TECHNICAL FIELD
The present disclosure relates to a shelter for high altitude regions, the shelter involves the utilization of Multi transformation Phase Change Material (MTPCM) which helps in maintaining a suitable temperature inside the shelter. The shelter is eco-friendly.
BACKGROUND
The trans-Himalayan region of India (particularly Ladakh) has unique geo-climatic conditions characterized by extreme temperature variation (-400C to + 400C), precipitation mostly in the form of snow, less oxygen availability, high wind velocity, low humidity and rugged & uneven terrain. The tough geo-climatic conditions of the area, in turn, adversely affect the health and acts as a deterrent to physical and mental performance. Suitable living conditions with oxygen enrichment and controlled micro-climate could surely be of considerable significance in ameliorating the adverse effects of extreme altitude on human health.
Accordingly, shelters are considered with various load conditions (snow and wind) along with all the basic amenities and ergonomic construction. Sufficient working space and proper layout, proper insulation from surrounding temperature for retention of energy, proper electrical circuiting along with the flexibility of installation at any uneven surface including snow/ice surfaces needs to be kept in mind while constructing the shelters.
Meeting the power requirements with the help of external source like generator sets also involves lots of cost (Fuel cost + transportation cost). Further, heating system comprises of Diesel generator sets coupled with boilers or hot air blowers which again add to the total cost. Optimized power calculations (energy budgeting) with minimal thermal dissipation nodes and energy efficient electrical circuiting is absent in FRP and Polymer Shelters The rough and undulating terrain with loose soil requires a degree of flexibility in the shelter foundation to adjust at different surfaces. While most of the existing shelters like the FRP and Polymer Shelters are suitable for only plain surfaces on land, the flexibility for installation at rugged terrain including snow and ice tops is extremely essential in the context of the trans-Himalayan region. The presence of a material in the shelter which helps in the maintenance of set temperature is necessary particularly at atmospheric temperature as low as -40 degrees. Existing shelters (FRP and Polymer Shelters) use only glasses to trap the sunlight during sunny days and try to retain it for maximum period of time but as such no material is found in the existing shelters which play the role of active heat source/sink that maintains the temperature when it deviates from the set value and releases or absorbs heat accordingly.
US Patent 4,729,326 discloses a walk-in shelter providing protection against undesired heat, radiation, and gas and water action. The inner and outer layers are constructed as a closed metal envelope. Further, all the layers are set up independently of one another, are self-supporting and not mechanically interconnected.
US Patent 2011/0289860 discloses a manually configurable rigid shelter including the solar powered electrical supply circuit. Further, external shelter elements have solar energy collector cells that form part of an external element.
US Patent 2011/0154775 discloses a geo synthetic insulation panel for roofing applications. Further, the geo-textile material provides an absorption zone for any adhesive used to glue water proof membranes onto the insulation panel.
US Patent 2013/0104947 discloses a portable, insulated shelter which consists of flexible inner and outer layers, light weight fabric panels, a system, such as HVAC unit for actively controlling the interior environment of the shelter.
US 2014/0069486 discloses a three dimensional solar photovoltaic device comprised of multiple rows of photovoltaic cells that are situated in rows along a horizontal plane. Further, the device is stackable and can be integrated to other such photovoltaic devices.
Some of the major drawbacks in the existing construction of shelter (FRP and Polymer Shelters) for high altitude regions are dependence on fossil fuel for electricity and heating systems, bukhari or hot air blower based heating systems that either cause toxic gas buildup or lowering of humidity, absence of active heat storage and release mechanisms for optimal utilization of solar energy, absence of standalone snow melting systems, sub-optimal energy budgeting, non-utilization of wind energy, high heat dissipation from shelter and lack of micro-climate control features. The solar panels used in the existing shelter ((FRP and Polymer Shelters) construction require large illuminated area near the shelter thereby restricting its use in several locations. Another important aspect that necessitated the construction of shelter is the customization of the building blocks to enable their airlift through choppers for their constructions in glaciated regions. Further, there is no proper construction in terms of various loads particularly snow loads and other forces of snow in the snow bound areas which actually plays a major role in the survivability of the shelter in the long run.
OBJECTS OF THE DISCLOSURE
The main object of the disclosure is to provide a shelter for high altitude regions.
Another object of the present disclosure is to provide a shelter which can withstand wind force and snow load in extreme climatic conditions and temperature variations.
Another object of the present disclosure is to provide a shelter with minimum thickness of insulation layers, which in turn can efficiently handle the heating conditions.
Yet another object of the shelter is to provide an environment friendly shelter.
SUMMARY
The present disclosure provides a shelter that has energy source as an integral part of the shelter (to reduce the pipelines) and at the same time works on natural source of energy to minimize utilization of fossil fuel and be environment friendly in the long run. The shelter has the flexibility of installation at any surface and has the provision of heat sink that may store or release thermal energy based on the requirement. The shelter incorporates insulated electrical circuiting and be constructed based on appropriate energy budgeting for efficient use of the sparse energy available. The construction also takes into consideration the various loads and forces acting on the shelter for safety features/ requirements.
The present disclosure provides a shelter for high altitude regions comprising a floor with a plurality of layers wherein at least a top layer is a thermally conducting layer, the lower side of the top layer being in contact with a layer having a multi transformation phase change material; a wall structure comprising a plurality of layers of an insulating material; a roof structure comprising an internal roof and an external roof, each roof having a plurality of layers of an insulating material, the external roof being a peaked sloping roof and the internal roof being flat, wherein the external roof comprises of translucent materials capable of transmitting solar energy ; a plurality of solar concentrators interspersed in the external roof material for collecting solar energy; atleast one photovoltaic panel suspended from the external roof and arranged in space between the external roof and the internal roof; a plurality of evacuated tube solar collectors for collecting solar energy and converting into heat energy; and the shelter being provided with ventilation ducts for controlled renewal of air inside the shelter. The sloping roof is made of aero gel/nanogel and having solar concentrators installed at particular locations; this in turn provide the concentrated solar light on photovoltaic panels installed between the internal and external roof. The photovoltaic panel is suspended from the external roof residing on the internal roof.
An embodiment of the present disclosure provides a shelter wherein the multi transformation phase change material used consists of 35-65% lauric acid, 65-35 % palmitic acid and 5-15% expanded graphite.
An embodiment of the present disclosure provides a shelter wherein the layer having multi transformation phase change material is capable of storing and releasing heat energy, the said layer is further supported on the other side by at least one insulating layer.
