JP2006266665A - Heat pump heating system - Google Patents

Abstract

There is provided a heat pump type heating device capable of improving the efficiency of equipment.
A circulation amount of a circulation pump is controlled based on a temperature efficiency calculated from a fluid inlet temperature and a fluid outlet temperature of a heating terminal and a room temperature of a room in which the heating terminal is installed.
[Selection] Figure 1

Description

  The present invention relates to a heat pump type heating device that increases the efficiency of equipment in a heating device that heats by circulating a fluid heated by a heat pump.

  In general, in a hot water heating apparatus, a heat source device and a heating terminal are connected by a hot water pipeline, and for example, hot water heated to about 60 ° C. is circulated in the pipeline, and heating is performed by the heating terminal. For example, heating by floor heaters has high comfort and is becoming popular. In addition, combustion-type hot water heaters using oil or gas as fuel have problems in terms of energy consumption and safety, and heat pump hot water heaters have been commercialized as alternatives.

  For example, there has been proposed a heat pump type floor heating device that shortens the startup time of a floor heating appliance by controlling the amount of hot water circulation according to the temperature of a water-refrigerant heat exchanger that heats hot water (see Patent Document 1).

  In addition, a heat pump floor heating device that stabilizes the hot water temperature and increases efficiency by detecting the return water temperature of the hot water heating circuit and controlling the compressor rotation speed to the minimum rotation speed for a predetermined time has been proposed. (See Patent Document 2).

JP 2002-122334 A JP 2000-46417 A

  Generally, the floor heating panel connected to the heat pump type floor heating apparatus varies depending on the size of the room, for example, the number of tatami mats. At this time, there is a hot water circulation amount at which the COP (heating capacity / input) is the highest for each tatami mat. The reason for this will be described below.

  FIG. 5 shows the relationship between the hot water inlet temperature, the floor heating capacity (FIG. 5 (a)) and the hot water outlet temperature (FIG. 5 (b)) of a floor heating panel of a certain tatami mat. Medium, small). In addition, the room temperature is assumed to be constant. The water temperature at the hot water inlet of the floor heating panel will be described below as the hot water inlet temperature, and the water temperature at the hot water outlet of the same floor heater will be described as the hot water outlet temperature.

  Under the condition of the same floor heating capacity, it is necessary to raise the hot water inlet temperature if the hot water circulation rate is reduced. In this case, the temperature of the hot water outlet decreases, and the temperature difference between the hot water inlet and the hot water outlet increases.

  At this time, the heat pump type floor heating apparatus performs heating from the hot water outlet temperature of the floor heating panel to the hot water inlet temperature. A refrigeration cycle diagram of the heat pump floor heating apparatus is shown in FIG. In FIG. 6, the hot water circulation amount is shown as a parameter (large, medium, small) on the Mollier diagram. The refrigerant used is carbon dioxide.

  The smaller the amount of hot water circulated, the larger the temperature rise range of the hot water heating in the heat pump floor heating device, and the larger the temperature difference between the refrigerant side inlet and outlet of the gas cooler. Therefore, the enthalpy difference per unit mass is also increased.

  On the other hand, the heat transfer rate on the water side of the water refrigerant heat exchanger (gas cooler) decreases as the flow rate of hot water decreases, due to the decrease in flow velocity. Therefore, if the same heating capacity is to be obtained, the temperature difference between the water side and the refrigerant side becomes large, resulting in an increase in the discharge pressure of the compressor and an increase in compression work per unit mass.

  In other words, the smaller the hot water circulation rate, the greater the enthalpy difference and the compression work. However, since their increase rates are different, COP at a certain hot water circulation rate (however, the compressor efficiency is assumed to be constant and the circulation pump input is not included) There is a point where becomes a peak.

In addition, when warm water is fed by a DC pump, the pump input decreases as the warm water circulation rate decreases. Accordingly, the COP peak including the pump input has a slightly shifted distribution toward the smaller hot water circulation amount than the COP peak not including the pump input.

  In summary, FIG. 7 shows a schematic diagram of the COP with respect to the hot water circulation amount for each tatami mat (large, medium, and small). From the figure, there is a hot water circulation amount at which the COP peaks for each number of tatami mats. However, in the heat pump type floor heating device, the conventional technology has not adjusted the amount of hot water circulation for each tatami mat. Similarly, in the heat pump hot water heating apparatus, the amount of hot water circulation is not adjusted for each heating terminal.

  This invention solves the said subject and provides the heat pump type heating apparatus which can achieve high efficiency of an apparatus.

