained thus far reveal that Vel-Therm performance is significantly degraded by fibers being exposed to high compression. It also shows that performance is somewhat negatively impacted by previous compression, thereby, raising the question of repeatability. In addition, early results show a significant dependence on temperature. A computer aided mathematical analysis of the test setup is ongoing. The results will be correlated to actual results. The correlation will examine such details as parasitic loses, conduction down the power leads and many other concerns.

Bellomy-Ezell, Jenny↗

Fire-station solar-energy system--Kansas City, Missouri

Screen-walled, flat-plate air collectors are part of award-winning architectural design; concrete-box storage subsystem, domestic hot-water preheat tank, blowers, pumps, heat exchangers, ducting, controls, and plumbing complete solar system. Design provides half of space heating and 75 percent of heat for domestic hot-water for fire station. Report includes historical narrative of project along with detailed drawings, charts, and product literature.

Source record↗

ECAR-6580 Rev 0 ASME Section III, Division 5 Analysis of the MARVEL PCS and GVS Top Corner

The purpose of this Engineering Calculations and Analysis Report (ECAR) is to document the structural evaluation for part of the Microreactor Applications Research Validation and Evaluation (MARVEL) Primary Coolant System (PCS) and Guard Vessel System (GVS). For the PCS this relates specifically to the Distribution Plenum (DP), The Intermediate Heat Exchanger (IHX), and the Upper Downcomer (UD). For the GVS, this will include only the top corner that is machined into the DP Top Plate. These components will be evaluated using the 2021 version of ASME Section III, Division 5 [1] which is a design code that governs the construction of vessels, storage tanks, piping, pumps, valves, supports, core support structures and nonmetallic core components for use in high temperature reactor systems and their supporting systems. Materials at high temperature are subject to creep and fatigue mechanisms that require additional analyses that aren’t covered in ASME Section III, Division 1 rules. Division 5 contains two approaches: elastic or inelastic, however, additional Code Cases specific to Division 5, allow for an Elastic-Perfectly Plastic (EPP) approach. The components analyzed in this ECAR will use a combination of the elastic and EPP approach. Only Design and Service Levels A and B are evaluated in this ECAR. Service Level D evaluations for the entire PCS are documented in ECAR-6564, “MARVEL Project Primary Coolant System Pressure Vessel Stress Documentation” [2] and for the entire GVS are documented in ECAR-6574, “MARVEL Guard Vessel System FEA and ASME Analysis” [3]. The Design and Service Level A and B analyses for the PCS Downcomer piping and Core Barrel are documented in ANL-24/36, "Engineering Calculations and Analysis of the Core Barrel and Downcomer Piping in the MARVEL PCS” [4], and the GVS (except for the top corner) is in ECAR-6574, “MARVEL Guard Vessel System FEA and ASME Analysis.” See Section 2.0 for more detail on the analysis boundaries.

21 - SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLAN↗

Influence of design and operating parameters for additively manufactured intensified packing devices on CO 2 -Absorption column cooling and capture efficiency

Solvent-based CO 2 absorption is technologically a matured CO 2 capture pathway but suffers from: high regeneration energy demand, and solvent temperature rise and decreased capture efficiency caused by the heat of reaction. While research has focused on developing non-aqueous and low-aqueous solvents for decreasing the regeneration energy, the temperature bulge due to exothermic absorption is typically dealt with by cooling the solvent with an external inter-stage heat-exchanger. This approach may increase the overall process footprint, as well as capital and operating costs. Here, the current study explores a process intensification approach by incorporating inside the column an additively manufactured intensified packing device that consists of corrugated plates and internal coolant channels. The corrugated plates provide surface area for mass transfer between gas and liquid, while cooling fluid inside the internal channels removes heat from the exothermic reactive system. Two different intensified devices with specific surface areas of 266 m 2 /m 3 and 359 m 2 /m 3 were designed, manufactured, and tested inside a 2.06-m long and 0.203-m diameter column packed with commercial Mellapak 250Y packing. The device with a lower surface area showed up to 27 % reduction in cooling performance. A steady-state heat transfer model provides good agreement with the experimental column temperature and intra-stage heat removal data. Although a decrease in heat transfer performance was observed for the device with lower surface area, CO 2 capture experiments performed with simulated flue gas and low-aqueous solvent demonstrated that both intensified devices lead to a similar improvement of 12 % in capture efficiency. This study provides an understanding on simplifying the intensified packing device geometry and decreasing the device fabrication cost by 25 % without compromising with the CO 2 absorption performance of the packed column.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Development and test fuel cell powered on-site integrated total energy systems. Phase 3: Full-scale power plant development