An embodiment of the present disclosure provides a shelter wherein the top layer of the floor of the shelter is a soft silicone film.
Another embodiment of the present disclosure provides a shelter wherein the insulating material of the floor of the shelter is selected from the group consisting of expanded polystyrene foam, cellulose insulation material, cement particle board, aluminum foil and kraft paper shield.
Yet another embodiment of the present disclosure provides a shelter of high altitude regions wherein the solar concentrator interspersed in the external roof is a biconvex lens.
Still another embodiment of the present disclosure provides a shelter for high altitude regions wherein the top surface of the external roof is coated with a water repellent material.
Yet another embodiment of the present disclosure provides a shelter for a high altitude regions wherein the external roof of the shelter comprises of alternate panels of a triple glazed fibre glass and a sheet selected from the group consisting of nanogel, aerogel and kalwall sheet.
Still another embodiment of the present disclosure provides a shelter for a high altitude regions wherein the wall structure and the internal roof of the shelter comprise atleast eight layers selected from the group from inner to outer layers consisting of wooden felt, kraft paper and aluminium foil shield, cellulose insulation material, polyurethane foam, expanded polystyrene foam, polyurethane foam, cellulose insulation material and ethylene propylene diene monomer finish layer with stainless steel cladding.
Yet another embodiment of the present disclosure provides a shelter for a high altitude regions wherein the shelter rests on a platform comprising stainless steel mesh with a zig zag structure supported by stainless steel (SS) cladded plywood floor further supported on plurality of telescopic columns.
Still another embodiment of the present disclosure provides a shelter for a high altitude regions wherein the telescopic columns have locking arrangement with octagonal allen screws provided in the telescopic columns.
Another embodiment of the present disclosure provides a shelter for a high altitude regions wherein the telescopic columns have a plurality of hollow legs filled with concrete waste.
According to another aspect of the invention, the present disclosure provides a composition of multi-transformation phase change material, wherein composition comprises of 25-65% lauric acid, 65-25% palmitic acid and 5-15% expanded graphite.
These and other features, aspects, and advantages of the present subject matter will become better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features, aspects, and advantages of the subject matter will be better understood with regard to the following description, appended claims, and accompanying drawings where:
Figure 1 shows a schematic diagram of the shelter of the present disclosure.
Figures 2a shows a layout and electrical circuit diagram of the shelter.
Figures 2bshows symbols and description of elements for layout and electrical circuit diagram of the shelter used in figure 2a.
Figure 3 shows the schematic diagram of the roof of the shelter.
Figure 4a shows DSC (Differential scanning calorimetry) curve for 60% lauric acid + 40 % palmitic acid.
Figure 4b shows DSC (Differential scanning calorimetry) curve for 63% lauric acid + 37 % palmitic acid.
Figure 4c (Differential scanning calorimetry) shows DSC curve for 25% lauric acid + 75 % palmitic acid.
Figure 4d shows DSC (Differential scanning calorimetry) curve for 60% lauric acid + 40 % palmitic acid after 100 cycles of heating- cooling cycles.
Figure 5 shows the schematic diagram of the floor (1) divided into six layers.
Figure 6a shows front view of beams to be attached to make base for shelter.
Figure 6b shows the front view of the telescopic column of the shelter.
Figure 6c shows perspective view of the beam structure having two key for the locks at the face of the column.
Figure 7 shows the cross section of beams and position of telescopic columns of the shelter.
Figure 8 shows the basic structure of the frame of the shelter analyzed in STAAD PRO.
Figure 9 shows the type of sections used in the frame of the shelter analyzed in STAAD PRO.
Figure 10 shows reactions at various axis of the frame of the shelter analyzed in STAAD PRO.
Figure 11shows the maximum displacement of the sections of the frame of the shelter analyzed in STAAD PRO.
Figure12 shows the maximum load on the sections of the frame of the shelter analyzed in STAAD PRO.
Figure 13 shows the total load on the sections of the frame of the shelter analyzed in STAAD PRO.
While the invention is described in conjunction with the illustrated embodiment, it is understood that it is not intended to limit the invention to such embodiment. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention disclosure as defined by the claims.
DETAILED DESCRIPTION
The present disclosure provides a shelter (8) for high altitude regions where the construction of the walls (3), the floor (1) and the roofs (4) which are the blocks of the shelter (8) is done for easy transportation to different locations. Further, the material used for the building blocks of the walls (3) and the roofs (4) is composed of different layers of thermal insulation materials listed from inner to outer layer as used. Layers used are as follows:
1. Wooden felt as the finishing layer
2. Kraft paper and aluminium foil shield to protect against water vapour.
3. 10 mm cellulose insulation.
4. 150 mm Polyurethane foam (PUR/PIR).
5. 30 mm Expanded Polystyrene foam (Graphite) 60 (15Kg/m3).
6. 150 mm Polyurethane foam (PUR/PIR).
7. 10 mm Cellulose Insulation.
8. An EPDM (Ethylene propylene diene monomer) finish layer outside shelter skin providing air tightness with SS (stainless steel) cladding.
The main insulation layer consists of 5 layers described in point 3 to 7 above. Furthermore, the thickness of these 5 layers will be 35 cm to provide a U-value of 0.07 W/m2K which is considered to be the best value at this level of thickness."U-value" is the overall heat transfer coefficient that describes how well a building element conducts heat or the rate of transfer of heat (in watts) through one square meter of a structure divided by the difference in temperature across the structure. The total heat resistance is 13.62 m2 K/W for these layers. Also, the Kraft layer and aluminium foil layer checks the water vapour infiltration and protects from the same. The outer layer of EPDM provides air tightness to the shelter (8). The block is pre-fabricated, transported and assembled at the site. Still further, the dimensions of the shelter (8) are decided after taking into account the proper working space necessary for comfortable living and at the same time it should be of appropriate size for easy transportation. Accordingly, the total carpet area usage is 90 m2. Different blocks are fastened together with the help of fasteners and assemblage is also easy. The main fastener is silicone as it provides better fastening and less/minimum air leakage.
Next step in the construction process is the proper ergonomic structure for better habitation and comfortable stay. Figure 2 (a) shows a layout and electrical circuit diagram of the shelter (8). Figure 2 (b) shows the symbols and description of elements for layout and electrical circuit diagram of the shelter used in figure 2(a).
Every aspect in the shelter from working space to kitchen construction to bedding etc. in the shelter (8) are constructed after giving due considerations to the comfort level of the inhabitants. The bedding system to be used is two tier system having dimension of 2 m2 providing enough comfortable space for the habitants along with 0.75 m of almirah and mirror for storage of personal things. Further, a total of 4 almirah and mirrors will be provided. Also, four types of the bedding systems are used so to accommodate 8 habitants in the shelter (8). Since the inhabitants will be eventually spending most of their time in the shelter (8), proper attention is given towards the working space of the shelter (8) that is decided after giving due considerations to the comfort levels. Furthermore, construction of beds and lighting are done for comfortable stay. In floor-level storage space, drawers are preferred rather than cupboards.

