Multiphase Pump Refrigeration System for Process Plant Water Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Refrigeration methods and systems in petrochemical processing plants are costly due to high capital and operating expenses, necessitating more efficient cooling of process plant water.
Innovation Solution
A closed-loop method and system for cooling process plant water using a heat exchange system with a refrigerant, involving multiple heat exchangers, expansion valves, and a multiphase pump to efficiently transfer heat and separate vapor and liquid phases, allowing for the recycling of cooled water.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If traditional refrigeration methods with two-stage compressors, flash drums, liquid pumps, cooling towers and heat exchangers are used, then cooling capability is achieved, but capital and operating costs increase
Solution Approach 1:
The refrigeration cycle is segmented into distinct functional zones: evaporator for heat absorption, condenser for heat rejection, expansion device for pressure reduction, and compressor for pressure increase. This segmentation allows each component to be optimized independently while simplifying the overall system architecture compared to integrated traditional systems
Solution Approach 2:
The system uses a single refrigerant loop that serves multiple cooling purposes: process water cooling, condenser cooling, and potential integration with other plant cooling needs. The heat exchangers are designed to handle multiple fluid streams, reducing the total number of separate cooling systems required
2Temperature
If traditional refrigeration methods with two-stage compressors, flash drums, liquid pumps, cooling towers and heat exchangers are used, then cooling capability is achieved, but operating costs increase
Solution Approach 1:
The system incorporates temperature and pressure sensors throughout the refrigeration cycle that provide real-time feedback to the control system. This enables automatic adjustment of expansion valve opening, compressor speed, and refrigerant flow rates to optimize energy consumption while maintaining required cooling capacity under varying load conditions
Solution Approach 2:
The system dynamically changes operating parameters including refrigerant pressure, temperature, and flow rates based on cooling demand. By continuously optimizing these parameters rather than operating at fixed settings, the system reduces energy consumption while maintaining effective cooling capability
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 method effectively lowers the temperature of process plant water while reducing costs by utilizing a refrigerant with a low boiling point and high viscosity, achieving efficient heat exchange and recycling of cooled water within the system.
Implementation Method 1
exchanging heat between a first process water stream and a liquid refrigerant within a first heat exchanger to lower the temperature of the process water stream
Implementation Method 2
The refrigerant is partially vaporized upon the exchange of heat with the first process water stream to generate a partially vaporized refrigerant having a vapor phase and a liquid phase
Implementation Method 3
The pressure of the partially vaporized refrigerant is increased in a multiphase pump
Implementation Method 4
lowering the pressure and/or temperature of the partially vaporized refrigerant portion and transferring the partially vaporized refrigerant portion to a vapor-liquid separator to separate the liquid phase from the vapor phase thereof
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present disclosure provides methods and system for the cooling of process plant water. A system can include a first heat exchanger for exchanging heat between a first process water stream and a refrigerant; a multiphase pump, coupled to the first heat exchanger, to increase the pressure of the refrigerant; a second heat exchanger, coupled to the multiphase pump and the first heat exchanger, for exchanging heat between a second process water stream and the refrigerant; a first expansion valve, coupled to the second heat exchanger, for lowering the temperature of the refrigerant; a vapor-liquid separator, coupled to the first expansion valve and the multiphase pump, for separating the liquid and vapor phases of the refrigerant; and a second expansion valve, coupled to the vapor-liquid separator and the first heat exchanger, for lowering the temperature of the liquid phase of the refrigerant.