The on-site system application analysis is summarized. Preparations were completed for the first test of a full-sized single cell. Emphasis of the methanol fuel processor development program shifted toward the use of commercial shell-and-tube heat exchangers. An improved method for predicting the carbon-monoxide tolerance of anode catalysts is described. Other stack support areas reported include improved ABA bipolar plate bonding technology, improved electrical measurement techniques for specification-testing of stack components, and anodic corrosion behavior of carbon materials.

Kaufman, A.↗

Status of the US Space Station ECLSS and internal TCS

The U.S. Space Station includes many elements and systems. Responsibility for these have been delegated to four NASA centers via a work packaging concept. Marshall Space Flight Center (MSFC) is responsible for work package one (WPOI) which includes the habitation, laboratory modules, the logistic carrier elements, as well as the environmental control and life support system (ECLSS), the internal thermal control system (ITCS), and the internal audio and video systems. Current status of the ECLSS and internal thermal are the subjects of this paper. The ECLSS is composed of six subsystem groups: the temperature humidity control, the atmosphere control and supply, the air revitalization, water reclamation and management, fecal waste management, and the fire detection and suppression subsystems. The internal TCS consists of all WP01 elements of passive and active thermal measures. The ECLSS and ITCS provide services for the permanently orbiting pressurized modules as well as the pressurized and unpressurized logistics carriers. The logistics carriers are used as ground-to-station ferries for both resupply and initial delivery of selected new equipment and later replacement items. Equipment, which cannot be subjected to the rigors of the space environment, will be carried in the pressurized logistic carrier; while an unpressurized carrier is used to resupply other commodities, such as external fluid consumables. The laboratory module houses the equipment for both payloads and subsystem maintenance and repair. The habitation module is dedicated to providing living and sleeping quarters including a galley, sleeping provisions, hygiene facilities, medical services as well as services for exercise and relaxation. The four nodes that join the two modules at their ends also house electronics as well as work stations and outside viewing cupolas. The airlocks, one providing an emergency hyperbaric chamber capability, are also attached. This assembly constitutes the U.S. provided portion of the initial station. Additional international modules and docking provisions for future attached pressurized payload as well as dual logistic module and growth capabilities are also provided. The primary heat rejection mechanism is achieved via a central set of radiators provided by another work package. The interface with the central TCS at the module heat exchangers defines the active control interface boundary of the ITCS with the central TCS. All internal cooling of the permanent orbital elements are provided via internal active fluid loops within the elements utilizing water as the transport media. Cabin and equipment cooling are provided by forced air flow and cold plate heat sinks. A special active cooling loop is provided in the laboratory module to accommodate experiments and other payloads. Coatings and insulation are used in conjunction with the active components to passively limit heat losses/gains. The most challenging ECLSS new technology issues relate to oxygen and water recovery. Closure of the oxygen loop requires the use of new regenerative CO 2 removal and concentration techniques, CO 2 reduction to convert the CO 2 to water with a waste by-product, and the electrolysis of water to produce breathing oxygen for water recovery. For water recovery three separate loops are currently planned. One loop provides potable water by utilizing a combination of recovered condensate and CO 2 reduction water. A second loop purifies hygiene water from waste from the showers, clothes washer, hygiene/hand wash stations and a dishwasher. The third loop provides hygiene water by the reclamation and purification of urine water. This paper outlines the basic services provided by the ECLSS and ITCS and describes the ECLSS functional distribution throughout the pressurized assembly.