The roof (4) construction includes various features that utilizes the greenhouse effect and improve the efficiency and life of the photovoltaic cells (6) and evacuated tube collectors (7).
Figure 3 shows the schematic diagram of the roof (4) of the shelter. The roof (4) comprises of alternate panels of triple glazed fibre glass and Nanogel / Aerogel/ Kalwall sheets. Further, the fibre glass sheets are used in areas over the photovoltaic cells and aerogel is utilized in the other areas of the roof (4). Also, Aerogel is a super-futuristic form of “frozen silica smoke” – made of a special type of super-porous silicon foam that is 99% air. Typically, it is incredibly strong, incredibly insulating and incredibly light. Further, Aerogels have extremely small pores, which makes them one of the best thermal insulators in the world. Nanogel is a trademark of Cabot Corporation for its family of translucent silica aerogels that are light in weight, extremely insulating and translucent. Furthermore, solar concentrators (5) (biconvex lens) are interspersed in the nanogel sheet in the areas over evacuated tube collectors (7) to improve their efficacy and provide greater energy input.
Solar energy is easily used as a source of power to meet the energy requirements of the shelter. The basic need is the proper energy budgeting of the shelter and efficient use of the available solar energy. In addition to solar power, additional energy is generated using the wind energy that is an alternate source to meet the energy requirement of the shelter in tandem with solar energy. The approach will not only be eco-friendly but also reduces logistic bottlenecks and the cost of transportation of fossil fuel to remote locations.
The present disclosure is therefore aimed at constructing of a shelter based on the utilization of available non-conventional energy to meet the energy requirements of the shelter. The energy utilization is for catering to electricity requirements and heating of the shelter. The construction is done keeping in view all the load conditions like snow loads, wind loads etc. and it also includes the various effects and forces of snow on the shelter expected in the snow bound areas and complies to Swiss guidelines. The construction involves the utilization of “STAAD pro” software to find out the forces on various points and accordingly involves choosing of the materials which can easily withstand such loads and at the same time selection of proper shape particularly the roof (4). The construction also includes electrical circuiting and energy budgeting which ensures efficient and essential use of the limited available energy. The shelter also makes use of the Multi transformation Phase Change Material (MTPCM) (2) in the floor (1) which act as heat sink and maintain the set temperature by absorbing or releasing the stored energy by endothermic or exothermic reactions respectively. The present disclosure is entirely different from the available/existing shelters as it makes use of only non-conventional energy to meet the energy requirements, MTPCM as heat sink and is also cost effective. The fuel generators used are only for backup in case of emergency.
Solar energy is in abundance at trans-Himalaya region of India. Hence, solar energy can be used for space heating in shelters. However, the solar energy is only available during day time and can’t be used during night time. Therefore, storage of solar energy is critical in enhancing the applicability and performance of the shelter. Out of various thermal energy storage methods, latent heat thermal energy storage (LHTES) based on phase change material (PCM) is preferred because of its high storage density and small temperature variation from storage to retrieval. Conventionally, PCM stores solar energy during day time by changing its phase from solid to liquid and releases heat to ambient during night time by changing its phase from liquid to solid.
A Multi transformation phase change material (MTPCM) (2) having composition 25-65 % lauric acid (wt. %) and 65-25 % palmitic acid (wt. %) is synthesized for shelter applications. MTPCM has multiple phase transformations between melting temperature 32.50 – 42.5 degree C and latent heat about 170 kJ/kg. This MTPCM is found suitable due to large latent heat, suitable temperature range and proper thermal characteristics such as little or no super cooling, low vapour pressure, good thermal and chemical stability, and self-nucleating behaviour. The MTPCM (2) absorbs and releases thermal energy in a wide temperature range by multiple phase changes as compared to conventional PCM which absorbs/release thermal energy in a narrow temperature range (2-50C temperature range of melting temperature). Figures 4a-4d show the DSC (Differential scanning calorimetry) curves for composition of lauric acid (wt. %) and palmitic acid (wt. %). The composition of lauric acid and palmatic acid can be varied and other possible composition may be 25% lauric acid and 75% palmatic acid, 63% lauric acid and 37% palmatic acid. Other combination of these materials can also be used for floor heating applications. Further other fatty acids i.e. capric acid, myristic acid can also be used to prepare multi transformation phase change material. The multi transformation phase change material (2) used has the following characteristics: Latent heat of composition 60% Lauric acid and 40% Palmatic acid is about 170kJ/kg and phase transformation ( solid to liquid) is in the range of 32.5 °C to 42.5 °C. Latent heat of composition 63% Lauric acid and 37% Palmatic acid is about 170 kJ/kg and phase transformation (solid to liquid) is in the range of 33.7 °C to 40.2 °C. Latent heat of composition 25% Lauric acid and 75% Palmatic acid is about 185 kJ/kg and phase transformation (solid to liquid) is in the range of 30 °C to 56.5 °C.
Generally, the floor of the shelter demands to be tough, leak proof to moisture, water, temperature gradient. Figure 5 shows the schematic diagram of the floor (1) divided into six layers. The floor (1) has been constructed in various layers to achieve the sustainable and effective construction. Further, the floor (1) has been divided into 6 layers as described below:
1. Thermally conductive soft silicone film as finishing layer and acts as controlled heat transfer system from MTPCM to floor.
2. MTPCM/EG composite having dimension of 2m2 enclosed in aluminium blocks.
3. 30 mm Expanded Polystyrene foam (Graphite) 60 (15Kg/m3).
4. 10 mm cellulose insulation.
5. 20 mm Cement Particle Board.
6. Aluminium foil & Kraft paper shield to protect against water vapour.

