Control method for reducing electricity utilization cost of air energy hot water unit

Abstract

The invention discloses a control method for reducing power consumption cost of an air energy hot water unit. The invention relates to a hot water supply system utilizing air energy to heat stored water. The water storage and heat preservation assembly comprises a water storage tank, a water temperature sensing probe and a water level sensing probe, two control modes of hot water storage are set, and seamless connection is performed in different periods: by controlling the water supplementing and heating time, the mains supply is utilized as much as possible to supplement water and heat in the electricity trough period; and in other time periods, the warm water supply system can be in the heat storage energy which can basically meet the water use requirement, and water replenishing and heating are not needed as much as possible. Therefore, the water supply and power consumption cost of the air energy hot water unit can be lowest, meanwhile, the peak clipping and valley filling power consumption requirements of the commercial power supply network can be responded, and the micro contribution of power consumption balance is made.

Description

Technical Field

[0001] The present invention relates to a hot water supply system that uses air energy to heat water storage, and specifically to a control method for an air energy water heater to reduce electricity costs. Technical Background

[0002] Currently, the vast majority of warm and hot water supply systems provided in public places such as hotels use air energy water heaters, including air energy heating units, water storage and insulation components mainly composed of water storage tanks, and control systems, which are generally installed on the roof. The warm and hot water in the water storage tank is distributed to each water-using room through pipelines. This type of water heater has good reliability and high thermal efficiency, and its commercial applications are very extensive and mature. When in use, according to industry specifications, the temperature is generally controlled between 42°C and 55°C, and the water level is controlled between the low water level and the high water level. When the water level reaches the low point, water replenishment starts, and when the water level reaches the high water level point, water replenishment stops; when the temperature reaches the low temperature point (42°C), heating starts, and when the water temperature reaches the high temperature point of 55°C, heating stops. The problem is that regardless of the peak and valley periods of the municipal power grid, water replenishment and heating are carried out at any time. There are many possible situations where water replenishment and heating are carried out during the peak period of the power grid, while the system does not use electricity during the low valley period of the power grid. Due to the widespread use of the price difference policy for power wave valleys and peaks in China, this situation will increase electricity costs. Summary of the Invention

[0003] The purpose of the present invention is to control the timing of water replenishment and heating, so that the warm and hot water supply system can minimize electricity costs to the greatest extent, and at the same time make a micro contribution to the power grid's electricity balance.

[0004] The technical solution of the present invention is as follows: A control method for an air energy water heater to reduce electricity costs, which involves an air energy heating unit, a water storage and insulation component, and a control system. The water storage and insulation component includes a water storage tank, a water temperature induction probe, and a water level induction probe. The control mode of hot water storage is set to two types, seamlessly connected in different time periods: When the power grid is in a non-valley stage, water replenishment starts when the water level in the water storage tank reaches below the set low water level point, and water replenishment stops when it reaches this low water level point. Heating starts when the temperature reaches the set low temperature point, and stops when it is 2 - 3°C higher than the set low temperature point; When the power grid is in a valley stage, the water replenishment stop switch of the water storage tank is controlled at the highest water level point set for the water tank, and the water storage heating stop switch is controlled at the set high temperature point.

[0005] Specifically, according to industry specifications, the set low temperature point is 42°C, and the set high temperature point is 55°C.

[0006] The starting point of the above technical idea is: by controlling the timing of water replenishment and heating, the air source heat pump water heater can utilize the power grid's valley electricity period as much as possible for water replenishment and heating, so that the heat storage in the water storage tank can reach the maximum level. During other periods, the heat storage in the hot water supply system can be maintained at a level that can basically meet the water usage requirements, and water replenishment and heating should be minimized as much as possible.

[0007] By adopting the above control method, the electricity cost of the air source heat pump water heater can be minimized, and at the same time, it can respond to the peak shaving and valley filling requirements of the municipal power grid and make a micro contribution to the power balance. Specific implementation method

[0008] Taking the valley electricity price schedule plan of a certain city in 2025 as an example: from January to February, the period from 11:00 to 14:00 every day is the valley electricity consumption stage. As long as the water temperature in the water storage tank is lower than 55 degrees Celsius, start the air source heat pump unit, raise the water temperature in the water storage tank to 55 degrees and then stop; at the same time, open the inlet valve to fill the water storage tank to the highest limit level.

[0009] During other time periods, if the water temperature in the water storage tank is not lower than 42 degrees, do not start the air source heat pump unit; only when the water temperature in the water storage tank is lower than 42 degrees Celsius, start the air source heat pump unit, raise the water temperature in the water storage tank to 42 degrees and then stop; at the same time, monitor the water level of the water storage tank. When the water level of the water storage tank is lower than one-fourth of the water level, open the inlet valve to fill the water storage tank to one-fourth of the water level and then stop filling.

[0010] The peak-valley electricity price difference and time period vary for each city and each season. The heating and water replenishment control parameters can be adjusted at any time according to the local peak-valley electricity policy to achieve the purpose of reducing electricity costs.

Claims

1. A control method for reducing electricity costs of an air-energy water heater unit, involving an air-energy heating unit, a water storage and insulation component, and a control system. The water storage and insulation component includes a water storage tank, a water temperature sensing probe, and a water level sensing probe, characterized in that The hot water storage control mode is set to two types, with seamless connection in different time periods: When the power grid is in the non-trough stage, the water level in the water tank reaches the set low water point and starts to replenish water. When the water level reaches the low water point, the replenishment stops. When the temperature reaches the set low temperature point, the heating starts and stops when the temperature is 2-3°C higher than the set low temperature point. When the power grid is in the trough stage, the water tank replenishment stop switch is controlled at the highest water point set in the water tank, and the water storage heating stop switch is controlled to the set high temperature point.

2. The control method for reducing electricity cost of an air-energy water heater as claimed in claim 1, characterized in that The set low temperature point is 42°C, and the set high temperature point is 55°C.