Phân tích nhiệt động của một số loại môi chất lạnh dùng trong tủ lạnh và kho lạnh công nghiệp=Thermodynamic Analysis Of Some Refrigerants Used In Refrigerator and Industrial Refrigeration

0 Người đánh giá. Xếp hạng trung bình 0

Tác giả: Thành Niên Lê

Ngôn ngữ: vie

Ký hiệu phân loại:

Thông tin xuất bản: Khoa học Giáo dục KT, 2024

Mô tả vật lý: tr.20-28

Bộ sưu tập: Metadata

ID: 251336

Thêm vào giỏ

Exergy analysis is a powerful tool in the design, optimization and performance evaluation of energy systems. In this paper, the author analyzes the thermodynamics of single-stage refrigeration systems that compress the refrigerant R22, R717, R404A, R507A, R1234yf, R134a, R600a by parameters: Compressor ejector temperature T2 [K], volume specific refrigeration capacity qv [kJ/m3] , cooling coefficient COP, exergy efficiency COPex, cycle completion η[%], exergy loss Exd,total [kW] at condensing temperature Tk = 315[K], evaporating temperature T0 = 268[K], 265[K], 258[K], 253[K], 248[K], 243[K], 238[K]. Thereby, the author found that in the negative temperature refrigeration systems with small capacity such as refrigerators and ice cream cabinets, the refrigerant R600a results in cooling coefficient COP, exergy efficiency, specific volume refrigeration capacity, cycle completion is greater than R134a and is the highest among refrigerants in use today. In industrial refrigeration systems, refrigerant R22 has a lower end temperature of compression than NH3, so it may not be necessary to have an additional compressor cooling system, the COP is almost the same, loss exergy NH3 is too large even though the exergy performance is almost the same. In terms of environmental impact, NH3 refrigerant is still the preferred choice compared to R22.Phân tích exergy là công cụ mạnh mẽ trong thiết kế, tối ưu hóa và đánh giá hiệu suất của hệ thống năng lượng. Trong bài báo này, tác giả phân tích nhiệt động của các hệ thống lạnh một cấp nén môi chất R22, R717, R404A, R507A, R1234yf, R134a, R600a bằng các thông số: Nhiệt độ đầu đẩy máy nén T2 [K], năng suất lạnh riêng thể tích qv [kJ/m3] , hệ số làm lạnh COP, hiệu suất exergy COPex, độ hoàn thiện chu trình η[%], tổn thất exergy Exd,total [kW] tại nhiệt độ ngưng tụ Tk = 315[K], nhiệt độ bay hơi T0 = 268[K], 265[K], 258[K], 253[K], 248[K], 243[K], 238[K]. Qua đó, tác giả nhận thấy rằng trong các hệ thống lạnh nhiệt độ âm có công suất nhỏ như tủ lạnh, tủ kem thì môi chất R600a vì cho kết quả hệ số làm lạnh COP, hiệu suất exergy, năng suất lạnh thể tích riêng, độ hoàn thiện chu trình lớn hơn R134a và cao nhất trong các loại môi chất lạnh được sự dụng hiện nay. Trong các hệ thống kho lạnh công nghiệp thì môi chất R22 có nhiệt độ cuối tầm nén thấp hơn NH3 dẫn đến có thể không bắt buộc có thêm hệ thống làm mát đầu đẩy máy nén, hệ số làm lạnh COP gần giống nhau, tổn thất exergy NH3 quá lớn dù hiệu suất exergy gần giống nhau. Nếu xét về mặt ảnh hưởng tới môi trường thì môi chất lạnh NH3 vẫn là ưu tiên lựa chọn so với R22.

1. Đọc trực tuyến

1. Đọc trực tuyến

Tạo bộ sưu tập với mã QR