Purge system for closed-cycle absorption heat pumps
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing absorption heat pump systems face inefficiencies due to the presence of non-condensable gases (NCGs), which reduce thermal power and efficiency, and current purge systems have disadvantages such as refrigerant loss, maintenance requirements, and lack of flexibility in handling varying operating conditions.
Innovation Solution
A motorless purging system using a vacuum-tight adiabatic absorption vessel, water-to-solution heat exchanger, solution splitter, and associated valves to collect and evacuate NCGs, allowing for efficient separation and removal without the need for complex ejectors or continuous vacuum pump operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a vacuum pump is used to remove NCGs, then NCG removal effectiveness is improved, but refrigerant loss and maintenance requirements increase
Solution Approach 1:
The patent extracts and removes only the harmful non-condensable gases from the system while preserving the refrigerant. The purging system selectively separates NCGs from the refrigerant vapor through controlled pressure differential and condensation, allowing NCG removal without significant refrigerant loss.
Solution Approach 2:
The patent introduces a purging system with a purger and condenser as an intermediary mechanism between the absorption system and the environment. This intermediary system facilitates selective NCG removal by condensing refrigerant vapor while allowing NCGs to be discharged, thereby protecting the main system from refrigerant loss.
2Object-affected harmful factors
If a vacuum pump is used to remove NCGs, then NCG removal effectiveness is improved, but system complexity and operational maintenance increase
Solution Approach 1:
The purging system operates automatically using the inherent pressure differential between the absorption system and atmosphere, along with the condensation of refrigerant vapor. The system self-regulates the purging process without requiring external vacuum pumps or complex control mechanisms, thereby reducing device complexity and maintenance requirements.
3Duration of action of stationary object
If NCGs are present in the system, then system operation continues, but thermal power and efficiency deteriorate
Solution Approach 1:
The patent implements periodic purging cycles where the purging system operates intermittently to remove accumulated NCGs. The system switches between normal operation mode and purging mode, allowing continuous overall operation while periodically restoring thermal efficiency by removing NCGs that would otherwise degrade performance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively removes NCGs, maintaining system efficiency and reliability, with a simpler design that adapts to various operating conditions and reduces energy costs by minimizing refrigerant loss and operational complexity.
Implementation Method 1
a portion of the absorbent solution of the closed cycle absorption heat pump is collected in an adiabatic absorption vessel... the absorbent solution absorbs absorbate vapor entering the absorption vessel
Implementation Method 2
a water-to-solution heat exchanger, solution splitter, and associated valves and instruments for controlling the purging operation
Implementation Method 3
closing of the further valved passageways is configured to increase the pressure in the absorption vessel, such that when the second valve is open, the non-condensable gases are collected in the exhaust vessel
Data Source
AI summary
A high-efficiency, motorless purge system for closed-cycle absorption heat pumps, adapted for both absorption heat transformers and absorption chillers, using a series of valves to control the entry and exit of absorbent solution into a low-pressure, secondary absorption vessel. A small percentage of the total circulating solution is forced under pressure into the secondary absorption vessel via a spray nozzle, causing adiabatic absorption of absorbate vapor by the solution. Non-condensable gases accumulate in the secondary absorber until a certain vapor pressure is reached, upon which, gas, and possibly liquid, are transferred to an exhaust vessel having an exit vent for non-condensable gases. In an absorption chiller system, the secondary absorber has an internal heat exchanger to lower the temperature of the solution within, to facilitate the absorption process.