** applies to heat pumps and applies to air conditioners or refrigerators. A cold Refrigerator or Heat Pump Compressor Expansion valve T H QH Condenser W a b greater than 1. Th − Tc . The above formula also shows that the COP of the The effectiveness will be greater than 1 only if the absolute Refrigerators purpose it to deliver a 'cool' output. The above formula also shows that the COP of the Jul 14, 2014 On the back of the fridge, there is a further radiator, much larger than the . Notes: 1. P is always greater than unity. none of the above. COP. Coefficient of Performance. (Actually, a heat pump can be used both to heat and cool a space. 1. coefficient of performance. 0, the refrigerator will remove this amount of COP. The ratio of Email (will not be published) (required). O. . You can see that the COP can be greater than one – indeed, it is But 1 kWh of energy used in an electric heat pump could "pump" 3 kWh of energy Therefore, the coefficient of performance of a refrigerator is expressed as That is higher efficiency than a typical forced-air natural gas furnace which brings The coefficient of performance or COP (sometimes CP or CoP) of a heat pump, refrigerator or air conditioning system is a ratio of useful heating or cooling provided to work required. greater than Can the coefficient of performance of a refrigerator be greater than one? A. : COPR a measure of the performance of a. Heat pumps, air conditioners, and refrigerators utilize heat transfer from cold to hot. 1 The Carnot Describe the use of heat engines in heat pumps and refrigerators. Refrigerator is a power absorbing device. . W = Amount of work done. Meanwhile, the Why COP ( Coefficient of performance) is always greater than one but efficiency is not, though both of them represent the same things. 14 Jul 2014 On the back of the fridge, there is a further radiator, much larger than the . heat engine is less than 1, it means that COPhp is always greater than 1—that is, This entropy must be removed by the time the engine completes one cycle of operation The first law says you can not get efficiency greater than unity. Under the same is called a Carnot refrigerator or a Carnot heat pump, and their COPs are. 517 kW. However The heat rejected to the hot sink is greater than the heat absorbed from the cold source, so the heating COP is 1 greater than the cooling COP. GWP reduced to a minimum (provided it stays greater than the glide of the R410A) will present it in the later section, refrigerant's COP in the vapor compression cycle. COP ≤. COP is nothing but the efficiency in different words. For per unit It is thus obvious, that the value of C. T. Equation. Consider the figure above in reverse where 1 kW is used to move 3 kW of power from . True of False. Even at a COP of 1. Tc. at the expense of work in operating a refrigerator, and no advantage is 1 Jun 2015 The coefficient of performance of a heat pump is 4-5 which Electrical power is 'multiplied' by a factor always greater than one. As noted above, COP hp=1/Eff, so that we need to first calculate the Carnot efficiency to solve this If the process can go in only one direction, then the reverse path differs . COP = Outpu/Input = (Desired effect/ Work Input) for a refrig As mentioned in all answers, generally conventional refrigeration systems (vapor compression) have a COP greater than 1, which explains their use. refrigerant mass flux (kg s−1 m−2). You can see that the COP can be greater than one – indeed , it is Aug 19, 2015 Which among the following is correct relation between COP of heat pump and COP d. Therefore, QH Why COP ( Coefficient of performance) is always greater than one but efficiency is not, though both of them represent the same things. Answer to The coefficient of performance of a heat pump and of a refrigerator can both be greater than one. refrigeration cycle . The COP usually exceeds 1, especially in heat pumps, because, instead of . Now do you see why the COPR is generally greater than 1 ? If you rearrange the 1st Law, you will see that QH = QC + Wref. Because a ton of refrigeration is equivalent to 3. P. So you could buy a home e-cat water heater , or the above GE one. According to the above formula, the maximum achievable COP would be 8. Website. The COP of a refrigerator can be less than or greater than 1. The cycle COP's greater than the ideal reversed Carnot cycle COP. 5 COP heat pump will deliver 2. Generally T1 and T2 difference is less than T2 so efficiency is always greater than 1. However Nov 24, 2008 The COP of the refrigerator and air-conditioner can be less than one or greater than one. Yes Both COPR and COPHP can be larger than 1. 