R. Humphries↗

Numerical thermal analyses of heat exchangers for the stirling engine application

The Regenerator, Cooler and Heater for the NASA Space Power Research Engine (SPRE) have been analyzed in detail for laminar, incompressible and oscillatory flow conditions. Each component has been analyzed independently and in detail with the regenerator being modeled as two-parallel-plates channel with a solid wall. The ends of the channel are exposed to two reservoir maintained at different temperature thus providing an axial temperature gradient along the channel. The cooler and heater components have been modeled as circular pipes with isothermal walls. Two different types of thermal boundary conditions have been investigated for the cooler and heater, namely, symmetric and asymmetric temperature inflow. In symmetric temperature inflow the flow enters the channel with the same temperature in throughout the velocity cycle whereas, in asymmetric temperature inflow the flow enters with a different temperature in each half cycle. The study was conducted over a wide range of Maximum Reynolds number (RE(max) varying from 75 to 60000, Valensi number (Va) from 2.5 to 800, and relative amplitude of fluid displacement (A(sub r) from 0.357 to 1.34. A two dimensional Finite volume method based on the SIMPLE algorithm was used to solve the governing partial differential equations. Post processing programs were developed to effectively describe the heat transfer mechanism under oscillatory flows. The computer code was validated by comparing with existing analytical solutions for oscillating flows. The thermal field have been studied with the help of temperature contour and three dimensional plots. The instantaneous friction factor, wall heat flux and heat transfer coefficient have been examined. It has been concluded that in general, the frictional factor and heat transfer coefficient are higher under oscillatory flow conditions when the Valensi number is high. Also, the thermal efficiency decreases for lower A(r) values. Further, the usual steady state definition for the heat transfer coefficient does not seem to be valid.

Kannapareddy, Mohan Raj↗

Integrated Heat Exchanger-Phase Change Material Thermal Energy Storage System

The purpose of this study is to experimentally investigate the thermal performance of an innovative thermal energy storage (TES) system that combines the advantages of the phase-change material (PCM)/graphite foam latent heat TES medium developed at Argonne National Laboratory (Argonne) and the internally supported plate-fin (ISPE) cell architecture heat transfer fluid (HTF) flow channels developed at Brayton Energy (Brayton). Several essential tasks were accomplished: (1) Thermal property characterization. Thermal properties of the graphite foam were characterized, providing necessary data for experimental result analysis and numerical simulation. (2) Design and optimization of lab-scale test module. Based on Brayton’s full-scale heat exchanger (HX)-TES system, the experimental test module was designed, optimized, and fabricated. (3) Thermal performance testing and data analysis. Five cycle tests were successfully conducted—including one with approximately 3.5 psig of pressure applied to the diaphragms—to investigate the thermal performance of the experimental test module for charging and discharging. Temperature profiles were generated for each charging test and discharging test as a function of time. The temperature profiles clearly show three TES stages: sensible heat (temperature increase), latent heat (melting), and sensible heat (temperature increase) for the charging process. Similarly, the temperature profiles clearly show three thermal energy release stages: sensible heat (temperature decrease), latent heat (solidification), and sensible heat (temperature decrease). Melting and solidification of the PCM generally occurred in relatively narrow temperature ranges, indicated by the flattened temperature regions in the temperature profiles. These phase changes ranged approximately 3°C for melting and 3.5°C for solidification. The charging and discharging temperature profiles were similar for similar experimental parameter tests whether or not pressure was applied to the diaphragm to eliminate the gap between the HX surface and the TES subsystem. This indicates that the effect of a small gap between the HX surface and the TES subsystem is insignificant for charging and discharging. (4) Comparison of experimental data and simulation results. We compared the experimental data to the numerical simulation results. Numerical simulations were conducted by using the ANSYS FLUENT 2019 R3 commercial computational fluid dynamics software. The predicted phase-change times agreed reasonably well with those from the experimental data. In most cases, the estimated time differences between the relative phase changes were within 16%. The predicted start and end times for the charging process agreed well with those from the experimental data. However, the simulation results showed earlier start and end times than the experimental data for the discharging process. Overall, the experimental data and its comparison with the simulation predictions verified the technical viability of the integrated ISPF HX-PCM/graphite foam latent-heat TES system.

25 ENERGY STORAGE↗

Solar-heated bank-Marks Mississippi

Report describes air solar-energy collectors which supply 60 percent of space heating load for full-service bank. Contemporary structure supports 468 square feet of flat-plate arrays, and features onsite temperature and power measurement readouts. Air-flow collectors minimize problems experienced with conventional liquid solar equipment and eliminate need for heat exchanger for space heating.

Source record↗