In terms of its structure, solar water heaters can generally be categorized into several types based on different criteria.
1. Based on the heat collection part:
1) Glass vacuum tube solar water heater
This type includes all-glass vacuum tubes, heat pipe vacuum tubes, U-shaped tube vacuum tubes, and integrated heat storage boring types. The most commonly used is the all-glass vacuum tube type. It offers advantages such as safety, energy efficiency, environmental friendliness, and cost-effectiveness. Solar water heaters with auxiliary electric heating are mainly powered by solar energy, supplemented by electricity to ensure year-round operation and maintain high efficiency even in low temperatures. However, this type has some drawbacks, such as a larger size, fragile glass tubes, easy scaling inside the tubes, and inability to operate under pressure. To address these issues, Tsinghua Sunshine has developed a heat pipe-type vacuum tube that uses a heat transfer medium, which effectively solves problems like fragility, scaling, and freezing. This design also improves the heat collection efficiency by nearly ten percentage points compared to traditional tubes.
2) Flat-plate solar water heater
Flat-plate collectors come in various designs, including tube-plate type, wing-tube type, coil type, flat box type, round tube type, and heat pipe type. Their main advantages include good overall performance, long lifespan, low failure rate, reduced safety risks, ability to operate under pressure, and strong thermal stability. They are also easy to integrate with buildings and resistant to drying. However, they have poor insulation due to the non-vacuum environment inside the cover plate, leading to lower efficiency in cold weather or when high-temperature water is needed. If frost damage occurs, the entire collector may need replacement, making them more suitable for southern regions where freezing is not an issue.
3) Ceramic hollow flat solar water heater
Ceramic solar panels are made from a hollow, thin-walled flat-box structure using common ceramic as the base and a three-dimensional mesh vanadium-titanium black porcelain as the surface layer. These panels are waterproof, durable, non-corrosive, and resistant to aging, fading, and radiation. Their sunlight absorption rate remains stable over time, achieving a high photothermal conversion efficiency. According to the National Solar Water Heater Quality Supervision and Inspection Center, ceramic solar panels have an absorption ratio of 0.95, and their daily heat output reaches 8.6 MJ, far exceeding the national standard. These panels are cost-effective, have a long lifespan matching that of buildings, and can serve as structural, insulating, and waterproof layers. They are ideal for integrating with building facades, balconies, and walls to provide hot water, heating, and air conditioning. Additionally, they support industrial, agricultural, and aquacultural applications, as well as large-scale solar power generation and desalination projects in arid areas.
2. Based on structural design:
1) Compact solar water heater: This design directly inserts the vacuum glass tube into the water tank, using natural convection to heat the water. It is the most common type found in the market.
2) Split-type solar water heater: This system separates the collector from the water tank, allowing for greater capacity and improved usability. It avoids the falling water method, expanding its application range.
3. Based on water tank pressure:
1) Pressure-bearing solar water heater: These systems deliver water under pressure, typically operating with top-water feeding, and do not require a pressurized tank.
2) Non-pressure-bearing solar water heater: Most traditional models fall into this category. The water tank is open to the atmosphere, relying on the height difference between the roof and the home to generate pressure during use. These units are safer, cheaper, and have a longer service life compared to pressure-bearing types.
Birch Plywood,Birchwood Plywood,Staining Birch Plywood,Birch Veneer Plywood
LINYI JIUHENG IMPORT AND EXPORT CO.,LTD , https://www.jiuhengwood.com