Cost performance optimization analysis of the hott

Cost performance optimization analysis of glue injection and threading insulation technology system

in recent years, the scope of national power rationing has been further expanded, which has sounded an alarm for us The continuous introduction of the national building energy conservation policy also makes us see the hope of realizing energy conservation At the same time, we also see another phenomenon With the continuous deepening of the national policy of effectively controlling house prices, China's house prices have begun to stabilize gradually The cost of heat insulation and energy-saving aluminum windows is bound to be higher than that of ordinary aluminum windows. We began to hear about the contradiction between energy-saving doors and windows and stabilizing house prices Is it really difficult to control the cost performance of insulated aluminum windows? What are the main differences between the glue injection insulation system from the United States and the strip through insulation system from Europe

recently, there are many topics around us, including two issues that need our special attention First, the newly put into operation generating units in 2005 will be between 68.4 million and 70 million KW, and the power consumption of the whole society will reach 242.2 billion kwh. The largest gap in power supply throughout the year will reach 23 million KW, significantly lower than last year In the existing power consumption structure, the power consumption of air conditioning in summer accounts for one third The second is the government's many regulatory policies for the phenomenon of excessive growth of housing prices across the country We see that the government has made building energy conservation the top priority of national development For real estate developers and door, window and curtain wall companies, an efficient and energy-saving heat insulation technology with moderate cost should be the best choice

there are two main heat insulation aluminum door and window technologies in the current construction market One is the strip insulation technology from Europe, and the other is the glue injection insulation technology from North America At present, the "heat and cold bridge technology" generally refers to the strip insulation technology Most people don't understand the characteristics of glue injection heat insulation technology In fact, both glue injection and threading belong to the category of "heat cut and cold bridge technology" The technical prototype of glue injection insulation technology was born in the United States as early as 1937 In the 1970s, the leading production line of rubber insulated aluminum was also introduced from Hong Kong to Guangdong, China Therefore, the glue injection heat insulation technology is not unfamiliar to us

then, are all heat insulation and energy-saving aluminum windows and curtain wall products energy-saving products with heat insulation performance but high cost? Is it true that with the continuous adjustment of house prices, thermal insulation aluminum windows and curtain wall products will be carefully selected by developers? Our answer is No The "energy saving star" plan of the United States and the "low interest loan building door and window energy saving plan" led by the Ministry of construction and industry of Japan have been designated to use glue injection heat insulation technology This fully shows that the glue injection heat insulation technology is an advanced structural heat insulation technology with moderate cost, which meets the international building energy efficiency standards

next, we will analyze the difference between glue injection heat insulation technology and strip through heat insulation technology from several points

I. thermal insulation performance

for thermal insulation aluminum, the K value of thermal insulation material has a crucial impact on the thermal insulation performance of the whole aluminum material The K value of thermal insulation glue, the core of glue injection thermal insulation aluminum material, is 0.12 The K value of PA66 + air (or strip filler), the core of strip insulation aluminum, is larger than that of insulation glue Thus, the U value of glued insulated aluminum and insulated doors and windows is lower than that of threaded insulated aluminum and insulated doors and windows In China, we use these two different thermal insulation design structures to make the same 45mm inner opening window (1500mm × 1500mm), and the thermal insulation performance is simulated and analyzed by American professional calculation software therm and windows From the infrared analysis diagram and test results of the thermodynamic properties of the two types of heat insulation windows, it can be seen that the heat insulation performance of glue injected heat insulation windows is significantly better than that of strip type heat insulation windows on the premise that the width of door and window profiles, the configuration of glass system and the width of heat insulation materials are the same

finally, we found that when the heat insulation performance of the two heat insulation windows is the same, the width of the strip type heat insulation material is at least 4mm larger than that of the glue type heat insulation material This feature provides a way for users to reduce the cost of doors and windows while keeping the heat insulation performance of doors and windows unchanged