  In order to solve the above problems, a heat pump heating device of the present invention decompresses a compressor, a heat exchanger that performs heat exchange between the refrigerant compressed by the compressor and a fluid, and the heat-exchanged refrigerant. A decompression device, an evaporator that performs heat exchange between the decompressed refrigerant and air, a heat pump refrigerant circuit connected by a refrigerant line, a circulation pump that sends the fluid to the heat exchanger, and the water refrigerant heat A heating circuit in which a fluid inlet into which the fluid heated by the exchanger flows in and a heating terminal that has a fluid outlet through which the fluid flows out and radiates the heat of the fluid are connected by a conduit, and the heat pump refrigerant circuit And an operation control means for operating and controlling the equipment of the heating circuit, and a circulation amount control means for controlling the circulation pump based on the fluid inlet temperature and the fluid outlet temperature of the heating terminal.

  In the present invention, the heating circuit may control the hot water circulation amount of the circulation pump based on the fluid inlet temperature, the fluid outlet temperature of the heating terminal, and the room temperature of the room where the heating terminal is installed.

  In the above invention, the heating circuit may be provided with a hot water circulation amount sensor. Moreover, in the said invention, you may provide the circulation amount setting means of a circulation pump.

  The said invention may have a some heating terminal in a heating circuit, and may change the circulation amount of a circulation pump for every those heating terminals.

  In the said invention, a carbon dioxide can be used as a refrigerant | coolant of a heat pump refrigerant circuit.

  ADVANTAGE OF THE INVENTION According to this invention, the heat pump type heating apparatus which can achieve high efficiency of an apparatus can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a configuration diagram of a main part of a heat pump heating device to which the present invention is applied. The heat pump heating device includes a heat pump refrigerant circuit 1, a heating circuit 3, and an operation control means 5. The heat source unit 10 includes a heat pump refrigerant circuit 1, a part of the heating circuit 3, and an operation control circuit 101. The fluid circulating in the heating circuit 3 may be warm water containing no additives or warm water mixed with additives such as antifreeze agents and preservatives. Hereinafter, they are described as brine for hot water.

  The heat pump refrigerant circuit 1 is configured by a closed circuit in which a compressor 11, a water refrigerant heat exchanger 14, a pressure reducing device 17, and an evaporator 20 are sequentially connected by a refrigerant pipe, and a refrigerant is enclosed therein. The compressor 11 is capable of capacity control and has a configuration capable of controlling the rotational speed from low speed to high speed. The water refrigerant heat exchanger 14 includes a refrigerant side heat transfer tube and a hot water side heat transfer tube, and heat exchange is performed between them. The evaporator 20 is an air refrigerant heat exchanger that performs heat exchange between air and refrigerant.

  The heating circuit 3 is constituted by a closed circuit in which the circulation pump 41, the water refrigerant heat exchanger 14, and the heating terminal 48 are sequentially connected by piping, and a brine for hot water is enclosed. The circulation pump 41 is provided in the middle of the pipe connecting the heating terminal 48 and the hot water side heat transfer pipe inlet of the water refrigerant heat exchanger 14. The operation of the circulation pump 41 circulates the hot water brine in the direction of the arrow shown in the heating circuit 3. The circulation pump 41 has a configuration capable of controlling the hot water circulation amount by the control means.

  The heating terminal 48 has a structure that releases heat mainly to the floor surface when the brine heated by the water-refrigerant heat exchanger 14 passes through the heat transfer pipe 48a. For example, there are floor heating terminals (floor heating panels) and bathroom heating terminals.

A fluid inlet (outward) temperature sensor 50 that detects a fluid temperature toward the floor heating panel is attached to a pipe that connects a hot water pipe outlet of the water-refrigerant heat exchanger 14 and a heat transfer pipe 48 a inlet of the heating terminal 48. The fluid outlet (return) temperature sensor 51 that detects the fluid temperature from the floor heating terminal 48 toward the water refrigerant heat exchanger 14 is connected to the heat transfer pipe 48 a outlet of the floor heating terminal 48 and the hot water pipe inlet of the water refrigerant heat exchanger 14. It is attached to the pipe to be connected. Each sensor senses the temperature of the warm water going back and forth. The room temperature sensor 52 senses the room temperature of the room where floor heating is performed. Although the room temperature sensor 52 is integrated with the remote controller 105 in the drawing, it may be a separate body.

  The operation control means 5 includes a control circuit 101, a remote controller 105, and sensors. The control signal of each sensor such as a temperature sensor for detecting the operation setting of the remote controller 105, a temperature sensor for detecting the temperature of each part, and a pressure sensor for detecting pressure is input to the control circuit 101.

