The nao la tiet kiem va tiet kiem dien

Khai niem “ tiet kiem ” nen duoc hieu theo nghia rong hon, khong nen nghi mot cach don gian “tiet kiem” la phai giam tien trong hoa don dien. Tiet kiem cho gia dinh hay quoc gia, do cung la tiet kiem. Giam dong dien lang phi la giam duoc chi phi dau tu ban dau, hoac tang do ben cho he thong...

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Gui toi: Ban Khoa hoc
Tieu de: The nao la "tiet kiem" va "tiet kiem dien"

Doi voi dien dan dung, can phan biet ro cac khai niem: Thiet bi tieu thu it dien, Thiet bi ho tro viec tiet kiem dien (ten do toi dat) va Thiet bi tiet kiem dien (tam goi).

a. Thiet bi tieu thu it dien: Khai niem nay thi moi nguoi deu de hieu, thi du nhu: bong compact, chan luu dien tu, man hinh LCD…

b. Thiet bi ho tro viec tiet kiem dien co the duoc hieu nhu sau: nhung thiet bi cung chuc nang nhung lam viec o nhung vi tri khac nhau nen can nhung che do van hanh khac nhau, va dam nhan chuc nang van hanh do la do mot thiet bi gan kem. Thi du chiec may lanh lam viec o phong mo hoac phong hoi suc, no cu “thay” nhiet do moi truong tang qua muc cai dat thi no phai chay che do lam mat va khi ha du nhiet do can thiet, no chi chay che do quat de luu thong khong khi va luon luon nhu the (o che do quat, duong nhien muc tieu thu dien la it hon). Nhung chiec may do khi lap dat o nha dan, mot so nguoi nghi rang, chi can no chay khi troi nong, con ve dem khuya khi moi nguoi da ngu say, nhiet do ben ngoai giam thi chang can lam lanh nua (hoac chi thinh thoang lam lanh chut xiu thoi), ma chi can quat la du. Vay la nguoi ta che ra mot bo dieu khien, cai dat va cu den gio do la no lam chuc nang nhu the va co nguoi da dat cho no ten goi la bo “Thiet bi tiet kiem dien thong minh dung cho may lanh”, va quang cao la co the tiet kiem len den den 50% (?). (Da tat may ma con goi la tiet kiem dien?!).

Nhung thiet bi nhu the som muon cung bi dao thai vi khong ai co may lanh ma muon ngu nong ca (ai bao dam rang, sau 24h vao mua he, nhiet do trong phong kin la khong den 26-27 do C?). Quy vi nao co may moi, xin dung lap them vao vi no can thiep den bo xu ly dieu khien cua may, chang ai bao hanh cho san pham do ca. Neu muon mot che do nhu vay, quy vi co the lam theo cach thu 2: hen gio tat cua may lanh (may nao chang co), mua mot bo hen gio mo danh cho quat may, the la xong.

c. Thiet bi tiet kiem dien: No cung la mot thiet bi gan kem nhung co chuc nang khac b. Phan lon cac dong co dan dung (co trong may giat, may lanh, quat dien…) hien nay deu bi buoc chay o che do dien ap (dao dong nho) va tan so co dinh (220V/50Hz), trong khi tai luon thay doi, dan den ton that dien nang trong dong co. Dieu do khien nhieu nguoi nghien cuu thiet bi co the cai thien duoc tinh trang nay va thuc te la lam duoc (thong qua DSP va IGBT). Toi du doan chi khoang vai nam nua se co dai tra nhung chiec tu lanh, may lanh, may giat, tham chi quat dien cung se duoc tich hop cum nay. Nhung con nhieu thiet bi da san xuat truoc day thi sao, day la mot van de kho giai quyet triet de vi moi dong co deu phai gan mot bo dieu khien va doi khi gia mot bo nhu vay hien nay con dat hon ca thiet bi (vi du nhu chiec quat dien).

Khai niem “tiet kiem” nen duoc hieu theo nghia rong hon, khong nen nghi mot cach don gian “tiet kiem” la phai giam tien trong hoa don dien (du do la tieu chi quan trong). Tiet kiem cho gia dinh hay quoc gia, do cung la tiet kiem. Giam dong dien lang phi la giam duoc chi phi dau tu ban dau (do giam tiet dien day dan, cac thiet bi dong cat can tri so vua phai…), hoac tang do ben cho he thong (neu da co san)… Trong vi du 1 (noi ve on ap nha toi), thuc ra toi dau co tiet kiem gi, chang qua la do lap them on ap de dien ap nha toi ve dung dien ap can thiet (220V). Con ly do tai sao dien qua ap lon vay thi trong nhieu ly do, co mot ly do quan trong do la do nganh chuc nang du kien su gia tang phu tai, cong them cong suat phan khang… gay sut ap (cac may bien ap ha the ghi kVA chu dau co ghi kW), nha toi co 238V thi nha cuoi nguon may lam moi la 220V.