Thermally conductive soft-silicone film KU-TXE: HEATPAD® KU-TXE is a soft silicone film filled with thermally conductive ceramic for excellent thermal conductivity, superior elasticity and high dielectric strength. KU-TXS meets the highest requirements regarding thermal transfer. Total thermal transfer resistance is minimized by this material. It is laminated with KU-E (same as KU-EGF but without fibre glass reinforcement) on one side for mechanical stability. It is self-adhesive on the uncoated side.

Figure 6a shows the front view of beams to be attached to make base for shelter. Figure 6(b) shows the face of the telescopic column. The full floor construction and shelter rests on Stainless Steel (SS) mesh of a zig zag structure followed by plywood floor resting on the Stainless Steel (SS) cladding made of following construction, resting on telescopic columns. However, the face of the telescopic columns is octagonal having lock and key mechanism for adjustment of the upper mesh to the columns. The columns have 5 hollow legs filled by concrete and certain amount of Construction & demolition (C&D) waste in order to eradicate the chances of expansion and contraction of concrete due to low temperature. Figure 6(c) shows the perspective view of the beam structure having two key for the locks at the face of the column. Figure 7 shows the presence of telescopic columns shown with green circles to bear the load of the shelter. However, the joining lines show the beam structure to provide the platform for building the floor and shelter. Additionally, if ridge is provided at the site, the construction becomes simple and less number of columns are required thereof.