  According to the operation setting of the remote controller 105, operation / stop of the heat pump refrigerant circuit 1 and rotation speed control of the compressor 11 are performed, and hot water circulation amount control of the circulation pump 41 of the hot water heating circuit 3 is performed. Further, immediately after the start of the heating operation, in order to shorten the heating start-up time, the compressor 11 is controlled to operate at a predetermined high speed.

  Next, the hot water circulation amount control of the heat pump type hot water heating apparatus according to the present invention will be described.

By the way, the moving unit number NTU on the hot water side of the floor heating panel can be expressed as follows.
NTU = KA _p / (αMC _p ρ) (1)
Here, K is the heat transfer rate from hot water to air, A _p is the surface area of the floor heating panel, α is the upper surface heat dissipation rate of floor heating, M is the amount of hot water circulation, C _p is the specific heat of water, and ρ is the water density. .

Further, the temperature efficiency ε on the hot water side can be expressed as follows.
ε = (T _in T _out ) / (T _in T _r )
= 1 exp (-NTU) (2)
Here, T _in is the fluid inlet temperature of the floor heating panel, T _out is the fluid outlet temperature of the floor heating panel, and _Tr is room temperature.

Since the heat resistance on the air side is dominant in the heat transfer rate K from the hot water to the air in the formula (1), even if the circulation amount M on the hot water side changes to some extent, the influence is small, and the value of K is almost the same. Can be considered constant. Further, the values of A _p , α, C _p , and ρ in equation (1) are also constant values or almost constant values.

  Therefore, according to the equations (1) and (2), there is a substantially one-to-one relationship between the temperature efficiency ε and the hot water circulation amount M, so that the temperature efficiency ε corresponding to the predetermined hot water circulation amount M is obtained. By controlling the circulation pump 41, a desired amount of hot water circulation can be obtained. That is, the circulation pump 41 is appropriately controlled so that the temperature efficiency calculated from the values of the fluid inlet temperature sensor 50 of the floor heating panel 48, the fluid outlet temperature sensor 51 of the floor heating panel 48, and the room temperature sensor 52 becomes a predetermined value. By doing so, a heat pump type hot water heater can be operated with high efficiency.

  The target temperature efficiency corresponding to the hot water circulation amount at which the COP peaks in the installed floor heating panel is input from the remote controller 105, for example.

  Alternatively, if the target temperature efficiency corresponding to the hot water circulation amount at which the COP reaches a peak does not change much depending on the size of the floor heating panel, the target temperature efficiency is stored in the control circuit 101 in advance. Also good.

  Therefore, since it can control to the amount of hot water circulation suitable for the installed floor heating panel, highly efficient operation is possible.

  The block diagram of the principal part of the heat pump type hot water heating apparatus which concerns on FIG. 2 at 2nd Example is shown. The difference between this embodiment and the first embodiment is that the room temperature sensor 52 is not provided, and the room temperature input means 110 is provided in the remote controller 105a instead.

When the room is heated by the heat pump hot water heater and the room temperature becomes substantially constant, the room temperature at that time is input to the remote controller 105a. Control circuit 101, a room temperature T _r which is input calculates the temperature efficiency ε from the fluid inlet temperature T _in the fluid outlet temperature T _out of the floor heating panel temperature sensor 50 and 51, so that its value becomes the target value The circulation amount of the circulation pump 41 is controlled.

  Therefore, since it can control to the amount of hot water circulation suitable for the installed floor heating panel similarly to Example 1, highly efficient driving | operation is possible.

  Further, compared with the first embodiment, the cost can be reduced by the amount that the room temperature sensor can be eliminated.

  Further, the room temperature input means 110 is not provided, and after the floor heating operation is stabilized, the room temperature is assumed to be, for example, 20 ° C., the temperature efficiency is calculated, and the circulation amount of the circulation pump 41 is controlled so that the value becomes the target value. It may be.

  The block diagram of the principal part of the heat pump type hot water heating apparatus which concerns on FIG. 3 at the 3rd Example is shown. The difference between this embodiment and the first and second embodiments is that the flow rate sensor 55 is provided in the hot water heating circuit 3.

The control circuit 101 controls the circulation pump 41 so that the value of the flow sensor 55 becomes a predetermined hot water circulation amount. As the predetermined amount of hot water circulation, a value suitable for the installed floor heating panel is input from the remote controller 105.

  Therefore, since it can control to the amount of hot water circulation suitable for the installed floor heating panel, highly efficient operation is possible.

  Moreover, since the amount of hot water circulation is directly controlled as compared with the first and second embodiments, the amount of hot water circulation can be adjusted with higher accuracy, and high-efficiency operation is easy.

