Absorption Heat Pump Booster Circuit for High-Temperature Water
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Solution Overview
Problem
Existing absorption heat pumps face inefficiencies in low ambient temperature conditions, requiring oversizing or backup systems to achieve high delivery water temperatures, leading to increased costs and complexity, and existing booster systems compromise efficiency in domestic hot water production.
Innovation Solution
A modified booster system with controlled valves and heat exchangers to manage refrigerant flow, optimizing thermal input and efficiency by reducing refrigerant withdrawal and increasing flow to the evaporator, especially in high delivery water temperature conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a conventional absorption heat pump is used, then it operates efficiently at high ambient temperatures, but it requires oversizing or backup systems to achieve high delivery water temperatures in low ambient temperature conditions
Solution Approach 1:
The system is divided into two functional circuits: a primary circuit for normal heating operations and a booster circuit for high-temperature domestic hot water production. The booster circuit includes a separate generator, condenser, and expansion device that operates in parallel with the primary circuit, allowing independent optimization of each circuit for its specific function.
Solution Approach 2:
The heat pump system is designed to perform multiple functions: it provides space heating through the primary circuit and domestic hot water through the booster circuit. The system can operate in different modes (heating only, DHW only, or both simultaneously) depending on demand, making it a multi-functional thermal system.
2Temperature
If oversizing is applied to meet high delivery water temperature requirements, then the heat pump can achieve the required temperature, but the system cost increases
Solution Approach 1:
Instead of oversizing a single system, the solution segments the thermal production into two dedicated circuits. The primary circuit is sized appropriately for space heating, while the booster circuit is specifically designed for high-temperature DHW production, allowing each component to be optimally sized for its specific function rather than being oversized for all conditions.
Solution Approach 2:
The system changes operating parameters dynamically by activating the booster circuit when high-temperature DHW is required. The booster circuit operates at different temperature and pressure levels than the primary circuit, allowing efficient high-temperature operation without requiring the entire system to be oversized.
3Productivity
If a booster system is introduced to increase power in extreme conditions, then the operating range is expanded, but the system complexity increases
Solution Approach 1:
The booster system is segmented as a separate, self-contained circuit with its own generator, condenser, and expansion device. This modular segmentation allows the booster to be added as a distinct unit rather than integrating complexity into the primary circuit, making the system easier to install, maintain, and control.
Solution Approach 2:
The booster circuit acts as an intermediary system that supplements the primary heat pump circuit when high-temperature thermal power is required. It mediates between the heat source and the domestic hot water storage tank, providing high-temperature heat without requiring modifications to the primary heating circuit.
4Use of energy by moving object
If refrigerant flow is increased to the evaporator, then the thermal input and efficiency increase, but the refrigerant withdrawal for the booster circuit must be reduced
Solution Approach 1:
The refrigerant flow is segmented into two independent circuits: the primary circuit receives refrigerant from the evaporator for space heating, while the booster circuit has its own separate refrigerant loop with dedicated expansion devices. This segmentation allows each circuit to optimize its refrigerant flow independently without competing for the same refrigerant supply.
Solution Approach 2:
The booster circuit performs preliminary action by producing high-temperature domestic hot water when required, independent of the primary circuit's operation. The control system activates the booster circuit in advance when high-temperature thermal demand is detected, allowing it to draw refrigerant independently before the primary circuit needs to reduce its flow.
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
Enhances heat pump efficiency and performance in low ambient temperatures and high delivery water temperature scenarios, reducing the need for oversizing and backup systems while maintaining efficiency in domestic hot water production.
Implementation Method 1
evaporates at a low pressure in the evaporator, removing low temperature heat from the service fluid
Implementation Method 2
the refrigerant condenses at a high pressure in the condenser, transferring high temperature heat to the service fluid
Implementation Method 3
the low-pressure refrigerant vapor is absorbed by the absorbent solution
Implementation Method 4
absorption machines exploit the ability of a liquid substance (the absorbent) to chemically 'absorb' a second chemical species in a gaseous state (the refrigerant)
Implementation Method 5
In the generator, the solution is heated up to boiling, with the consequent production of high-pressure refrigerant vapor
Implementation Method 6
the solution is heated up to boiling
Implementation Method 7
passes from the high pressure environment (condenser) to the low pressure environment (evaporator) through an expansion or throttling stage
Data Source
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AI summary
An absorption heat pump apparatus for optimizing performance in low air temperature and/or high delivery water temperature operating conditions which maintains all the functions of the so-called booster systems, preventing the generator from exceeding the maximum temperature limits. Furthermore, the apparatus allows a significant increase in the efficiency of the heat pump when the booster mode is activated for producing high temperature hot water in the case of medium or high outdoor temperatures, i.e., conventionally, for producing domestic hot water which is required throughout the year.