There are some misconceptions about the flat panel collector solar system. One is the four-day all-weather operation of the flat panel collector solar system. Many people think that the flat collector solar system cannot be operated in the winter. In fact, this view is wrong. At present, the flat collector solar system generally adopts the recirculation emptying technology and the secondary circulation technology (through the antifreeze heat transfer), and the problem of wintering and antifreezing of the collector can be conveniently solved in the northern region, and there is no worries of the collector being frozen. It can also solve the problem of overheating of the system in summer (or when the hot water load is not matched), which is very beneficial to the solar heating system. In addition, the technical scheme of backflow and anti-overheating and antifreeze is also widely used in European countries such as the Netherlands, which is a very mature technical solution [9]. Another misunderstanding is that the heat collector of the flat plate collector has a problem. Many people think that the heat gain (or water production) of the flat-plate collector solar water heating system is lower than that of the vacuum tube collector hot water system. The actual test shows that the black chromium is selected. The water quality of the coated flat plate collector hot water system is higher than that of the same total area of ​​the vacuum tube collector hot water system [5]. The test results are as follows: Fig. 2 Comparison of daily average water production per unit area of ​​black chrome-selective coated flat plate collector and vacuum tube collector It can be seen from the test results that in Beijing, the high-efficiency flat-plate collector solar water heating system produces more water than the equivalent-area vacuum tube collector system. One of the important reasons is that the light collecting area of ​​the vacuum tube collector under the same area is lower than that of the flat collector. A juicy, tender steak is aperfect steak experience,but the absence of a sharp,handy knife can really spoil the wxperience.We can provide customers all over the world with the best quality and comfortable bakelite handle steak knives,also we can customize different steak knives according to the living habits of different countries. Serrated Steak Knives,Serrated Steak With Bakelite Handle,Rivet Bakelite Handle Steak Knife,Bakelite Handle Steak Knife HONG TAO KITCHEN INDUSTRY CO.,LTD , https://www.jmhtkitchenware.com