A solar tower power plant with an electric power output Pel of 40 MW and an electrical efficiency ηel of 20% uses an SHS with a thermal capacity sufficient for the plant operation duration τ = 5 h a day.

Refrigeration and Air Conditioning Technology (MindTap Course List)

8th Edition

ISBN:9781305578296

Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Publisher:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Chapter44: Geothermal Heat Pumps

Section: Chapter Questions

Problem 7RQ

See similar textbooks

Similar questions

A CSP supercritical steam power plant using a concentrating collector arrayfor DSG (refer to Figure 8.12) is operating under the following conditions:• Plant electric power output Pel = 28 MW• Intensity of beam solar radiation incident on the concentrator apertureIbc = 798 W/m2• Aperture area of a single concentrator module Aap = 420 m2• Efficiency of the collector ηc = 0.7• Power plant thermal efficiency ηth = 0.39• Efficiency of the electric generator ηg = 0.97• HTF is water/steam• Superheated steam condition at the absorber outlet/turbine inlet:ps = 250 bars, ts = 600°C• Feedwater temperature at the absorber inlet = tw = 280°C Calculate (i) the power plant overall (electrical) efficiency, (ii) the thermal capacity of the power plant, (iii) the rate of useful heat output of aDSG collector module, (iv) the number of concentrator modules, and (v) the steam generation rate of the solar collector.
Steam enters the condenser of a steam power plant at a flow rate of 18000 kg/h, a degree of dryness of 0.86 and a pressure of 15 kPa, leaving the condenser as a saturated liquid at the same pressure.A nearby river water is used for the cooling of the condenser.Calculate the water flow rate of the cooler if the water of the river can be heated up to 10°C in order to avoid thermal pollution. (Cp,su=4,18 kj/kgK) (Note: the potential energy change is negligible.)
An ice plant produces 10 tons of ice per day at 0°C using water at room temperature of 33°C. Estimate the power rating (Electrical Power consumed by the motor to run compressor) of the compressor-motor, if the C.O.P. of the plant is 3.0 and overall electro-mechanical efficiency (η) is 91%. Note: Latent heat of ice is 335 kJ/kg, Cp = 4.18 kJ/kg.K.
Gases after combustion are discharged from a flue in a facility to the atmosphere at a temperature of 250 °C and a flow rate of 25000 m3/h. It is desired to benefit from the heat of this waste gas in heating. There is a site with 40 residences, each with a heating load of approximately 8 kW, located 3 km from the facility.1- Determine the substation capacity to be used, taking into account the hot water requirement for each house on the site.2- Determine the substation inlet/outlet temperature and the heat exchanger water inlet/outlet temperatures. The temperature of the water leaving the heat exchanger is required not to exceed 95 ° C. The pipeline between the facility and the site is underground pipeline. Determine the required data by considering the region where the facility is located, calculate the heat losses in the line and find the required insulation thickness.3- Calculate the total capacity including losses and determine the required exchanger dimensions. insulation…
Gases after combustion are discharged from a flue in a facility to the atmosphere at a temperature of 250 °C and a flow rate of 25000 m3/h. It is desired to benefit from the heat of this waste gas in heating. There is a site with 40 residences, each with a heating load of approximately 8 kW, located 3 km from the facility.1- Determine the substation capacity to be used, taking into account the hot water requirement for each house on the site.2- Determine the substation inlet/outlet temperature and the heat exchanger water inlet/outlet temperatures. The temperature of the water leaving the heat exchanger is required not to exceed 95 ° C. The pipeline between the facility and the site is underground pipeline. Determine the required data by considering the region where the facility is located, calculate the heat losses in the line and find the required insulation thickness.3- Calculate the total capacity including losses and determine the required exchanger dimensions.
