Absorption Refrigerator Single-Effect vs Double-Effect COP

Overview of Technical Issues:

In single-effect absorption refrigerators, the heat source provides thermal energy but the system exhibits insufficient heat utilization - only one generator stage extracts useful work from the available temperature potential, resulting in COP limited to approximately 0.7 and higher energy consumption per unit cooling output; the goal is to understand how double-effect configurations improve heat cascade utilization to achieve COP of 1.2-1.4 and determine optimization strategies for efficiency improvement.

Solution directions generated for this problem

Problem Direction 1 :

ImproveHeat utilization efficiency
VS
ConstraintSystem component complexity

Inspiration 1 : Cross-domain reference

Application Principle: #1 Segmentation
Cross-domain applicability Assess applicability
Power factor correction circuit and method including dual bridge rectifiers
Innovative Solution Refine solution

Modular plug-and-play dual-generator absorption chiller with standardized thermal interfaces

Modular dual-generator with standardized interfaces
How to solve :
  • Design high-temperature generator module (180°C) and low-temperature generator module (120°C) as independent plug-and-play units with ISO-standardized flange connections (DN50/PN16 for solution flow, DN80/PN10 for refrigerant vapor)
  • Each module integrates solution pump, level sensor, and temperature controller into a factory-tested cartridge assembly with quick-disconnect fittings, enabling field installation within 2 hours without custom piping
  • Implement dual-function intermediate heat exchanger serving both as inter-stage thermal coupling and low-temperature generator solution preheater, reducing total component count by 18% versus separate units, with brazed plate design achieving 3.5 kW/K per m³ thermal density
Expected Effect : COP increases to 1.25-1.35, assembly time reduced 60%, component count +28% vs single-effect (versus +45% conventional dual-effect)
Risk Control :
  • flange seal leakage under thermal cycling
  • solution concentration drift between modules
  • brazed plate heat exchanger fouling

Problem Direction 2 :

ImproveEnergy conversion stage count
VS
ConstraintHeat transfer surface area requirement

Inspiration 1 : Cross-domain reference

Application Principle: #17 Another dimension
Cross-domain applicability Assess applicability
Electrocoagulation reactor
Innovative Solution Refine solution

Helical-coil nested generator for dual-stage heat extraction

Nested helical-coil design for compact dual-stage heat extraction
How to solve :
  • Design nested helical-coil generators with high-temp coil (180°C, outer layer, 12mm OD) wrapped around low-temp coil (120°C, inner layer, 8mm OD) in concentric arrangement, achieving two-stage extraction in single cylindrical vessel 600mm diameter × 1200mm height
  • Use copper-aluminum composite tubes (thermal conductivity ≥220 W/(m·K)) with 0.8mm wall thickness, coil pitch 15mm for outer/10mm for inner layer, providing 18m² effective area in 0.34m³ volume versus 12m² in 0.6m³ for conventional flat-plate dual generators
  • Implement counter-flow solution circulation — concentrated LiBr (58%) enters outer coil top at 185°C, intermediate solution (54%) transfers to inner coil at 125°C, dilute solution (50%) exits at absorber temperature, with intermediate heat recovery efficiency ≥85%
Expected Effect : COP 1.3, area density 53m²/m³ (+120% vs flat-plate), footprint -43%
Risk Control :
  • coil pitch tolerance ±0.3mm critical for uniform flow
  • tube-to-tube thermal contact resistance management
  • solution distribution uniformity across coil layers

Problem Direction 3 :

ImproveTemperature potential extraction depth
VS
ConstraintSystem component complexity

Inspiration 1 : Cross-domain reference

Application Principle: #1 Segmentation
Cross-domain applicability Assess applicability
Circuits for a hybrid switched capacitor converter
Innovative Solution Refine solution

Modular plug-and-play dual-temperature generator with standardized thermal interfaces

Divide cascade into independent modules
How to solve :
  • Design high-temperature generator module (180°C inlet, 150°C outlet) and low-temperature generator module (150°C inlet, 120°C outlet) as factory-sealed units with ISO-standardized flange interfaces (DN50, PN16 rating)
  • each module integrates solution pump, level sensor, and temperature controller internally, eliminating field piping complexity
  • Establish plug-and-play thermal coupling via quick-connect fittings (316L stainless steel, PTFE gaskets) — high-temp module exhaust directly feeds low-temp module inlet through single insulated pipe (thermal loss <2%), avoiding complex intermediate heat exchanger networks
  • each module independently factory-tested to ±0.05 MPa pressure tolerance and ±2°C temperature uniformity, field-replaceable within 4 hours without system redesign, enabling incremental capacity expansion from single-effect (COP 0.7) to double-effect (COP 1.2-1.4) by adding second module
Expected Effect : COP increase from 0.7 to 1.3, component count +25% vs traditional +55%, field installation time -60%
Risk Control :
  • thermal interface leakage under cycling
  • module performance degradation mismatch
  • standardized sizing limits custom optimization
Patsnap Eureka Solution