Scheffler-based solar heating system

Abstract

System (100) for a solar thermal storage capsule, wherein the system (100) comprises: a Scheffler solar concentrator (102) configured to direct concentrated solar flux onto a container of water; and a heat storage capsule comprising a shell enclosing a removable tube (104) arranged in a cantilever configuration, the removable tube containing a phase-change material (106), wherein heated water from the receiver transfers heat energy to the phase change material (106) to store latent heat during a charging phase, and wherein the removable tube (104) is removable to release the stored heat energy to heat water when no solar energy is available.

Description

AREA

[0001] The present disclosure relates in general to a solar thermal storage capsule comprising a Scheffler solar concentrator, a receiver, a shell, a tube and a phase change material. GENERAL STATE OF THE ART

[0002] Solar thermal systems are widely used to capture and utilize solar radiation for heating purposes in homes, industry, and agriculture. Conventional technologies include flat-plate collectors, evacuated tube collectors, and solar concentrators such as parabolic, Fresnel, and Scheffler systems. While flat-plate and evacuated tube collectors are suitable for moderate temperatures, concentrator-based systems achieve higher temperatures by focusing solar radiation onto a receiver. Thermal energy storage systems, including sensible heat storage and latent heat storage with phase-change materials (PCMs), are used to extend energy availability beyond daylight hours.However, existing systems often suffer from low energy density, large size, limited transportability and inefficient heat storage, highlighting the need for compact, efficient and reliable solar thermal storage solutions. SUMMARY

[0003] The subject matter of the present invention is defined in the claims. BRIEF DESCRIPTION OF THE FIGURES Fig. Figure 1 illustrates a solar thermal storage capsule comprising a Scheffler solar concentrator, a receiver, a shell, a tube and a phase change material. DETAILED DESCRIPTION OF THE INVENTION

[0004] Solar thermal heating systems face the challenge of reliably providing heat even with low or no solar radiation, particularly in rural and underserved regions. Conventional sensible heat storage systems have low energy density and require considerable space, necessitating compact, efficient, and portable thermal energy storage solutions.

[0005] The present disclosure provides a solar thermal storage capsule system comprising a Scheffler solar concentrator, a receiver, and a removable thermal capsule incorporating a phase-change material. The Scheffler solar concentrator is configured to focus concentrated solar radiation onto a water-filled receiver and heat the water to elevated temperatures. The heated water is circulated into a thermal capsule comprising a stainless steel shell enclosing a removable aluminum alloy tube arranged in a cantilever configuration. The tube contains paraffin wax as the phase-change material, which changes from a solid to a liquid state during the charging phase, thereby absorbing latent heat.A water jacket positioned between the casing and the pipe facilitates efficient heat transfer from the heated water to the PCM, while polyurethane foam insulation surrounding the casing minimizes heat loss. During discharge, the removable pipe can be taken out of the casing and used independently to release the stored thermal energy for heating water when no solar energy is available. The system is compact, with a casing length of approximately 500 mm and a pipe length of approximately 300 mm. The receiver has a water capacity of approximately 8 liters and can reach temperatures of approximately 90 °C within 30 to 40 minutes of solar exposure. The PCM quantity of approximately 10.21 kg allows for the storage of approximately 3140.25 kJ of thermal energy, which can be used to heat approximately 15 liters of water at a temperature of approximately 75 °C.The system is portable, durable and suitable for use in homes, institutions and rural areas.

[0006] Fig.Figure 1 illustrates a solar thermal storage capsule system 100, comprising a Scheffler solar concentrator 102, a receiver, a removable tube 104, and phase-change material (PCM) 106. The Scheffler solar concentrator 102 is configured to focus the incident solar radiation onto the receiver, which contains water and absorbs the concentrated solar flux. The heated water from the receiver is directed into the thermal storage capsule, where it surrounds the removable tube 104, which is arranged in a cantilever configuration within a shell. The tube 104 contains PCM 106, such as paraffin wax, which absorbs thermal energy during the charging phase by undergoing a solid-to-liquid transition.The stored latent heat is retained in the PCM 106 and can be released by removing the tube 104 from the casing and bringing it into contact with water, thus releasing the stored energy to heat the water when no solar energy is available. The figure schematically shows the flow of solar energy, the heat transfer from the receiver to the PCM, and the modular arrangement of the capsule components, highlighting the integration of the concentrator-based heating system with latent heat storage in a portable and removable configuration.

[0007] Although embodiments of the present invention have been described with respect to certain structural features, components, and operating arrangements of a Scheffler-based solar thermal storage capsule system, it should be noted that the appended claims are not limited to the disclosed specific embodiments. The described features and configurations serve as examples and can be provided without deviation from the scope and spirit of the present invention as defined by the claims.

Claims

[1] System (100) for a solar thermal storage capsule, wherein the system (100) comprises: a Scheffler solar concentrator (102) configured to direct concentrated solar flux onto a container of water; and a heat storage capsule comprising a shell enclosing a removable tube (104) arranged in a cantilever configuration, the removable tube containing a phase-change material (106), wherein heated water from the receiver transfers heat energy to the phase change material (106) to store latent heat during a charging phase, and wherein the removable tube (104) is removable to release the stored heat energy to heat water when no solar energy is available. [2] System (100) according to claim 1, wherein the phase change material (106) comprises paraffin wax and wherein the casing comprises a water jacket surrounding the removable tube (104) to facilitate heat transfer from the heated water to the phase change material. [3] System (100) according to claim 1, wherein the casing is made of stainless steel and insulated with polyurethane foam and wherein the removable tube (104) is made of an aluminium alloy.

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