Green Energy
- Bbc: Why Does Sweden Have More Boys Than Girls?
From the BBC: There is something odd going on with the ratio between boys and girls in Sweden. The latest estimates suggest there are 123 boys for every 100 girls among 16 and 17-year-olds. That's an even greater imbalance than in the same age...
- Cascade Control Loops
Cascade Control Loops -The general concept of cascade control is to place one feedback loop inside another. In effect, one takes the process being controlled and finds some intermediate variable within the process to use as the set point for the main...
- Boiler Control Theory (feed Water Control)
Boiler Control Theory (Feed water Control) The feed water is controlled to keep the drum level . Water-level controls continuously monitor the level of water in a steam boiler in order to control the flow of feed water into the boiler and to protect...
- Advanced Process Controller (apc) For Controlling Steam Power Plant {part 1}.
"Control of Steam Power Plant is very big job need Care to fulfill the appropriate degree of stability and dependability for such this big system " In many countries, plants have to fulfill specific requirements of the electrical grid (such as frequency...
- Advanced Process Controller (apc) For Controlling The Main Steam Pressure Of A Steam Power Plant.
In many countries, plants have to fulfill specific requirements of the electrical grid (such as frequency control, dispatch control, automatic generation control (AGC), and so on) and are paid accordingly, based on their performance. Under these circumstances,...
Green Energy
Ratio Control Loops
Ratio Control Loops
- Based on hardware, ratio control is quite often confused with cascade control. The basic operation of ratio control, however, is quite different.
- Ratio control is often associated with process operations in which two or more streams must be mixed together continuously to maintain a steady composition in the resulting mixture. A practical way to do this is to use a conventional flow controller on one stream and to control the other stream with a ratio controller that maintains flow in some preset ratio or fraction to the primary stream flow. A preset ratio regulates the flow of the controlled variable. For example, if the ratio is 10 to 1, then for every gallon per minute of the uncontrolled variable that is flowing, ten gallons per minute of the controlled variable are allowed to flow.
- Use the signal from the uncontrolled flow transmitter, or wild flow, as the ratio input of the ratio controller. Multiply the value by an adjustable factor or ratio setting to determine the set point of the flow controller. The process variable to the controller is the flow of the controlled stream. The output from the ratio controller adjusts the control valve.
- You can use a ratio control loop with any combination of suitably related process variables, and the control action selected is normally proportional plus integral. The response to process upsets of a control loop with ratio control is the same as the response found in a single-feedback loop.
- Bbc: Why Does Sweden Have More Boys Than Girls?
From the BBC: There is something odd going on with the ratio between boys and girls in Sweden. The latest estimates suggest there are 123 boys for every 100 girls among 16 and 17-year-olds. That's an even greater imbalance than in the same age...
- Cascade Control Loops
Cascade Control Loops -The general concept of cascade control is to place one feedback loop inside another. In effect, one takes the process being controlled and finds some intermediate variable within the process to use as the set point for the main...
- Boiler Control Theory (feed Water Control)
Boiler Control Theory (Feed water Control) The feed water is controlled to keep the drum level . Water-level controls continuously monitor the level of water in a steam boiler in order to control the flow of feed water into the boiler and to protect...
- Advanced Process Controller (apc) For Controlling Steam Power Plant {part 1}.
"Control of Steam Power Plant is very big job need Care to fulfill the appropriate degree of stability and dependability for such this big system " In many countries, plants have to fulfill specific requirements of the electrical grid (such as frequency...
- Advanced Process Controller (apc) For Controlling The Main Steam Pressure Of A Steam Power Plant.
In many countries, plants have to fulfill specific requirements of the electrical grid (such as frequency control, dispatch control, automatic generation control (AGC), and so on) and are paid accordingly, based on their performance. Under these circumstances,...