Sources of Renewable Energy:
Wind Turbines: The construction of Wind Turbines for high altitude and low temperature zone is affected due to various factors. Thus, operation of wind turbines in cold areas and remote places highly demands appropriate construction.
The Kingspan KW3, 3 kW passive tone downwind turbine has been selected based on controlled better scores in most of the criteria. Based on dynamic simulations, installation of approximately 12.8 KW wind power is required. Further, for balancing the phases of the network a multiple of 2 of the selected wind turbines are needed. Therefore, atleast four wind turbine are installed on the site. However, based on the topographic measurements and requirements erection of wind turbines, a maximum of 6 wind turbines can be installed on the north side of shelter or can be installed on the roof (4) of the main entrance of the shelter.
Evacuated Tube Solar Collectors: Apricus AP evacuated tube solar collectors (7) are used for the shelter to convert energy from the sun into usable heat. Further, this energy can be used for hot water heating, space heating or even air conditioning. Furthermore, the tank can be boosted by an electric element, gas/oil boiler, or the solar tank can simply feed an existing water heater tank with solar pre-heated water. The collectors (7) are installed on the roof (4) and on the ground to avoid snow accumulation.
Mounting of solar heat collectors: The solar heat collectors (7) are mounted in the space between the external roof (4b) and the internal roof (4a) to reduce the dissipation of heat and passive heating of the air space between the external roof (4b) and the internal roof (4a). Further, the heat collected by the evacuated tube collectors is channelized to the phase change material for storage.
Solar Thermal System: To minimize energy demand, all thermal applications are driven directly by the sun. A solar heating system i.e. Evacuated Tube Collectors are installed to produce heat to low and medium temperature up to 90 degrees C. The heat produced is used for: a. Snow melting. The primary circuit of solar heating is redirected to the unit melting snow to provide enough heat to melt the snow. b. Hot water production: Water (melted and recycled) is directly heated by evacuated tube collectors (7). Water is not stored at elevated temperatures (sanitary storage) since the risk of legionella growth is high.
All evacuated tube collectors (7) are installed inside the external roof (4b) of the shelter. This surface orientation ensures good thermal performance of the system. Preferably, as a core technique, the stratified water storage tanks are placed just below the roof section (4) in between the kitchen and bathroom area to provide heated water to both facilities. Therefore, the distance of tube is minimized. Thereby, the minimum size of the tank can be 1.5 cubic meter. Accordingly, the specific insulation is used to reduce the diameter and height.
Photovoltaic Panels: Photovoltaic (PV) panels (6) provide electricity mainly during the summer, when the sun is plentiful. Special attention has been paid to the reflection of radiation in the snow (albedo equal to 0.8) and low ambient temperatures. Typically, photovoltaic cells (6) tend to function better in cold climates (except amorphous silicon panels).
In order to obtain an initial understanding of the solar radiation and the influence of orientation and the tilt angle, generally solar assessment has been performed. A part of the photovoltaic system (6) is installed in the shelter (Building Integrated Photovoltaic - BIPV). The roof (4) of the shelter is constructed with a main angle of 60 - 70 degrees to optimize the performance of the photovoltaic modules (6) mounted on the skin. The rest of the PV modules are installed in the field in the vicinity of the shelter (Stand -alone PV - SAPV) integrated photovoltaic.
Building Integrated photovoltaic: The surface of skin (the internal and external roof space) available in the main building for the integration of photovoltaic generators is 110 m². To optimize the available space module, the specifications in table 1 are used. Table 1 shows the properties of the PV module in reference to table 2, the corresponding module configurations optimized.
Table 1
Module
Type Monocrystalline
Efficiency at STC > 22.5 %
Peak power (PMPP) 435 WP (Watt power)
Peak power voltage (VMPP) 72.9 V
Open circuit voltage (Voc) 85.6 V
Length 1500 mm
Height 1000 mm
Thickness 50 mm

Table 2
Orientation Location Module
Number of modules m²
South West Roof 38 57
South East Roof 34 51
Total 72 108
Generators: The generators are essentially the backup power sources of hybrid system. Also to be used for load operations to power large phase loads that are used occasionally viz. Drilling, welding etc. Reliability and robustness are key to the selection of the generator. In case of failure of power electronics and renewable energy interface sources and storage, power generators may be used as backup source of power for the shelter.
The selected generator diesel generator is a 4-pole low speed. Diesel generators are preferred because it has higher fuel efficiency than gasoline engines. Besides that diesel can be more easily available and stored for long periods of time. Table 3 shows the types of generators used and their estimated lifetime.
Table 3
Generator type Size range [kW] Estimated lifetime [hrs]
High speed (3,600 rpm) air- cooled gasoline, natural gas, or propane 1 – 10 250 – 1000
High speed (3,600 rpm) air-cooled diesel 4 – 20 6000 – 10000
Low speed (1,800 rpm) liquid- cooled natural gas or propane 15 – 50 6000 – 10000
Prime power liquid-cooled
Diesel 7 – 10000 20000 – 40000
Natural gas micro turbine 25 – 500 50000 – 80000

The dimensioning of a single generator is based mainly in the emergency operating mode. The worst case is simulated in the following cases: No electricity producing wind turbines, No electricity producing photovoltaic panels (6) or all comfort levels are maintained (building temperatures, energy use, water use, and lighting).
There is a maximum power consumption of 24 kW. Based on this, a single generator must have a rated capacity of at least 24 kW. The other generator is identical and is projected as a backup generator. Sensitivity analyzes (energy analysis) will be applied to evaluate the total annual operating time of a generator based on the availability of renewable energy sources and energy storage availability.
In normal operation, the generators can work for 150 hours per year (total operating hours for generators). The number of start-ups is 30, the execution time as normal is 4.5 hrs. In a complete system failure, the generator still has to operate continuously to supply all the energy needed.

