Solar energy heat gain estimation and control method for heat pump and solar water heater combined system

Abstract

The invention relates to a solar energy heat gain estimation and control method for a heat pump and solar water heater combined system. The method is characterized by comprising the steps that a functional expression of the temperature rise delta T of a water storage tank changing with time t, a solar radiation average value Ia in unit time, the average environment temperature ThP and the initial temperature TC of the water storage tank is established; a neural network model is established according to the historical hourly solar radiation sequence and the average environment temperature parameters, the temperature rise real-time condition of the water storage tank and the average environment temperature with estimation started for former 2-6 hours during operation of a hot water system on the application day are collected as network input, a temperature rise estimated value, output by the network model, of the water storage tank is input into a controller, and a total temperature rise value delta T' of the water storage tank is obtained; and the sum of the estimated total temperature rise value delta T' and the initial water temperature TC is the final temperature TZ, the difference delta T'' between the user set water temperature TS and the final temperature TZ is the required assisting heating amount by a heat pump water heater, and operation is stopped after the heat pump water heater completes assisting heating to the heat amount. The method has the advantages that the solar energy effective heat gain is estimated more accurately, the energy efficiency ratio is higher, and the energy-saving effect of the system is obvious.

Description

Technical field [0001] The invention relates to a predictive control method for solar heat gain in a heat pump and solar water heater combined system. Background technique [0002] The air source heat pump water heater auxiliary solar water heater has the advantages of energy saving and strong environmental adaptability, and has been more and more widely used in domestic hot water supply. The traditional control method in the combination of air source heat pump water heater and solar water heater is to give priority to solar heating. When the user uses hot water, if the water temperature does not meet the requirements, the heat pump water heater is turned on for heating, or it is manually turned on in advance or at a fixed time Turn it on in advance. The main problem with the above control method is that the energy efficiency ratio of the air source heat pump water heater increases with the outdoor ambient temperature, but decreases with the increase of the water tank temperatur...

AI Technical Summary

Problems solved by technology

The main problem of using the above control method is that the energy efficiency ratio of the air source heat pump water heater increases with the increase of the outdoor ambient temperature, but decreases with the increase of the water temperature of the water tank. The ambient temperature is generally 5-8°C lower than the highest temperature at noon, and the water temperature of the water tank at noon is also relatively low

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