Absorption Refrigerator Economic Analysis for Solar Cooling

Overview of Technical Issues:

The absorption refrigerator's solar collector provides insufficient and intermittent thermal energy transmission to the generator due to solar radiation variability, causing insufficient cooling capacity during periods of low solar availability or high cooling demand; this functional insufficiency necessitates costly auxiliary heating systems or oversized thermal storage, undermining the economic viability goal of achieving competitive cost-per-ton cooling compared to conventional vapor-compression systems.

Solution directions generated for this problem

Problem Direction 1 :

ImproveCollector thermal capture efficiency
VS
ConstraintSystem capital cost

Inspiration 1 : Cross-domain reference

Application Principle: #26 Copying
Cross-domain applicability Assess applicability
Electrical system enhancer
Innovative Solution Refine solution

Low-cost reflective concentration array for flat-plate solar collectors

Multiply effective solar flux without upgrading absorber materials
How to solve :
  • Deploy aluminized polymer film reflectors (0.2mm thickness, 85% reflectivity) mounted on corrugated cardboard backing at 30° angle flanking each flat-plate collector to achieve 1.6–1.8× concentration ratio
  • reflector width equals collector width, positioned 0.3m laterally to redirect diffuse and low-angle radiation onto absorber surface
  • Install passive seasonal tilt adjustment using two-position hinged mounts (summer 15°, winter 45°) to maintain optimal incident angle year-round, requiring manual adjustment twice annually with no motors or sensors
  • Apply selective surface retrofit coating (black chrome or cermet, emissivity <0.15 at 100°C) only to existing absorber plates via spray deposition, achieving >70% efficiency at concentration without replacing entire collector units
Expected Effect : Efficiency 42%→73%, cost +18% vs +95% for evacuated tubes, payback 2.1 years
Risk Control :
  • reflector film degradation under UV exposure
  • wind load on reflector frames causing misalignment
  • coating adhesion failure on aged absorber surfaces

Problem Direction 2 :

ImproveThermal storage buffer capacity
VS
ConstraintSystem capital cost

Inspiration 1 : Cross-domain reference

Application Principle: #35 Parameter changes
Cross-domain applicability Assess applicability
Improved CO2 cycle for long-endurance unmanned underwater vehicles and the resulting linear frequency modulated acoustic performance
Innovative Solution Refine solution

Stratified phase-change thermal storage with direct solution integration

Direct solution storage eliminates heat exchangers
How to solve :
  • Store hot ammonia-water solution directly in tank instead of separate water storage, eliminating 15-20% heat exchanger losses and reducing required volume by 30%
  • Integrate encapsulated paraffin PCM modules (melting point 85-90°C, latent heat ≥200 kJ/kg) within solution tank, achieving 3.5x energy density — 10-hour capacity in 600-liter tank vs 2000-liter water-only baseline
  • Use natural density stratification — hot solution (95°C, density 0.92 g/cm³) floats above cooler layers (70°C, 0.96 g/cm³), maintaining ±3°C stable output without active mixing valves or sensors
Expected Effect : 10-hour storage capacity achieved with 70% volume reduction, capital cost reduced 55% vs conventional dual-tank systems, energy retention efficiency ≥92% over 12-hour cycle
Risk Control :
  • PCM encapsulation integrity under ammonia exposure
  • solution concentration gradient disrupting stratification
  • long-term PCM cycling degradation beyond 5000 cycles

Problem Direction 3 :

ImproveThermal energy transmission stability
VS
ConstraintSystem structural complexity

Inspiration 1 : Cross-domain reference

Application Principle: #35 Parameter changes
Cross-domain applicability Assess applicability
Planar cavity MEMS and related structures, methods of manufacture and design structures
Innovative Solution Refine solution

Phase-change material thermal buffer with passive temperature regulation

PCM buffer stabilizes thermal flow passively
How to solve :
  • Install encapsulated PCM module (paraffin wax, melting point 88±2°C, latent heat ≥200 kJ/kg) between collector outlet and generator inlet as thermal flywheel
  • Size PCM mass at 15–25% of hourly thermal load — absorbs excess during high solar flux, releases during dips, maintaining generator inlet at 85–92°C without sensors
  • Use aluminum foam matrix (porosity 90–95%, thermal conductivity ≥200 W/(m·K)) encasing PCM to accelerate charge/discharge, achieving response time <10 minutes
Expected Effect : Transmission stability 85–95%; zero active control components; maintenance-free operation
Risk Control :
  • PCM encapsulation leakage over thermal cycles
  • aluminum foam cost and availability
  • phase separation after 500+ cycles

Problem Direction 4 :

ImproveSystem energy utilization efficiency
VS
ConstraintSystem structural complexity

Inspiration 1 : Cross-domain reference

Application Principle: #30 Flexible shells and thin films
Cross-domain applicability Assess applicability
Induction heating assembly for a vapour generating device
Innovative Solution Refine solution

Aerogel-film composite insulation wrap for passive thermal loss suppression

Passive thermal loss reduction via flexible insulation
How to solve :
  • Wrap all collector piping and storage tank surfaces with 10mm aerogel blanket film (thermal conductivity ≤0.015 W/(m·K), R-value ≥10 m²·K/W) secured by stainless steel banding at 300mm intervals
  • Apply reflective aluminum foil outer layer (emissivity ≤0.05) over aerogel to suppress radiative heat loss, sealed with UV-resistant adhesive tape at all joints
  • Install pre-formed aerogel pipe sleeves on collector outlet/inlet lines with snap-fit assembly, eliminating rigid multi-layer assemblies and active control components
Expected Effect : Total system energy loss reduced to 12-14%; thermal leakage from piping cut by 65%; storage tank standby loss reduced from 8%/day to 3%/day; no added pumps, valves, or sensors; material cost +8% vs baseline insulation
Risk Control :
  • aerogel blanket compression during installation reducing effective R-value
  • moisture ingress at seam joints degrading insulation performance over 3-5 years
  • reflective foil delamination under thermal cycling

Problem Direction 5 :

ImproveThermal storage buffer capacity
VS
ConstraintMust not deteriorate

Inspiration 1 : Cross-domain reference

Application Principle: #1 Segmentation
Cross-domain applicability Assess applicability
Multi-chambered tissue containment system for molecular and histology diagnostics
Innovative Solution Refine solution

Modular distributed thermal storage array with independent charging zones

Divide storage into independent modules
How to solve :
  • Deploy 4-6 modular 150-liter tanks distributed across building zones instead of one central 900-liter unit — each module provides 2-hour buffer, total system capacity 8-12 hours
  • Each module operates independently with local temperature stratification (top layer 90-95°C, bottom 70-75°C) using natural convection, eliminating complex valve networks
  • Install modules near point-of-use locations (roof, mechanical room, basement) — reduces distribution piping by 60%, cuts thermal loss from 25% to <12%
Expected Effect : 8-12h total capacity; per-unit cost -40%; installation flexibility +70%; thermal loss <12%
Risk Control :
  • inter-module flow balancing deviation
  • stratification layer mixing during low-flow periods
  • distributed leak detection complexity
Patsnap Eureka Solution