1. Introduction
Separate heat pipe heat exchanger is a new type of heat exchange equipment evolved from heat pipe heat exchanger. It can be installed on the flue, gas pipe and combustion air pipe of hot blast stove respectively. The arrangement of tube bundles in split heat pipe heat exchangers is generally arranged in rows, that is, rectangularly arranged. This will reduce the heat transfer coefficient (about 30% of the fork row), but the pressure drop of fluid through the heat exchanger There is a large drop, and it is also convenient to use a blower to remove dust.
2. When the evaporation section of the heat pipe is heated, the working medium in the heat pipe evaporates and vaporizes. The steam flows to the condensation section under a small pressure difference to release heat and condense into a liquid, which flows back to the evaporation section under the action of gravity. This cycle continues, and heat is transferred from one end to the other. The heat transfer principle of the heat pipe determines the basic characteristics of the heat pipe:
a. Large heat transfer capacity. The heat pipe cleverly organizes the two phase transition processes of boiling and condensation with low thermal resistance, making its thermal conductivity up to several times to thousands of times of copper thermal conductivity. Zh
b. Excellent isothermal properties. The steam in the inner tube of the heat pipe is in a saturated state. The pressure difference between the saturated steam flowing from the evaporation section to the condensation section is small, so the heat pipe has excellent isothermal properties. Zh
c. There is no need for a delivery pump and seal lubrication is missing, and the structure is simple without moving parts and noise. A heat pipe with a length of 0.6m and a diameter of 13mm and a weight of 0.34kg transmits 200W of energy at a working temperature of 100 掳 C, and its temperature drops by 0.5 掳 C. The weight of a solid copper rod that transports the same energy and is the same length is 22.7kg, with a temperature difference of up to 70 掳 C. Zh
The heat pipe heat exchanger composed of heat pipes has the following advantages:
a. The heat pipe heat exchanger can completely separate the hot and cold fluids through the middle partition of the heat exchanger. During operation, a single heat pipe is damaged due to wear, corrosion, overtemperature, etc., but it is only a failure of the single heat pipe. Doping of hot and cold fluids can occur. Therefore, the heat pipe heat exchanger has high reliability for heat exchange occasions such as easy, explosive, and corrosive fluids. Zh
b. The cold and hot fluids of the heat pipe heat exchanger are completely separated and flow, and it is relatively easy to realize the complete counter-current heat exchange of the cold and hot fluids. At the same time, the cold and hot fluids are flowing outside the tube, because the heat transfer coefficient of the outside flow is much higher The heat transfer coefficient flowing in the tube, and the heating surface on both sides can adopt the extended heating surface. It is very economical to recover lower grade thermal energy. Zh
c. For fluids with high dust content, the heat pipe heat exchanger can expand the heating surface form through the heat pipe structure size to solve the problem of wear and ash blocking of the heat exchanger. Zh
d. When the heat pipe heat exchanger is used for waste heat recovery with corrosive flue gas, the temperature of the heat pipe wall can be adjusted by adjusting the heat transfer area of the evaporation section and the condensation section, so that the heat pipe can avoid the largest corrosion area as much as possible.
3. Basic characteristics of heat pipe working principle and advantages of heat pipe heat exchanger
Heat pipe is a novel heat transfer element with extremely high thermal conductivity. The heat pipe originated in the United States in the 1960s. In 1967, a stainless steel-water heat pipe was first sent into the Earth satellite orbit and successfully operated. Once the thermal management theory was put forward, it has been highly valued by scientists from various countries, and a lot of research work has been carried out, which has enabled the rapid development of heat pipe technology. Heat pipe technology began to be mainly used in the aerospace field. Since the 1970s, China has conducted research on heat pipes. Since the 1980s, heat pipe gas-gas heat exchangers, heat pipe gas-water heat exchangers, heat pipe waste heat boilers, Various types of heat pipe products such as heat pipe steam generator, heat pipe hot blast stove. Because carbon steel-water two-phase gravity heat pipe has simple structure, low price, convenient manufacturing, and basic solution of carbon steel-water compatibility, this type of heat pipe is widely used in power, chemical, drying, building materials and other fields.
4. Working Principle
Separate heat pipe heat exchanger is composed of several high frequency finned tube groups welded and independent of each other. It has good thermal conductivity, and the tube bundles corresponding to the cold and hot ends are connected through a steam duct and a return duct to form independent closed pipeline systems.
Separate heat pipe heat exchanger is the development of single pipe heat pipe heat exchanger. In a single-tube heat pipe heat exchanger, the evaporation section and the condensation section are two parts of a heat pipe, and the heat exchanger is composed of several single pipes. Separate heat pipe heat exchangers are different. The evaporation section and the condensation section are no longer composed of separate heat pipe components, but are separated into two parts to form two heat exchangers: the evaporator and the condenser.Heat Pipe Exchanger manufacturers