Application scheme of lithium battery pack for ultrasonic flowmeter
1、 Introduction of ultrasonic flowmeter
Based on the principle of "velocity difference method", the pipe section ultrasonic flowmeter is used to measure the liquid flow in the pipe. It adopts advanced multi pulse technology, digital signal processing technology and error correction technology, so that the flow meter can be more suitable for the industrial environment, and the measurement is more convenient, economical and accurate. The products have reached the advanced level at home and abroad, and can be widely used in the fields of petroleum, chemical industry, metallurgy, electric power, water supply and drainage, etc.
2、 Requirements for lithium battery pack of ultrasonic flowmeter
The working current of the ultrasonic flowmeter is about 1.5-2a, which requires continuous operation for 3 hours, and the cycle life is required to be more than 500 times. Therefore, our company adopts the bick cell for combination. The battery has the advantages of high energy ratio, light weight, small volume, high cycle life, high safety, high voltage consistency, etc.
Battery pack model
11.1V-4.4AH
Model of single battery
BIC lithium ion 18650 cell
Battery combination mode
4 strings
Cell voltage
3.7V
Voltage after battery pack combination
11.1v (3.7V / section * 6 sections)
Battery charge and discharge voltage range after combination
9－12.6V
Cell capacity
4400mAh
Combined battery capacity
2200mAh / section * 1 Section
Battery pack power
25W
Battery pack size
109*19*67*mm
Maximum discharge current
＞2A
Instantaneous discharge current
＞4A
Maximum charging current
＞0.2-0.5C
Charge and discharge times
> 500 times
3、 Power scheme
Lithium battery protection function of portable comprehensive flue gas analyzer
1. Protection board (PCM): it is mainly a protection circuit designed for rechargeable lithium battery. Due to the chemical characteristics of lithium battery, it needs to provide intelligent power calculation, overcharge, overdischarge, short circuit, overcurrent and other protection functions. To avoid the risk of combustion, explosion, etc.
2. Protection IC: the main protection function chip of the design scheme, which can monitor the overcharge, over discharge, over-current, short circuit and other functions of the electric core on-line at any time, so that the electric core can work in a safe, stable and efficient range.
3. Temperature switch: mainly designed for temperature protection function. When the temperature of the battery reaches 70 ± 5 ℃ due to other abnormal problems, the temperature switch acts to protect the temperature
4. 18650 Li ion cell / 18650 / 2500mah / 3.7V Li ion cell.
5. MOSFET: MOSFET, which plays a switching role in the protection circuit. It will never increase or decrease the voltage at both ends of the load, so as to ensure the voltage stability.