In a cyclic comprising of air compressor and expansion, workdone by a prism during the compression stroke is 9.2KJ and the heat rejected to the surrounding is 50KJ. During the expansion stroke workdone by air on the prism is 8.4KJ. a) Determine the quality of heat transferred to or from the system. Tullow oil has discovered a large volume of crude deposit at Cape-3-Point along the western coast of Ghana after years of intensive exploration. In the Company’s bid to start exploration, Green Ghana an environmental protection NGO took Tullow to court to prevent the Company from embarking on the said project citing numerous environmental concerns. b) As an energy and sustainability expert, what do you think are the side effects of the project and their remedies? A cooling water pump is operating at a speed of 1800rpm. Its flow rate is 1800L/minutes at a head of 14.4m and the power of the pump is 45kw. c) Determine the power required if the pump speed is increased…
A 75-kW refrigeration load is to be carried by an air refrigerating system with a discharge pressure of 1,370 kPa and a refrigerator pressure of 345 kPa. Compression and expansion processes are polytropic with n = 1.37. The pressure at the start of expansion is 1344 kPa and the temperature is 32OC. Air temperature leaving the refrigerator is 0OC and entering the compressor is 5OC. Clearance for both compressor and expander is 5%. Draw the (a) Schematic diagram, (b) the P-V diagram and (c) the T-S diagram. Determine (d) the piston displacement of the compressor, (e) the piston displacement of the expander, (f) the net work and (g) the COP
A vapor compression refrigeration system is designed to have a capacity of 150 tons of refrigeration. It produces chilled water from 22°C to 2°C. Its actual coefficient of performance is 5.86 and 35% of the power supplied to the compressor is lost in the form of friction and cylinder cooling losses. Determine the condenser cooling water required for a temperature rise of 10°C.
A reversed heat engine absorbs 250 kJ of heat from a low temperature region and has a mechanical input of 100kJ. What would be the heat transferred to the high temperatur region? Also evaluate the coefficient of performance of the reversed engine when working a refrigerator and as a heat pump.
A boiler plant incorporates and economizer and air preheater and generates steam at 40 bar and 300oC with fuel heating value of 33000 kg/hr. The temperature of feedwater is raised from 40oC to 125oC in the economizer and the flue gases are cooled at the same time from 395oC to 225oC. The flue gas then enters the air preheater at a pressure of 1.2 bar and 16oC with a pressure rise across the fan of 18 mm of water. The power input to the fan is 5 kW and it has mechanical efficiency of 78%. Neglecting heat losses and assuming the flue gases as ideal gas with constant specific heat of Cp = 1.01 kJ/kg-K, calculate: (a) the mass flow rate of the air, (b) the temperature of flue gases leaving the plant, (c) the mass flow rate of the steam, and (d) the efficiency of the boiler.
The winter air conditioning system has a preheat coil, an air washer, and a reheat coil as processing units. It supplies air at 38°C db-temperature to a space maintained at 21°C db-temperature and 13°C wb-temperature. The sensible and latent heat loads on the space are 50 kW and 25 kW, respectively. Of the return air from the space, 40% by dry air mass is discharged to the ambient and replaced with fresh outdoor air at 2°C db-temperature and 95% relative humidity. In the preheater, the air is heated to a db-temperature of 21°C. Assume that the water added in the air washer is at the wb-temperature of the air entering it. The pressure is constant at 95 kPa. Determine:The mass flow rate of supply air in kg/s.The rate of heat input in the preheat coil in kW.The mass flow rate of water sprayed in the air washer in kg/s.
An air-conditioning absorption system has an evaporator capacity of 350 kW with a COP of 0.90 operating at a temperature of 25 C with a condensing temperature of 35 C. The same cooling tower was used to reject the heat from the condenser and the absorber operating 45 C & providing 1 kg/s of water plus lithium bromide solution to the generator. Consider the heat rejection ratio of condenser to evaporator is 1.05, Determine the following: 1. Heat given by the generator & the size of condenser in kW 2. Leaving condenser & evaporator enthalpies & the mass of refrigerant water flowing from the generator to the condenser then to the evaporator & to the absorber (using evaporator heat balance). 3. Weight of lithium bromide in kg/s, concentration in percent & enthalpy from the absorber to the generator in kJ/kg 4. Enthalpy from the generator to condenser in kJ/kg (using condenser heat balance) & concentration in percent & enthalpy from generator to absorber…