Energy-saving effect of free-standing flow control valve

Abstract: In recent years, due to the rising price of water, coal and electricity, the cost of heating has been increased, making heating enterprises difficult. In order to reverse the loss situation of heating enterprises, on the one hand, it is necessary to actively strive for the government to adjust the charging standards for heating bills on the one hand, and on the other hand, it should constantly dig out the potential within the enterprise and reduce the cost of heating. Self-acting flow control valve in the role of pipe network balance has been recognized by most people in the heating sector, and the energy-saving effect of self-operated flow control valve, most people still do not know. In fact, through the correct selection of self-operated flow control valve, to achieve network balance at the same time, more importantly, has made the heat, electricity, water saving effect. Keywords: flow control valve energy-saving pipe network balance In recent years, due to rising water, coal, electricity prices, resulting in increased heating costs, making the heating business difficult. In order to reverse the loss situation of heating enterprises, on the one hand, it is necessary to actively strive to adjust the charging standards for heating bills and, on the other, continue to dig deep into the internal potential of enterprises and reduce the cost of heating. The role of free-standing flow control valve in the pipe network balance has been recognized by most people in the heating sector, and the energy-saving effect of self-operated flow control valve, many people do not recognize. In fact, through the correct selection of self-operated flow control valve, to achieve network balance at the same time, more importantly, has made the heat, electricity, water saving effect. First, the heat to a 4,000 square meters of residential as an example, assuming that in the absence of self-operated flow control valve, the indoor temperature of 21 ° C households, using the self-flow control valve, the indoor temperature dropped to 18 ° C, saving 3 ° C heat. According to the calorific power formula: QV1 = qv * vw * (tn1-tw) and QV1 = qF1 * F QV2 = qv * vw * (tn2-tw) and QV2 = qF2 * F QV1: The amount of heat, W. QV2: Building Heat Consumption at Room Temperature 21 ° C, W. qv: Volumetric thermal index of the building, W / m3 ° C. vw: Peripheral volume of the building, m3 tn1: indoor standard temperature 18 ° C. tn2: indoor temperature exceeded 21 ° C. tw: outdoor average temperature, -8.5 ° C degrees (Changchun area). F: building area, m3. qF1: Area thermal index of the building at 18 ° C, taking 55W / m2h qF2: Area thermal index of the building at 21 ° C, W / m2h. Put the above data into the formula: qv * vw * (18 +8.5) / qv * vw * (21 + 8.5) = (4000 * 55) / 4000 * qF2 It can be concluded that the heat loss at room temperature of 21 ° C is 61.2W / m2 * h, When the heat consumption of 5.8W / m2 * h, a 4,000 square meters of residential, annual consumption of more heat: Q = 5.8 * 24 * 4000 * 170 = 94.656Mw / year equivalent to 340.76GJ / year if the heat to be 17 yuan / GJ calculation , Saving 340.76 * 17 = 5792.92 yuan / year Second, the room temperature of household saving power increased from 18 ° C to 21 ° C, the fundamental reason is that the building's circulating flow greatly exceeds the design flow. Professor Shi Zhaoyu in his book "Heating System Operation Regulation and Control," a book made it clear: "When the near-end user room temperature reaches 20 ° C or even hot window, the heat user's flow is generally more than the design flow Of the 2-3 times, when the end user even at room temperature 10 ° C are not reached, the water flow is generally not more than 0.5 times the design flow. "With normal water flow 3kg / m2h calculation, 4000 square meters of its floor Design flow should be 12 t / h, according to Professor Shi Zhao Yu's discussion, the actual flow of more than double the design flow. The general circulation of the pump head is 30-40 meters, with an average of 35 meters, the pump efficiency of 82%, a heating period of 170 days, then: more consumption per hour: G * H / (367 * 82% = 12 * 35 / (367 * 0.82) = 1.4Kw Consumption of energy per year: 1.4 * 24 * 170 = 5712 Kw If the price of 0.6 yuan / Kw calculation, the annual savings: 5712 * 0.6 = 3427.2 yuan Thermal system, there are three reasons for the loss of water: First, the leakage of the pipe network; second is due to the system is not hot water users; third is the user to steal water. The use of self-operated flow control valve for network balance can eliminate user heating caused by the user is not hot water. According to some heating enterprises before and after the balance of the pipe network found that after the pipe network to reach equilibrium, the general system of water loss can be reduced by more than 15%. Because the water replenishment system is cold water, the general water temperature at 10-15 ° C. We make up for 12 ° C, water supply temperature is 56 ° C, return water temperature is 40 ° C, heating one kilogram of cold water required heat: QL = (40 ° -12 °) * 1 = 28Kcal From the above calculation shows, Heating one kilogram of cold water is 28Kcal calories, with a daily water loss of 100 tons of units, for example, if the daily reduction of 15% of water loss, a heating period of 170 days to calculate the heat to 17 yuan / GJ, you can save : Heat: 100 * 15% * 1000 * 28 * 170 * 4.1868 * 10-6 = 298.93GJ / year Equivalent: 298.93 * 17 = 5081.8 yuan / year Water: 15 * 170 = 2550 tons / year Water fee calculated according to 4 yuan . 2550 * 4 = 10,200 yuan / year It can be seen through the above analysis, the use of self-flow control valve for pipe network balance, not only to solve the problem of hydraulic imbalance, the user's room temperature is reasonably controlled, more importantly, greatly reduced The heat wasted, saving heating costs.