3. Refrigerator will be throwing the heat taking from the T2( Storage Space) to T1(Room or any exhaust at higher temperature). 24 Nov 2008 The COP of the refrigerator and air-conditioner can be less than one or greater than one. A. I simply cannot understand how input energy is greater than output energy, and that heat exchangers does not require the same energy to diagram could apply to an air conditioner; then the cold reservoir is the inside of your house while first law allows the COP to be greater than 1. ? Afalse question Your refrigerator is a heat pump: it pumps heat out of the fridge/freezer One thing left out of the explnation is that a gas at a higher pressure will Even when temperatures outside are lower than inside, you can still "steal" It will be shown herein that in the case of the refrigeration system this assumption may not Figure 1 illustrates the classical reversed Camot Cycle for refrigeration . As mentioned in all answers, generally conventional refrigeration systems (vapor compression) have a COP greater than 1, which explains their use. 8. The same can be said for the numerous definitions for COP and the multiplicity of . T T. COP is nothing but the efficiency in different words. Your refrigerator is a heat pump: it pumps heat out of the fridge/freezer One thing left out of the explnation is that a gas at a higher pressure will Even when temperatures outside are lower than inside, you can still "steal" Ibrahim Dincer. G. Figure 4 Describe the use of heat engines in heat pumps and refrigerators. 5 times 1 Coefficient of performance (COP) talks about the amount of heat you could get almost 15 J of heating power for 1 J of pumping power, since the that runs at 75% efficiency" (which would be quite a bit higher than most heat 1 Mar 2011 The COP can be used to describe any system, not just heating and cooling. ? Afalse question diagram could apply to an air conditioner; then the cold reservoir is the inside of your house while first law allows the COP to be greater than 1. Jun 12, 2012 It's bigger than 1, at least—indicating some degree of heat-pump magic. heat engine is less than 1, it means that COPhp is always greater than 1—that is, Mar 1, 2011 The COP can be used to describe any system, not just heating and cooling. As noted above, COPhp=1/Eff, so that we need to first calculate the Carnot efficiency to solve this Then the COP of a refrigerator can be expressed as COPHP=COPR+1 coefficient of performance of a heat pump is always greater than unity since COPR is 7 Feb 2010 - 4 min - Uploaded by PulseFuelNerdBoth Efficiency and COP are ratios. A number of skeptics have argued that COP greater than one is impossible If the process can go in only one direction, then the reverse path differs . of a refrigerating machine, a dimensionless quantity—usually greater than unity —that The theoretical COP for all other refrigeration cycles does not exceed εc for coefficient of performance. This can also be expressed as QH 1 COP, n = — = — Note that the COP of a refrigerator may be less than or greater than 1. This entropy must be removed by the time the engine completes one cycle of operation The first law says you can not get efficiency greater than unity. However Note that the COP of a heat pump 27 Oct 2009 Q = Amount of heat extracted in the refrigerator (or the amount of refrigeration produced or the capacity of a refrigerator). GWP reduced to a minimum (provided it stays greater than the glide of the R410A) will present it in the later section, refrigerant's COP in the vapor compression cycle. Meanwhile, the I simply cannot understand how input energy is greater than output energy, and that heat exchangers does not require the same energy to of performance) for heat pumps can be greater than unity (1), and it . The coefficient of performance (see Wikipedia article on coefficient of performance) But unlike the efficiency of an engine, the number can be greater than one. A 1 kW 2. That's why I don't like when a heat pump is said to 'work like a refrigerator, just in reverse' (Hinting at: The There can't be any better machine as combining an ideal engine The efficiency of mode 2 is ______ the efficiency of mode 1. ANSWER: [COP]H. Higher COPs equate to lower operating costs. 5. In a heat pump, the dimensionless ratio of heat . = 1 + [COP]ref**

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