Storage: Energy storage is an important part of the hybrid power system. Storage is needed for electricity and heat to deal with fluctuations in natural resources. If enough energy will be available, the energy is stored to be used later. There are multiple storage systems for electrical energy through commercially viable hybrid power systems. The most promising technologies for our application are batteries and hydrogen storage. Batteries are preferred because they have been used for many years in all climates. However, there are different types of batteries that are available to do the job. The selection of a battery is often a compromise since no single battery provides a completely satisfactory solution. The batteries are stored in electrical circuit room, which is a controlled temperature zone (temperature always above 0 degrees C). Two specific types can be distinguished in valve-regulated lead-acid battery (VRLA), i.e., gel cell and absorbed glass mat (AGM). In the gel electrolyte cell, the electrolyte is "gelled" by the addition of silica gel, converting the acid into a solid mass. In AGM, the electrolyte is absorbed in a very thin fiber glass/borosilicate fiber. Both types have the advantage of the electrolyte being immobilized and therefore ideal for air transport (lowest risk class). AGM is recommended as the best technology to power hybrid systems for the proposed shelter construction.
For each battery bank, battery converters of 8 kVA is used. They convert the DC power from AC power battery during discharge and during charging backwards. These converters aid in networking and maintaining the quality of the power (voltage amplitude and frequency) by controlling the power electronics (PV, wind turbines). Finally, these converters will also optimize loading and unloading algorithms in order to maximize battery life. They are critical components in the hybrid system.
All electronics for the office and living zone are standard equipment that are commercially available. Even the kitchen equipment are standard appliances. Each item is selected on the basis of its compactness and energy efficiency. The lighting for the complete station has been constructed for year-round operations. For each lighting zone, a technology tradeoff is established, based on efficiency, reliability, lifetime, allowed temperature, harmonic distortion and cost.
Table 4 shows the technology that is used for lighting.
Table 4
Technology Location
TL5 (Tube Light 5) All locations in the shelter with temperature > 0°C.
LED (Light Emitting Diode) Locations where temperature can drop below 0°C

Boiling water-based space heating is avoided as the shelter construction is capable of active heat transfer through MTPCM and additional heating is only required in periods without sun. Besides that water-based space heating system requires Diesel Generator sets. A heating system integrated to the ventilation is also avoided since during the winter period it is advantageous to heat without having the ventilation operational. A decentralized electrical heating (natural convectors) is chosen because it offers a lot of flexibility.
During the summer, almost no additional heating is required. The passive solar gains and internal gains (due to human presence and machines) are sufficient to heat all the building zones. Table 5shows the comfort temperatures maintained at all times in different zones.
Table 5
Zone Comfort temperature
Living / office zone 20 °C
Sleeping rooms / entrance/ telecommunication Area 16 °C
Sanitary zone/Medical Room 23 °C

A total of 8 convectors (total capacity of 8 KW) are installed in the shelter to ensure sufficient heating under all conditions.
Electrical Consumption: The main electrical consumption of the shelter includes basic requirements as lighting and heating, Additional Requirements: Computers, laptops, electronic appliances, kitchen appliances.
While the primary circuit represented by dot lines referred in figure 2 (a) cater to the basic requirements, a separate circuit called secondary circuit represented by solid line in the electrical circuit diagram becomes functional only when sufficient Direct Current (DC) energy (say above 50%) is available from the batteries and this switchover between the primary and secondary circuits will takes place automatically by means of sensors and electrical circuit breaker. The additional requirement is met only when the availability of battery energy is sufficient and sunlight is optimal. Table 6 shows the type and number of basic requirements (Category 1) as under:
Table 6
S.No Appliances/Equipment Watts(Ratings) No. of Appliances Total power consumption
1. Heater (Portable) 750-1500 1 1500
2. T5 tube light 16 10 160
3. LED 10 13 130
4. Heating Convector 1000 8 8000
Gross Total 9790(watts)
Table 7 shows the type and number of accessories (Category 2) along with power consumption details as shown below:
Table 7
S.No. Appliances/Equipment Watts(Ratings) No. of Appliances/ equipment Total Power Consumption
1. Water heater(40 gallons) 4500-5500 1 5500
2. Microwave oven 750-1500 1 1500
3. Health monitoring system 5000-6000 1 6000
4. Computer 300 3 900
5. Television 150 1 150
6. Laptops 50 2 100
Gross Total 14150(watts)

