JPH02223767A - Heat pump type hot water supply equipment - Google Patents

Abstract

PURPOSE:To maintain hot water supply temperature within the range of normally preset value and prevent an increase and decrease in a hot water supply capacity at a hot water supply temperature by controlling a compressor with a control circuit which converts an output frequency of a inverter in proportion with the deviation between hot water supply temperature and preset temperature. CONSTITUTION:When compressor 1 starts its operation by a control circuit 5, and increases its rotary speed in conformity with a rise in an output frequency of an inverter 9, the compression ratio of refrigerant will be increased so that the refrigerant may be gasified at not temperature, responding with the compression ratio of the refrigerant. The gasified refrigerant passes through a primary side pipeline 2a of a user side heat exchanger and discharges condensation heat to supply water which flows in a secondary pipeline, and liquefied. The liquefied refrigerant passes through an expansion valve 3, gets expanded, takes away vaporization heat from open air in a heat source side heat exchanger 4, turns to the gaseous state again, and returns to the suction side of the compressor 1. When the output hot water temperature is high and an attempt is made to drop the output frequency of the inverter 9, the rotary speed of the compressor 1 will drop and the compression ratio of the gasified refrigerant will drop as well so that the gasified refrigerant at a relatively low temperature may be supplied to the primary side pipeline 2a of the user side heat exchanger 2. This serves to lower the temperature of supply water thus heat exchanged.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an instantaneous water boiling type heat pump type water heater,
More specifically, the present invention relates to a method of controlling hot water temperature.

[Conventional technology]

Conventionally, in a heat pump type water heater that instantaneously boils water using the heat of condensation generated by compressing refrigerant gas with a compressor 1, the hot water supply temperature at the lower hot water supply amount is detected by a temperature sensor 8 and input into the control circuit 5 in advance. If the detected hot water supply temperature is higher than the set value, the flow rate control valve 6 is opened to increase the amount of water supplied and lower the hot water temperature, and if the detected hot water temperature is lower than the set value, the flow rate control valve 6 is opened. The system throttles down the flow rate, reduces the amount of water supplied, and increases the temperature of the hot water.

In this case, the heat of condensation generated by compressing the refrigerant gas with the compressor 1 does not change, so lowering the set value will increase the amount of hot water supplied, and increasing the set value will decrease the amount of hot water supplied. can't get the required amount of hot water,
Extra electricity and water charges were incurred.

[Problem to be solved by the invention]

The present invention has been made in view of the above conventional problems, and an object of the present invention is to provide a heat pump type water heater that constantly maintains the hot water supply temperature within a set value range and that the amount of hot water supply does not increase or decrease depending on the hot water supply temperature.

[Means to solve the problem]

In order to achieve the first object, the compressor 1 is controlled by a control circuit 5 that converts the output frequency of the inverter 9 according to the difference between the hot water supply temperature and the set temperature.

[Effect]

According to the above configuration, when the detected hot water supply temperature is lower than the set temperature, the control circuit 5 increases the output frequency of the inverter 9 and the rotation speed of the compression IT, compresses the refrigerant to high temperature and high pressure, and uses it. High-temperature gas is sent to the side heat exchanger 2 to return the hot water temperature to the set temperature range, and if the detected hot water temperature is higher than the set temperature, the control circuit 5 lowers the output frequency of the inverter 9 and turns the compressor l. , the temperature of the user-side heat exchanger 2 is lowered, and the hot water supply temperature is returned to the set temperature range.

〔Example〕

The details of the present invention will be explained with reference to the drawings.

FIG. 1 is a piping block diagram showing the configuration of the present invention, in which the refrigerant circuit runs from the compressor l to the primary piping 2a of the utilization side heat exchanger 2.
It is formed by a circulation path that returns to the compressor 1 via the expansion valve 3 and the heat source side heat exchanger 4.

On the other hand, the water supply circuit is formed by a route extending from the water supply pipe, through the secondary piping 2b of the user-side heat exchanger 2, to the snake lower.

The user side heat exchanger 2 consists of a double pipe heat exchanger, and the inner pipe is used as the secondary side pipe 2b to distribute water from the water supply pipe, and the outer pipe is used as the primary side pipe 2a to distribute the refrigerant. is formed.

