Ammonia Reaction Heat Exchanger Layout for Lower Exhaust Heat Loss
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Solution Overview
Problem
Existing gas turbine plants using ammonia as a raw material suffer from increased thermal energy loss and inefficient utilization of reaction gas heat, leading to reduced thermal efficiency.
Innovation Solution
A raw material fluid treatment plant with a preheater and reactor system that utilizes two distinct heating media to optimize heat exchange, incorporating exhaust heat utilization equipment and a two-stage reaction process to minimize thermal energy loss and enhance efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If one heat exchange device is used to heat liquid ammonia with exhaust gas, then the ammonia can be heated for thermal decomposition, but the thermal energy loss of the exhaust gas increases
Solution Approach 1:
The single heat exchange device is divided into two separate heat exchange devices: a preheater for low-temperature heat exchange and a reactor for high-temperature heat exchange. This segmentation allows each device to operate at its optimal temperature range, improving overall heat recovery efficiency and reducing thermal energy loss of the exhaust gas.
Solution Approach 2:
A heat storage medium is introduced as an intermediary between the exhaust gas and the liquid ammonia. The heat storage medium first absorbs heat from the exhaust gas in the preheater, then transfers heat to the ammonia in the reactor. This intermediary approach enables more complete heat recovery from the exhaust gas, reducing thermal energy loss.
2Device complexity
If one heat exchange device is used for both preheating and reaction, then the structure is simpler, but the heat of the reaction gas after reaction is not effectively utilized
Solution Approach 1:
The heat exchange process is segmented into two distinct stages using two separate devices: preheating in the first device and thermal decomposition in the second device. This allows the reaction gas to be properly utilized as it passes through the preheater first, then the reactor, maximizing energy utilization while maintaining manageable structural complexity.
Solution Approach 2:
The preheater performs preliminary heating of the liquid ammonia using the reaction gas before the ammonia enters the reactor. This preliminary action ensures that the reaction gas heat is effectively utilized before the ammonia undergoes thermal decomposition, improving overall energy efficiency.
3Productivity
If high temperature heat is used for preheating, then the preheating is more efficient, but the thermal energy loss increases due to temperature mismatch
Solution Approach 1:
Different temperature levels of heat are applied at different stages: low-temperature heat from the exhaust gas is used in the preheater for preheating, while high-temperature heat is used in the reactor for thermal decomposition. This local quality approach matches the temperature requirements of each process stage, improving preheating efficiency while minimizing thermal energy loss due to temperature mismatch.
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 utilizes heat at different temperature levels, reducing thermal energy loss and improving overall plant efficiency by optimizing heat input and output.
Implementation Method 1
The preheater is a heat exchanger that heats the raw material fluid by exchanging heat between the raw material fluid and the second heating medium
Implementation Method 2
The reactor is a heat exchanger that heats and reacts the raw material fluid by exchanging heat between the raw material fluid and the first heating medium
Implementation Method 3
The thermal decomposition reaction is performed on the ammonia to generate a reaction gas including the hydrogen and the nitrogen
Data Source
AI summary
A raw material fluid treatment plant is provided with a raw material reaction apparatus for reacting a raw material fluid to form a reaction gas. The raw material reaction apparatus includes preheaters and a reactor. The preheaters are heat exchangers that perform heat exchange between a second heat transfer medium and the raw material fluid to heat the raw material fluid. The reactor is a heat exchanger that performs heat exchange between a first heat transfer medium differing from the second heat transfer medium and the raw material fluid having been heated by the preheaters to heat and react the raw material fluid.