T5 tube lights and LEDs will be used for lighting to save energy and cause efficient illumination at such low temperatures in high altitude areas. Total number of T5 and LEDs has been decided after taking into consideration the minimum Lux level suitable for comfortable stay in every compartments of the shelter and keeping in view the activities to be carried out in each compartment. For heating purposes, atleast8 convectors are installed with capacity of 1KW each, to ensure sufficient heating at such harsh and cold climatic areas. Three cases are considered:
Further, there are losses in Alternating current (AC) and Direct Current (DC) circuits. Thus for DC circuits, 30% losses are taken i.e. 24000×0.3=7200 watts.
1. Final (Gross) electrical requirement of the shelter including all accessories heating and lighting=24000+7200(losses) =31200watts = 31.2KW (approx.32KW).
2. Minimum electrical energy requirement from the sources to support the essential services of the shelter i.e. lighting and heating=8290watts+2487(losses) =10777watts (approx.. 11 KW)
3. The electrical energy required from the sources to support the essential services of the shelter i.e. lighting and heating and some essential accessories like Microwave oven, Heater(portable),Health monitoring system and three number of computers=18190watts+5457(losses) = 23647W (or 23.647KW).
Hence, a minimum of 23.647 KW of electrical energy is required to carry out the day to day activities of the shelter from the non-conventional energy sources viz. solar and wind. This can easily be fulfilled by the selected sources of energy i.e. wind turbines and photovoltaic panels (6).
The electrical circuit comprises of a primary circuit connected to Category 1 equipment and a secondary circuit connected to Category 2 equipment. While the primary circuit is connected to continuous power supply, the secondary circuit receives power supply only when the battery bank is charged more than fifty percent. The switching off and switching on of the secondary circuit will be automatic through electronic switches connected to battery bank indicator. Alternative manual mode is also provided through change over switch.
Integrated bio-toilet complex:
An integrated bio-toilet complex with bio-digester is incorporated in the shelter according to the layout plan. The bio-toilet complex has non-conventional energy based water boilers.
Ventilation and Microclimate control: The sensor based ventilation provides fresh and humidified air in the building. The ventilation also cools the building when overheating occurs. Ultrasonic humidifiers will be used for the same. Each area of the shelter and the main ventilation ducts will be provided with temperature sensors and CO & CO2 concentration sensors to regulate the air flow.
Example 1
STAAD PRO Analysis in Support of the Present Disclosure
The following example is given by way of illustration and therefore, should not be construed to limit the scope of the present disclosure.
The proper shelter structure is planned after taking into account the various wind and snow loads acting on the shelter with the help of software viz. STAAD PRO. The detailed loads acting on every point of the shelter are shown clearly in the figures. Every force on the shelter is analysed properly. Thereafter, proper shape and material for the shelter is decided.
Basic Structural Alignment and Frame Construction:
The STAAD Pro Analysis provides the truss structure on which the shelter is fabricated. The basic frame used is steel to give the shelter desired strength to withstand the wind and heavy snowfall. The load bearing capacity of all the nodes and beams are calculated and found suitable according to the construction. The various type of sections that are to be used in the frame of the shelter are given in Table 8. They are in accordance with Indian Standards. Table 8 shows ISMB and IS Cold formed sections used in frame construction.
Table 8
S.No. Material Section
1. STEEL ISMB150
2. STEEL ISMB175
3. STEEL 110ZS45x3.15
4. STEEL ISMB100
The ISMB is Indian Standard Medium Beam and 110ZS is IS Cold formed Section. Some of the main properties of cold formed steel are lightness in weight, high strength and stiffness, ease of prefabrication and mass production, fast and easy erection and installation, substantial elimination of delays due to weather, non-shrinking and non-creeping at ambient temperatures, no framework needed, termite-proof and rot proof, uniform quality, economy in transportation and handling, non-combustibility, recyclable material, panels and decks can provide enclosed cells for conduits.
The following STAAD analysis represents various sections used at various places in frame for the shelter followed by load calculations.
Basic Structure Alignment: FrameConstruction
Figure 8 illustrates the basic structure alignment of the shelter. The frame for the shelter (8) is divided into 6 equal parts. Further, each frame has maximum size of 2 meters. Specifically, each and every section is placed in such a way that none of the section exceeds the limit of 2 m length. Thereafter, the load as per BIS codes is calculated. Also, Dead Load of the walls is calculated. Furthermore, the load of solar panels to be installed on the roof (4), is calculated. Still further, the load on inner roof (4), is calculated. Also, Self-Weight of the structure is calculated. Wind Load as per 0 degree inclination and 90 degree inclination is calculated. Furthermore, the wind load entering inside the construction and the outer wind pressure, is calculated.
Figure 9 shows the type of sections used in the frame of the shelter. The roof (4) is mainly constructed with ISMB150 to accumulate the solar panel and show loads. The inner frame supporting the roof (4) is made of ISMB100 and IS Cold formed Section, to support the heating shelter placed in between the external roof (4b) and internal roof (4a) of the shelter. Figure 10 shows the reactions at various axes of the frame of the shelter. The side walls (3) are supported by ISMB175 to support the maximum load to underneath mesh that holds the shelter load. Finally, transferring it to the telescopic columns to the ground for better support. Table 9 shows the reaction at various axes of the frame.
Table 9
S.No. Axis Reaction
1. X 0.749 KN
2. Y 21.727 KN
3. Z 0.414 KNm

