37 results about "Logarithmic mean temperature difference" patented technology

A temperature regulating apparatus includes a heat exchanger and regulates a temperature of a first medium by performing heat exchange between the first medium and a second medium via the heat exchanger. A regulating operation unit generates a flow rate regulating signal so that the temperature of the first medium flowing out from a primary side outlet of the heat exchanger becomes equal to a target temperature. A control valve regulates a flow rate of the second medium based on the flow rate regulating signal. A correcting operation unit (a) calculates, based on temperatures detected by first, second, third and fourth temperature sensors, a heat exchange amount of the heat exchanger, a logarithmic mean temperature difference or an average temperature in the heat exchanger, and the flow rate of the second medium, (b) calculates an overall heat transfer coefficient of the heat exchanger based on the calculated heat exchange amount and the calculated logarithmic mean temperature difference or the calculated average temperature, and the flow rate of the second medium, (c) obtains a ratio (ΔG) of a change (Q2-Q′2) in the heat exchange amount to a change (ΔF2) in the flow rate of the second medium based on the calculated flow rate (F2) of the second medium and the calculated overall heat transfer coefficient (K), and (d) corrects a gain of the regulating operation unit based on the obtained ratio.

The invention provides an ocean thermal energy conversion method and an ocean thermal energy conversion device. The method comprises the following steps of: heating a low-boiling-point working medium by using hot seawater on a surface of ocean; evaporating the low-boiling-point working medium; feeding into a turbine to push a turbo generator set to work for power generation; condensing working medium gas which is exhausted from the turbine into liquid by using cold seawater on a deep layer of the ocean; heating by using the hot seawater; feeding into the turbine to make the working medium gasevaporated; pushing the turbo generator set to work for the power generation; cyclically executing the steps; and continuously carrying out power generation. Power is generated by using ocean surfacewind power, a heat pump device is driven by the power, the temperature of the working medium is further raised by using a medium of the heat pump device, and the volume expansion ratio of the workingmedium is improved; and the temperature of the cold seawater is further reduced by using the medium of the heat pump device, the working medium exhausted gas is condensed by using the low-temperatureseawater, and a condensing effect of the working medium exhausted gas is improved. The method and the device improve the efficiency of closed cycle generation of ocean thermal energy conversion, realize the comprehensive utilization of ocean thermal energy and wind energy, have an important practical value, provide environment-friendly energy sources, and are easy to use and promote in large scale.

The invention relates to a high-enthalpy heat island lead large on-way temperature difference and small heat transmission temperature difference back heating type air disinfector which comprises a high-enthalpy heat island and at least one atmospheric heat exchanger, wherein the atmospheric heat exchanger is connected with the high-enthalpy heat island, the outer end head of the atmospheric heat exchanger comprises an air inlet and an air outlet, the inner end head of the atmospheric heat exchanger comprises a low-temperature side air outlet and a high-temperature side air inlet, the air inlet at the outer end head is communicated with the low-temperature side air outlet of the atmospheric heat exchanger, the air outlet at the outer end head is communicated with the high-temperature side air inlet of the atmospheric heat exchanger, and the high-enthalpy heat island is positioned between the low-temperature side air outlet and the high-temperature side air inlet of the atmospheric heat exchanger. According to the invention, the high-enthalpy heat island lead is adopted, large on-way temperature difference and small heat transmission temperature difference are built inside the atmospheric heat exchanger, high-temperature air heat quantity after disinfection can be recycled, and the technical problems of incomplete disinfection, medicine residue, toxic and side effects and the like in conventional air disinfecting technology can be solved.

The invention provides a tunnel-typed residual-heat recovery semiconductor temperature difference generation method and a device. The generation method is characterized in that a movable heat source which emits residual heat runs pass a tunnel-typed heat collector which receives the heat emitted by the movable heat source and transmits the collected heat to a heat surface of a semiconductor temperature difference generation module; a radiator is arranged at one side of a cooling surface of the semiconductor temperature difference generation module; the cooling surface is cooled to a temperature much lower than that of the heat surface by the radiator, thus generating a large temperature difference at two end surfaces of the semiconductor temperature difference generation module; the semiconductor temperature difference generation module directly converts the temperature difference into the electric potential difference which is used as a power supply after being converted by a stabilizer circuit and AC / DC. The device of the invention comprises the semiconductor temperature difference generation module, the tunnel-typed heat collector, and a radiator; the method and the device of the invention have the advantages that the recovered residual heat energy can be directly converted into electric power, the generation process has no noise, no abrasion and no medium leakage, furthermore, the generator has the small volume, light weight, convenient movement, maintenance-free and long service life, etc.

The invention discloses a device and a working method for switching the operation of a heat exchanger and a circulating pump in a heat exchange station. Electric regulating valve of primary water inlet pipe, water temperature sensor of secondary water outlet pipe of heat exchanger, check valve, frequency conversion speed controller of circulating pump, water temperature sensor of water separator, water temperature sensor of water collector, differential pressure sensor of water collector and heat exchanger Solenoid valve of the secondary return pipe; the logarithmic average temperature difference is introduced to quantitatively describe the heat exchange capacity of the heat exchanger, and the logarithmic average temperature difference of the heat exchanger is also used as a criterion when adding or subtracting heat exchangers; the electric control valve opening, cycle Pump frequency, water supply temperature, pressure difference and the time for maintaining these parameters are used as criteria to provide equipment operation switching for heat exchangers and circulation pumps in two typical structures of heat exchange stations: "first in series and then in parallel" and "first in parallel and then in series". The working method can effectively improve the heat supply adjustment range of the heat exchange station.