Study On Some Key Points In The Evaporative Cooling Comprehensive Test Bench

As an efficient, environmentally friendly, economical cooling way,Evaporative air conditioning technology is becoming more and more popular in the air conditioning area and the products has formed a series of production. With the diversification of the evaporative air conditioning equipment and the formulation of its performance standards, the product performance and quality of evaporative air conditioning equipment have attracted the extensive attention worldwide. And these parameters that can used to reflect the performance of evaporative air conditioning equipment generally include the cooling capacity, energy efficiency ratio, power consumption, cooling rate, which can not be directly measured. Instead, these parameters can be calculated by measuring the relevant physical quantities in a certain continuous stable state environmental condition. In addition, the evaporative air conditioning equipment is also highly influenced by the environmental meteorological parameters.Therefore, the standard comprehensive test bench should be established to simulate the reliable and wanted inlet conditions, which can provide an advanced platform for the evaporative cooling research and the product development.At present, the experiment of the evaporative cooling product is usually did outside directly. Because of the uncontrollable of the outdoor weather conditions, it is hard to get the satisfactory experimental results. In addition, due to the special way of evaporative cooling air treatment, when the experiments are did on the traditional refrigeration air conditioning test bench, the operation cost of the bench may be very high, even worse, it may be can not meet the experiment requirements. With the expansion of the scale of the products and more and more attention are paid to the quality of the products, the importance of the establishment of a special product performance test has been realized by some manufacturers. Shaanxi yousida Environmental Technology Co., Ltd is an evaporative cooling equipment manufacturer, by who this subject is entrusted to study on the key points in the development of the evaporative cooling comprehensive test bench,which is belongs to the company.(1) first, combining with the manufacturer’s production, the objects and the scopes as well as the experiment methods of the test bench should be determined. The test objects mainly include four types of evaporative air conditioning units as followed, the DEC units, the IDEC+DEC units, evaporative cooling water chillers as well as the evaporative cooling and mechanical refrigeration integrated air conditioning units, of which the determined meths of related performance parameters(refrigeration capacity,humidification quantity, energy efficiency ratio, air and water temperature, etc.) also should be provided. Considering the concept of modular production, the air flow rate isdesigned as 10000m3/h. Combination the methods to determine the performance parameters of the four types of equipment, the refrigeration capacity, the humidification quantity, as well as the outlet air and water temperature in the design conditions can be calculated, based on which, the scope can be obtained as follows, the water side cooling capacity is in the range of 20~100k W, the air side cooling capacity is in the range of10~60k W, water flow rate is in the range of 2~16m3/h, the dry bulb temperature is about-15~50℃, the relative humidity of the environment is about 20%~90%. Considering the need for capacity expansion at late stage, the air rate design of the large air flow measurement device is about 1500~30000m3/h and the small one is about1000~10000m3/h. To design two size air flow measuring devices, on the one hand considering the equipment types, on the other hand considered that the secondary air flow of the indirect evaporative cooling equipment also should be test sometimes.(2) Studies on the key parameters of energy saving design of the air conditioning system of the test bench were did, which mainly include the capacity design of the air conditioning unit as well as the reasonable design of the heat and cold source,maintaining the temperature and humidity of the environment controlled. Mainly according to the typical urban summer outdoor design parameters of the dry areas and taking the high humidity areas into account as well, the simulated indoor air parameters of the test bench, that is design value of the inlet air parameters of the tested evaporative cooling equipment, are determined as follows. These design values is that the dry bulb temperature is 50℃ and the wet bulb temperature is 21.5℃ in the dry design condition while the dry bulb temperature is 40℃ and the wet bulb temperature is 29.8℃ in the high humidity design condition respectively. Finally, the refrigeration capacity and the heating capacity of the test bench are both designed as 150 k W, and the humidifying capacity is70kg/h and four water chillers of 12 HP are chosen, which is determined according to the summer outdoor design parameters in Baoji area and the characteristic of the air treatment of various types of evaporative cooling equipment.(3) The energy saving operation schemes in different conditions experiments of the test bench air conditioning system were studied. The purpose is to make full use of the cooling capacity and humidity in the outlet air of the tested evaporative cooling equipment and reduce the load of the air conditioning system. According to the requirements of the national standard GB/T25860-2010 "evaporative air conditioner",two standard operating conditions were determined. Inside, take the dry bulb temperature38℃, and the wet bulb temperature 23℃ as the Standard dry condition, while the dry bulb temperature 38℃, and the wet bulb temperature 28℃ as the Standard high humidity condition. Based on the outdoor meteorological conditions in Baoji, two standard conditions experiments were did to explore the methods that to obtain the optimal adjustment ratio of the outdoor air and the exhaust air flow with the outdoormeteorological conditions changing. The method has general characteristics for other non-standard operating conditions, which can provide an advanced operational reference for the test personnel.(4) Finally, the evaporative air conditioner comprehensive test bench was used to simulate the standard dry condition and the standard high humidity condition. Then the experiment on the performance of an evaporative air conditioner was did to explore the operation condition of the test bench. In the view that the fresh air can not be introduced by the air conditioning system of the test bench and the limitations of the products can be tested, an advanced improvement scheme was proposed. Both the environmental test room two and the fresh air system were increased to the test bench to meet the need of diversification and promote the development of the products, and makes it relatively energy saving.