  The block diagram of the principal part of the heat pump type hot water heating apparatus which concerns on FIG. 4 at 4th Example is shown. The difference of this embodiment from the first to third embodiments is that an instruction voltage input means 111 as a warm water circulation amount setting means of the circulation pump 41 is provided in the remote controller 105c.

The installer or the user calculates the water flow resistance in the hot water heating circuit at that time using the hot water circulation amount (described in the construction manual or the like) suitable for the installed floor heating panel 48. Next, the command voltage of the circulation pump (DC pump) 41 that balances the hot water circulation amount and the water flow resistance is obtained from the pump head-flow rate curve (described in the construction manual or the like). Next, the command voltage is input via command voltage input means 111 provided on the remote controller 105c. That is, a means for changing the setting relating to the pump rotation speed control of the circulation pump 41 according to the heating terminal combined with the heat pump heating apparatus is provided, and for example, a means for inputting the set value to the remote controller 105c is provided.

  During the operation of the heat pump heater, the control circuit 101 gives an appropriate instruction voltage to the circulation pump 41. Therefore, since the heat pump type hot water heating apparatus is operated with an appropriate amount of hot water circulation, high efficiency operation is possible.

  In Examples 1 to 4, a floor heating panel is provided as a heating terminal. However, for other terminals such as a bathroom heating dryer, for example, there is a hot water circulation amount that maximizes energy efficiency for each model. The present invention can also be applied to terminals other than the floor heating panel.

It is a block diagram of the principal part of the heat pump type heating apparatus which concerns on 1st Example of this invention. It is a block diagram of the principal part of the heat pump type heating apparatus which concerns on 2nd Example of this invention. It is a block diagram of the principal part of the heat pump type heating apparatus which concerns on the 3rd Example of this invention. It is a block diagram of the principal part of the heat pump type heating apparatus which concerns on the 4th Example of this invention. It is a figure which shows the relationship between the fluid inlet_port | entrance temperature of a floor heating panel, floor heating capability, and fluid outlet temperature. It is the figure which showed the refrigeration cycle figure of a heat pump type floor heating apparatus on the Mollier diagram by using the amount of hot water circulation as a parameter. It is the figure which showed COP with respect to the amount of warm water circulation when a tatami mat number was made into the parameter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Heat pump refrigerant circuit, 3 ... Hot water heating circuit, 5 ... Operation control means, 11 ... Compressor,
DESCRIPTION OF SYMBOLS 14 ... Water refrigerant heat exchanger, 17 ... Expansion valve, 20 ... Evaporator, 41 ... Circulation pump, 48 ... Floor heating terminal (floor heating panel), 48a ... Heat transfer pipe, 50 ... Fluid inlet temperature sensor, 51 ... Fluid outlet Temperature sensor 52 ... Room temperature sensor 55 ... Flow rate sensor 101 ... Control circuit 105, 105a, 105b, 105c ... Remote control 110 ... Room temperature input means 111 ... Circulating pump command voltage input means

Claims (6)

A compressor, a heat exchanger that exchanges heat between the refrigerant compressed by the compressor and a fluid, a decompression device that decompresses the heat-exchanged refrigerant, and an evaporation that exchanges heat between the decompressed refrigerant and air A heat pump refrigerant circuit connected by a refrigerant line;
A circulation pump that sends the fluid to the heat exchanger, a fluid inlet through which the fluid heated by the water-refrigerant heat exchanger flows in, and a fluid outlet through which the fluid flows out to dissipate the heat of the fluid. And a heating circuit connected by pipes,
Operation control means for controlling the operation of the heat pump refrigerant circuit and the heating circuit;
A heat pump heating device comprising: a circulation amount control means for controlling the circulation pump based on a fluid inlet temperature and a fluid outlet temperature of the heating terminal.   The heat pump heating device according to claim 1, wherein the circulation amount control means controls the circulation pump based on a difference between a fluid inlet temperature and a fluid outlet temperature of the heating terminal.   The heat pump heating device according to claim 1, wherein the circulation amount control means controls the circulation pump from a fluid inlet temperature, a fluid outlet temperature of the heating terminal, and a room temperature of a room in which the heating terminal is installed.   The heat pump type heating device according to claim 1, wherein a circulation amount sensor is provided in the heating circuit.   The heat pump heating device according to any one of claims 1 to 5, wherein the heating circuit has a plurality of heating terminals, and the circulation amount control means changes a circulation amount of the circulation pump for each heating terminal. The heat pump heating device according to any one of claims 1 to 6, wherein the refrigerant of the heat pump refrigerant circuit is carbon dioxide.

Images