Dien luc chi tinh dien tren cong suat tieu thu (kW), nhung trong don gia do la tong cong cua nhieu khoan, de mang cho nguoi tieu dung 1 kW dien, Dien luc phai san xuat it nhat 1,12 kVA tuc don gia do tuong ung 1,12kVA (hao hut den nay duoc tinh la 12%, toi khong tin so lieu nay, cho do la “con so thanh tich” nhung tam chap nhan). Vay, neu moi thiet bi deu giam dong lang phi + dien luc nang cap he thong giam cac that thoat khac, tuc de dung 1kW dien, chi can mot cong suat 1,08kVA (Thai Lan chi can 1,05KVA) thi ro rang don gia dien se giam.

Theo so lieu tu EVN (http://www.evn.com.vn/) san luong dien cung cap cho Quan ly -tieu dung dan cu chiem 42,16% tong san luong dien quoc gia. Vay ma viec quan ly cong suat phan khang cua doi tuong khach hang nay khong duoc quan tam hay noi ro hon, no duoc tha long hoan toan.

Dieu khien dong co dien voi bien tan, thong qua DSP (bo xu ly tin hieu) va cac IGBT, nom na la bien doi dong dien xoay chieu hinh sin o tan so 50Hz thanh dong xoay chieu co tan so khac. Tuy theo muc do tai, DSP co the thuc hien viec dieu khien: tan so, dien ap, dong dien, goc pha de dam bao toc do quay va Momen quay cua dong co han che nhung ton that khi dong co lam viec o che do khong tai hoac non tai. Day la mot trong nhung ung dung quan trong cua mach bien tan va la mot trong nhung cong nghe duoc danh gia cao ve tinh hieu qua trong thap ky qua. Cong nghe nay duoc danh gia la “mot trong nhung cong nghe lam thay doi bo mat cua he thong do luong va dieu khien” cua the gioi. Mot so hang san xuat nhu Lenze, Toshiba, Mithsubishi, Nord Reducteur, GE Power Control, Schneider, Siemens, Ranfos, Erotherm, Vitesse variable, Rockwell Automation, Alstontenze, Le Roy Somer, Hitachi, GE Power Control, Fuji, Hitachi... thi co the tin tuong. Nhung hang khac, ke ca Viet Nam cung nen xem xet lai tru khi nhap linh kien tu nhung nguon uy tin ve lap rap. Tuy nhien, theo toi biet, gia nhung thiet bi nay chua duoc re trong khi moi dong co phai can mot bo, va khong phai dong co cua thiet bi nao cung ap dung duoc, nhat la trong cac day chuyen san xuat tu dong thi muc do ap dung lai con han che hon.

Thuc te, khi co “hang that” thi tuc co “hang gia”, khi co hang “chat luong cao” tuc co hang “chat luong thap”. Toi duoc biet co su viec truyen hinh va bao chi cung da len tieng. Va khi moi chuyen chua to tuong, thi doi khi chinh anh hang that, hang chat luong cao lai bi va lay vi ban chang ai mua (nguoi ta cu xem nhu lua). Toi chua thay thiet bi nay nhung thu phan tich (tu bai bao tren).

Thiet bi nay xuat hien khi du luan dang nong ve van de tang gia dien, nguoi mua mat binh tinh khi di mua, nguoi mua khong hoac it hieu biet ve dien, long tham cua con nguoi (no tiet kiem dien hay an cap dien thi deu mua !?). Do do, nguoi mua mo mat va khi nhin thay chiec dong ho chay cham lai thi nguoi mua xem nhu da bi chinh phuc. Van de nguoi mua thay ro rang dong ho chay cham lai khi nguoi ban cam them cuc Tiet kiem dien thi sao? Do nguoi mua da khong hieu ve dien lai them nhung yeu to tam ly tac dong nen nguoi mua khong the phan biet duoc do la cai dong ho gi. Thuc ra, nguoi ban da dung mot dong ho (cong to) dien nhung la loai “dong ho vo cong” (don vi do la kVARh), chu khong phai dung “dong ho huu cong” (don vi do la kWh) de bieu dien cho khach hang. Loai dong ho nay thuong duoc lap o cac nha may de nganh dien theo doi cong suat phan khang de co bien phap xu ly, xu phat khach hang mua dien. Loai dong ho nay binh thuong khong chay khi tai thuan tro (nhu bong den soi dot), nhung lai chay khi dung mot bo den huynh quang chan luu sat tu. Do do, khi lap them mot tu dien duoc nguy trang trong mot hop kin thi dong ho chay cham lai do da giam di phan nao cong suat phan khang. Vay thi no van tiet kiem day chu, nhung la tiet kiem cho nganh dien, cho quoc gia va vay thi loi do nguoi mua khong hieu biet hay loi do nguoi ban khong huong dan day? Va yeu to “lua” nen xem xet o goc do nao?
Va xin hoi quy vi, neu goi do la “thiet bi tiet kiem dien cho quoc gia” thi quy vi nghi sao?