II. Cost of door and window profiles

from the thermal insulation performance analysis just now, we can find that on the premise that the width of door and window profiles, the configuration of glass system and the width of thermal insulation materials are the same, banks should reduce the door sill. The thermal insulation performance of glue injection thermal insulation windows is significantly better than that of strip type thermal insulation windows So does better insulation performance mean higher material costs? The answer is No We have selected two kinds of products with the same frame width and the same insulation material width in China, which can reach the second level molding; The conditions are mild and the profile design is analyzed below

from the above two structural designs, it can be seen that due to the difference in the design specified size between the glue injection insulation structure and the strip through insulation structure, the aluminum cavity size a is at least 4mm smaller than B Therefore, on the premise of the same cavity design and the same wall thickness, the meter weight of glued insulation aluminum is less than that of threaded insulation aluminum For insulated aluminum windows with the same design and insulating glass configuration, the weight of glue injection insulated aluminum windows is much lower than that of strip type insulated aluminum windows

for the unit price per square meter of insulated aluminum window, weight is a crucial item Because the weight of glue injection type insulated aluminum window is lower than that of strip type insulated aluminum window, its cost price is also much lower than that of strip type insulated aluminum window

we follow 1500mm × The size of 1500mm standard sample window was analyzed and priced. The results showed that the cost of aluminum material per square meter of glue injection heat insulation window was about 20% lower than that of strip type heat insulation window This cost price can basically meet the requirements of the majority of users to meet the national heat insulation performance index (k value or U value) on the premise of a small increase in the cost of aluminum windows

III. profile strength (composite moment of inertia)

for whether the thermal insulation aluminum can be used as a main bearing heavy-duty body for large-scale and before use, one of the keys to carefully browse the operation manual for windows or curtain walls in high-rise buildings is whether the strength (or composite moment of inertia) of the thermal insulation aluminum can meet the requirements of the designer Then, is the strength of glued insulation aluminum, threaded insulation aluminum and ordinary aluminum equal? We also calculated and analyzed this We refer to the relevant standards of the European Union (prEN 14024:2000 "performance requirements and testing of thermal insulation metal profiles") and the relevant standards of the United States (AAMA TIR a8:2004 "structural performance and analysis of aluminum alloy profiles for thermal insulation buildings") In order to fairly consider the strength difference of thermal insulation aluminum, we use the EU prEN 14024:2000 standard as the theoretical basis for calculation and analysis The following is part of the original translation of the standard:

calculation method of effective moment of inertia of thermal insulation profiles

B.1 the deflection of thermal insulation profiles can be calculated by common deflection formula, but the combined moment of inertia of elastic combination of metal profiles should be considered

b.2 the calculation formula of effective moment of inertia is:

ief = is · (1-)/(1- · C) (1)

where: is = I1 + I2 + A1 12 + A2 22 (2)

v= (A1 12 + A2 22)/is (3)

c= λ 2/（π2+ λ 2) (4)

(5)

where: IEF - effective moment of inertia (unit: CM4)

is -- rigid moment of inertia (unit: CM4)

v -- combined parameter of rigid moment of inertia

c - elastic binding parameter

λ——— Geometric parameters

l - span of beam (unit: cm)

c -- elastic constant or combined elastic value of thermal insulation material (unit: n/mm2)

e -- elastic modulus of aluminum alloy (unit: n/mm2)

a1 -- sectional area of A1 area (unit: cm2)

a2 -- sectional area of A2 area (unit: cm2)

1 - distance from the centroid of A1 area to the centroid of heat insulation profile (unit: cm)

2 - distance from the centroid of A2 area to the centroid of heat insulation profile (unit: cm)

i1 - moment of inertia of section material in zone A1 (unit: CM4)

i2 -- moment of inertia of A2 area profile (unit: CM4)

note: 1) because λ It depends on the span of the beam, so the effective moment of inertia is a function of the span For large span, its value is close to the rigid value

2) the formula of C is strictly valid for sinusoidal load, and has high accuracy for constant load and triangular load

b.3 calculation example:

area a1=253.7mm2

a2=336.3mm2

centroid distance a1=27.3mm

a2=25.2mm