A refrigerator using R-134a refrigerant as a working fluid can be modeled using the ideal vapor-compression...
Fantastic news! We've Found the answer you've been seeking!
Question:
Transcribed Image Text:
A refrigerator using R-134a refrigerant as a working fluid can be modeled using the ideal vapor-compression refrigeration cycle: a. The refrigerant starts the cycle as a saturated vapor with P = 0.18 MPa. What is the enthalpy and entropy of the working fluid at this state? b. The temperature and pressure of the working fluid after isentropic compression, T2 and P2, is 60 c and 1.40 MPa, respectively. What working fluid enthalpy at this state? c. If the mass flow rate of the refrigerant is 0.05 kg/s, what is the power input to the refrigerator compressor? d. After compression, the refrigerant undergoes an isobaric heat rejection step and the refrigerant is a saturated liquid at the end of this stage. What is the enthalpy of the working fluid at this state? e. What is the rate of heat rejection to the environment? f. The pressure of the refrigerant is returned to the original value in a throttling valve. What is the enthalpy of the working fluid after throttling? g. What is the temperature of the working fluid at this state? h. Finally, the working fluid can do its main job and take in heat from the refrigerated space. What is the rate of heat transfer during this evaporator process? i. What is the coefficient of performance for this refrigerator? j. Before it is powered on, the refrigerator contains air at 300K. After the refrigerator is powered on, what is the temperature of the refrigerated space (1 m of air) after 1 second assuming the space is insulated from the surrounding room? k. This cycle is designed to keep the refrigerated space at a cool temperature even though there actually is heat gain from the surrounding room. What is the rate of heat transfer out of the refrigerated space air at steady-state operation of the refrigeration system given the operating conditions above? A refrigerator using R-134a refrigerant as a working fluid can be modeled using the ideal vapor-compression refrigeration cycle: a. The refrigerant starts the cycle as a saturated vapor with P = 0.18 MPa. What is the enthalpy and entropy of the working fluid at this state? b. The temperature and pressure of the working fluid after isentropic compression, T2 and P2, is 60 c and 1.40 MPa, respectively. What working fluid enthalpy at this state? c. If the mass flow rate of the refrigerant is 0.05 kg/s, what is the power input to the refrigerator compressor? d. After compression, the refrigerant undergoes an isobaric heat rejection step and the refrigerant is a saturated liquid at the end of this stage. What is the enthalpy of the working fluid at this state? e. What is the rate of heat rejection to the environment? f. The pressure of the refrigerant is returned to the original value in a throttling valve. What is the enthalpy of the working fluid after throttling? g. What is the temperature of the working fluid at this state? h. Finally, the working fluid can do its main job and take in heat from the refrigerated space. What is the rate of heat transfer during this evaporator process? i. What is the coefficient of performance for this refrigerator? j. Before it is powered on, the refrigerator contains air at 300K. After the refrigerator is powered on, what is the temperature of the refrigerated space (1 m of air) after 1 second assuming the space is insulated from the surrounding room? k. This cycle is designed to keep the refrigerated space at a cool temperature even though there actually is heat gain from the surrounding room. What is the rate of heat transfer out of the refrigerated space air at steady-state operation of the refrigeration system given the operating conditions above?
Expert Answer:
Related Book For
Fundamentals Of Chemical Engineering Thermodynamics
ISBN: 9781111580704
1st Edition
Authors: Kevin D. Dahm, Donald P. Visco
Posted Date:
Students also viewed these mechanical engineering questions
-
Your company has just received an order from a good customer for a specially designed electric motor. The contract states that, starting on the 13th day from now, your firm will experience a penalty...
-
Y 0.0444 0.0481 0.0519 0.0550 0.0593 0.0637 0.0682 0.0728 0.0773 0.0819 0.0866 0.0918 0.0964 0.1011 0.1058 0.1105 0.1157 0.1201 0.1247 0.1300
-
A refrigeration unit operates on the ideal vapor compression refrigeration cycle and uses refrigerant-22 as the working fluid. The operating conditions for this unit are evaporator saturation...
-
What is the advantage of using computing to simulate an automobile crash test as opposed to actually staging a crash?
-
Regarding conditional probability: a. What is it? b. Which event is the "given event"?
-
A random sample of 100 observations results in 40 successes. a. What is the point estimate for the population proportion of successes? b. Construct 90% and 99% confidence intervals for the population...
-
On September 30, balances in Manufacturing Overhead are: Wendy Company- debit \($1,800\), Mahmoud Company-credit $3,000: Indicate how each company should re- port its balance at September 30,...
-
In the 1990s, Pfizer, Inc., developed a new antibiotic called Trovan (trovafloxacin mesylate). Tests showed that in animals Trovan had life-threatening side effects, including joint disease, abnormal...
-
Find the linearization L(x) of the function at a. f(x) = x/5, a = 32 L(x) = Question Help: Message instructor
-
The Purchases Ledger Control Accounts of Pfozer, a private company, for the month of January 2018 was prepared as shown below: Cash paid to suppliers Discount received Balance c/f Purchases Ledger...
-
Describe a facility you are familiar with in your work (or past work), its layout, efficiencies, inefficiencies, and challenges. Finally, if given the opportunity, how could you improve the...
-
Describe the best "targets" for your recruiting efforts by considering the job and organizational context. Evaluate the various methods of recruiting in terms of whether they seem more like "open" or...
-
You work as a director of leadership and learning for an organization that makes prosthetics. This year's employee engagement survey results for the organization show that some leadership practices...
-
Use the information above to prepare flexible budget for the month of July assuming 85,000 units will be sold. Assume that the company has existing capacity and will not incur any additional fixed...
-
A 78-year-old male patient presents to the ED with weakness on his left side and aphasia. The ED physician orders tests, and the patient is admitted with a cerebrovascular accident (CVA). What...
-
Problem 5. Find the limit below if it exists or show that it does not exist lim (x,y)(0,0)2+ y xy Hint: use squeeze theorem and consider the fact that 1.
-
What is the background and critical details of the client?. George is a 55-year-old male who has been struggling with paranoia. He has a history of mistrust and suspicion, often believing that others...
-
In what ways does a well-designed enterprise search software vary from popular search engines (e.g., Bing, DuckDuckGo, and Google)?
-
On a Txy plot, where does the single vapor phase exist? Select the correct answer from the choices given. A. Above the dew-point curve B. Below the dew-point curve C. Above the bubble-point curve D....
-
Explain why the integral test for thermodynamic consistency is only a necessary condition, while the direct test is a sufficient condition.
-
Estimate the mole fraction of oxygen in water at 25C and at 75C and 1 atm.
-
Gwynn & Co. is a small firm of chartered accountants in Cardiff. The audit partner has been asked to make a proposal to Alhambra Bingo Clubs (ABC), a Cardiff-based company, which wants to change from...
-
Cuzco Carpets, S.A., is the Peruvian subsidiary of the U.S. firm, Carolina Fabrics, Inc. Cuzco Carpets manufactures high-quality carpets from llama wool and sells its finished carpets to its U,S....
-
Elliott Transmitters (ET) imports and sells special telephone equipment such as portable telephones and car phones and also walkie-talkies. Its customers include chain stores, mail order companies...
Study smarter with the SolutionInn App