Ammonia Synthesis Circuit Bypass Cooling for Partial-Load Stability
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Solution Overview
Problem
Conventional ammonia synthesis plants face challenges in maintaining stable operation at varying load conditions, particularly during partial loads, due to fluctuating hydrogen supply from renewable energy sources, leading to ammonia condensation and potential damage to the conveying device.
Innovation Solution
The ammonia synthesis plant incorporates a first bypass line parallel to the conveying device, allowing a partial gas flow to bypass the converter, and a second bypass line parallel to the cooling device, enabling flexible operation by adjusting the gas flow to maintain optimal temperature and prevent ammonia condensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the gas flow is cooled in the cooling device to prevent overheating, then the temperature is reduced, but ammonia condensation occurs which damages the conveying device
Solution Approach 1:
The gas flow is divided into two separate streams: one stream is cooled in the cooling device to remove excess heat, while the other stream bypasses the cooling device and maintains higher temperature. These two streams are then recombined to provide temperature compensation, preventing ammonia condensation while still achieving effective cooling.
Solution Approach 2:
The uncooled gas stream acts as an intermediary that carries thermal energy from the cooled stream. By mixing the cooled and uncooled streams, the warm gas compensates for the cooling effect, preventing the temperature from dropping below the ammonia dew point while maintaining overall heat removal.
2Productivity
If the conveying device operates at high flow rates to maintain productivity, then the ammonia production efficiency is improved, but the temperature control becomes difficult leading to ammonia condensation
Solution Approach 1:
The high flow rate gas stream is segmented into cooled and uncooled portions. The cooled portion removes excess heat generated at high production rates, while the uncooled portion maintains temperature. This segmentation allows the system to handle high productivity demands without sacrificing temperature stability.
Solution Approach 2:
The system dynamically adjusts the flow distribution between the cooled and uncooled streams based on operating conditions. At high productivity rates, the bypass flow is increased to provide temperature compensation, while the cooled flow maintains heat removal. This parameter adjustment allows stable operation across varying load conditions.
3Adaptability or versatility
If the plant operates at partial load with fluctuating hydrogen supply, then the adaptability to renewable energy sources is improved, but the stable operation is compromised due to temperature fluctuations
Solution Approach 1:
The system dynamically adjusts the flow distribution between the cooled and uncooled streams in response to varying load conditions. At partial load, the bypass flow ratio is increased to maintain temperature stability. This dynamic adaptation allows the plant to operate stably across the full load range, from full capacity down to partial load conditions.
Solution Approach 2:
The flow rates and temperature parameters are continuously adjusted based on the operating load. The control system modifies the split between cooled and uncooled streams to maintain optimal temperature conditions at each load level, enabling stable partial-load operation while adapting to fluctuating hydrogen supply from renewable sources.
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
This configuration ensures stable operation at different partial loads without significant ammonia condensation, protecting the conveying device and maintaining efficient ammonia production even with fluctuating hydrogen supply.
Implementation Method 1
the first bypass line has a cooling device designed for cooling the first partial flow of the gas mixture
Implementation Method 2
a converter configured for the catalytic conversion of nitrogen and hydrogen at least partially to ammonia
Implementation Method 3
a conveying device configured for the cyclic conveying of a gas mixture containing nitrogen, hydrogen, and ammonia in a synthesis cycle conveying direction
Data Source
Figure 1~2
Figure 3~4
AI summary
The present invention relates to an ammonia synthesis plant having a hydrogen device and a synthesis circuit, wherein the synthesis circuit has a conveying device, a converter and a first bypass line. The hydrogen device is designed to provide hydrogen. The conveying device is designed to cyclically convey a gas mixture, containing nitrogen, hydrogen and ammonia, in a synthesis circuit conveying direction, wherein the conveying device has a suction side and a pressure side. The converter is designed to catalytically convert nitrogen and hydrogen at least partially into ammonia, wherein the converter has an inlet and an outlet, wherein the inlet of the converter is fluidically connected to the pressure side of the conveying device and the outlet of the converter is fluidically connected to the suction side of the conveying device. The first bypass line is arranged from the suction side of the conveying device to the pressure side of the suction device parallel to the conveying device in the fluidically opposite direction and is designed for the stoppable return of a first partial stream of the gas mixture from the pressure side of the conveying device to the suction side of the conveying device, wherein the first bypass line has a cooling device which is designed to cool the first partial stream of the gas mixture. The first bypass line has a second bypass line, which is arranged parallel to the cooling device in the fluidically same direction, and which is designed for the stoppable guiding through of a second partial stream of the first partial stream in order to bypass the cooling device.