What is heating engineering?

What is heating engineering?

1, How to control the supply and return water temperature during system operation? What is the usual temperature difference between the supply and return water in China's heating system?

Answer: The regulations for heating design in our country are as follows: the water supply temperature is 95 ℃, the return water temperature is 70 ℃, and the temperature difference is 25 ℃. However, in recent years, based on advanced heating experience both domestically and internationally, there has been a downward trend in supply and return water temperature and temperature difference. The design of supply and return water temperature ranges from 80/60 ℃ to 20 ℃.

2, What are the forms of heat exchange? What is the heat transfer coefficient? What are the main forms of heat exchange for surface heat exchangers?

Answer: There are three forms of heat exchange (or heat transfer): conduction, convection, and radiation. For a face-to-face heat exchanger, the main forms of heat transfer are convection and conduction. The calculation formula for convective heat transfer is: Q= α A (t2-t1), the calculation formula for thermal conductivity and heat transfer is: Q=( λ/δ) A (t2-t1). Convective heat transfer occurs on both sides of the heat transfer element in a surface heat exchanger, and heat conduction occurs inside the element.

3, What are the forms of surface heat exchangers? What are its principles, advantages and disadvantages?

Answer: The main forms of surface heat exchangers include shell and tube heat exchangers, plate heat exchangers, heat pipe heat exchangers, etc. It can be subdivided into many forms, with common drawbacks: large volume, large footprint, high investment, low heat exchange efficiency (compared to hybrid), and short lifespan; Their advantages are light pollution of condensed water quality and easy recovery.

4, Sometimes it is found that some users have hot radiators while others are not, why? How to solve it?

Answer: This is called system hydraulic imbalance, and the reasons for it are complex, roughly including the following reasons:

(1) The pipe diameter design is unreasonable, and some parts of the pipe diameter are too thin;

(2) Some components have excessive resistance, such as the valve not being able to fully open, etc;

(3) There is debris blocking the system

(4) The uneven slope direction of the pipeline prevents the air from being completely discharged from the system;

(5) The system loses a large amount of water;

(6) The system's constant pressure is too low, causing insufficient water operation;

(7) Insufficient flow rate and head of circulating water pump;

To solve the problem of system imbalance, the first step is to identify the cause and then take corresponding measures

Www.superbheater.com