Do you know how to design the power of liquid electric heater?

The power of the designed liquid electric heater, without considering the heat loss, can be calculated by the following formula;

The calculation formula is: required power (kw) = weight of water (kg) * Temperature difference * specific heat capacity of water {kJ/(kg·℃)} / time (seconds)

Then knowing the formula, it is actually very easy to calculate the power of the liquid electric heater, we only need to know the weight of water, the time required to warm up, the value of the temperature difference, and the specific heat capacity of water.

One of the parameters that are a bit confusing for you is the specific heat capacity of water {kJ/(kg·℃).

The specific heat capacity is explained by the Baidu entry

Specific Heat Capacity (symbol c), referred to as specific heat, also known as Specific Heat Capacity, is a physical quantity commonly used in thermodynamics, representing the ability of an object to absorb heat or dissipate heat. The larger the specific heat capacity, the stronger the body's ability to absorb or dissipate heat. It refers to the amount of heat absorbed or emitted per unit mass of a substance by increasing or decreasing its temperature. The SI unit is joule per kilogram Kelvin [J/(kg · K)], or the energy required to raise the temperature of a kilogram of material by 1 Kelvin.

Wikipedia says specific heat capacity

Heat capacity or thermal capacity is a measurable physical quantity equal to the ratio of the heat added to (or removed from) an object to the resulting temperature change.[1] The unit of heat capacity is joule per kelvin, or kilogram meter squared per kelvin second squared in the International System of Units (SI). The dimensional form is L2MT−2Θ−1. Specific heat is the amount of heat needed to raise the temperature of one kilogram of mass by 1 kelvin. L2mt −2 θ −1. Specific heat is the amount of heat needed to raise the temperature of one kilogram of mass by 1 Kelvin.

So for example, the specific heat capacity of water is actually the heat required for 1g of water to rise by 1 degree Celsius (joules), which is calculated to be 4.17J/(g·℃).

So it takes 4.17 joules to raise the temperature of one gram of water by 1 degree Celsius.

Let's expand the specific heat of ice

Specific reference is as follows

It takes 2.03 joules of heat to raise the temperature of 1g of ice by 1℃.

Specific heat capacities of common substances

Specific heat of water: 4.179J/(g·℃)

Specific heat of air: 1.01J/(g·℃)

Specific heat of wood: 1.76J/(g·℃)

Specific heat of aluminum: 902J/(g·℃)

Specific heat of gold: 129J/(g·℃)

Specific heat of iron: 450J/(g·℃)

Power design of the liquid electric heater

For example:

For example, if the initial temperature is 10℃, what is the power of the liquid electric heater required for heating 500kg water to 90℃ by 60mins (360s)?

Power required (kw) = weight of water (kg) * Temperature difference * specific heat capacity of water {kJ/(kg·℃)} / time (seconds)

Total power = 500*(90-10)*4.17/3600=46.33kw

The above is the power calculation method for the liquid electric heater