Research on Matching of Refrigeration System of Small Ice Machine (Part 1)
In recent years, with the diversification of national consumption concepts, the production of gas-liquid separators, evaporators and demand for ice machines has increased year by year. This paper takes the trial production development process of Shanghai Tianfeng TF-ZBJ-23 ice machine as an example, and performs matching calculation and research on its refrigeration system to achieve the optimal design effect. 1 Overview of the refrigeration system The prototype of this machine is a model designed only by matching test. In the early stage of trial production, the cooling effect is poor, the daily ice volume is insufficient, and there are design defects. The overview of its refrigeration system is: the use of a closed compressor; corrugated fin condenser; capillary pressure reduction and throttling; small square ice ice tank evaporator: heating solenoid valve to assist de-icing. 2 Determination of cooling capacity (1) Basic parameters Ambient temperature: 20 ℃; Inlet water temperature: 15 ℃; De-icing temperature: 18oC; Water c = 4.20kJ / (kg · K); Latent heat of water: 335kJ / kg; Ice c = (2) Calculation process The ice consumption of the ice machine is composed of the following parts: E4186 (twl-0) + 335 + 2.26 (0-tb) / 23, Q3 = Ⅳ × fallen, Q4 = 900xFxlIxQlX, In the formula: G is the ice making capacity of the equipment for 24h (k; g is the mass of each ice cube (kg); tw. Is the initial temperature of water (℃); t is the final temperature of ice (℃); Ⅳ is the water pump The actual power (w); F is the surface area of ​​each piece of ice (m2): Z is the thickness (m) that needs to be melted to release the ice cube; T de-icing is the time when de-icing within 1 cycle (min), take 2min; The ice machine's cooling consumption is in Q. Accounts for most of the; Q, can be read directly from the nameplate of the pump used; for spray evaporators, Q in (900xFx Consider their impact. That is, the actual cooling consumption is Q = (Ql + Q2 + 《× 厼 ， (0-18) / 2. 3 Matching of compressor (1) Basic parameters of ice machine: ambient temperature: 20 ℃; inlet water temperature: 15 ℃; de-ice temperature: 18 ℃; water c = 4.20kJ / (kg · K); latent heat of water: 335kJ / kg; Ice c = 2.26kJ / (kg · K). Jewelry Display Rack,Wood Jewelry Display Display Stand,Jewelry Display Window,Jewelry Display Rack For Retail Dongguan Display Leader Co., Ltd , https://www.displayonestop.com
In view of the current roughness of the design of the ice machine refrigeration system, according to the refrigeration characteristics of the small ice machine, the selection ideas of each refrigeration device are analyzed, and the matching calculation method is emphatically described to provide the optimal design of the ice machine refrigeration system. reference.
2.26kJ / (kg.K).
Q-the cooling consumption of water cooling, freezing and ice cooling to minus zero; the cooling consumption of the Q factory cooling the ice mold, refrigerant and pipeline; the cooling consumption of the water pump motor of the Q factory; p_ thaw Cooling consumption; Q factory cooling air, water leakage loss, etc.
So the total cooling consumption is ∑Q = Q + Qz + Q, + Q + Qs.
Part of the total cooling consumption can be calculated according to the following formulas:
1 total 1 total
llg / sXQ) is approximately equal to 0.2Q. Q and Q are difficult to calculate accurate values. In addition, the cooling bridge adds cooling, and the method of taking the safety factor J, 7 can be used to synthesize
The safety factor is often taken as 1.2.
For the ZBJ18P ice maker, the ice making capacity is 18k and the water pump power is 60w. The cooling consumption per unit time is about [-1000x18 / 24 / 3600x [(15-0) x4.22 + 335 + (0-18) x2.26 / 2] x (1 + 0.2x2 / 28) + 60x26 / 28] xI. 2 = 162.6W.
When de-icing, the temperature on the side of the ice wall is -18 ° C, and the temperature on the side of the ice tank is close to zero degrees, so the average value when considering the temperature drop of ice is
The evaporating temperature of the compressor: a 2O ℃; condensing temperature: 40 ℃.
Through the look-up table interpolation method, the cooling capacity input power, current, COP, mass flow rate of each type of compressor can be obtained.
(2) Calculation process The calculation principle is to calculate the actual cooling capacity of the ice machine, and at the same time find out the calibrated cooling capacity of the compressor, and then compare the two sizes.
â‘ Calculate the cooling consumption of the corresponding model according to the calculation method of the cooling consumption of the ice maker: For the ZBJ18P ice maker, the compressor model is Electrolux L45TN, and the previous calculation shows that the cooling consumption per unit time is 162. 6W;
②According to the table, the cooling capacity of IA5TN is 157W when the condensation temperature is 40 ℃ and the evaporation temperature is 20 ℃;
â‘¢ It can be seen from comparison that the IA5TN compressor basically meets the requirement of 18kg / a ice-making cooling capacity.