DRAFT – Energy Flows 2

A customer build a hydraulic setup composed of a re-circulation loop, with a BPS-600 (600.17 pump-head) pumping 40 lpm at 1.6 bar.

The customer need to estimate the power consumption of the pump system.

What is the total electrical power absorbed by the system?

Consider the same system of the previous question (hydraulic setup composed of a re-circulation loop, with a BPS-600 pumping 40 lpm, at a pressure of 1.60 bar).

What is the hydraulic power provided by the pump?

The customer is now interested in a detailed breakdown of the energy flow and power conversions in the pump system.

Consider the system from the previous questions: BPS-600 operating at 7000 rpm, 40 lpm, and 1.6 bar (hydraulic power 107 W, electrical input power 275 W).

In the plot below it is shown the hydraulic efficiency of the pump.

How much was the mechanical power developed by the motor?

How much were the electrical losses in the controller and motor (together)?

How much were the hydraulic losses in the pump head?

The customer is worried that his process fluid might warm up, so he wonders about the temperature increase in the pumphead.

Consider the system from the previous questions

BPS-600, operating at 40 lpm, 1.6 bar, 7000 rpm

Electrical power absorbed = 275 W

Mechanical power provided by motor = 228 W

Hydraulic power by pump = 107 W

How much will the fluid temperature increase across the pump, in each pass? (consider only T@outlet – T@inlet)

Consider a specific heat Cp = 4.180 kJ/kg*K

The customer now mentions that the process fluid and the ambient air are quite hot, so he worries about the motor’s temperature and asks for a recommendation.

Consider the system from the previous questions:

BPS-600 operating at 7000 rpm, delivering 40 lpm at 1.6 bar (600.17 pump head).

The environmental temperature is Ta = 40 degC, and the fluid temperature is Tl = 40 degC.

There is no active cooling module on the motor (only natural convection applies).

Using the plots and formulas below (taken from the manual), estimate the motor internal temperature.

What’s the motor temperature? Is it acceptable?

As found out in the previous question, the motor without cooling would heat up to 77 degC.

To tackle the problem, you would recommend a fan cooling module.

Before making the recommendation, provide an estimate of the motor temperature once a Levitronix fan cooling module is applied.

Pump head 600.17

Ambient temperature Ta = 40 degC

Fluid temperature Tl = 40 degC

What is the new motor temperature, with this air cooling module? Is it acceptable?

The motor is not the only electronic element that could suffer from overheating: the controller could be affected too.

The BPS-600 doesn’t have an integrated controller: let’s assume it is exposed to the same environmental conditions of the motor (Ta = 40 degC).

What will the controller temperature be? Is it acceptable? If necessary, recommend a solution to the customer, if necessary.

Working point: 40 lpm, 7000 rpm, electrical power input 275 W.

Use the plot and formulas below (taken from the manual).