產(chǎn)品展示
聯(lián)系我們
聯(lián)系人：麥女士
手機(jī)：+86 15270269218
電話：
Q Q：3136378118
郵箱：stodcdcs@gmail.com
地址：江西省九江市瑞昌市東益路23號(hào)賽湖農(nóng)商城401號(hào)
MU-PLAM02
例如，在冷卻系統(tǒng)中，控制器設(shè)置為在空間溫度達(dá)到78F時(shí)打開冷卻閥，在溫度降至76F時(shí)關(guān)閉閥。兩個(gè)溫度（2華氏度）之間的差值就是差分間隙。受控變量在兩個(gè)溫度之間波動(dòng)。基本的雙位置控制適用于許多應(yīng)用。然而，為了進(jìn)行嚴(yán)密的溫度控制，必須加速或定時(shí)循環(huán)。基本兩位控制在基本兩位控制中，控制器和終控制元件相互作用，無需來自機(jī)械或熱源的修改。其結(jié)果是受控設(shè)備的循環(huán)運(yùn)行，以及受控變量在兩個(gè)值（開和關(guān)點(diǎn)）之間來回循環(huán)的情況，并受系統(tǒng)滯后的影響。在受控變量達(dá)到差速器兩個(gè)極限中的一個(gè)或另一個(gè)極限之前，控制器不能改變終控制元件的位置。因此，差速器是受控變量的小可能擺動(dòng)。圖21顯示了典型的加熱系統(tǒng)循環(huán)模式。溫度（°F）OFF ON 75 74 73 72 71 70 69 68時(shí)間欠調(diào)條件差分刻度盤設(shè)置過調(diào)條件C2088
An example of differential gap would be in a cooling system in which the controller is set to open a cooling valve when the space temperature reaches 78F, and to close the valve when the temperature drops to 76F. The difference between the two temperatures (2 degrees F) is the differential gap. The controlled variable fluctuates between the two temperatures. Basic two-position control works well for many applications. For close temperature control, however, the cycling must be accelerated or timed. BASIC TWO-POSITION CONTROL In basic two-position control, the controller and the final control element interact without modification from a mechanical or thermal source. The result is cyclical operation of the controlled equipment and a condition in which the controlled variable cycles back and forth between two values (the on and off points) and is influenced by the lag in the system. The controller cannot change the position of the final control element until the controlled variable reaches one or the other of the two limits of the differential. For that reason, the differential is the minimum possible swing of the controlled variable. Figure 21 shows a typical heating system cycling pattern. TEMPERATURE (°F) OFF ON 75 74 73 72 71 70 69 68 TIME UNDERSHOOT CONDTION DIFFERENTIAL DIAL SETTING OVERSHOOT CONDTION C2088
相關(guān)產(chǎn)品
