Reference no: EM132497114

CHNG2801 Fluid Mechanics - The University of Sydney

Pump and Control Valve

Learning Objectives
1. Understand the components and operation of the rig.
2. Working in teams to plan, performing experiments and gather data safety.
3. Write a short report which communicates your findings.
4. Explain how valves and/or a variable speed drive can control the flow in a system.
5. Perform calculations to determine loss coefficients.
6. Learn about typical liquid velocities in pipes (0.5 - 5 m/s).
7. Learn about the application of Bernoulli's equation to real water pumping circuits.
8. Learn about the application of pumps and pumping theory.

Experimental Procedure (for you to note, sorry that this is not something that you can actually do, you can copy this section into your laboratory report, but you must acknowledge the source of the information, as in Lab Notes (2020), Water Flow Experiment)

Part 1 Understanding the Rig
1.1 Checkyou are wearing the required safety gear and understand the safety protocols
1.2 While the rig is off examine the set-up. Identify the main pieces of equipment (Tank, Pump, Control Valve, Pressure Transducers and Flow Meter). Trace the flow through the rig.
1.3 The tutor will briefly explain how a pneumatically actuated valve works.
1.4 Allocate a system and/or roles in the group for performing experiments and recording results. You can swap roles between experiments.

Part 2 Initial Valve and Pump Experiments
2.1 Set the valve opening to 100% and pump frequency to 50 Hz on the electronic control panel.
2.2 Verify all valves are in the correct position before turning on the pump.
2.3 You will be changing the valve opening electronically (50 to 100%) and measureflowrate, upstream/downstream valve pressure and the air pressure to the valve diaphragm.
2.4 Go over your results and explain to the tutor what happens to the flowrate and pressure drop as you change valve opening. Explain with system and pump curve diagrams.
2.5 Reset the valve to 100% open.
2.6 You will be changing the pump frequency electronically (25 to 50 Hz) and measure flowrate and upstream valve pressure. Take note of the change in the pitch of the pump noise as the pump frequency is changed.
2.7 Go over your results and explain to the tutor what happens to the flowrate and pressure drop as you change pump frequency. Explain with system and pump curve diagrams.

Part 3 Valve Based Flow Control
3.1 The tutor will put the valve in manual control and show you how to change the air regulator to change the air pressure. NOTE: Remember to reset the pump frequency to 50Hz.
3.2 Slowly change the air pressure from 100 kPa to 60 kPa, and pay particular attention on how the stem of the valve moves. Is this an "air to open" or "air to close" type valve?
3.3 The tutor will give you a flowrate to achieve. Use the results from step 2.3 to determine the air pressure required to achieve this.
3.4 Adjust the air pressure to this value and check if you have reached the required flowrate.
3.5 The tutor will put the valve in automatic control. Take note of how the controller changes the valve opening until the desired flowrate is achieved. Record the valve opening, air pressure and upstream/downstream valve pressure.

Part 4 Variable Speed Drive Based Flow Control
4.1 The tutor will give you a flowrate to achieve. Use the results from step 2.6 to determine the pump frequency required to achieve this. NOTE: Reset the valve opening to 100%.
4.2 Adjust the pump frequency to this value and check if you have reached the required flowrate.
4.3 The tutor will put the pump in automatic control. Take note of how the controller changes the pump frequency until the desired flowrate is achieved.

Part 5 Experiment Overview
5.1 Reflect on the different ways to control the rig.
5.2 The tutor will briefly explain how the electronic control systems work.
5.3 The tutor will explain how a self-actuating valve works. You will need to perform a valve sizing calculation in your report. Make sure you understand how to do this (see the final page of these notes for an explanation).

Aspects to Cover in the Report

A select number of graphs that depict trends observed with valve opening and pump frequency. Include references to pump and system curves in your explanation.

The diameter of the pipe is 50 mm ID. Calculate the loss coefficient for the valve when it is fully open (Use results from step 2.3). Also calculate the loss coefficient of the valve to achieve the flowrate which is given to you in the email.

The diameter of the valve actuator diaphragm is 230 mm. Using the results from step 5.3calculate the diaphragm diameter of a back and forward pressure self-regulating valve to achieve the required flowrate. Assume the same spring as the experiments is used.

Remember: P=F/A

Explain the different ways to control the flow in a system. Give some features, advantages and disadvantages for each.

Attachment:- Pump and Control Valve.rar