A temperature sensor 8 detects the hot water temperature in the vicinity of the lower hot water supply amount, and periodically detects the hot water temperature and sends the information to the control circuit 5.

Reference numeral 9 denotes an inverter for controlling the compressor 1, which changes the output frequency according to a signal from the control circuit 5, changes the rotational speed of the compressor 1, and controls the temperature of the user-side heat exchanger 2.

The control circuit 5 compares the outlet temperature near the hot water supply amount lower detected by the temperature sensor 8 with the set temperature, and if the outlet temperature is low, increases the output frequency of the inverter 9 to increase the rotation speed of the compressor 1. When the hot water temperature is high by increasing the temperature, the output frequency of the inverter 9 is operated in a downward direction to control the rotation speed of the compressor 1 to be lowered.

The control circuit 5 starts the compressor 1, and as the output frequency of the inverter 9 increases, the rotation speed of the compressor 1 increases, and the compression ratio of the refrigerant gas (for example, 1?-22) increases. It is converted into high-temperature gas according to the
It passes through the primary side piping 2a, releases condensation heat to the feed water flowing through the secondary side piping 2b, liquefies it, and expands through the expansion valve 3.
The heat source side heat exchanger 4 removes heat of vaporization from the outside air, returns it to a gaseous state, and returns to the suction side of the compressor 1.

When the output frequency of the inverter 9 is operated in a downward direction by the control circuit 5 due to a high outlet temperature, the rotation speed of the compressor 1 decreases, the compression ratio of the refrigerant gas also decreases, and the refrigerant gas at a relatively low temperature is used as heat on the user side. The temperature of the water supplied to the primary side piping 2a of the exchanger 2 and subjected to heat exchange is lowered.

By repeating this circulation, heat is removed from the outside air in the form of heat of vaporization of the refrigerant by the heat exchanger 4 on the heat source side, and heat of condensation of the refrigerant is transferred from the heat exchanger 2 on the user side to the water flowing through the secondary piping 2b. It performs a heat pump action that provides heat and heats the water supply.

When the hot water supply amount lower is opened and hot water supply starts, the temperature of the outlet water near the hot water supply amount lower decreases, and in response to the signal from the temperature sensor 8, the control circuit 5 increases the output frequency of the inverter 9 and starts the compressor 1, and from then on, the outlet water temperature decreases. The operation of the compressor 1 is controlled in accordance with the fluctuations in the temperature to maintain the outlet temperature within the set temperature range.

When the lower hot water supply amount is closed, the hot water temperature near the lower hot water supply amount rises, and the control circuit 5 lowers the output frequency of the inverter 9 and stops the compressor 1.

〔Effect of the invention〕

As described above, by detecting the outlet temperature near the hot water supply amount lower and comparing it with the set temperature, the control circuit 5 controls the operation of the compressor 1, so that the temperature matches the set temperature regardless of the increase or decrease in the amount of hot water supplied. We can provide heat pump type water heaters that can supply hot water of 100 liters of water, and can respond immediately when the set temperature is changed.We can supply hot water at the required temperature and in the required amount, reducing waste on electricity and water bills. I was able to avoid a lot of expenses.

[Brief explanation of the drawing]

FIG. 1 is a piping block diagram showing the configuration of the present invention, and FIG. 2 is a piping block diagram showing the configuration of a conventional example. In the figure, ■ is a compressor, 2 is a heat exchanger on the user side, 2a is piping on the same primary side, 2b is piping on the secondary side, 3 is an expansion valve, 4 is a heat exchanger on the heat source side, 5 is a control circuit, and 7 8 is a hot water faucet, 8 is a temperature sensor, and 9 is an inverter.

Claims (1)

[Claims] In a heat pump water heater that compresses refrigerant gas using a compressor and uses the condensation heat generated to boil water using a heat exchanger on the user side, the compressor converts the output frequency of the inverter according to the difference between the hot water supply temperature and the set temperature. A heat pump type water heater characterized in that it is controlled by a control circuit that controls the heat pump type water heater.