Maximum Displacement:
Figure 11 shows the maximum displacement the frame can take due to heavy loads that can occur beside the calculated loads. The roof (4) is divided into 3 parts along the elevation. The first part can have a maximum displacement of 0.949 mm. The second part can have a maximum displacement of 1.278 mm due to maximum tension and load on this section. The third and last section of the roof (4) will have a maximum displacement of 0.864 mm. All the displacements of the roof (4) are well below the limits and the shelter can have the maximum load. Figure 12 shows the maximum displacement of the sections of the frame. The frame for wall (3) will have a maximum displacement of 0.331 mm for above sections and 0.270 mm for below sections joining them to mesh and columns. Figure 13 shows the total load on the sections of the frame of the shelter. The maximum loads that can be accumulated by the sections are divided into 5 main joint sections that can be seen in below representations. The tip of the frame can accumulate maximum of 2.59 KNm and 3.38 KN. The angled roof (4) can have maximum of 1.063 KNm and 1.567 KN. The resting of roof (4) on wall frame can have maximum of 1.029 KNm and 1.947 KN. The wall frame will have two joint points to have 2 meter length condition satisfied. They can have maximum of 1.532 KNm and .646 KN load. Cumulative Snow loads & Wind forces are also analyzed in the Staad Pro software.
ADVANTAGES
1. The shelter makes use of the available non-conventional source of energy primarily solar energy to meet the energy requirements of the shelter, like for electricity and heating purposes.
2. The shelter is flexible enough for installation at undulating surfaces including mountain tops and ice surfaces.
3. The shelter has been made by keeping in view the various harsh conditions associated with high altitude areas characterized by extreme temperature variation, thin atmosphere with high UV-radiation, low oxygen level, high wind velocity, low humidity, snow loads and other snow forces.
4. The construction of shelter also includes electrical circuiting and energy budgeting which ensures efficient and essential use of the limited available energy.
5. The shelter also makes use of the Multi transformation Phase Change Material (MTPCM) (2) in the floor which act as a heat sink and maintain the set temperature by absorbing or releasing the stored energy by endothermic or exothermic reactions respectively.
6. The roof construction includes various features that utilize the greenhouse effect and improve the efficiency and life of the photovoltaic cells and evacuated tube collectors.

Although the subject matter has been described in a considerable detail with reference to certain preferred embodiments thereof, other embodiments are possible. As such, the spirit and scope of the appended claims should not be limited to the description of the preferred embodiment contained therein.

CLAIMS:WE CLAIM:
1. A shelter (8) for high altitude regions, comprising:
a. a floor (1) with a plurality of layers wherein atleast a top layer is a thermally conducting layer, the lower side of the top layer being in contact with a layer having a multi transformation phase change material (2);

b. a wall structure (3) comprising a plurality of layers of an insulating material;

c. a roof structure (4) comprising an internal roof (4a) and an external roof (4b), each roof having a plurality of layers of an insulating material, the external roof (4b) being a peaked sloping roof and the internal roof (4a) being flat, wherein the external roof (4b) comprises of translucent materials capable of transmitting solar light ;

d. a plurality of solar concentrators (5) interspersed in the external roof (4b) material for collecting solar energy;

e. atleast one photovoltaic panel ( 6) suspended from the external roof (4b) and arranged in space between the external roof (4b) and the internal roof (4a);

f. a plurality of evacuated tube solar collectors (7) for collecting solar energy and converting into heat energy; and

2. A shelter, as claimed in claim 1, wherein the multi transformation phase change material (2) used comprises of 25-65% lauric acid, 65-25% palmitic acid and 5-15% expanded graphite.
3. A shelter, as claimed in claim 2, wherein the layer having multi transformation phase change material (2) is capable of storing and releasing heat energy, the said layer is further supported on the other side by atleast one insulating layer.
4. A shelter, as claimed in claim 1, wherein the top layer of the floor (1) is a soft silicone film.
5. A shelter, as claimed in claim 1, wherein the insulating material used in the floor (1) is selected from the group consisting of expanded polystyrene foam, cellulose insulation material, cement particle board, aluminium foil and kraft paper shield.
6. A shelter, as claimed in claim 1, wherein the solar concentrator (5) used is a biconvex lens.
7. A shelter, as claimed in claim 1, wherein top surface of the external roof (4b) is coated with a water repellent material.
8. A shelter, as claimed in claim 1, wherein the external roof (4b) consists of alternate panels of a triple glazed fibre glass and a sheet selected from the group consisting of nanogel, aerogel and kalwall sheet.
9. A shelter, as claimed in claim 1, wherein the wall structure (3) and the internal roof (4a) comprise atleast eight layers selected from the group from inner to outer layers consisting of wooden felt, kraft paper and aluminium foil shield, cellulose insulation material, polyurethane foam, expanded polystyrene foam, polyurethane foam, cellulose insulation material and ethylene propylene diene monomer finish layer with stainless steel cladding.
10. A shelter, as claimed in claim 1, wherein the shelter (8) rests on a platform comprising stainless steel mesh with a zig zag structure supported by stainless steel cladded plywood floor (1) further supported on plurality of telescopic columns.
11. A shelter, as claimed in claim 11, wherein the telescopic columns have locking arrangement with octagonal allen screws provided in the telescopic columns.
12. A shelter, as claimed in claim 12, wherein the telescopic columns have a plurality of hollow legs filled with a concrete waste.
13. Multi-transformation phase change material (2) composition comprising of 25-65% lauric acid, 65-25% palmitic acid and 5-15% expanded graphite.