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What is the difference between constant temperature and humidity machine and constant temperature and humidity unit?
2018-05-15 22:41
In addition to adjusting the air temperature, the constant temperature and humidity machine also has the functions of humidity adjustment and dust removal. Compared with ordinary air-conditioners, the constant temperature and humidity precision air conditioning system can run all the year round without stopping, so its reliability is very high. There are many options for the air supply system of constant temperature and constant humidity machine. The common ones include the down delivery, the upper and the lower, and the upper side. The standard type constant temperature and humidity machine adopts medium efficiency filter to clean indoor air. According to customer needs, sub efficient air filters can be selected.
Features of constant temperature and humidity unit:and
Characteristics of constant temperature and constant humidity unit:
1. The refrigeration capacity is generally between 10HP and 200HP
1. the cooling capacity is generally between 10HP-200HP;
2. The electric heating and electrode type humidification are configured, and the heating amount is generally large, while the humidification capacity of air conditioner is relatively small, which needs to be recalculated. Generally, it is necessary to increase one model or configure more than one set;
2. configuration of electric heating and electrode humidification, the heating amount is generally rich, air conditioner configuration humidification is small, need to be recalculated, the general need to increase a model or multi - configuration one;
3. Rated air volume is required
3. the rated air volume requirements;
4. It has rated cooling water requirement
4. the rated cooling water requirements;
The resistance of the condenser is less than 0.453
5. the resistance of the condenser is generally at 0.82-3.45mH2O;
6. The size of air conditioning unit is small
6. the size of the air conditioning unit is small;
7. Temperature control range: 18 ~ 25, sensitivity: & plusmn; 1; humidity control range: 50 ~ 70, sensitivity: & plusmn; 5;
7. temperature control range: 18~25, sensitivity: + 1; humidity control range: 50~70, sensitivity: + 5;
8. The external static pressure is generally between 100 and 550
8. machine is generally between 100~550.
9. Design conditions: inlet dry bulb temperature 23 ℃, wet bulb temperature 17 ℃; cooling water inlet temperature 30 ℃, outlet water temperature 35 ℃;
9. design conditions: intake air dry bulb temperature 23 C, wet bulb temperature 17 centigrade, cooling water inlet temperature 30 C, effluent temperature 35 C;
It is generally applicable in the case of temperature and humidity control or small design area. If the project area is large, the system is divided more, and the location of the air conditioning room is relatively scattered, the management and control of the system will be inconvenient, which is not conducive to the unified distribution of energy, and the energy waste is serious. In this case, the general area is more than 2000m2, so it is recommended to adopt the design form of chiller + combined air handling unit.
Generally, it is suitable for temperature and humidity control or the whole design area is not large. If the area is large, the system is divided more, the position of the air conditioning machine room is relatively scattered, the management and system control will be inconvenient, and it is not conducive to the unified distribution of energy, and the waste of energy is more serious. In this case, the general area is greater than 2000m2, and the design of chiller + combined air handling unit is recommended.
The purpose of constant temperature and humidity unit is divided into two parts:
The use of constant temperature and constant humidity unit is divided into two pieces.
1. Workshop with constant temperature and humidity, but no purification requirements
1, constant temperature and constant humidity workshop, but no purification requirements;
2. Both constant temperature and humidity are required, and purification level control is required
2, both constant temperature and humidity requirements, and the need for purification level control;
Room condition:
The situation of the room:
1) the sensible heat in the room is large
1.) the heat in the room is larger.
2) the sensible heat in the room is small; the above two points are analyzed:
2.) the sensible heat in the room is small;
a. From the aspect of load:
A. consideration of the load:
The air supply volume of the system is determined by the temperature difference between sensible heat and supply air in the room, rather than the total cooling capacity (sensible heat and latent heat) of the system. The refrigeration capacity of constant temperature and humidity unit generally accounts for 50% of sensible heat and 50% of latent heat, which is equivalent to about 20% of the total air supply volume of fresh air. When the sensible heat in the room is large and the fresh air volume is not large, the calculated air supply volume is large, so the refrigeration capacity of constant temperature and humidity unit can not be selected according to the total cooling capacity.
The air volume of the system is determined by the sensible heat and air temperature difference in the room, not by the total refrigerating capacity of the system (the sensible heat and latent heat of the room). The cooling capacity of constant temperature and humidity unit is 50%, and latent heat is 50%, which is equivalent to 20% of the fresh air volume. When the heat is larger in the room, and when the new air volume is small, the amount of air supply is larger, and it can not be determined according to the refrigerating capacity of the constant temperature and constant humidity unit.
b. Considering from the external residual pressure:
B. from external pressure consideration:
With constant temperature and humidity, but no purification requirements, the system does not have high requirements on the residual pressure outside the air conditioning unit, which mainly overcomes the supply and return air duct, valve, diffuser, primary filter, etc., and the conventional unit can meet the requirements
Constant temperature and humidity, but no purification requirements of the system for air conditioning units outside pressure requirements are not high, mainly to overcome the air supply and return pipes, valves, diffuser, initial filter, and other conventional units can meet the requirements;
The system which has the requirements of constant temperature and humidity, and also needs purification level control has higher requirements on the external residual pressure of air conditioning unit. The general system total resistance is between 1100pa and 1400pa. It mainly overcomes the following problems: supply and return air pipeline, valve, diffuser, primary filter (initial resistance 50pA, final resistance 100Pa), medium efficiency filter (initial resistance 150pa, final resistance 300pa), high efficiency filter (initial resistance 250pa) The conventional unit can not meet the requirements. If the system needs to set up the secondary return air, the clean type constant temperature and humidity unit cannot be selected; in the case of primary return air, the design form of constant temperature and humidity unit + pressure box is difficult to match with the fan in the constant temperature and humidity unit when selecting the type of pressure fan, the total air volume of fans with different types and powers in series or in parallel is not simply added, so the calculation is relatively relatively relatively relatively It is suggested that single fan system should be designed as far as possible in the general design process.
The system not only has the requirement of constant temperature and humidity, but also needs the system of purifying grade control to have high external pressure requirement for air conditioning unit. The general system resistance is between 1100Pa and 1400Pa, which mainly overcomes the air supply and return pipe, valve, diffuser, initial effect filter (initial resistance 50Pa, final resistance 100Pa), middle effect filter (initial resistance 150Pa, final). Resistance 300Pa), high efficiency filter (initial resistance 250Pa, final resistance 500Pa) and so on, conventional units can not meet the requirements. If the system needs to set two return air, the clean type constant temperature and constant humidity unit can not be selected; the first return air condition, the design form of the constant temperature and constant humidity unit + pressurization box, because it is difficult to match the fan in the constant temperature and humidity unit when choosing the type of the pressure fan, the different type and different power fan are in series or parallel. When the total air volume is not simply added, the calculation is relatively complex. It is suggested that the single fan system should be designed as far as possible in the general design process.
